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Sample records for dynamic locking plate

  1. COMPARATIVE STUDY OF FOREARM FRACTURES TREATED WITH LOCKING COMPRESSION PLATE LIMITED CONTACT DYNAMIC COMPRESSION PLATE

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    Jayachandra Reddy

    2015-02-01

    Full Text Available OBJECTIVES: This study has been carried out to compare the functional outcome of fracture fixation in diaphyseal forearm fractures by using Locking Compression Plate versus Limited contact dynamic compression Plate. To study the difference in the duration of union & complications with LCP & LC - DCP. METHODOLOGY: It is a prospective randomised comparative study which was carried out from December 2012 to December 2014 in our In stitution. In Group I, 20 patients were subjected to open reduction and internal fixation with 3.5 mm stainless steel LCP and locking head/nonlocking screws. In Group II, 20 patients were managed by 3.5mm LCDCP and non - locking screws. Clinical assessments regarding pain and function, radiological assessments were undertaken at the final follow - up. RESULTS - The time required for LCP fixation (mean 93.5 min, range 75 - 120 min was found to be more than that required for LC - DCP (mean 81.94 min, range 60 - 110 mi n. But this time difference was not significant (P=0.07, unpaired t test. The mean time of union for the forearm fixed with LCP was found to be 18 weeks (range 14 - 26 weeks in comparison to 16 weeks (range 10 - 22 weeks for the LC - DCP group. CONCLUSION - LC plating is an effective treatment option for fractures shaft of forearm. The present study could not prove the superiority of LCP over LC - DCP. It is the proper application of the principles of plating and not the type of plate which decides the outco me. Further long - term multicentric study is required to prove behaviors of the implant.

  2. The mechanical behavior of locking compression plates compared with dynamic compression plates in a cadaver radius model.

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    Gardner, Michael J; Brophy, Robert H; Campbell, Deirdre; Mahajan, Amit; Wright, Timothy M; Helfet, David L; Lorich, Dean G

    2005-10-01

    The purpose of this cadaveric study was to compare the mechanical behavior of a locked compression plate, which uses threaded screw heads to create a fixed angle construct, with a dynamic compression plate construct in a cadaver radius model. Mechanical study with cyclic testing and high-speed optical motion analysis. Biomechanics laboratory at an academic institution. Eighteen pairs of fresh-frozen human cadaver radii were divided into 3 groups of 6 to be tested as a group in each of the following force applications: anteroposterior (AP) bending, mediolateral bending, or torsion. Each bone was osteotomized leaving a 5-mm fracture gap and then fixed with a plate. For each pair, 1 radius received a standard plate (limited-contact dynamic compression plates; LC-DCP), the contralateral radius was fixed with a locking compression plate (LCP), and specimens underwent cyclic loading. Normalized stiffness, average energy absorbed, and Newton-cycles to failure were calculated. In addition, a 3-dimensional, high-speed, infrared motion analysis system was used to evaluate motion at the fracture site. Construct stiffness, fracture site motion, cycles to failure, and energy absorption. Repeated measures ANOVA were used to detect differences between groups with time. In the torsion group, LCP specimens failed at 60% greater Newton-cycles than the LC-DCP (1473 vs. 918; P different biomechanical behavior with time. As cycling progressed in the LC-DCP specimens under torsion testing, stiffness (measured at the actuator at the bone ends) did not change significantly; however, fracture motion (measured at the fracture surfaces) decreased significantly (P = 0.04). The LCP specimens did not display similar behavior. Our findings indicated that LCP constructs may demonstrate subtle mechanical superiority compared with the LC-DCP. The LCP specimens had less energy absorption in the AP group and survived longer in the torsion group. Discordance of motion between measurement regions was

  3. EFFECTIVENESS OF LOCKING VERSUS DYNAMIC COMPRESSION PLATES FOR DIAPHYSEAL HUMERUS FRACTURES

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    Penugonda Ravi Shankar

    2015-02-01

    Full Text Available The aim of this study was to compare the effectiveness of locking compression plate (LCP over dynamic compression plate (DCP in the management of diaphyseal fractures of the humerus. 38 patients with diaphyseal fracture of the shaft of the humerus were randomized prospectively and treated by open reduction and internal fixation with LCP or DCP. 11 patients underwent internal fixation by LCP and 27 by DCP. Fixation was done through an anterolateral or posterior approach. The outcome was assessed in terms of the union time, union rate, functional outcome, ROM and the incidence of complications. Functional outcome was assessed using the Romen’s et al series grading system . On comparing the results by tests of significance like Chi - sqare test, there was no significant difference in Romen’s et al scores between the two groups ( P >0.05. Though the average union time and recovery of ROM was found to be better for LCP as compared to DCP, it is not statistically significant. Complications such as infection were found to be higher with DCP as compared to LCP. This study proves that LCP can be considered a better surgical option for the management of diaphyseal fractures of the humerus as it offers a short union time and lower incidence of serious complications like infection. However, there appears to be no difference between the two groups in terms of the rate of union and functional outcome

  4. The concept of locking plates.

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    Cronier, P; Pietu, G; Dujardin, C; Bigorre, N; Ducellier, F; Gerard, R

    2010-05-01

    After a short historical review of locking bone plates since their inception more than a century ago to the success of the concept less than 15 years ago with today's plates, the authors present the main locking mechanisms in use. In the two broad categories - plates with fixed angulation and those with variable angulation - the screw head is locked in the plate with a locknut by screwing in a threaded chamber on the plate or by screwing through an adapted ring. The authors then provide a concrete explanation, based on simple mechanical models, of the fundamental differences between conventional bone plates and locking plates and why a locking screw system presents greater resistance at disassembly, detailing the role played by the position and number of screws. The advantages of epiphyseal fixation are then discussed, including in cases of mediocre-quality bone. For teaching purposes, the authors also present assembly with an apple fixed with five locking screws withstanding a 47-kg axial load with no resulting disassembly. The principles of plate placement are detailed for both the epiphysis and diaphysis, including the number and position of screws and respect of the soft tissues, with the greatest success assured by the minimally invasive and even percutaneous techniques. The authors then present the advantages of locking plates in fixation of periprosthetic fractures where conventional osteosynthesis often encounters limited success. Based on simplified theoretical cases, the economic impact in France of this type of implant is discussed, showing that on average it accounts for less than 10% of the overall cost of this pathology to society. Finally, the possible problems of material ablation are discussed as well as the means to remediate these problems.

  5. Comparison of limited-contact dynamic compression plate and locking compression plate constructs for proximal interphalangeal joint arthrodesis in the horse

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    Rocconi, Richard A.; Carmalt, James L.; Sampson, Sarah N.; Elder, Steve H.; Gilbert, Eric E.

    2015-01-01

    This study compared in vitro monotonic and cyclic mechanical properties of equine proximal interphalangeal joint arthrodeses stabilized using an open or closed technique combined with axial 4.5 mm narrow limited-contact dynamic compression plate (LC-DCP) or 4.5 mm narrow locking compression plate (LCP). Ten forelimb pairs were randomly assigned to LCP or LC-DCP groups. One limb in each pair was assigned to either open or closed technique. Limbs were tested for cyclic fatigue at 20 000 cycles ...

  6. Plate osteosynthesis of fractures of the shaft of the humerus: comparison of limited contact dynamic compression plates and locking compression plates.

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    Singh, Ashutosh Kumar; Narsaria, Nidhi; Seth, R R; Garg, S

    2014-06-01

    The aim of this retrospective study was to compare outcomes and complications of displaced fractures of the shaft of the humerus treated with limited-contact dynamic compression plates (LCDCPs) and locking compression plates (LCPs). Two hundred and twelve patients with displaced fractures of the shaft of the humerus, treated with plate osteosynthesis from January 2005 to December 2009 were reviewed. One hundred and two patients (group A) were treated with LCDCP osteosynthesis and 110 patients (group B) were treated with LCP osteosynthesis. Clinical and radiological assessments were made at monthly intervals for the first 6 months and then at 2-month intervals for the next 6 months. Primary outcome measures like operative time, duration of hospital stay, time to fracture union, union rate and secondary outcome measures (functional outcome and complications such as infection, malunion, delayed union, nonunion, implant failure and iatrogenic radial nerve palsy) were compared between both groups. The ULCA scoring system and Mayo elbow performance index (MEPI) were used to assess shoulder and elbow functions, respectively. Rodriguez-Merchan criteria were used to assess the functional outcomes of the fracture fixation. There was no significant difference found between the two groups in terms of primary outcome measures. According to Rodriguez-Merchan criteria, comparison of functional outcomes of both groups showed insignificant difference (p = 0.48). There was no significant difference found between the two groups regarding mean ULCA score (p = 0.34) and mean MEPI sore (p = 0.54). In terms of complications, no significant difference was found between the two groups. This study concludes that the principle of fracture fixation was more important than plate selection in fractures of the shaft of the humerus. Level 3.

  7. Comparison of limited-contact dynamic compression plate and locking compression plate constructs for proximal interphalangeal joint arthrodesis in the horse.

    Science.gov (United States)

    Rocconi, Richard A; Carmalt, James L; Sampson, Sarah N; Elder, Steve H; Gilbert, Eric E

    2015-06-01

    This study compared in vitro monotonic and cyclic mechanical properties of equine proximal interphalangeal joint arthrodeses stabilized using an open or closed technique combined with axial 4.5 mm narrow limited-contact dynamic compression plate (LC-DCP) or 4.5 mm narrow locking compression plate (LCP). Ten forelimb pairs were randomly assigned to LCP or LC-DCP groups. One limb in each pair was assigned to either open or closed technique. Limbs were tested for cyclic fatigue at 20 000 cycles and then single-cycle to failure under 3-point dorsopalmar bending. There was no significant difference in stiffness of constructs during cyclic fatigue testing or on force or stiffness at failure in single cycle to failure testing between open and closed techniques or between plate types. Both implants, surgical technique, or combinations thereof are suitable for clinical use. More work is necessary to define the interaction between implant type and surgical technique.

  8. The strength of polyaxial locking interfaces of distal radius plates.

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    Hoffmeier, Konrad L; Hofmann, Gunther O; Mückley, Thomas

    2009-10-01

    Currently available polyaxial locking plates represent the consequent enhancement of fixed-angle, first-generation locking plates. In contrast to fixed-angle locking plates which are sufficiently investigated, the strength of the new polyaxial locking options has not yet been evaluated biomechanically. This study investigates the mechanical strength of single polyaxial interfaces of different volar radius plates. Single screw-plate interfaces of the implants Palmar 2.7 (Königsee Implantate und Instrumente zur Osteosynthese GmbH, Allendorf, Germany), VariAx (Stryker Leibinger GmbH & Co. KG, Freiburg, Germany) und Viper (Integra LifeSciences Corporation, Plainsboro, NJ, USA) were tested by cantilever bending. The strength of 0 degrees, 10 degrees and 20 degrees screw locking angle was obtained during static and dynamic loading. The Palmar 2.7 interfaces showed greater ultimate strength and fatigue strength than the interfaces of the other implants. The strength of the VariAx interfaces was about 60% of Palmar 2.7 in both, static and dynamic loading. No dynamic testing was applied to the Viper plate because of its low ultimate strength. By static loading, an increase in screw locking angle caused a reduction of strength for the Palmar 2.7 and Viper locking interfaces. No influence was observed for the VariAx locking interfaces. During dynamic loading; angulation had no influence on the locking strength of Palmar 2.7. However, reduction of locking strength with increasing screw angulation was observed for VariAx. The strength of the polyaxial locking interfaces differs remarkably between the examined implants. Depending on the implant an increase of the screw locking angle causes a reduction of ultimate or fatigue strength, but not in all cases a significant impact was observed.

  9. Biomechanical Properties of 3-Dimensional Printed Volar Locking Distal Radius Plate: Comparison With Conventional Volar Locking Plate.

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    Kim, Sung-Jae; Jo, Young-Hoon; Choi, Wan-Sun; Lee, Chang-Hun; Lee, Bong-Gun; Kim, Joo-Hak; Lee, Kwang-Hyun

    2017-09-01

    This study evaluated the biomechanical properties of a new volar locking plate made by 3-dimensional printing using titanium alloy powder and 2 conventional volar locking plates under static and dynamic loading conditions that were designed to replicate those seen during fracture healing and early postoperative rehabilitation. For all plate designs, 12 fourth-generation synthetic composite radii were fitted with volar locking plates according to the manufacturers' technique after segmental osteotomy. Each specimen was first preloaded 10 N and then was loaded to 100 N, 200 N, and 300 N in phases at a rate of 2 N/s. Each construct was then dynamically loaded for 2,000 cycles of fatigue loading in each phase for a total 10,000 cycles. Finally, the constructs were loaded to a failure at a rate of 5 mm/min. All 3 plates showed increasing stiffness at higher loads. The 3-dimensional printed volar locking plate showed significantly higher stiffness at all dynamic loading tests compared with the 2 conventional volar locking plates. The 3-dimensional printed volar locking plate had the highest yield strength, which was significantly higher than those of 2 conventional volar locking plates. A 3-dimensional printed volar locking plate has similar stiffness to conventional plates in an experimental model of a severely comminuted distal radius fracture in which the anterior and posterior metaphyseal cortex are involved. These results support the potential clinical utility of 3-dimensional printed volar locking plates in which design can be modified according the fracture configuration and the anatomy of the radius. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  10. Biomechanical comparison of dynamic condylar screw and locking compression plate fixation in unstable distal femoral fractures: An in vitro study

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    Ashutosh Kumar Singh

    2013-01-01

    Full Text Available Background: Distal femur fractures are difficult to manage and the selection of implant for internal fixation remains controversial. The objective of this study is to establish the relative strength of fixation of a distal femoral locking plate (DFLP compared with the dynamic condylar screw (DCS in the distal femur fractures. Materials and Methods: Study was conducted on 16 freshly harvested cadaveric distal femoral specimens, eight implanted with DCS and other eight with DFLP. The construct was made unstable by removing a standard sized medial wedge of 1 cm base (gap-osteotomy beginning 6 cm proximal to the lateral joint line in distal metaphyseal region with the loss of medial buttress. Fatigue test was conducted under load control mode at the frequency of I Hz. Specimens were subjected to cyclic loading of 2 kN, under observation for 50,000 cycles or until failure/cutout, which ever occurred earlier. Results: In DFLP group, there was no implant failure and the average number of cycles sustained was 50,000. Six out of eight specimens completed 50,000 cycles and two failed in DCS group. The average number of cycles sustained by DCS was 46150. Though the bone quality as assessed by dual energy X-ray absorptiometry DEXA was comparable in both DFLP and DCS group ( P = 0.06, none failed in DFLP group and subsidence was 1.02 ± 0.34 mm (range: 0.60-1.32 mm, which was significantly 43% lower ( P = 0.006 than subsidence in DCS group (1.82 ± 0.58; range: 1.20-3.08 mm. The average stiffness of DCS group was 52.8 ± 4.2 N/mm, which was significantly lower than average stiffness of locked condylar plate group (71.2 ± 5.1 N/mm ( P = 0.02. Conclusions: DFLP fixation of the distal femur fractures resulted in stronger construct than the DCS fixation in both cyclic loading and ultimate strength in biomechanical testing of a simulated A3 distal femur fracture.

  11. Locking plate osteosynthesis of clavicle fractures

    DEFF Research Database (Denmark)

    Fridberg, Marie; Ban, Ilija; Issa, Zaid

    2013-01-01

    PURPOSE: Locking plate osteosynthesis has become the preferred method for operative treatment of clavicle fractures. The method offers stable fixation, and would theoretically be associated with a low rate of fracture-related complications and reoperations. However, this remains to be explored...... in a large cohort, and our purpose was to assess the overall rates of complications and reoperations following locking plate osteosynthesis of mid-shaft clavicle fractures. METHODS: We identified all locking plate osteosynthesis of mid-shaft clavicle fractures operated upon in our department from January...... 2008 to November 2010 (n = 114). Nine patients did not attend the follow-up at our institution. The study group of 105 fractures (104 patients, 86 males) had a median age of 36 years (14-75 years). Follow-up ranged from 0.5 to 3.5 years. No patients were allowed to load the upper extremity for six...

  12. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  13. [Tibiotalocalcaneal arthrodesis using a humeral locking plate].

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    Cabrera Méndez, M P; Gamba, C; Hernández, E; Molano, J; Andrade, J C

    2016-01-01

    To describe the results of tibiotalocalcáneal arthrodesis (TTC) using a humeral locking plate. A retrospective, observational study was conducted between January 2007 and December 2013 in the Hospital Militar Central de Bogotá. The study included patients with symptomatic osteoarthritis diagnosed clinically and radiologically, and who underwent TTC arthrodesis using a humeral locking plate with a minimum follow up of 6 months. The total number patients was 35, of whom 7 (20%) were women and 28 (80%) men, with a mean age 36.3 years (19.77). 74% with post-traumatic arthritis, most of them secondary to gunshot wounds and fragmentation weapons, and neuropathic in 20%. An autogenous graft was used in 13 cases, and 14 cases using both, with a mean consolidation time of 4.37 months. Complications include, delayed union in 3 cases, and surgical site infection in 4. The postoperative functionality (AOFAS) mean was 66.7/100 points, with a score of 2.35 on a visual analogue pain scale. TTC arthrodesis using a humeral locking plate is a suitable option for fixing this type of arthrodesis, with a low rate of complications, and postoperative results that revealed satisfactory improvement in pain and consolidation. Copyright © 2015 SECOT. Published by Elsevier Espana. All rights reserved.

  14. Locking plates in proximal humerus fractures.

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    Strohm, P C; Helwig, P; Konrad, G; Südkamp, N P

    2007-12-01

    It is well known that proximal humerus fractures are among the three most frequent fracture types. Epidemiological invetsigations show that in people elder than 60 years the fracture of the proximal humerus is more frequent than fractures of the hip region (17). Over the last decades several techniques have been applied for treatment of proximal humerus fractures. Widely accepted is the initiation of a conservative treatment regimen for undisplaced fractures, however, the standard treatment for displaced fractures, especially three and four part fractures, is still the center of scientific debate. Many different implants have been tested and investigated, thus demonstrating lack of sufficient results. Over the last years the development of angle stable, locking implants started and clinical studies demonstrated encouraging results. In our clinic the locking proximal humerus plate and the PHILOS plate advanced to the implant of choice for treatment of displaced proximal humerus fractures. There are still cases of implant failure and humerus head necrosis, but most of these complications were caused by the fracture type and not an implant specific problem. However the overall results with these new implants are encouraging. Key words: locking plates, proximal humerus fracture, humerus, humerus fracture, PHILOS, PHP.

  15. The dynamic locking blade plate, a new implant for intracapsular hip fractures: biomechanical comparison with the sliding hip screw and Twin Hook.

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    Roerdink, W H; Aalsma, A M M; Nijenbanning, G; van Walsum, A D P

    2009-03-01

    Internal fixation of intracapsular hip fractures results in a high failure rate with non-union and avascular necrosis being the two most important complications. In order to prevent these possible complications treatment should consist of an anatomical reduction and stable fixation by insertion of a low volume, dynamic implant, providing angular and rotational stability to the femoral head. According to these principles a new implant, the dynamic locking blade plate (DLBP) was designed for the fixation of intracapsular hip fractures. We performed a biomechanical analysis in synthetic bone to compare the rotational stability and cut out resistance of the DLBP with a conventional sliding hip screw (SHS) and the more recently developed Twin Hook. The rotational stability of the DLBP proved to be three times higher than the rotational stability of a SHS and two times higher than the Twin Hook. There was no major difference in cut out resistance between the different implants. The design of the DLBP and possible advantages with regard to the healing of an intracapsular hip fracture are discussed.

  16. Development of site-specific locking plates for acetabular fractures.

    Science.gov (United States)

    Xu, Meng; Zhang, Li-Hai; Zhang, Ying-Ze; He, Chun-Qing; Zhang, Li-Cheng; Wang, Yan; Tang, Pei-Fu

    2013-05-01

    Site-specific locking plates have gained popularity for the treatment of fractures. However, the clinical use of a site-specific locking plate for acetabular fractures remains untested due to production limits. To design a universal site-specific locking plate for acetabular fractures, the 3-dimensional (3D) photographic records of 171 pelvises were retrospectively studied to generate a universal posterior innominate bone surface. Using 3D photographical processing software, the 3D coordinate system was reset according to bony landmarks and was scaled based on the acetabular diameter to allow a direct comparison between surfaces. The measured surface was separated into measurement units. At each measurement unit, the authors calculated the average z-axis values in all samples and obtained the 3D coordinate values of the point cloud that could be reconstructed into the universal surface. A plate was subsequently designed in 3D photographical processing software, and the orientation and distribution of locking screws was included. To manufacture a plate, the data were entered into Unigraphics NX version 6.0 software (Siemens PLM Software, Co, Ltd, Plano, Texas) and a CNC digital milling machine (FANUC Co, Ltd, Yamanashi, Japan). The resulting locking plate fit excellently with the reduced bone surface intraoperatively. Plate contouring was avoided intraoperatively. Universal 3.5-mm locking screws locked successfully into the plate, and their orientations were consistent with the design. No screw yielded to acetabular penetration. This method of designing a site-specific acetabular locking plate is practical, and the plates are suitable for clinical use. These site-specific locking plates may be an option for the treatment of acetabular fractures, particularly in elderly patients.

  17. Outcome of locking compression plates in humeral shaft nonunions

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    Malhar N Kumar

    2013-01-01

    Conclusions: Locking compression plating and cancellous bone grafting is a reliable option for achieving union in humeral diaphyseal nonunion with failed previous internal fixation and results in good functional outcome in patients with higher physiological demands.

  18. FINITE ELEMENT STRUCTURAL & THERMAL ANALYSIS OF LOCK PLATE

    OpenAIRE

    Mr. Ketan Patil; Mr. Roshan Marode; Prof. V. M. Chidri; Prof. A.J. Keche

    2012-01-01

    In Centrifugal Pipe Casting machine, hot molten metal is injected from one end and the other end remains closed by a covering plate having standard dimension. This covering plate is locked by a worker with the help of a spanner. This covering plate again needs to be opened after completion of casting process for the extraction of the pipe from the mould. This paper discuss mainly focused on the analysis of locking plate and its new design so that the humaninterference must be reduced to highe...

  19. Application of Shape Lock-on Method in Plate Rolling

    Institute of Scientific and Technical Information of China (English)

    HU Xian-lei; WANG Jun; WANG Zhao-dong; LIU Xiang-hua; WANG Guo-dong

    2004-01-01

    AGC system can improve the plate gauge precision, and damage the plate shape if the shape control loop is left quite open. This damage will cause wave during rolling wide-thin plate. A control strategy named shape lock-on method is afforded for plate shape control. This method requires APC instead of AGC at last one or two passes during rolling wide-thin plate. Approved by theory and on-line application, this method is good for the plate shape and crown control with small effect on gauge control.

  20. Notch sensitivity jeopardizes titanium locking plate fatigue strength.

    Science.gov (United States)

    Tseng, Wo-Jan; Chao, Ching-Kong; Wang, Chun-Chin; Lin, Jinn

    2016-12-01

    Notch sensitivity may compromise titanium-alloy plate fatigue strength. However, no studies providing head-to-head comparisons of stainless-steel or titanium-alloy locking plates exist. Custom-designed identically structured locking plates were made from stainless steel (F138 and F1314) or titanium alloy. Three screw-hole designs were compared: threaded screw-holes with angle edges (type I); threaded screw-holes with chamfered edges (type II); and non-threaded screw-holes with chamfered edges (type III). The plates' bending stiffness, bending strength, and fatigue life, were investigated. The stress concentration at the screw threads was assessed using finite element analyses (FEA). The titanium plates had higher bending strength than the F1314 and F138 plates (2.95:1.56:1) in static loading tests. For all metals, the type-III plate fatigue life was highest, followed by type-II and type-I. The type-III titanium plates had longer fatigue lives than their F138 counterparts, but the type-I and type-II titanium plates had significantly shorter fatigue lives. All F1314 plate types had longer fatigue lives than the type-III titanium plates. The FEA showed minimal stress difference (0.4%) between types II and III, but the stress for types II and III was lower (11.9% and 12.4%) than that for type I. The screw threads did not cause stress concentration in the locking plates in FEA, but may have jeopardized the fatigue strength, especially in the notch-sensitive titanium plates. Improvement to the locking plate design is necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A failure study of a locking compression plate implant

    Directory of Open Access Journals (Sweden)

    Nirajan Thapa

    2015-04-01

    Full Text Available In this case study a failed locking compression plate was investigated. Such plating systems are used to provide the stability to fractured bone and fixation. The locking compression plate had been separated in two pieces. One of the fracture surfaces from the failed component was investigated for surface topographical features. The visual, optical and scanning electron microscopy results indicated the presence of beach marks, intermetallic inclusions, corrosion pits and striations indicating fatigue crack propagation and overload failure. Some corrosion damage also was documented on the fractography. This case study shows that corrosion may have initiated fatigue crack which grew by the activities of daily living causing the failure.

  2. Influence of plate-bone contact on cyclically loaded conically coupled locking plate failure.

    Science.gov (United States)

    Rotne, Randi; Bertollo, Nicky; Walsh, William; Dhand, Navneet K; Voss, Katja; Johnson, Kenneth A

    2014-03-01

    The maintenance of friction between locking plates and bone is not essential, so that they can be applied with a gap between the plate and underlying bone. We hypothesised that the presence of a gap under a locking plate with a conical coupling mechanism would reduce fixation stability or allow uncoupling of the locking screws from the plate. Locking plates with two conically coupled locking screws were applied to 6 pairs of adult canine femora. One of each pair had plate to bone contact and the contralateral construct had a 2 mm plate to bone gap. Constructs were cyclically loaded in cantilever bending with 10 percent incremental increases every 1000 cycles at 2 Hz, starting at 250 N. The constructs were fatigued to failure. To evaluate fatigue life of the conical coupling, testing was repeated with aluminium tubing replacing the bone, to eliminate screw-bone cutout failure. The mean sustained loads and cycles to failure in the contact group (420.80, standard error [SE] 14.97 N; 7612.00, SE 574.70 cycles) were significantly greater than in the gap group (337.50, SE 14.97 N; 4252.00, SE 574.70 cycles), (pplate fatigue and breaking, with one construct having elevation of the plate over the screw head. Elevation of locking plates with a conical coupling system by 2 mm from the bone reduced construct fatigue life but did not result in screw head uncoupling from the plate. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. In vitro biomechanical comparison of a 4.5 mm narrow locking compression plate construct versus a 4.5 mm limited contact dynamic compression plate construct for arthrodesis of the equine proximal interphalangeal joint.

    Science.gov (United States)

    Ahern, Benjamin J; Showalter, Brent L; Elliott, Dawn M; Richardson, Dean W; Getman, Liberty M

    2013-04-01

    To compare the in vitro biomechanical properties of a 4.5 mm narrow locking compression plate (PIP-LCP) with 2 abaxially located transarticular screws and a 4.5 mm limited contact dynamic compression plate (LC-DCP) with 2 abaxially located transarticular screws using equine pasterns. Experimental. Paired in vitro biomechanical testing of 2 methods for stabilizing adult equine forelimb PIP joints. Adult equine forelimbs (n = 8 pairs). Each pair of PIP joints were randomly instrumented with either a PIP-LCP or LC-DCP plate axially and 2 parasagitally positioned 5.5 mm transarticular screws. The proximal aspect of the proximal phalanx (P1) and the distal aspect of the middle phalanx (P2) were embedded to allow for mounting on a mechanical testing machine. Each construct was tested in both cyclic and subsequently single cycle to failure in 4-point bending. The displacement required to maintain a target load of 1 kN over 3600 cycles at 1 Hz was recorded. Maximum bending moment at failure and construct stiffness was calculated from the single cycle to failure testing. In cyclic testing, significantly more displacement occurred in the LC-DCP (0.46 ± 0.10 mm) than for the PIP-LCP (0.17 ± 0.11 mm) constructs (P = .016). During single cycle testing there was no significant difference in the bending moment between the LC-DCP (148.7 ± 19.4 N m) and the PIP-LCP (164.6 ± 17.6 N m) constructs (P = .553) and the stiffness of the LC-DCP (183.9 ± 26.9 N mm) was significantly lower than for the PIP-LCP (279.8 ± 15.9 N/mm) constructs (P = .011). All constructs failed by fracture of the bone associated with the transarticular screws and subsequently bending of the plates at the middle hole. Use of the PIP-LCP resulted in a stiffer construct of the same strength as the LC-DCP in vitro using this 4-point bending model. © Copyright 2013 by The American College of Veterinary Surgeons.

  4. Congruency of scapula locking plates: implications for implant design.

    Science.gov (United States)

    Park, Andrew Y; DiStefano, James G; Nguyen, Thuc-Quyen; Buckley, Jenni M; Montgomery, William H; Grimsrud, Chris D

    2012-04-01

    We conducted a study to evaluate the congruency of fit of current scapular plate designs. Three-dimensional image-processing and -analysis software, and computed tomography scans of 12 cadaveric scapulae were used to generate 3 measurements: mean distance from plate to bone, maximum distance, and percentage of plate surface within 2 mm of bone. These measurements were used to quantify congruency. The scapular spine plate had the most congruent fit in all 3 measured variables. The lateral border and glenoid plates performed statistically as well as the scapular spine plate in at least 1 of the measured variables. The medial border plate had the least optimal measurements in all 3 variables. With locking-plate technology used in a wide variety of anatomical locations, the locking scapula plate system can allow for a fixed-angle construct in this region. Our study results showed that the scapular spine, glenoid, and lateral border plates are adequate in terms of congruency. However, design improvements may be necessary for the medial border plate. In addition, we describe a novel method for quantifying hardware congruency, a method that can be applied to any anatomical location.

  5. Outcome Analysis of Locking Plate Fixation in Proximal Humerus Fracture

    Science.gov (United States)

    Pathak, Abhishek; Gaur, Sanjiv

    2016-01-01

    Introduction Proximal humerus fractures account for approximately 5% of all fractures. Stable minimally displaced fractures can be treated nonoperatively but the management of displaced fractures remain controversial with various modalities of treatment available. Locking plates provide stable fixation and enable early postoperative mobilization specially in osteoporotic proximal humerus fracture. Aim To evaluate the functional outcome of locking plate fixation and to compare the results of two approaches used for fixation. Materials and Methods This prospective study was conducted at a tertiary level hospital between September 2011 to December 2013. PHILOS plates were used for internal fixation of displaced proximal humerus fractures Neer’s type 2 part, 3 part and 4 part fractures on 26 patients (M/F ratio 1.36:1; mean age 46 years). According to Neer classification, 5,12 and 9 patients had displaced 2, 3 and 4 part fractures respectively. Deltopectoral and deltoid splitting approaches were used for fixation on 13 patients each. Functional outcome was assessed using Constant-Murley shoulder score. Graphpad software version 6.0 was used with Chi-square test and Fisher-exact test are used to compare data. The p-value .05) and all fractures were united. Conclusion Our study demonstrates that locking plate fixation gives good functional outcomes in treatment of proximal humerus fractures. There was no significant difference in the two approaches used for exposure. Our results are comparable to various studies conducted by other authors which states that locking plates provide better functional and radiological outcomes as compared to other fixation methods like Tension band wiring, percutaneous K-wire fixation, non-locking plates, intramedullary nails. PMID:27656515

  6. Displaced proximal humeral fractures: an Indian experience with locking plates

    Directory of Open Access Journals (Sweden)

    Aggarwal Sameer

    2010-08-01

    Full Text Available Abstract Background The treatment of displaced proximal humerus fractures, especially in elderly, remains controversial. The objective of this study was to evaluate functional outcome of locking plate used for fixation of these fractures after open reduction. We also attempted to evaluate the complications and predictors of loss of fixation for such an implant. Methods Over two and a half years, 56 patients with an acute proximal humerus fracture were managed with locking plate osteosynthesis. 47 of these patients who completed a minimum follow up of 1 year were evaluated using Constant score calculation. Statistical analysis was done using SPSS 16 and a p value of less than 0.05 was taken as statistically significant. Results The average follow up period was around 21.5 months. Outcomes were excellent in 17%, good in 38.5%, moderate in 34% while poor in 10.5%. The Constant score was poorer for AO-OTA type 3 fractures as compared to other types. The scores were also inferior for older patients (> 65 years old. Complications included screw perforation of head, AVN, subacromial impingement, loss of fixation, axillary nerve palsy and infection. A varus malalignment was found to be a strong predictor of loss of fixation. Conclusion Locking plate osteosynthesis leads to satisfactory functional outcomes in all the patients. Results are better than non locking plates in osteoporotic fractures of the elderly. However the surgery has steep learning curve and various complications could be associated with its use. Nevertheless we believe that a strict adherence to the principles of locking plate use can ensure good result in such challenging fractures.

  7. Ex vivo biomechanical evaluation of pigeon (Columba livia) cadaver intact humeri and ostectomized humeri stabilized with caudally applied titanium locking plate or stainless steel nonlocking plate constructs.

    Science.gov (United States)

    Darrow, Brett G; Biskup, Jeffrey J; Weigel, Joseph P; Jones, Michael P; Xie, Xie; Liaw, Peter K; Tharpe, Josh L; Sharma, Aashish; Penumadu, Dayakar

    2017-05-01

    OBJECTIVE To evaluate mechanical properties of pigeon (Columba livia) cadaver intact humeri versus ostectomized humeri stabilized with a locking or nonlocking plate. SAMPLE 30 humeri from pigeon cadavers. PROCEDURES Specimens were allocated into 3 groups and tested in bending and torsion. Results for intact pigeon humeri were compared with results for ostectomized humeri repaired with a titanium 1.6-mm screw locking plate or a stainless steel 1.5-mm dynamic compression plate; the ostectomized humeri mimicked a fracture in a thin cortical bone. Locking plates were secured with locking screws (2 bicortical and 4 monocortical), and nonlocking plates were secured with bicortical nonlocking screws. Constructs were cyclically tested nondestructively in 4-point bending and then tested to failure in bending. A second set of constructs were cyclically tested non-destructively and then to failure in torsion. Stiffness, strength, and strain energy of each construct were compared. RESULTS Intact specimens were stiffer and stronger than the repair groups for all testing methods, except for nonlocking constructs, which were significantly stiffer than intact specimens under cyclic bending. Intact bones had significantly higher strain energies than locking plates in both bending and torsion. Locking and nonlocking plates were of equal strength and strain energy, but not stiffness, in bending and were of equal strength, stiffness, and strain energy in torsion. CONCLUSIONS AND CLINICAL RELEVANCE Results for this study suggested that increased torsional strength may be needed before bone plate repair can be considered as the sole fixation method for avian species.

  8. OUTCOME OF LOCKING PLATES IN DISTAL TIBIA FRACTURES TREATMENT

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    Lokesh

    2016-05-01

    Full Text Available INTRODUCTION Most of these fractures except intra-articular fractures are treated with interlocking nail. 1,2 These nails are a boon for these fractures. But as the fracture nears to the joint stability the fracture fixation will be compromised due to malreduction and alignment, it leads to increased chances of delayed and nonunion. 3 Locking anatomical plates are evaluated for anatomical and relative stability fixation. Since then most intra and near intra-articular fractures are fixed with these plates with minimally invasive percutaneous plate osteosynthesis method, these plates have given excellent result 4 . But again these plates have some disadvantages 5 . This study is done to see the outcome of locking plates in distal tibia fracture. METHODS This study is done in the Department of Orthopaedics, Bangalore Medical College, Bangalore. This study is done from 2013 to 2015. 30 patients who came to outpatient department were treated with locking plates. All patients above 16 years having distal third tibia fracture are included. All open fractures except type 1 and elderly above 60 years and pathological fractures are excluded in our study. All patients were followed up for initial 5 months, thereafter, once in 3 months, for clinical and radiological evaluation of union status, knee range of motion, ankle range of motion and other complications. Assessment of the patient with functional recovery was done with American Orthopaedic Foot and Ankle Surgery(AOFAS 6 minimum 5 months after injury. RESULTS Majority of the patients are from age group 18-29 years (50%. Average age group was 30 years. Majority of the patients were males 80.6% (25. All fractures were closed fractures except 2 cases which are type 1. There were 12 cases of AO type A, 8 patients were AO type B and 10 patients were type C. Majority of the patients had fracture due to road traffic accidents, 74%. All fractures were united by the end of 20 weeks. There was delayed union in

  9. Increased rates of wound complications with locking plates in distal fibular fractures

    NARCIS (Netherlands)

    T. Schepers (Tim); E.M.M. van Lieshout (Esther); M.R.D. Vries; M. van der Elst (Maarten)

    2011-01-01

    textabstractIntroduction: There is a growing use of locking compression plates in fracture surgery. The current study was undertaken to investigate the wound complication rates of locking versus non-locking plates in distal fibular fractures. Patients and methods: During a 6-year study period all co

  10. Locking plates in distal humerus fractures: study of 43 patients

    Directory of Open Access Journals (Sweden)

    Gupta Rakesh Kumar

    2013-08-01

    Full Text Available 【Abstract】Objective: The treatment of multi-fragmentary, intraarticular fractures of the distal humerus is difficult, even in young patients with bone of good quality. Small distal fragment, diminished bone mineral quality and increased trauma-associated joint destruction make stable joint reconstruction more problematic. The anatomically preshaped locking plates allow angular stable fixation for these complex fractures. We evaluated functional results of patients treated with open reduction and internal fixation with distal humerus locking plates for complex distal hu-merus fractures. Methods: Forty-three consecutive patients with ar-ticular fractures of the distal humerus were treated by open reduction and internal fixation with AO distal humerus plate system and locking reconstruction plates. Forty patients were available for the final outcome analysis. According to AO/ASIF classification, there were 2 cases of type A2, 4 cases of type A3, 1 case of type B1, 1 case of type B2, 14 cases of type C1, 7 cases of type C2 and 11 cases of type C3. Open reduction with triceps splitting technique was used in all patients. The clinical and radiographic follow-up was performed and outcome measures included pain assessment, range of motion, and Mayo elbow performance score. Results: Forty patients were available for the final outcome analysis. There were 29 males and 11 females with an average age of 38.4 years (18-73 years. Clinical and ra-diological consolidation of the fracture was observed in all cases at an average of 11.6 weeks (9-14 weeks. The average follow-up was 12 months (10-18 months. Using the Mayo elbow performance score the results obtained were graded as excellent or good results in 33 patients (82.5%. One pa-tient had superficial infection, and 4 had myositis ossificans. There were no cases of primary malposition or secondary displacement, implant failure or ulnar neuropathy. Conclusion: Anatomically preshaped distal humerus locking

  11. Unstable Distal Radius Fractures Treated by Volar Locking Anatomical Plates

    Science.gov (United States)

    Jose, Anto; Deniese, Pascal Noel; Babu, Abey Thomas; Rengasamy, Kanagasabai; Najimudeen, Syed

    2017-01-01

    Introduction Fracture of the distal end of radius represents the most common fracture of the upper extremity accounting for 16-20% of all fractures. Plating is now emerging as the gold standard for management of distal radius fractures due to increased rate of complications such as malunion, subluxation/dislocation of distal radio-ulnar joint or late collapse of fracture. Procedures such as closed reduction and cast immobilization, ligamentotaxis with external fixator and percutaneous pin fixation are no longer acceptable. Aim The purpose of the study was to evaluate the functional and radiological outcome of unstable distal radius fractures treated with the volar locking plate. Materials and Methods We reviewed 53 patients from January 2011 to December 2015, treated for unstable distal radius fractures using a volar locking compression plate. Standard radiographic and clinical assessment after 12 months (range 12-16 months) were measured and final functional and radiological outcome were assessed using the Modified Mayo wrist scoring system and Sarmiento’s modification of Lindstorm criteria respectively. Results There were 42 males and 11 females with an average age of 39.12±31.78 years (18-71 years). At the end of 12 months, 36 patients had an excellent radiological outcome and 10 patients had good radiological outcome as per Sarmiento’s modification of Lindstorm criteria. Eleven patients had an excellent functional outcome and 26 patients had a good functional outcome as per modified Mayo wrist scoring system. There was one case of superficial wound infection which subsided with intravenous antibiotics. Conclusion The volar locking plate fixation helps in early mobilization of the wrist, restores anatomy, allows early return to function, prevents secondary loss of reduction and hence is an effective treatment for unstable fractures of the distal radius. PMID:28274009

  12. Locking plates in distal humerus fractures: study of 43 patients

    Institute of Scientific and Technical Information of China (English)

    Rakesh Kumar Gupta; Vinay Gupta; Dickey Richard Marak

    2013-01-01

    Objective:The treatment of multifragmentary,intraarticular fractures of the distal humerus is difficult,even in young patients with bone of good quality.Small distal fragment,diminished bone mineral quality and increased trauma-associated joint destruction make stable joint reconstruction more problematic.The anatomically preshaped locking plates allow angular stable fixation for these complex fractures.We evaluated functional results of patients treated with open reduction and internal fixation with distal humerus locking plates for complex distal humerns fractures.Methods:Forty-three consecutive patients with articular fractures of the distal humerus were treated by open reduction and internal fixation with AO distal humerus plate system and locking reconstruction plates.Forty patients were available for the final outcome analysis.According to AO/ASIF classification,there were 2 cases of type A2,4 cases of type A3,1 case of type B1,1 case of type B2,14 cases of type C1,7 cases of type C2 and 11 cases of type C3.Open reduction with triceps splitting technique was used in all patients.The clinical and radiographic follow-up was performed and outcome measures included pain assessment,range of motion,and Mayo elbow performance score.Results:Forty patients were available for the final outcome analysis.There were 29 males and 11 females with an average age of 38.4 years (18-73 years).Clinical and radiological consolidation of the fracture was observed in all cases at an average of 11.6 weeks (9-14 weeks).The average follow-up was 12 months (10-18 months).Using the Mayo elbow performance score the results obtained were graded as excellent or good results in 33 patients (82.5%).One patient had superficial infection,and 4 had myositis ossificans.There were no cases of primary malposition or secondary displacement,implant failure or ulnar neuropathy.Conclusion:Anatomically preshaped distal humerus locking plate system is useful in providing stable fixation for complex

  13. Dynamics of Tectonic Plates

    CERN Document Server

    Pechersky, E; Sadowski, G; Yambartsev, A

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

  14. Dynamics of Tectonic Plates

    OpenAIRE

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend ...

  15. A review of locking compression plate biomechanics and their advantages as internal fixators in fracture healing.

    Science.gov (United States)

    Miller, Danielle L; Goswami, Tarun

    2007-12-01

    Metallic implants are often involved in the open reduction and internal fixation of fractures. Open reduction and internal fixation is commonly used in cases of trauma when the bone cannot be healed using external methods such as casting. The locking compression plate combines the conventional screw hole, which uses non-locking screws, with a locking screw hole, which uses locking head screws. This allows for more versatility in the application of the plate. There are many factors which affect the functionality of the plate (e.g., screw placement, screw choice, length of plate, distance from bone, etc.). This paper presents a review of the literature related to the biomechanics of locking compression plates and their use as internal fixators in fracture healing. Furthermore, this paper also addresses the materials used for locking compression plates and their mechanical behavior, parameters that control the overall success, as well as inherent bone quality results.

  16. Complications of the locking plate for displaced proximal humeral fractures

    Institute of Scientific and Technical Information of China (English)

    LU Yi; WANG Man-yi; ZHU Yi-ming; JIANG Chun-yan

    2010-01-01

    Background Although the locking plate has become popular for treating displaced proximal humeral fractures in recent years, the complications of this method are still underestimated. We tried to evaluate the factors that have an influence on the complications experienced after proximal humeral fractures fixed by locking plates and compare the results from patients having complications with those having no complications.Methods From September 2004 to September 2007, 92 out of 111 displaced proximal humeral fractures treated by open reduction and internal fixation with a locking plate were available for follow-up, with an average time of 15.2months (12-36 months). The range of motion, Visual Analog Score (VAS) for pain, American Shoulder and Elbow Surgeons' Form (ASES), Constant-Murley, University of California-Los Angles scoring system (UCLA) score, and Simple Shoulder Test (SST) for function evaluation was all recorded at the latest follow-up. The results from patients with complications were evaluated according to the indices listed above and compared with those patients without any complications.Results There were 17 patients with complications, an 18.5% complication rate. Among them, the forward flexion,external rotation and internal rotation were 139.1°±24.3°, 24.1°±19.6°, and up to T10 level on average. The mean VAS score was 1.0±1.1, the ASES score was 82.9±13.8, the Constant 82.1±11.8, the UCLA 28.5±4.1 and the mean SST 9.5on average. There was no significant difference of complication rate among different age, sex, and injured side, fresh or delayed fracture, combined with other injury or not groups. Compared with the group without complications, patients with complications showed significantly less external rotation and lower Constant-Murley and UCLA functional scores (P <0.05). A significant difference in results was seen between patients with complications and those without complications.Conclusion The indication control and appropriate

  17. Adult periarticular locking plates for the treatment of pediatric and adolescent subtrochanteric hip fractures.

    Science.gov (United States)

    Sanders, Samuel; Egol, Kenneth A

    2009-01-01

    Two cases are presented in which adult, precontoured, lower-extremity periarticular locking plates were utilized for fixation of subtrochanteric femur fractures in pediatric patients. Recognition of the fact that a distal tibial locking plate in a small child and a proximal tibial locking plate in an adolescent anatomically ft the proximal femur in each case may provide a surgeon treating subtrochanteric hip fractures in this population increased options for operative stabilization.

  18. Interface contact profiles of a novel locking plate and its effect on fracture healing in goat

    Institute of Scientific and Technical Information of China (English)

    WEI Da-cheng; ZHAO Yu-feng; XING Shu-xing; WANG Ai-min

    2010-01-01

    Objective: To evaluate the interface characteristics of the new-designed locking plate (LP) and limited contact-dynamic compression plate (LC-DCP) and compare the fracture healing between LP and LC-DCP in a goat tibia fracture model.Methods: Eight-hole LP and LC-DCP were applied to fix flesh goat tibiae in a reproducible manner. The average pressure, force and interface contact area were calculated using Fuji prescale pressure sensitive film interposed among the plate and the bone and image analysis system. Eighthole LP and LC-DCP were applied to each tibia in a goat tibia fracture model. The fracture healing was evaluated by X-ray photography at postoperative 8 weeks. The goats were sacrificed at postoperative 12 weeks. Three-point bending test was conducted in the tibiae.Results: The interface contact of LP system was smaller than that ofLC-DCP (P<0.05), while interface contact force of LP system was higher than that of LC-DCP (P<0.05). Radiographs revealed that the fracture line disappeared in the LP group, while the fracture line was visible in DCP group at postoperative 8 weeks. At postoperative 12 weeks, the bending strength and bending load of fractured tibia were higher in LP group than in DCP group, respectively.Conclusion: The new-designed locking plate can significantly decrease the contact area on the bone interface,which further provides better fracture healing than conventional plates.

  19. Comparative clinical study of locking screws versus smooth locking pegs in volar plating of distal radius fractures.

    Science.gov (United States)

    Boretto, J G; Pacher, N; Giunta, D; Gallucci, G L; Alfie, V; De Carli, P

    2014-09-01

    The present study was performed to test the null hypothesis on no difference in stability of fixation after volar plating of intra-articular distal radius fractures (AO C2-C3) with either locking smooth pegs or locking screws in a clinical setting. A retrospective evaluation included adult patients with C2-C3 AO fractures treated with a volar plate with locking smooth pegs or locking screws. Radiographic assessment was performed to evaluate extra- and intra-articular parameters in the early postoperative period and after bone union. Twenty-seven consecutive patients were included. Thirteen cases had fixation with locking screws and 14 had fixation with locking smooth pegs. Both groups had bone fragment displacement after fixation. However, there were no significant differences between the groups either in extra- or intra-articular parameters defined by Kreder et al. (1996). Our study shows that, in a clinical setting, there is no difference in stability fixation between locking screws or smooth locking pegs in C2-C3 distal radius fractures.

  20. Complications during removal of conventional versus locked compression plates: is there a difference?

    Science.gov (United States)

    Neumann, Hanjo; Stadler, Anne; Heuer, Hinrich; Auerswald, Marc; Gille, Justus; Schulz, Arndt Peter; Kienast, Benjamin

    2017-08-01

    Osteosynthesis plate removal is one of the most commonly performed procedures in orthopaedic surgery. Due to technological advances and the quality of increasing osteosynthesis material, more and more locked plates have been implanted over the last 20 years. The aim of this study was to determine whether the complication rate during plate removal differs between conventional and locked plates. In this retrospective cohort study, 620 patients were included and divided into two groups based on the type of plate (locked and conventional). Technical complications during implant removal included screw breakage, destroyed screw head, implant breakage, remaining implant material, refracture, bony or soft tissue overgrowth. The following plate-associated complications were identified: osteosynthesis plate not detachable, plate bent or broken, necessity of special tools or plate loosened. Three types of screw-related complications were observed: screw not detachable, screw broken or screw dislocated. Overall, complications related to the plate or screws were documented in 110 of the 620 cases. These complications occurred in 48 of the 382 cases involving conventional osteosynthesis (7.7% of all removals, 12.6% of all conventional removals) and in 62 of the 238 cases involving locked plate osteosynthesis (10.0% of all removals, 26.1% of all locked plate removals). The statistical analysis showed a significantly higher implant-related complication rate with locked plates compared to the conventional plates (p < 0.01). Hardware removal can be a complication-afflicted operation, especially cases involving locked-plate removal should only be performed if a strong indication is evident. Possible benefits of the procedure should be considered carefully, taking the cost-benefit ratio into account.

  1. Failure of volar locking plate fixation of an extraarticular distal radius fracture: A case report

    Directory of Open Access Journals (Sweden)

    Ozer Kagan

    2010-11-01

    Full Text Available Abstract Background Volar locking plates provide significant structural stability to the distal radius. Failure of a volar locked plating is a rarely reported complication in the literature. Case Presentation A 40 year-old, obese female patient who presented with a displaced extraarticular distal radius fracture, underwent open reduction and internal fixation of the fracture using a volar locking plate. Radiographs taken at 10 weeks postoperatively showed failure of fixation with breakage of the four distal locking screws. A hardware removal was performed at 6 months, and the patient was then lost to follow-up. She presented again at 18 months after the first surgery, with significant pain, and radiographic signs of a radial collapse and a fracture-nonunion. A total wrist fusion was performed as the method of choice at that point in time. Conclusion Volar locked plating represents the new "gold standard" of distal radius fracture fixation. However, despite the stability provided by locking plates, hardware failure may occur and lead to a cascade of complications which will ultimately require a wrist fusion, as outlined in this case report. Additional structural support by bone grafting may be needed in selected cases of volar locked plating, particularly in patients with a high risk of developing a fracture-nonunion.

  2. The relationship between interfragmentary movement and cell differentiation in early fracture healing under locking plate fixation.

    Science.gov (United States)

    Miramini, Saeed; Zhang, Lihai; Richardson, Martin; Mendis, Priyan; Oloyede, Adekunle; Ebeling, Peter

    2016-03-01

    Interfragmentary movement (IFM) at the fracture site plays an important role in fracture healing, particularly during its early stage, via influencing the mechanical microenvironment of mesenchymal stem cells within the fracture callus. However, the effect of changes in IFM resulting from the changes in the configuration of locking plate fixation on cell differentiation has not yet been fully understood. In this study, mechanical experiments on surrogate tibia specimens, manufactured from specially formulated polyurethane, were conducted to investigate changes in IFM of fractures under various locking plate fixation configurations and loading magnitudes. The effect of the observed IFM on callus cell differentiation was then further studied using computational simulation. We found that during the early stage, cell differentiation in the fracture callus is highly influenced by fracture gap size and IFM, which in turn, is highly sensitive to locking plate fixation configuration. The computational model predicted that a small gap size (e.g. 1 mm) under a relatively flexible configuration of locking plate fixation (larger bone-plate distances and working lengths) could experience excessive strain and fluid flow within the fracture site, resulting in excessive fibrous tissue differentiation and delayed healing. By contrast, a relatively flexible configuration of locking plate fixation was predicted to improve cartilaginous callus formation and bone healing for a relatively larger gap size (e.g. 3 mm). If further confirmed by animal and human studies, the research outcome of this paper may have implications for orthopaedic surgeons in optimising the application of locking plate fixations for fractures in clinical practice.

  3. Use of locking plates for fixation of the greater trochanter in patients with hip replacement

    Directory of Open Access Journals (Sweden)

    Allison K. Tetreault, BA

    2016-12-01

    Conclusions: Locking plate technology is a successful method of fixation of the greater trochanter in patients with THA. Postoperative trochanteric pain and reoperation for hardware-related issues remain a challenge.

  4. Locking plate osteosynthesis in displaced 4-part fractures of the proximal humerus

    DEFF Research Database (Denmark)

    Brorson, Stig; Frich, Lars H; Winther, Annika;

    2011-01-01

    There is considerable uncertainty about the optimal treatment of displaced 4-part fractures of the proximal humerus. Within the last decade, locking plate technology has been considered a breakthrough in the treatment of these complex injuries....

  5. Reducing Postoperative Fracture Displacement After Locked Plating of Proximal Humerus Fractures: Current Concepts.

    Science.gov (United States)

    Newman, Jared; Kahn, Mani; Gruson, Konrad I

    2015-07-01

    The incidence of proximal humerus fractures in the elderly has been rising. Concomitantly, operative fixation with use of locking plates has been increasing. Postoperative complications of locking plate fixation, particularly in the setting of osteoporotic bone, include screw penetration of the articular surface, progressive fracture displacement, and avascular necrosis. Intraoperative techniques to enhance the fixation construct and reduce complications include use of rotator cuff sutures, bone void fillers (fibular strut allograft, cancellous allograft, autograft, bone cement), appropriate placement of divergent and shorter locking screws, and medial calcar reduction and support. More recent clinical and biomechanical studies suggest that use of these strategies may reduce complications after locked plating of osteoporotic proximal humerus fractures. Furthermore, a multidisciplinary approach to the evaluation and treatment of osteoporosis may be beneficial in these patients.

  6. Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

    Science.gov (United States)

    Karakasli, Ahmet; Hapa, Onur; Erduran, Mehmet; Dincer, Cemal; Cecen, Berivan; Havitcioglu, Hasan

    2015-01-01

    For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

  7. Periprosthetic Vancouver type B1 and C fractures treated by locking-plate osteosynthesis

    DEFF Research Database (Denmark)

    Froberg, Lonnie; Troelsen, Anders; Brix, Michael

    2012-01-01

    internal fixation, and the introduction of locking-plate osteosynthesis may lead to improved outcome. We evaluated the outcome of Vancouver type B1 and C PFFs treated by locking-plate osteosynthesis, by assessing rates of fracture union and reoperations and by analyzing failure cases.......Historically, the treatment of periprosthetic femoral fractures (PFFs) has been associated with a high frequency of complications and reoperations. The preferred treatment is internal fixation, a revision of the femoral stem, or a combination of both. An improved understanding of plate use during...

  8. The Minimally Invasive Plate Osteosynthesis (MIPO Technique with a Locking Compression Plate for Femoral Lengthening

    Directory of Open Access Journals (Sweden)

    Tetsunaga,Tomonori

    2008-10-01

    Full Text Available A minimally invasive plate osteosynthesis technique using a locking compression plate (LCP has been used widely in trauma cases. Its advantages are that the MIPO technique does not interfere with the fracture site and thus provides improved biological healing, and that the LCP has excellent angular stability. Its use in bone lengthening, however, has not been established. In such cases, it is desirable to shorten the external skeletal fixation period as much as possible. Here, the MIPO technique using an LCP was applied to femoral distraction osteogenesis in an attempt to shorten the external skeletal fixation period. For femoral lengthening, the MIPO technique was performed in 2 stages. Orthofix external fixators (Orthofix, England were used to insert screws from the anterolateral side rather than from the lateral side of the femur for bone lengthening. When sufficient callus formation was detected postoperatively at the site of bone lengthening, and the absence of infection was ensured, limb draping was performed, including a whole external fixator, and then the MIPO technique was applied with an LCP. In 3 cases (5 limbs, the average duration of external skeletal fixation was 134days, the average external-fixation index was 24days/cm, and the average consolidation index was 22days/cm. The MIPO technique using an LCP made it possible to shorten the external skeletal fixation-wearing period in femoral lengthening.

  9. CLINICAL OUTCOMES OF LOCKING COMPRESSION PLATE FIXATION THROUGH MINIMALLY INVASIVE PERCUTANEOUS PLATE OSTEOSYNTHESIS IN THE TREATMENT OF DISTAL TIBIAL FRACTURE

    Directory of Open Access Journals (Sweden)

    Venkateswara Rao

    2015-07-01

    Full Text Available BACKGROUND: Distal diametaphyseal tibia fracture though requires operative treatment is difficult to manage. Conventional osteosynthesis is not suitable because distal tibia is subcutaneous bone with poor vascularity. Closed reduction and minimally invasive percutaneous plate osteosynthes is with locking compression plate (LCP has emerged as an alternative treatment option because it respects biology of distal tibia and fracture hematoma and also provides biomechanica l ly stable construct. OBJECTIVES: To find out suitability of minimally invasive percutaneous plate osteosynthesis with Locking compression plate for distal diametaphyseal tibia fracture including union time and complications. METHODS: Twenty patients with closed distal tibia fracture with or without intra articular extension (AO classification type - A1, type - A2, type - A3 treated with minimally invasive percutaneous plate osteosynthesis with Locking compression plate were prospectively followed for average duration of 12 months. RESULTS: Ave rage duration of injury - surgery interval was 4.5 days (Range 3 - 7 days all fractures got united with an average duration of 23.5 weeks (range17 - 30weeks. No non - union or mal - union were found. There was one superficial infection found which healed with exte nded period of intravenous antibiotics.

  10. Complications and functional outcome after fixation of distal tibia fractures with locking plate - A multicentre study

    DEFF Research Database (Denmark)

    Viberg, Bjarke; Kleven, Silje; Hamborg-Petersen, Ellen

    2016-01-01

    and X-ray images for 6 hospitals (1 level 1, 5 level 2) in the Region of Southern Denmark. Between January 2007 and April 2011 70 consecutive patients with 71 distal tibia fractures were treated with low-profile locking plate were included. The proportion of post-operative complications, classified......INTRODUCTION: The aim of this study was to evaluate the proportion of complications and the functional outcome following ORIF with low-profile locking plates in patients with distal tibia fractures. METHOD: Retrospective data was retrieved using county databases, operation books, health record...... score was 73. Thirty-three percent of working patients had not returned to work as a result of the fracture. CONCLUSIONS: Our study suggest that treatment of distal tibia fractures with low-profile locking plates might have a higher proportion of complications and worse functional outcome than...

  11. Locking, mass flux and topographic response at convergent plate boundaries - the Chilean case

    Science.gov (United States)

    Oncken, Onno

    2016-04-01

    On the long term, convergent plate boundaries have been shown to be controlled by either accretion/underplating or by subduction erosion. Vertical surface motion is coupled to convergence rate - typically with an uplift rate of the coastal area ranging from 0 to +50% of convergence rate in accretive systems, and -20 to +30% in erosive systems. Vertical kinematics, however, are not necessarily linked to horizontal strain mode, i.e. upper plate shortening or extension, in a simple way. This range of kinematic behaviors - as well as their acceleration where forearcs collide with oceanic ridges/plateau - is well expressed along the Chilean plate margin. Towards the short end of the time scale, deformation appears to exhibit a close correlation with the frictional properties and geodetic locking at the plate interface. Corroborating analogue experiments of strain accumulation during multiple earthquake cycles, forearc deformation and uplift focus above the downdip and updip end of seismic coupling and slip and are each related to a particular stage of the seismic cycle, but with opposite trends for both domains. Similarly, barriers separating locked domains along strike appear to accumulate most upper plate faulting interseismically. Hence, locking patters are reflected in topography. From the long-term memory contained in the forearc topography the relief of the Chilean forearc seems to reflect long term stability of the observed heterogeneity of locking at the plate interface. This has fundamental implications for spatial and temporal distribution of seismic hazard. Finally, the nature of locking at the plate interface controlling the above kinematic behavior appears to be strongly controlled by the degree of fluid overpressuring at the plate interface suggesting that the hydraulic system at the interface takes a key role for the forearc response.

  12. Role of locking plates in treatment of difficult ununited fractures: a clinical study

    Institute of Scientific and Technical Information of China (English)

    Ashok Kumar; Himanshu Gupta; Chandra Shekhar Yadav; Shah Alam Khan; Shishir Rastogi

    2013-01-01

    Objective:To present our experience in treatment of difficult ununited long bone fractures with locking plate.Methods:Retrospective evaluation of locking plate fixation in 10 difficult nonunions of long bone fractures was done.Fixation was done with locking plate for femoral shaft fracture (3 patients),supracondylar fracture of femur (gap nonunion),fracture of clavicle,fracture of both forearm bones (radius and ulna) fracture of ulna,fracture of shaft of humerus,fracture of tibial diaphysis and supracondylar fracture of humerus (one patient each).Five fractures had more than one previous failed internal fixation.One patient had infected nonunion which was managed by debridement with cast immobilization followed by fixation with locking plate at six weeks.Seven fractures were atrophic,two were oligotrophic,and one was hypertrophic.Fibular autograft was used in 2 cases and iliac crest cancellous bone graft used in all the patients.Results:Minimum follow-up was 6 months (range,6 months to 2.5 years).Average rime for union was 3.4 months (range 2.5 to 6 months).None of the patients had platerelated complications or postoperative wound infections.Conclusion:Along with achieving stability with locking compression plate,meticulous soft tissue dissection,acceptable reduction,good fixation technique and bone grafting can help achieve union in difficult nonunion cases.Though locking plate does not by itself ensure bony union,we have found it to be another useful addition to our armamentarium for treating difficult fracture nonunions.

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

    Directory of Open Access Journals (Sweden)

    Sampat S Dumbre Patil

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Relaxation towards phase-locked dynamics in long Josephson junctions

    DEFF Research Database (Denmark)

    Salerno, M.; Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    1995-01-01

    We study the relaxation phenomenon towards phase-locked dynamics in long Josephson junctions. In particular the dependence of the relaxation frequency for the equal time of flight solution on the junction parameters is derived. The analysis is based on a phase-locked map and is compared with dire...

  16. OPERATIVE MANAGEMENT OF INTRA-ARTICULAR DISTAL HUMERAL FRACTURES WITH LOCKING PLATES

    Directory of Open Access Journals (Sweden)

    Abhilekh

    2015-11-01

    Full Text Available BACKGROUND: Intra-articular distal humeral fractures are common, but complex elbow injuries. To obtain good results, anatomical reduction with rigid fixation and early range of mobilization is required. Treatment of these fractures with conventional plates is associated with many complications such as non-anatomic reduction of articular surfaces, malunion, non-union, loosening of implant, residual stiffness of the elbow and post-traumatic osteoarthrosis. In this situation the application of locking plates having a fixed angle plate screw construct can minimise most of the above complications. OBJECTIVE: To evaluate radiological and functional outcome of locking plate application for the management of intra-articular distal humeral fractures. MATERIAL AND METHODS: This prospective study was conducted from January 2013 to December 2014. We operated 20 patients of AO type-C intra-articular distal humeral fractures. Fracture was exposed using modified Campbell’s posterior approach in less comminuted fractures and a V-shaped Olecranon osteotomy was done to get better exposure of the articular surface in cases with severe articular comminution. The fracture was stabilized using an intercondylar screw, pre-contoured locking compression plates and/or locking reconstruction plates as per preoperative planning. Patients were reviewed at monthly interval for clinical-radiological evaluation. Final outcome measures included radiological assessment, range of motion and Mayo elbow performance score (MEPS. RESULTS: All the fractures were united at an average 12 weeks. Two patients developed numbness in the distribution of ulnar nerve and one patient developed superficial infection in immediate postoperative period. None of the patients had malunion and loosening of implant. The average arc of flexion-extension was 105`, although no patient had loss of supination/pronation. Mayo Elbow Performance Score was excellent in 15 (75%, good in 3 (15%, fair in 1 (5

  17. Dynamic plate osteosynthesis for fracture stabilization: how to do it

    Directory of Open Access Journals (Sweden)

    Juerg Sonderegger

    2010-01-01

    Full Text Available Plate osteosynthesis is one treatment option for the stabilization of long bones. It is widely accepted to achieve bone healing with a dynamic and biological fixation where the perfusion of the bone is left intact and micromotion at the fracture gap is allowed. The indications for a dynamic plate osteosynthesis include distal tibial and femoral fractures, some midshaft fractures, and adolescent tibial and femoral fractures with not fully closed growth plates. Although many lower limb shaft fractures are managed successfully with intramedullary nails, there are some important advantages of open-reduction-and-plate fixation: the risk of malalignment, anterior knee pain, or nonunion seems to be lower. The surgeon performing a plate osteosynthesis has the possibility to influence fixation strength and micromotion at the fracture gap. Long plates and oblique screws at the plate ends increase fixation strength. However, the number of screws does influence stiffness and stability. Lag screws and screws close to the fracture site reduce micromotion dramatically. Dynamic plate osteosynthesis can be achieved by applying some simple rules: long plates with only a few screws should be used. Oblique screws at the plate ends increase the pullout strength. Two or three holes at the fracture site should be omitted. Lag screws, especially through the plate, must be avoided whenever possible. Compression is not required. Locking plates are recommended only in fractures close to the joint. When respecting these basic concepts, dynamic plate osteosynthesis is a safe procedure with a high healing and a low complication rate. 

  18. Biomechanical Assessment of Locked Plating for the Fixation of Patella Fractures.

    Science.gov (United States)

    Wurm, Simone; Augat, Peter; Bühren, Volker

    2015-09-01

    To analyze the mechanical stability of locked plating in comparison with tension-band wiring for the fixation of fractures of the patella. Biomechanical tests were performed on artificial foam patella specimens comparing an angular stable plate and monocortical screws with tension-band wiring. Tests were performed under combined tension and bending until failure simulating physiological loading of the tibia during walking. Tension-band wiring failed at 66% of the failure load of plating (1052 N, P = 0.002) and had 5 times larger fracture gap displacements (P = 0.002). Based on the biomechanical advantages, locked plating of the patella may constitute a reasonable alternative in the treatment of patella fractures.

  19. The mechanical benefit of medial support screws in locking plating of proximal humerus fractures.

    Directory of Open Access Journals (Sweden)

    Wen Zhang

    Full Text Available BACKGROUND: The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs in the locking proximal humeral plate for treating proximal humerus fractures. METHODS: Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. RESULTS: Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001. When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P ≤ 0.0207. Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. CONCLUSIONS: Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure.

  20. Biomechanical performance of variable and fixed angle locked volar plates for the dorsally comminuted distal radius.

    Science.gov (United States)

    Martineau, D; Shorez, J; Beran, C; Dass, A G; Atkinson, P

    2014-01-01

    The ideal treatment strategy for the dorsally comminuted distal radius fracture continues to evolve. Newer plate designs allow for variable axis screw placement while maintaining the advantages of locked technology. The purpose of this study is to compare the biomechanical properties of one variable axis plate with two traditional locked constructs. Simulated fractures were created via a distal 1 cm dorsal wedge osteotomy in radius bone analogs. The analogs were of low stiffness and rigidity to create a worst-case strength condition for the subject radius plates. This fracture-gap model was fixated using one of three different locked volar distal radius plates: a variable axis plate (Stryker VariAx) or fixed axis (DePuy DVR, Smith & Nephew Peri-Loc) designs. The constructs were then tested at physiologic loading levels in axial compression and bending (dorsal and volar) modes. Construct stiffness was assessed by fracture gap motion during the different loading conditions. As a within-study control, intact bone analogs were similarly tested. All plated constructs were significantly less stiff than the intact control bone models in all loading modes (pbending (pbending.

  1. Computational modelling of long bone fractures fixed with locking plates - How can the risk of implant failure be reduced?

    LENUS (Irish Health Repository)

    Nassiri, M

    2013-03-01

    The Locking Compression Plate (LCP) is part of a new plate generation requiring an adapted surgical technique and new thinking about commonly used concepts of internal fixation using plates. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability and the risk of implant failure can best be controlled.

  2. Construction and biomechanical properties of polyaxial self-locking anatomical plate based on the geometry of distal tibia.

    Science.gov (United States)

    Liang, Weiguo; Ye, Weixiong; Ye, Dongping; Zhou, Ziqiang; Chen, Zhiguang; Li, Aiguo; Xie, Zong-Han; Zhang, Lihai; Xu, Jiake

    2014-01-01

    In order to provide scientific and empirical evidence for the clinical application of the polyaxial self-locking anatomical plate, 80 human tibias from healthy adults were scanned by spiral CT and their three-dimensional images were reconstructed using the surface shaded display (SSD) method. Firstly, based on the geometric data of distal tibia, a polyaxial self-locking anatomical plate for distal tibia was designed and constructed. Biomechanical tests were then performed by applying axial loading, 4-point bending, and axial torsion loading on the fracture fixation models of fresh cadaver tibias. Our results showed that variation in twisting angles of lateral tibia surface was found in various segments of the distal tibia. The polyaxial self-locking anatomical plate was constructed based on the geometry of the distal tibia. Compared to the conventional anatomical locking plate, the polyaxial self-locking anatomical plate of the distal tibia provides a better fit to the geometry of the distal tibia of the domestic population, and the insertion angle of locking screws can be regulated up to 30°. Collectively, this study assesses the geometry of the distal tibia and provides variable locking screw trajectory to improve screw-plate stability through the design of a polyaxial self-locking anatomical plate.

  3. FUNCTIONAL OUTCOME OF SUPRACONDYLAR FRACTURES OF FEMUR MANAGED BY OPEN REDUCTION AND INTERNAL FIXATION WITH LOCKING COMPRESSION PLATE

    Directory of Open Access Journals (Sweden)

    Madhusudhana

    2015-10-01

    Full Text Available INTRODUCTION : Incidence of distal femur fractures is approximately 37 per 1 , 00,000 person - years.¹Distal femoral fractures has two different injury mechanisms, high energy trauma and low energy trauma. In high - energy trauma, the problem of restoring the function in a destroyed knee joint persists. Complex knee ligament injuries frequently occur additionally to extensive cartilage injuries. In elderly patients, extreme osteoporosis represents a particular problem for anchoring the implant. 2 Supracondylar and inter condylar fractures often are unstable and comminuted and tend to occur in the elderly or those with multiple injuries. Treatment options are many with varied results. The final outcome would depend upon the type of fracture, stabilization of fixation and and perhaps patient general condition. 3 The options for operative treatment are traditional plating techniques that require compression of the implant to the femoral shaft (blade plate, Dynamic Condylar Screw, non - locking condylar buttress plate, antegrade nailing fixation, retrograde nailing, sub muscular locked internal fixation and external fixation. 4 However, as the complexity of fractures needing treatment has changed from simple extra - articular supra - condylar types to inter - condylar and metaphyseal comminuted types, these implants may not be ideal. Double plating, and more recently, locked plating techniques have been advocated 5 . However with double plating there is often extensive soft tissue stripping on both sides of the femur, resulting in reduced blood supply and potential non - union and failure of the implants 6 . The LCP is a single beam construct where the strength of its fixation is equal to the sum of all screw - bone interfaces rather than a single screw’s axial stiffness or pullout resistance as seen in unlocked plates 7,8 . Its unique biomechanical function is based on splinting rather than compression resulting in flexible stabilization

  4. Surgical Management of 3 and 4-Part Proximal Humerus Fractures with Locking Plates in Elderly

    Directory of Open Access Journals (Sweden)

    Emrah Kovalak

    2017-05-01

    Full Text Available Aim: Proximal humeral fractures are approximately 5% of all fractures and, %15-20 is displaced and unstable. By the introduction of locking plates there used to be a substantial rise in the osteosynthesis of the 3 and 4-part proximal humeral fractures. But there is still a lack of consensus for the optimal treatment of these complex fractures. In this retrospective study, we aimed to evaluate the functional outcomes and prognostic factors of 3 and 4-part proximal humerus fractures treated with locking plate osteosynthesis in elderly. Material and Method: 53 patients with displaced 3 and 4-part proximal humeral fractures treated with locking plate osteosynthesis between 2010 and 2015 were included. The fractures were classified according to Neer classification system. Outcomes were assessed by Constant-Murley scoring system (CMS, visual analog pain scale and plain radiographs. In reference to range of motion, forward elevation and abduction of the arm were measured.Results: No statistically significant differences found between the 3- part and 4- part fractures in CMS, forward elevation and, abduction (p>0.05. Pain was significantly higher in 4-part fractures (p=0.035. CMS, forward elevation, and abduction were inversely correlated with age and delay in surgery. There was statistical significance between the patients had complications and those not in terms of CMS, forward elevation and, abduction (p=0.029, p=0.017 and p=0.024. Discussion: Functional outcomes of locking plate fixation of proximal humerus fractures are associated with patient related factors, fracture pattern, surgeon and, the implant. When indications are carefully selected, locking plate osteosynthesis yield good outcomes in surgical treatment of 3 or 4-part proximal humerus fractures.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. Neuron-like dynamics of a phase-locked loop

    Science.gov (United States)

    Matrosov, Valery V.; Mishchenko, Mikhail A.; Shalfeev, Vladimir D.

    2013-10-01

    Dynamics of two coupled phase-controlled generators based on phase-locked loop systems with a high frequency filter in the control loop was studied. It was found that beating modes are synchronized in the systems and shown that different synchronization states form an overlapping structure in parameters space of the coupled systems. Usage of the phase-locked loop as a neuron-like element is proposed.

  7. STUDY OF FUNCTIONAL OUTCOME OF DISTAL FEMUR FRACTURES TREATED BY OPEN REDUCTION AND INTERNAL FIXATION WITH LOCKING COMPRESSION PLATE

    Directory of Open Access Journals (Sweden)

    Sahaya R

    2016-04-01

    Full Text Available BACKGROUND Distal femur fractures account for about 7% of all femur fractures. These fractures can lead to knee stiffness and have the tendency to collapse into varus. The management of distal femur fractures has seen a paradigm shift from nonoperative measures to biological fixation and evolution of modern implants like Locking Compression Plate has been used in current times. With the use of Locking Compression Plate double plating can be avoided. In our study, we have evaluated the short-term Functional Outcome of patients who underwent open reduction internal fixation with Locking Compression Plate using Sander’s criteria. Ours is both prospective and retrospective study of 20 patients with distal femur fractures treated operatively from April 2013 to October 2015. Our surgical modality of treatment is open reduction and internal fixation with locking compression plate using standard lateral approach. We have used AO classification to classify the distal femur fractures. With the results of our study, we have come to a conclusion that locking compression plate is a best option for both intra-articular and extra-articular distal femur fractures. It avoids the use of dual plating of distal femur which requires extensive soft tissue stripping in both sides, resulting in reduced blood supply, potential non-union and implant failure. Locking Compression Plate also helps in anatomical reduction of comminuted intra-articular fractures and it could also be used effectively in osteoporotic bone.

  8. Are there any differences in various polyaxial locking systems? A mechanical study of different locking screws in multidirectional angular stable distal radius plates.

    Science.gov (United States)

    Mehling, Isabella; Scheifl, Rebekka; Mehler, Dorothea; Klitscher, Daniela; Hely, Hans; Rommens, Pol M

    2013-04-01

    Numerous angular stable plates for the distal radius exist, and technically based comparisons of the polyaxial locking interfaces are lacking. The aim of this mechanical study was to investigate three different locking interfaces of angular stable volar plates by cantilever bending: VA-LCP Two-Column Distal Radius Plates 2.4 mm (Synthes® GmbH, Oberdorf, Switzerland), IXOS® P4 (Martin, Tuttlingen, Germany) and VariAX™ (Stryker®, Duisburg, Germany). We assessed the strength of 0°, 5°, 10° and 15° screw locking angles and tested the bending strength from 10° to 5° angles by cyclic loading until breakage. The final setup repeated the above assessments by inclusion of four locking screws. The single screw-plate interfaces of the VA-LCP showed the highest bending moment at an angle of 0° and 5°, the IXOS® P4 at an angle of 10° and 15° and the VariAX™ when changing the insertion angle from 10° into 5°. The strength of polyaxial locking interfaces and mechanism of failure proved to be different among the examined plates.

  9. Evidence based postoperative treatment of distal radius fractures following internal locking plate fixation.

    Science.gov (United States)

    Klein, S M; Prantl, L; Koller, M; Vykoukal, J; Dolderer, J H; Graf, S; Nerlich, M; Loibl, M; Geis, S

    2015-01-01

    Originally, the treatment method of choice for distal radial fractures (DRF) has been a non-operative approach with six to eight weeks of plaster casting. The introduction of volar locking plate systems at the beginning of the 21 st century has pushed trends towards open reduction and internal fixation (ORIF). While the introduction of fixed angle locking plates together with the increasing knowledge on wrist function and related variable outcomes has led to consensus that operative fixation in instable DRF is the treatment method of choice, there is no agreement on a postoperative care of these injuries. The authors will discuss the available evidence for current concepts of postoperative treatment of DRFs following fixed angle fixation under socioeconomical, biomechanical and burden of disease aspects. Further, relevant randomized controlled trials are evaluated with regard to applied postoperative treatment regimes and related risks for complications.

  10. A multiresolution finite element method based on a new locking-free rectangular Mindlin plate element

    CERN Document Server

    Xia, Yi-Ming

    2015-01-01

    A locking-free rectangular Mindlin plate element with a new multi-resolution analysis (MRA) is proposed and a multireolution finite element method is hence presented. The MRA framework is formulated out of a mutually nesting displacement subspace sequence. The MRA endows the proposed element with the resolution level (RL) to adjust the element node number, thus modulating structural analysis accuracy accordingly. As a result, the traditional 4-node rectangular Mindlin plate element and method is a mono-resolution one and also a special case of the proposed element and method. The meshing for the monoresolution plate element model is based on the empiricism while the RL adjusting for the multiresolution is laid on the rigorous mathematical basis. The accuracy of a structural analysis is actually determined by the RL, not by the mesh. The rational MRA enables the implementation of the multiresolution Mindlin plate element method to be more rational and efficient than that of the conventional monoresolution or o...

  11. Biomechanical Property of a Newly Designed Assembly Locking Compression Plate: Three-Dimensional Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Jiang-Jun Zhou

    2017-01-01

    Full Text Available In this study, we developed and validated a refined three-dimensional finite element model of middle femoral comminuted fracture to compare the biomechanical stability after two kinds of plate fixation: a newly designed assembly locking compression plate (NALCP and a locking compression plate (LCP. CT data of a male volunteer was converted to middle femoral comminuted fracture finite element analysis model. The fracture was fixated by NALCP and LCP. Stress distributions were observed. Under slow walking load and torsion load, the stress distribution tendency of the two plates was roughly uniform. The anterolateral femur was the tension stress area, and the bone block shifted toward the anterolateral femur. Maximum stress was found on the lateral border of the number 5 countersink of the plate. Under a slow walking load, the NALCP maximum stress was 2.160e+03 MPa and the LCP was 8.561e+02 MPa. Under torsion load, the NALCP maximum stress was 2.260e+03 MPa and the LCP was 6.813e+02 MPa. Based on those results of finite element analysis, the NALCP can provide adequate mechanical stability for comminuted fractures, which would help fixate the bone block and promote bone healing.

  12. One size does not fit all: distal radioulnar joint dysfunction after volar locking plate fixation.

    Science.gov (United States)

    Jones, Christopher W; Lawson, Richard D

    2014-02-01

    Background Fractures of the distal radius are among the most common injuries treated by orthopedic surgeons worldwide. Failure to restore distal radius alignment can lead to fracture malunion and poor clinical outcomes, including distal radioulnar joint (DRUJ) instability and limitation of motion. Case Description We present a unique case of DRUJ dysfunction following volar plate fixation of bilateral distal radius fractures and analyze the biomechanical causes of this complication. As a result of a relatively excessive tilt of the precontoured locking plate (in comparison to the patient's particular anatomy), the fracture on one side was "over-reduced," disrupting the biomechanics of the DRUJ, causing a supination block. Clinical Relevance Volar locking plates are not a panacea to all distal radius fractures. Plate selection and fixation technique must include consideration of patient anatomy. Robust plates offer the advantage of providing rigid fixation but can be difficult to contour when reconstructing normal anatomy. Restoration of patient-specific anatomy is crucial to the management of distal radius fractures.

  13. Outcomes of pin and plaster versus locking plate in distal radius intraarticular fractures.

    Science.gov (United States)

    Bahari-Kashani, Mahmoud; Taraz-Jamshidy, Mohammad Hosein; Rahimi, Hassan; Ashraf, Hami; Mirkazemy, Masoud; Fatehi, Amirreza; Asadian, Mariam; Rezazade, Jafar

    2013-01-01

    Distal radius fractures are among the most prevalent fractures predictive of probable occurrence of other osteoporotic fractures. They are treated via a variety of methods, but the best treatment has not been defined yet. This study was performed to compare the results of open reduction and internal fixation with locking plates versus the pin and plaster method. In this prospective study, 114 patients aged 40 to 60 years with Fernandez type III fracture referring to Imam-Reza and Mehr hospitals of Mashhad from 2009 to 2011, were selected randomly; after obtaining informed consent, they were treated with pin and plaster fixation (n = 57) or internal fixation with the volar locking plate (n = 57). They were compared at the one year follow up. Demographic features and standard radiographic indices were recorded and MAYO, DASH and SF - 36 tests were performed. Data was analyzed by SPSS software version 13, with descriptive indices, Mann-Whitney and Chi-square tests. SF-36 test demonstrated a better general health (P plaster group. Also, in the LCP group mean MAYO score (P plaster group. Mean DASH score was not different between the groups (P = 0.218). The rate of acceptable results of radiographic indices (P plaster method. In treatment of intra-articular distal radius fractures in middle-aged patients internal fixation with locking plates may be prefered to pin and plaster as the treatment of choice.

  14. FUNCTIONAL AND RADIOLOGICAL OUTCOME OF DISTAL FEMORAL FRACTURES TREATED WITH LOCKING COMPRESSION PLATE

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    Muktevi

    2015-05-01

    Full Text Available AIM: To evaluate the clinical and radiological outcome in the management of distal femur fractures treated by distal femoral locking compression plate. BACKGROUND : Distal femur fractures are one of the common fractures occurring in road traffic accidents. Different treatment modalities with varying outcomes are seen in literature in the management of th e s e fractures. MATERIALS & METHODS: The study was con ducted in the department of orthopaedics at the Kamineni Institute of Medical sciences Narketpally. Patients treated for distal femur fractures with ORIF using distal femoral locking compression plates were evaluated to assess their clinical and functional results using Neer’s scoring system and compared with the available literature. RESULTS: The mean time for union was 20 wks. With mean time to full weight bearing being 10.5 wks . CONCLUSION: Surgery in the form of ORIF with distal femoral locking compression plate for Distal femur fracture is a comparatively good treatment option for better out come and early mobilization with minimum complications.

  15. Comparison between two angular stable locking plates for medial opening-wedge high tibial osteotomy: Decisive wedge locking plate versus TomoFix™.

    Science.gov (United States)

    Shin, Young-Soo; Kim, Keong-Ho; Sim, Hyun-Bo; Yoon, Jung-Ro

    2016-11-01

    An adequate stable fixation implant should be used for medial opening-wedge high tibial osteotomy (MOWHTO) to promote rapid bone healing without complications. This study compared the radiographic and clinical outcomes as well as plate-specific complications between two angular stable locking plates in patients following MOWHTO. This prospective study involved 97 patients (50 with DWL(®), group I; 47 with TomoFix™, group II) undergoing MOWHTO for primary medial compartment osteoarthritis between 2010 and 2013. Clinical and radiographic evaluations were performed by using the HSS and WOMAC scores, and calculating mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and posterior tibial slope (PTS) on radiographs both preoperatively and after 3 years. A statistically significant difference was observed for the MPTA at the last follow-up between the two groups (P = 0.033). Additionally, the last follow-up MPTA of group I was associated with the osteotomy technique (P = 0.004) and preoperative JLCA (P = 0.034) whereas the last follow-up MPTA of group II was associated with gender (P = 0.001) and BMI (P = 0.008). Furthermore, the results showed that group I had a higher rate of non-union (4%) compared to that in group II (0%). Both locking plates are useful tools in the treatment of medial compartment knee osteoarthritis with varus deformity in young, active patients. However, under special consideration of the complication we found in present study, the TomoFix™ seems to be a better alternative in using the MOWHTO for highly demanding patients. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  16. Contralateral reversed distal femoral locking plate for fixation of subtrochanteric femoral fractures

    Institute of Scientific and Technical Information of China (English)

    Paritosh Gogna; Reetadyuti Mukhopadhyay; Amanpreet Singh; Ashish Devgan; Sahil Arora; Amit Batra; Sushil Kumar Yadav

    2015-01-01

    Purpose:Subtrochanteric fractures of the femur are being managed successfully with various intramedullary and extramedulary implants with reasonable success.However,these implants require precise placement under image intensifier guidance,which exposes the surgeon to substantial amount of radiation.It also restricts the management of these fractures at peripheral centers where facility of image intensifiers is not available.Keeping this in mind we designed this study to identify if contralateral reversed distal femoral locking plate can be used successfully without the use of image intensifier.Methods:Twenty-four consecutive patients (18 men and 6 women) with a mean age of 28 years (range 19-47 years) suffering subtrochanteric fractures of the femur underwent open reduction and internal fixation with reversed contralateral distal femoral locking plate.The outcome was assessed at the mean follow-up period of 3.2 years (range 2-4.6 years) using the Harris hip score.Results:Twenty-one fractures united with the primary procedure,with a mean time of consolidation being 11 weeks (range,9-16 weeks).One patient developed superficial suture line infection,which resolved with oral antibiotics.Another patient had a fall 3 weeks after surgery and broke the plate.Repeat surgery with reversed distal femoral locking compression plate was performed along with bone grafting and the fracture united.Two cases had nonunion,which went in for union after bone grafting.The mean Harris hip score at the time of final follow-up was 90.63 (range 82-97).Conclusion:The reversed contralateral distal femoral plate is a biomechanically sound implant,which when used for fixation of the subtrochanteric fractures with minimal soft tissue stripping shows results comparable to those achieved by using other extramedullary implants as well as intramedullary devices.The added advantage of this implant is its usability in the absence of an image intensifier.

  17. Effect of fixing distal radius fracture with volar locking palmar plates while preserving pronator quadratus

    Institute of Scientific and Technical Information of China (English)

    Fan Jian; Chen Kai; Zhu Hui; Jiang Bo; Yuan Feng; Zhu Xiaozhong; Mei Jiong

    2014-01-01

    Background L-shaped incision of pronator quadratus (PQ) muscle along its radial and distal borders was always taken for distal radius fractures reduction and internal fixation.Repair of the PQ muscle was always recommended at the end of operation for some instructive reasons.But repair of PQ is not satisfied because of poor quality of muscle and fascial tissues which may cause pain or impede forearm pronation and supination for post-operative scarring around PQ.Inserting the locking palmar plate to pass under the pronator quadratus muscle and the locking screws are inserted through miniincisions in pronator quadratus in some patients with distal radius fractures is a reasonable technique which can preserve the pronator quadratus.The purpose of this study was to evaluate and compare the clinical effects after volar plating of the distal radius fractures while preserving the pronator quadratus and pronator quadratus repair.Methods Between September 2010 and April 2012,65 patients (42 males and 23 females; aged 20-68 years and a mean age of 42.5 years) with distal radius fracture underwent open reduction and internal fixation using the volar locking palmar plates (Depuy or Smith companies).The patients were classified as 23A-2 through 23C-3 according to the Orthopaedic Trauma Association (OTA) classifications.All surgeries were completed by the same trained team.The volar locking palmar plates of distal radius performed with preserving pronator quadratus group involved 30 patients including 19 males and 11 females and performed with pronator quadratus repair group involved 35 patients including 23 males and 12 females.We compared the two groups for wrist pain,forearm range of motion,grip strength,pedoperative complications and wrist functional recovery score.Results The minimum follow-up for the whole cohort was one year.The differences between the two groups were significant with regard to wrist pain,forearm range of motion,grip strength and wrist function at 1,2,and

  18. Short-term follow-up of pertrochanteric fractures treated using the proximal femoral locking plate.

    Science.gov (United States)

    Johnson, Benjamin; Stevenson, Jonathan; Chamma, Ramsey; Patel, Amit; Rhee, Shin-Jae; Lever, Caroline; Starks, Ian; Roberts, Phillip J

    2014-05-01

    The proximal femoral locking compression plate is a fixed angled anatomically contoured stainless steel plate used to treat pertrochanteric fractures of the proximal femur. Recent reports quote a high failure rate associated with this implant. We aimed to identify the common methods of failure and determine the elements of surgical techniques that could be altered to potentially improve outcomes should this implant be used for the treatment of unstable pertrochanteric fractures. Retrospective chart analysis. Three separate centers. Twenty-nine patients with 29 fractures. All patients were treated for pertrochanteric fractures using the proximal femoral locking compression plate. The patient demographics, fracture classification, implant details, and complications. Twelve of 29 fractures (41.4%) suffered a complication associated with the implant, and 83% of these occurred in elderly women. Complications included bending, backing-out, fracture, or cut-out of the proximal screws and plate fracture. Common technical errors included the following: (1) leaving the plate proud proximally, (2) malposition of the proximal screws within the femoral neck/head, (3) inappropriate use of the hook plate, (4) creating too ridged a construct when used as a bridging plate. Our experience with the use of this implant suggests an unacceptably high failure rate (41.4%). A knowledge of the common pitfalls encountered when using this device is critical in an effort to reduce failure rates. Based on our data, we would urge caution when considering this device for unstable pertrochanteric fractures, especially in the elderly female. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

  19. Proximal Humeral Fractures: A Biomechanical Comparison of Locking Plate Constructs in a Cadaveric 3-Part Fracture Model

    OpenAIRE

    2010-01-01

    The purpose of our study was to biomechanically compare, under cyclic loading conditions, fracture site motion, humeral head collapse, and intra-articular hardware penetration in simulated 3-part osteoporotic proximal humeral fractures stabilized with 1 of 2 locking-plate constructs. We performed fixation on simulated 3-part proximal humeral fractures in 10 pairs of cadaveric osteoporotic humeri with a Hand Innovations S3 Proximal Humerus Plate (S3 plate) or an LCP Proximal Humerus Plate (LCP...

  20. A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries.

    Science.gov (United States)

    Nguyentat, Annie; Camisa, William; Patel, Sandeep; Lagaay, Pieter

    2016-01-01

    Previous biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone. Complex rotational ankle injuries involve an increased number of fractures, which can result in instability, potentially requiring the same fixed angle properties afforded by locking plates. However, the mechanical indication for locking plate technology has not been tested in this fracture model. The purpose of the present study was to compare the biomechanical properties of locking and conventional plate fixation for distal fibula fractures in trimalleolar ankle injuries. Fourteen (7 matched pairs) fresh-frozen cadaver leg specimens were used. The bone mineral density of each was obtained using dual x-ray absorptiometry scans. The fracture model simulated an OTA 44-B3.3 fracture. The syndesmosis was not disrupted. Each fracture was fixated in the same fashion, except for the distal fibula plate construct: locking (n = 7) and one-third tubular (n = 7). The specimens underwent axial and torsional cyclic loading, followed by torsional loading to failure. No statistically significant differences were found between the locking and conventional plate constructs during both fatigue and torque to failure testing (p > .05). Our specimen bone mineral density averages did not represent poor bone quality. The clinical implication of the present study is that distal fibular locking plates do not provide a mechanical advantage for trimalleolar ankle injuries in individuals with normal bone density and in the absence of fracture comminution. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Biomechanical evaluation of Caspar and Cervical Spine Locking Plate systems in a cadaveric model.

    Science.gov (United States)

    Clausen, J D; Ryken, T C; Traynelis, V C; Sawin, P D; Dexter, F; Goel, V K

    1996-06-01

    There exist two markedly different instrumentation systems for the anterior cervical spine: the Cervical Spine Locking Plate (CSLP) system, which uses unicortical screws with a locking hub mechanism for attachment, and the Caspar Trapezial Plate System, which is secured with unlocked bicortical screws. The biomechanical stability of these two systems was evaluated in a cadaveric model of complete C5-6 instability. The immediate stability was determined in six loading modalities: flexion, extension, right and left lateral bending, and right and left axial rotation. Biomechanical stability was reassessed following fatigue with 5000 cycles of flexion-extension, and finally, the spines were loaded in flexion until the instrumentation failed. The Caspar system stabilized significantly in flexion before (p < 0.05) but not after fatigue, and it stabilized significantly in extension before (p < 0.01) and after fatigue (p < 0.01). The CSLP system stabilized significantly in flexion before (p < 0.01) but not after fatigue, and it did not stabilize in extension before or after fatigue. The moment needed to produce failure in flexion did not differ substantially between the two plating systems. The discrepancy in the biomechanical stability of these two systems may be due to differences in bone screw fixation.

  2. A RETROSPECTIVE STUDY OF PROXIMAL HUMERUS INTERNAL LOCKING SYSTEM PLATING FOR DISPLACED PROXIMAL HUMERUS FRACTURES

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    Kumarswami Ramulu

    2016-05-01

    Full Text Available AIM The aim of the present study was to evaluate the functional outcome, benefits and complications of open reduction and internal fixation of displaced proximal humerus fractures with proximal humerus locking plate. METHODS We studied the functional outcome of 40 patients aged between 15 to 65 years from September 2013 to February 2015, who had displaced proximal humerus fracture and underwent PHILOS plate fixation for the same. Fractures were classified according to NEER’s and AO classification. Patients were followed up for a minimum period of 1 year. Functional outcomes and shoulder range of movement were assessed based on the Constant and Murley scoring system. RESULTS Patients were followed up for 12 months. All fractures healed satisfactorily; 12 weeks (27.5% was the most common union time (radiological finding in the study population followed by 8 weeks (22.5% and 10 weeks (20%. Avascular necrosis was noted in 1 patient, mild infection in 2 patients and stiffness in 2 patients. The mean Constant score at 6 weeks was 40.39, at 12 weeks was 59.24, at 6 months was 73.88 and at one year was 75.62. Constant score continues to improve till 1 year. CONCLUSION Proximal humerus locking plate gives a reliable, stable fixation for fractures of proximal humerus with a good radiological union and good functional outcome.

  3. Early outcomes of proximal humerus fracture fixation with locking plate and intramedullary fibular strut graft.

    Science.gov (United States)

    Tan, Edwin; Lie, Denny; Wong, M K

    2014-09-01

    Proximal humerus fractures are commonly encountered in elderly patients. Surgical treatment demonstrates high complication rates, including varus construct collapse and screw cutout. In this study, the authors evaluate the clinical outcome of locking plate fixation with intramedullary fibular strut graft augmentation as a primary surgical treatment in the prevention of early collapse and screw cutout. A total of 9 patients were evaluated. Surgery was performed for displaced proximal humerus fractures between April and December 2011. Patients were either class 2, 3, or 4, according to Neer classification. Mean patient age was 75.4 years. Preoperative and immediate, 6-week, and 3-month postoperative radiographs were evaluated. Head-shaft angles were measured to assess for varus collapse and displacement. Range of motion, complication rates, and functional recovery were also evaluated. Patients underwent open reduction and internal fixation with placement of an intramedullary fibular strut graft. Fixation was achieved with a Philos plate (Synthes, Oberdorf, Switzerland). Reduction and fixation were evaluated with radiographs. Passive exercises and range of motion were allowed immediately postoperatively, and all patients achieved active abduction and forward flexion 6 weeks postoperatively. Shoulder radiographs taken 12 weeks postoperatively revealed no loss of reduction or screw cutout. The introduction of the locking plate has improved outcomes. The addition of an intramedullary strut graft has shown improved preliminary results. Maintained reduction was observed in all 9 patients in the early postoperative period, and good functional motion was achieved. No incidence of screw cutout was recorded.

  4. Treatment of proximal humeral fractures using anatomical locking plate: correlation of functional and radiographic results

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    Antonio Carlos Tenor Junior

    2016-06-01

    Full Text Available ABSTRACT OBJECTIVE: To correlate the functional outcomes and radiographic indices of proximal humerus fractures treated using an anatomical locking plate for the proximal humerus. METHODS: Thirty-nine patients with fractures of the proximal humerus who had been treated using an anatomical locking plate were assessed after a mean follow-up of 27 months. These patients were assessed using the University of California Los Angeles (UCLA score and their range of motion was evaluated using the method of the American Academy of Orthopedic Surgeons on the operated shoulder and comparative radiographs on both shoulders. The correlation between radiographic measurements and functional outcomes was established. RESULTS: We found that 64% of the results were good or excellent, according to the UCLA score, with the following means: elevation of 124°; lateral rotation of 44°; and medial rotation of thumb to T9. The type of fracture according to Neer's classification and the patient's age had significant correlations with the range of motion, such that the greater the number of parts in the fracture and the greater the patient's age were, the worse the results also were. Elevation and UCLA score were found to present associations with the anatomical neck-shaft angle in anteroposterior view; fractures fixed with varus deviations greater than 15° showed the worst results (p < 0.001. CONCLUSION: The variation in the neck-shaft angle measurements in anteroposterior view showed a significant correlation with the range of motion; varus deviations greater than 15° were not well tolerated. This parameter may be one of the predictors of functional results from proximal humerus fractures treated using a locking plate.

  5. Open Reduction and Internal Fixation of Displaced Calcaneum, Intra-Articular Fractures by Locking Calcaneal Plate

    Science.gov (United States)

    Santosha; Singh, Arambam Mahendra; Waikhom, Sanjib; Pakhrin, Vishal; Mukherjee, Sagnik; Debbarma, Rajkumar; Prashant, Prabhu Shrinivas

    2016-01-01

    Introduction Calcaneal fractures constitute the most common fractures in hindfoot. Lots of controversies exist in the management of calcaneal fractures but now-a-days, it is preferable to perform open reduction and internal fixation and early mobilizatation. Aim To evaluate the functional outcome after open reduction and internal fixation of displaced intra-articular fractures of the calcaneum by locking calcaneal plate. Materials and Methods The study was conducted in the Department of Orthopaedic Surgery from September 2013 to April 2016. Thirty intra-articular fractures of the calcaneum were treated by locking calcaneal plate. Patients were followed up for a period of 24 months. Bohler’s angle was measured in preoperative, immediate Post-operative period and after 2 years, follow-up was compared. Results were evaluated according to American Orthopaedic Foot and Ankle Society (AOFAS) Score. Results After 24 months of follow-up, all 24 patients were available for evaluation. Radiological union was achieved in a mean time of 12.5 weeks. Mean duration of hospital stay was 21 days. Bohler’s angle was significantly higher after 2 years of follow-up when compared with preoperative x-ray. According to the AOFAS, Ankle–Hind foot Scale outcome score results were excellent in 43.3% of the patients, good in 33.3%, fair in 10%, and poor in 13.3% of patients. The mean AOFAS score was 79.9 (Range 49-96). Conclusion Open reduction and internal fixation of intra-articular fractures of the calcaneum with locking calcaneal plate gives good results. Maintenance of calcaneal height and Bohler’s angle helps to decrease the incidence of subtalar arthritis. PMID:28208957

  6. Outcome analysis following removal of locking plate fixation of the proximal humerus

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    Fischer Florian

    2008-10-01

    Full Text Available Abstract Background Concerning surgical management experience with locking plates for proximal humeral fractures has been described with promising results. Though, distinct hardware related complaints after fracture union are reported. Information concerning the outcome after removal of hardware from the proximal humerus is lacking and most studies on hardware removal are focused on the lower extremity. Therefore the aim of this study was to analyze the functional short-term outcome following removal of locking plate fixation of the proximal humerus. Methods Patients undergoing removal of a locking plate of the proximal humerus were prospectively followed. Patients were subdivided into the following groups: Group HI: symptoms of hardware related subacromial impingement, Group RD: persisting rotation deficit, Group RQ: patients with request for a hardware removal. The clinical (Constant-Murley score and radiologic (AP and axial view follow-up took place three and six months after the operation. To evaluate subjective results, the Medical Outcomes Study Short Form-36 (SF-36, was completed. Results 59 patients were included. The mean length of time with the hardware in place was 15.2 ± 3.81 months. The mean of the adjusted overall Constant score before hardware removal was 66.2 ± 25.2% and increased significantly to 73.1 ± 22.5% after 3 months; and to 84.3 ± 20.6% after 6 months (p Conclusion A significant improvement of clinical outcome following removal was found. However, a general recommendation for hardware removal is not justified, as the risk of an anew surgical and anesthetic procedure with all possible complications has to be carefully taken into account. However, for patients with distinct symptoms it might be justified.

  7. Use of a Proximal Humeral Locking Plate for Complex Ankle and Hindfoot Fusion.

    Science.gov (United States)

    Shearman, Alexander D; Eleftheriou, Kyriacos Iordanis; Patel, Akash; Pradhan, Rajib; Rosenfeld, Peter Francis

    2016-01-01

    Arthrodesis of the ankle and hindfoot in the setting of major deformity is challenging and associated with substantial risks. Patients often have significant comorbidities that lead to unforgiving soft tissues, poor vascularity, and poor bone quality. This creates the high-risk scenario of poor wound healing and poor implant fixation. Complications can be devastating, leading to loss of the limb and sepsis. The use of locking plate technology might provide biomechanical and operative technique advantages in such patients. We retrospectively assessed the results of the modified use of the PHILOS(™) (Synthes(®), Zuchwil, Switzerland) proximal humeral locking plate in 21 patients (11 males, 10 females; mean age 56.1 years, range 25 to 74 years) who had undergone complex fusions, including tibiotalar (n = 4), tibiocalcaneal (n = 7), or tibiotalocalcaneal (n =10) fusions. The average follow-up period was 14.6 (median 10, range 6 to 49) months. Of the 21 fusions, 18 achieved union (85.7%) at an average period of 4.8 (median 4.3, range 3 to 12) months. The overall deep infection rate was 14.3%. Overall, 17 of the 21 patients (81%) were satisfied with the result (good to excellent), 1 reported the result was fair (4.8%), and 3 patients developed nonunion and were dissatisfied with the procedure (14.3%). The present study is the largest series to date of patients undergoing complex ankle and hindfoot arthrodesis with the use of a proximal humeral locking plate and confirms previous findings that the technique is reliable with union, satisfaction, and complication rates comparable to those of other techniques.

  8. Distal Femoral Locking Compression Plate Fixation in Distal Femoral Fractures: Early Results

    Directory of Open Access Journals (Sweden)

    EJ Yeap

    2007-05-01

    Full Text Available We conducted a retrospective review on eleven patients who were treated for Type A and C distal femoral fractures (based on AO classification between January 2004 and December 2004. All fractures were fixed with titanium distal femoral locking compression plate. The patient’s ages ranged from 15 to 85 with a mean of 44. Clinical assessment was conducted at least 6 months post-operatively using the Schatzker scoring system. Results showed that four patients had excellent results, four good, two fair and one failure.

  9. Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

    Energy Technology Data Exchange (ETDEWEB)

    Telschow, Kenneth Louis; Deason, Vance Albert; Datta, S.K.

    1999-05-01

    A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of ultrasonic traveling wave surface displacement and phase in all planar directions simultaneously without scanning. The imaging method performs optical lock-in operation. A single antisymmetric Lamb wave mode image produces direct quantitative determination of the phase velocity in all planar directions showing plate stiffness anisotropy. Excellent agreement was obtained with modeling calculations of the phase velocity in all planar directions for an anisotropic sheet material. The approach functions with diffusely scattering surfaces, subnanometer motions and at frequencies from Hz to GHz.

  10. Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

    Energy Technology Data Exchange (ETDEWEB)

    K. L. Telschow; S. K. Datta (University of Colorado); V. A. Deason (INEEL)

    1999-05-01

    A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of ultrasonic traveling wave surface displacement and phase in all planar directions simultaneously without scanning. The imaging method performs optical lock-in operation. A single antisymmetric Lamb wave mode image produces direct quantitative determination of the phase velocity in all planar directions showing plate stiffness anisotropy. Excellent agreement was obtained with modeling calculations of the phase velocity in all planar directions for an anisotropic sheet material. The approach functions with diffusely scattering surfaces, subnanometer motions and at frequencies from Hz to GHz.

  11. THE FUNCTIONAL OUTCOME OF LOCKING VS NON-LOCKING DUAL PLATE FIXATION IN INTRAARTICULAR FRACTURE DISTAL END HUMERUS: A RETROSPECTIVE COMPARATIVE STUDY

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    Manish Bairagi

    2016-07-01

    Full Text Available BACKGROUND Despite all advances in treatment, it is a challenge to most of the orthopaedic surgeons to give better result in the management of distal end humerus intra-articular fractures, because it has complex anatomy. This study has been done to evaluate the functional outcome of double plate fixation with right angle to each other for intra-articular fracture of distal end humerus and compared with locking vs non-locking plate fixation. AIM This study has been done to evaluate the functional outcome of double plate fixation with right angle to each other for intraarticular fracture of distal end humerus with comparison of locking and non-locking plate fixation. METHODS This is retrospective comparative study done between 2006 and 2014 in the Department of Orthopaedics, G.R. Medical College and J.A. Group of Hospital, Gwalior (M.P., India. All patients who were presented to Department of Orthopaedics with intra-articular fracture, distal end humerus fracture, medically fit patient who were of age group between 18-80 years of age with close or type 1 GA (Gustilo Anderson compound fracture and fracture type AO type C were included. Other patients who sustained GA type 2 and 3, severely comminuted and severe osteoporotic bone were excluded. RESULT A total no. of 60 patients. The age of patients ranged from 22 to 65 years. To classifying according to AO classification, 15 cases were of type C1, 39 were of type C2 and 06 were of type C3. The results were rated using Jupiter’s criteria as excellent in 26 (43.3% cases, good in 16 (26.7%, fair in 11 (18.3% cases and poor in 07 (11.7%. CONCLUSION Double plate fixation is standard and effective method of treating intra-articular fracture of distal humerus, the method gives a stable fixation and allow early mobilization of elbow joint without risk of implant failure. In the study, there is no much advantage from the locking plate fixation in comparison with the non-locking plates.

  12. Locking internal fixator with minimally invasive plate osteosynthesis for the proximal and distal tibial fractures

    Institute of Scientific and Technical Information of China (English)

    TONG Da-ke; JI Fang; CAI Xiao-bing

    2011-01-01

    Objective: To investigate the efficacy of the locking internal fixator (LIF), which includes the locking compression plate (LCP) and the less invasive stable system (LISS), in the proximal and distal tibial fractures. Methods: We did a retrospective study on a total of 98 patients with either proximal or distal tibial fractures from January 2003 to January 2007, who had received the operation with LIF by the minimally invasive plate osteosynthesis (MIPO) technique. The data consisted of 43 proximal tibial fractures (type AO41C3) and 55 distal tibial fractures (type AO43C3). Results: No complications were observed in all patients after operation. The mean healing time was 8.4 months (range 5-14 months). Only two cases of delayed union occurred at postoperative 10 months. No infections were reported after the definitive surgery even in the cases of open fractures. All patients reached a full range of motion at postoperative 6 to 9 months and regained the normal functions of knee and ankle joints. Conclusion: Using LIF in MIPO technique is a reliable approach towards the proximal and distal tibial fractures that are not suitable for intramedullary nailing.

  13. Locking plate fixation combined with iliac crest bone autologous graft for proximal humerus comminuted fracture

    Institute of Scientific and Technical Information of China (English)

    Zhu Lian; Liu Yueju; Yang Zongyou; Li Han; Wang Juan; Zhao Changping; Chen Xiao

    2014-01-01

    Background Although the use of an intramedullary fibular allograft together with locking plate fixation can provide additional medial support and prevent varus malalignment in displaced proximal humeral fractures with promising results,the fibular autograft donor site often sustains significant trauma and cannot restore the articular surface of comminuted fractures.The aim of this study was to evaluate the clinical and radiographic outcomes of a locking plate and crest bone autologous graft for treating proximal humerus comminuted fractures.Methods We assessed the functional outcomes and complication rates in 40 patients with proximal humerus comminuted fractures.Eighteen patients were treated with a locking plate and an autologous crest bone graft (experimental group),and 22 were treated with only the locking plate and no bone graft (control group).Postoperative assessments included radiographic imaging,range of motion analysis,pain level based on the visual analogue scale (VAS),and the SF-36 (Short Form (36) Health Survey),as well as whether patients could retum to their previous occupation.Results All fractures healed both clinically and radiologically in the experimental group.There was no more than 2 mm collapse of the humeral head,and no osteonecrosis or screw penetration of the articular surface.In contrast,two patients had a nonunion in the control group,and they eventually accepted total shoulder replacements.The average time from surgery to radiographic union was significantly shorter in the experimental group ((4.66±1.63) months) compared with the control group ((5.98±1.57) months) (P <0.05).For the experimental versus controls groups,the mean shoulder active flexion (148.00±18.59 vs.121.73±17.20) degrees,extension (49.00±2.22 vs.42.06±2.06) degrees,internal rotation (45.00±5.61 vs.35.00±3.55)degrees,external rotation (64.00±9.17 vs.52.14±5.73)degrees,and abduction (138.00±28.78 vs.105.95±15.66) degrees were all significantly higher (all P

  14. Adult proximal humerus locking plate for the treatment of a pediatric subtrochanteric femoral nonunion: a case report.

    Science.gov (United States)

    Cortes, Luis E; Triana, Miguel; Vallejo, Francisco; Slongo, Theddy F; Streubel, Philipp N

    2011-07-01

    Nonunions of pediatric subtrochanteric femur fractures are exceedingly rare and have to date not been reported in the literature. We present the case of an 11-year-old boy who developed such a nonunion after open reduction internal fixation using a pediatric locked proximal femur plate. Using an adult proximal humerus locking plate, adequate proximal fixation of the nonunion was obtained. Furthermore, previously placed distal screw holes were safely bridged and the biomechanical environment around the nonunion site improved. Uneventful healing was possible with the use of adjuvant bone grafting. No short- or midterm complications occurred. Although other implants can certainly be adapted to a use different than that of its original design, the present case suggests that adult proximal humerus locking plates may be a safe option for revision surgery of the proximal pediatric femur.

  15. Osteosynthesis with long volar locking plates for meta- physeal-diaphyseal fractures of the distal radius

    Directory of Open Access Journals (Sweden)

    Gogna Paritosh

    2013-12-01

    Full Text Available 【Abstract】Objective: Metaphyseal-diaphyseal fractures of the distal radius are a major treatment dilemma and orthopaedic surgeons have to pay due consideration to restoration of anatomy of distal radius together with ro- tation of the radial shaft and maintenance of radial bow and interosseous space. We performed this study to evaluate the clinic-radiological outcome of metaphyseal-diaphyseal fractures of the distal radius treated with long volar locking plates. Methods: This prospective study involved 27 pa- tients (22 males and 5 females with metaphyseal-diaphy- seal fracture of the distal radius. Their mean age was (30.12± 11.48 years (range 19-52 years and the follow-up was 26.8 months (range 22-34 months. All patients underwent open reduction and internal fixation with a long volar locking plate. According to AO/OTA classification, there were 7 type A3, 13 type C2 and 7 type C3 fractures. Subjective assessment was done based on the disabilities of the arm, shoulder and hand (DASH questionnaire. Functional evaluation was done by measuring grip strength and range of motion around the wrist and the radiological determinants included radial angle, radial length, volar angle and ulnar variance. The final as- sessment was done according to Gartland and Werley scor- ing system. Results: Postoperative radiological parameters were well maintained throughout the trial, and there was signifi- cant improvement in the functional parameters from 6 weeks to final follow-up. The average DASH scores improved from 37.5 at 6 weeks to 4.2 at final follow-up. Final assessment using Gartland and Werley scoring system revealed 66.67% (n=18 excellent and 33.33% (n=9 good results. There was one case of superficial infection which responded to antibi- otics and another carpel tunnel syndrome which was ma- naged conservatively. Conclusion: Volar locking plate fixation for metaphy- seal-diaphyseal fractures of distal radius is associated with excellent to good

  16. Outcome of open reduction and internal fixation of intraarticular calcaneal fracture fixed with locking calcaneal plate

    Directory of Open Access Journals (Sweden)

    Jain Saurabh

    2013-12-01

    Full Text Available 【Abstract】Objective: Debate continues regarding the management of calcaneal fractures, between open re- duction and internal fixation and closed treatment. Hence we aim at evaluating the radiological and functional out- comes of open reduction and internal fixation in displaced joint depression type of calcaneal fractures fixed with lock- ing calcaneal plate. Methods: In this series, 28 patients (26 unilateral and 2 bilateral with joint depression type of calcaneal fractures as per Essex-Lopresti classification system were operated on with locking calcaneal plate within 3 weeks of injury. Patients were evaluated in terms of associated injuries and X-rays of anteroposterior, lateral and axial views of the calcaneum. CT scan was done to assess the amount of com- minution and articular depression. Patients were followed up clinically and radiologically at least for 1 year. Radiologi- cal assessment was done by Bohler’s angle and Gissane’s angle along with measurement of calcaneal height and width. Functional outcome was assessed using the American Or- thopaedics Foot and Ankle Society (AOFAS scale. Results: At average follow-up of 14.5 months, average AOFAS score was 86.3 (range 66 to 97, with 86% having excellent to good results and 2 (7.7% and 1 (3.7% having fair and poor results respectively. All patients had stable ankle joint with all having dorsiflexion and plantar flexion more than 30°. Average subtalar range of motion was 17°. The mean Bohler’s angle, mean Gissane’s angle, calcaneal height and width were 25.47°, 121.3°, 4.32 cm and 3.81cm respectively at final follow-up. Three patients had flap ne- crosis at incision site and one had superficial and deep infection. Subtalar arthritis was seen in 5 patients, whereas sural nerve hypoaesthesia in 1 patient. None of the patients had compartment syndrome, heel pad problems, peroneal tendinitis, reflex sympathetic dystropy or implant failure. Conclusion: Open reduction and

  17. Dynamic anterior cervical plating for multi-level spondylosis: Does it help?

    Science.gov (United States)

    Ragab, Ashraf A; Hodges, F Spain; Hill, Clint P; McGuire, Robert A; Tucci, Michelle

    2010-05-01

     Randomized controlled trial.  To compare fusion rates, time to fusion, complication rates and subsidence between 1) a static, 2) a dynamic angulation, and 3) a dynamic translation plate in anterior cervical discectomy and fusion for symptomatic degenerative cervical disease.  Thirty-six patients with two level, symptomatic cervical degenerative changes requiring surgery were randomized in a blinded fashion to receive a statically locked plate, Cervical Spine Locking Plate (CSLP) (Synthes, Paoli, PN, USA), an Atlantis Vision(®) Anterior Cervical Plate System (Medtronic, Memphis, TN, USA) which allows angular dynamization, or a Premier(®) Anterior Cervical Plate System (Medtronic) which allows translational dynamization. Structured data collection and measurement protocols were used. Intervertebral composite allograft cages were used in all groups. Identical external immobilization and antiinflammatory medication protocols were followed. X-rays were obtained at preset time points postoperatively. Assessment of the primary outcomes was blinded. Rate of and time to fusion, graft/instrumentation complications, subsidence, and reoperation for adjacent level disease were measured. Paired t-test and three-way Analysis of Variance test (ANOVA) were used to assess statistical differences between groups.  The three groups were similar demographically. Fusion rates in the CSLP, Atlantis and Premier plate groups were 100%, 91%, and 92% respectively. Mean time to fusion was 6.1, 8.3 and 6.3 months respectively but differences were not statistically significant. Mean subsidence in the groups was 1.9, 1.6, and 2.6 mm respectively. Subsidence was found even for the static (CSLP) plate, but no statistically significant differences were found.  We found no clinical advantage of dynamic plates over static plates with regards to fusion rates, time to fusion, subsidence, complications, or adjacent-level surgery. Static plating allows for subsidence at similar levels to

  18. STUDY OF OUTCOME OF DISTAL TIBIAL FRACTURES TREATED WITH LOCKING COMPRESSION PLATES: BY BOTH OPEN REDUCTION AND MIPO TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Ravikiran Nandiraju

    2016-07-01

    Full Text Available BACKGROUND Tibia being the most common fractured long bone of the body; 1. Distal metaphyseal fractures comprise 5-7% of these injures; 2. With or without involving the articular surface. Encouraging results for open reduction and internal fixation (Plate osteosynthesis and closed manual reduction with osteosynthesis with minimal invasive percutaneous locking plates has been noted for lower third tibial fractures. Locking compression plate provides the advantage of anatomic reduction, stable fixation, preservation of blood supply, preventing joint stiffness, less soft tissue injury. METHODS AND MATERIAL This study included (40 patients with distal tibia fractures between 18-65 years presenting in the Department of Orthopaedics in Osmania Medical College and Osmania General Hospital .This is prospective study. These patients are treated with locking compression plates. RESULTS Patients were evaluated using AOFAS7 score for hindfoot scale (100 points. Excellent - 26 (65%, Good - 12 (30%, Fair - 2 (5% comparable to other studies. CONCLUSION Reduction and internal fixation of distal tibial fractures using locking compression plate medially by open and MIPO technique is one of the acceptable forms of treatment for lower third tibia including the articular surface with or without communication.

  19. Osteosynthesis with long volar locking plates for metaphyseal-diaphyseal fractures of the distal radius

    Institute of Scientific and Technical Information of China (English)

    Paritosh Gogna; Harpal Singh Selhi; Rohit Singla; Mukul Mohindra; Amit Batra; Reetadyuti Mukhopadhyay; Rajesh Rohilla

    2013-01-01

    Objective:Metaphyseal-diaphyseal fractures of the distal radius are a major treatment dilemma and orthopaedic surgeons have to pay due consideration to restoration of anatomy of distal radius together with rotation of the radial shaft and maintenance of radial bow and interosseous space.We performed this study to evaluate the clinic-radiological outcome of metaphyseal-diaphyseal fractures of the distal radius treated with long volar locking plates.Methods:This prospective study involved 27 patients (22 males and 5 females) with metaphyseal-diaphyseal fracture of the distal radius.Their mean age was (30.12±11.48) years (range 19-52 years) and the follow-up was 26.8 months (range 22-34 months).All patients underwent open reduction and internal fixation with a long volar locking plate.According to AO/OTA classification,there were 7 type A3,13 type C2 and 7 type C3 fractures.Subjective assessment was done based on the disabilities of the arm,shoulder and hand (DASH) questionnaire.Functional evaluation was done by measuring grip strength and range of motion around the wrist and the radiological determinants included radial angle,radial length,volar angle and ulnar variance.The final assessment was done according to Gartland and Werley scoring system.Results:Postoperative radiological parameters were well maintained throughout the trial,and there was significant improvement in the functional parameters from 6 weeks to final follow-up.The average DASH scores improved from 37.5 at 6 weeks to 4.2 at final follow-up.Final assessment using Gartland and Werley scoring system revealed 66.67%(n=l8) excellent and 33.33% (n=9) good results.There was one case of superficial infection which responded to antibiotics and another carpel tunnel syndrome which was managed conservatively.Conclusion:Volar locking plate fixation for metaphyseal-diaphyseal fractures of distal radius is associated with excellent to good functional outcome,early rehabilitation and minimal complications.

  20. Outcome of open reduction and internal fixation of intraarticular calcaneal fracture fixed with locking calcaneal plate

    Institute of Scientific and Technical Information of China (English)

    Saurabh Jain; Anil Kumar Jain; Ish Kumar

    2013-01-01

    Objective:Debate continues regarding the management of calcaneal fractures,between open reduction and internal fixation and closed treatment.Hence we aim at evaluating the radiological and functional outcomes of open reduction and internal fixation in displaced joint depression type of calcaneal fractures fixed with locking calcaneal plate.Methods:In this series,28 patients (26 unilateral and 2 bilateral) with joint depression type of calcaneal fractures as per Essex-Lopresti classification system were operated on with locking calcaneal plate within 3 weeks of injury.Patients were evaluated in terms of associated injuries and X-rays of anteroposterior,lateral and axial views of the calcaneum.CT scan was done to assess the amount ofcomminution and articular depression.Patients were followed up clinically and radiologically at least for 1 year.Radiological assessment was done by Bohler's angle and Gissane's angle along with measurement ofcalcaneal height and width.Functional outcome was assessed using the American Orthopaedics Foot and Ankle Society (AOFAS) scale.Results:At average follow-up of 14.5 months,average AOFAS score was 86.3 (range 66 to 97),with 86% having excellent to good results and 2 (7.7%) and 1 (3.7%) having fair and poor results respectively.All patients had stable ankle joint with all having dorsiflexion and plantar flexion more than 30°.Average subtalar range of motion was 17°.The mean Bohler's angle,mean Gissane's angle,calcaneal height and width were 25.47°,121.3°,4.32 cm and 3.81cm respectively at final follow-up.Three patients had flap necrosis at incision site and one had superficial and deep infection.Subtalar arthritis was seen in 5 patients,whereas sural nerve hypoaesthesia in 1 patient.None of the patients had compartment syndrome,heel pad problems,peroneal tendinitis,reflex sympathetic dystropy or implant failure.Conclusion:Open reduction and internal fixation with locking calcaneal plate gives sound functional outcome

  1. Outcomes evaluation of locking plate osteosynthesis in displaced fractures of the proximal humerus

    Directory of Open Access Journals (Sweden)

    Mauro Emilio Conforto Gracitell

    2013-12-01

    Full Text Available Objective: To evaluate functional outcomes, radiographic findings and complications of proximal humeral fractures treated with locking plates and to determine prognostic factors for successful clinical outcomes. Methods: Forty patients undergoing internal fixation of fractures of the proximal humerus with the Philos(r plate were included in the study. The surgeries were performed between 2004 and 2011 and the patients underwent radiographic and clinical evaluation, by Constant -Murley and Dash score. Outcomes were analyzed by use of multivariate regression with several different variables. Results: Patients were on average of 61.8 ± 16.28 years, and most were female (70%. The Constant -Murley score was 72.03 ± 14.01 and Dash score was 24.96 ± 19.99. The postoperative radiographs showed a head-shaft angle of 135.43º± 11.82. Regression analysis showed that the patient's age and the Hertel classification influenced the Constant -Murley scale (p = 0.0049 and 0.012, respectively. Other prognostic criteria such as Neer and AO classification, head-shaft angle, the presence of metaphyseal comminution and extension of the humeral metaphyseal fragment showed no effect on prognosis. Complications occurred in four patients (10%. Conclusion: The fixation with the Philos(r plate provided good clinical and radiographic results in fractures of the proximal humerus, with a low complication rate. Patient's age and Hertel classification were defined as prognostic factors that led to worse functional outcomes.

  2. Finite Element-Derived Surrogate Models of Locked Plate Fracture Fixation Biomechanics.

    Science.gov (United States)

    Wee, Hwabok; Reid, J Spence; Chinchilli, Vernon M; Lewis, Gregory S

    2017-03-01

    Internal fixation of bone fractures using plates and screws involves many choices-implant type, material, sizes, and geometric configuration-made by the surgeon. These decisions can be important for providing adequate stability to promote healing and prevent implant mechanical failure. The purpose of this study was to develop mathematical models of the relationships between fracture fixation construct parameters and resulting 3D biomechanics, based on parametric computer simulations. Finite element models of hundreds of different locked plate fixation constructs for midshaft diaphyseal fractures were systematically assembled using custom algorithms, and axial, torsional, and bending loadings were simulated. Multivariate regression was used to fit response surface polynomial equations relating fixation design parameters to outputs including maximum implant stresses, axial and shear strain at the fracture site, and construct stiffness. Surrogate models with as little as three regressors showed good fitting (R (2) = 0.62-0.97). Inner working length was the strongest predictor of maximum plate and screw stresses, and a variety of quadratic and interaction terms influenced resulting biomechanics. The framework presented in this study can be applied to additional types of bone fractures to provide clinicians and implant designers with clinical insight, surgical optimization, and a comprehensive mathematical description of biomechanics.

  3. Treatment of distal clavicle fracture with distal radius volar locking compression plate

    Institute of Scientific and Technical Information of China (English)

    YU Chao; SUN Yue-hua; ZHAO Chang-qing; SHI Ding-wei; WANG You

    2009-01-01

    Objective: To observe the early clinical outcomes of the internal fixation with distal radius volar locking compression plate (LCP) in treatment of distal clavicle fracture.Methods: Six patients with unilateral distal clavicle fractures, identified as type Ⅱ according to Neer classification system, including 4 males and 2 females, were treated with open reduction and internal fixation using a distal radius volar LCP. Bone union was evaluated by routine X-ray radiography, and shoulder joint function were assessed by Constant score system.Results: All fractures achieved bone union at 6 to 8 weeks postoperatively, and Constant scores ranged from 95 to 100 at the postoperative 10 to 12 weeks.Conclusion: Fixation of distal clavicle fracture with distal radius volar LCP demonstrates excellent effects of bone union with rarely early complications, thus providing a new technique to treat distal clavicle fracture.

  4. Complications and functional outcome after fixation of distal tibia fractures with locking plate - A multicentre study

    DEFF Research Database (Denmark)

    Viberg, Bjarke; Kleven, Silje; Hamborg-Petersen, Ellen;

    2016-01-01

    INTRODUCTION: The aim of this study was to evaluate the proportion of complications and the functional outcome following ORIF with low-profile locking plates in patients with distal tibia fractures. METHOD: Retrospective data was retrieved using county databases, operation books, health record...... as minor and major complications, was retrieved from electronic health records and patient interviews. Long-term functional outcome assessed by EuroQol EQ-5D-5L questionnaire, AOFAS Ankle-Hindfoot scale, and return to pre-injury job function through patient interview and examination. RESULTS: There were 32...... 43A, 5 43B and 34 43C-fractures, 12 open and 10 high-energy fractures. Forty-nine cases (69%) experienced complications during the follow-up time, of which 34 were minor complications and 15 were major complications. Median EQ-5D-5L index value was 0.76, median EQ VAS-score was 80, and median AOFAS...

  5. The Outcome in Early Cases of Treatment of Subtrochanteric Fractures with Proximal Femur Locking Compression Plate

    Directory of Open Access Journals (Sweden)

    U Gunadham

    2014-07-01

    Full Text Available The objective of this study was to evaluate the outcome in early treatment of subtrochanteric fractures with proximal femur locking compression plate (PF-LCP.The patients included in this study were those with subtrochanteric fractures (AO type 32A-C treated with PF-LCP (Synthes between Jan 2009 and Jun 2011. The patient characteristics and details of clinical conditions were obtained from records. Clinical and radiographic follow-ups were done at one, two, four and 6 months intervals, and at one year. The primary outcome studied included fracture union and functional ambulatory status. Twenty-six patients were included in the study, 19 of whom were male with a mean age of 42.4 years. Fourteen patients (53.9% had sustained AO type 32B fractures, the majority in motor vehicle accidents. Twenty-two fractures (84.6% achieved union, while sixpatients (23.1% had complications such as broken plate, varus collapse, and broken screw. Four patients (15.4% underwent a second operation. At the end of the follow-ups, 25 patients (96.2% were community ambulators. We conclude that PF-LCP is an effective alternative treatment for subtrochanteric fractures when properly performed.

  6. 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.

  7. 髋动力锁定钢板、重建钉与动力髋钢板治疗高龄股骨转子间骨折患者的疗效分析%Effect of anatomical dynamic hip lock plate, proximal femoral nail, and dynamic hip screws in the treatment of subtrochanteric femoral fractures in elderly patients: a comparative study

    Institute of Scientific and Technical Information of China (English)

    许思亮; 朱智奇; 候明

    2012-01-01

    Objective To investigate the effect of anatomical dynamic hip lock plate (ADHLP), proximal femoral nail (PFN), and dynamic hip screws (DHS) in the treatment of subtrochanteric femoral fractures in elderly patients. Methods One hundred and four patients with subtrochanteric femoral fracture in our hospital were divided into three groups: the ADHLP group, the PFN group and the DHS group. The operation time, intraoperative bleeding, Harris score one month and 6, 12 months after surgery, the healing time and the complications were compared between the three groups. Results The operation time, intraoperative bleeding and fracture healing time in PFN group were significantly less than those in DHS and ADHLP group, P<0.05. In the threee groups, Harris scores 12 months after surgery showed statistically significant difference with the scores 1 month and 6 months after surgery, P<0.05. The incidence of complications in PFN group was significantly lower than that in the other two groups, P<0.05. Conclusion PFN is preferred for treating elderly patients with subtrochanteric femoral fracture than DHS and ADHLP, with shorter operation time, less intraoperative bleeding, faster fracture healing and lower complications.%目的 探讨髋动力锁定钢板、重建钉与动力髋钢板在高龄股骨转子间骨折患者中的疗效差别.方法 回顾性研究我院收治的股骨转子间骨折患者共104例,根据治疗方式不同分为髋动力锁定钢板(ADHLP)组、重建钉(PFN)组以及动力髋钢板(DHS)组.对比三组患者手术时间、术中出血术后1个月、6个月、12个月Harris评分、骨折愈合时间以及并发症发生情况.结果 PFN组患者手术时间、术中出血及骨折愈合时间显著低于DHS组及ADHLP组,结果比较差异有统计学意义(P<0.05).三组患者术后12个月Harris评分与术后1个月、6个月评分比较差异有统计学意义(P<0.05).PFN组患者术后并发症发生率显著低于另外两

  8. Benefits and harms of locking plate osteosynthesis in intraarticular (OTA Type C) fractures of the proximal humerus

    DEFF Research Database (Denmark)

    Brorson, Stig; Rasmussen, Jeppe Vejlgaard; Frich, Lars Henrik

    2012-01-01

    INTRODUCTION: Locking plate osteosynthesis of proximal humeral fractures are widely recommended and used, even in complex intraarticular fracture patterns such as AO/OTA Type C fractures. We systematically reviewed clinical studies assessing the benefits and harms of osteosynthesis with angle...... stable plates in AO/OTA Type C fractures of the proximal humerus. METHODS: We conducted an iterative search in PubMed, Embase, Cochrane Library, Web of Science, Cinahl, and PEDro in all languages from 1999 to November 2010. Eligible studies should study the outcome for Type C fractures after primary...... osteosynthesis with locking plate within two weeks of injury, and a follow-up period of six months or more. Patients should be evaluated with the Constant-Murley Score (CS). Two observers extracted data independently. RESULTS: Twelve studies and 282 Type C fractures were included. Results were categorised...

  9. Plate tectonics drive tropical reef biodiversity dynamics.

    Science.gov (United States)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J; de Santana, Charles N; Heine, Christian; Mouillot, David; Bellwood, David R; Pellissier, Loïc

    2016-05-06

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  10. Dynamic response of visco-elastic plates

    Science.gov (United States)

    Kadıoǧlu, Fethi; Tekin, Gülçin

    2016-12-01

    In this study, a comprehensive analysis about the dynamic response characteristics of visco-elastic plates is given. To construct the functional in the Laplace-Carson domain for the analysis of visco-elastic plates based on the Kirchhoff hypothesis, functional analysis method is employed. By using this new energy functional in the Laplace-Carson domain, moment values that are important for engineers can be obtained directly with excellent accuracy and element equations can be written explicitly. Three-element model is considered for modelling the visco-elastic material behavior. The solutions obtained in the Laplace-Carson domain by utilizing mixed finite element formulation are transformed to the time domain using the Durbin's inverse Laplace transform technique. The proposed mixed finite element formulation is shown to be simple to implement and gives satisfactory results for dynamic response of visco-elastic plates.

  11. Plate tectonics drive tropical reef biodiversity dynamics

    Science.gov (United States)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-01-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics. PMID:27151103

  12. Plate tectonics drive tropical reef biodiversity dynamics

    Science.gov (United States)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-05-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  13. Complex fractures of the proximal humerus in the elderly--outcome and complications after locking plate fixation.

    Science.gov (United States)

    Schliemann, B; Siemoneit, J; Theisen, Ch; Kösters, C; Weimann, A; Raschke, M J

    2012-05-01

    Open reduction and internal fixation (ORIF) with locking plates or primary arthroplasty remains a controversial issue in the management of complex proximal humerus fractures. Aim of this study was to evaluate the surgeon- and patient-based outcome of patients older than 65 years who underwent ORIF using locking plate fixation of a 3- or 4-part fracture of the proximal humerus. Twenty-seven patients older than 65 years were treated with locking plate fixation (PHILOS, Fa. Synthes, Umkirch, Germany). At an average follow-up of 44 months, the clinical and the subjective outcome were evaluated, and complications were analyzed. The mean age- and gender-related Constant score was 70% (30–100%) compared with 92% (47–108%) of the contralateral non-injured shoulder. The mean DASH score was 29 points (0–71). Five patients (18.5%) showed clinical signs of an impingement, which was related to malpositioning of the plate in 3 cases. Screw cutout was seen in 22.2% (6 patients). Avascular necrosis of the head or the tubercula was found in 8 patients (29.6%). The revision rate was 29.6%. However, the patients considered the functional status of their shoulder as “good” or “satisfactory.” The functional and patient-orientated results of the locking plate fixation of complex displaced proximal humerus fractures in the elderly are comparable to those of primary arthroplasty and minimally invasive treatment. Proper surgical technique (screw length, plate position) is mandatory for reducing the revision rate.

  14. Ex vivo biomechanical comparison of a 3.5 mm locking compression plate applied cranially and a 2.7 mm locking compression plate applied medially in a gap model of the distal aspect of the canine radius.

    Science.gov (United States)

    Uhl, Justin M; Kapatkin, Amy S; Garcia, Tanya C; Stover, Susan M

    2013-10-01

    To compare a medially applied 2.7 mm locking compression plate (LCP) to a cranially applied 3.5 mm LCP in a cadaveric distal radial fracture gap model. In vitro mechanical testing of paired cadaveric limbs Paired radii (n = 8) stabilized with either a 2.7 mm LCP medially or a 3.5 mm LCP cranially. Simulated distal radial comminuted fractures were created and stabilized with an LCP plate on the cranial surface in 1 limb, and on the medial surface in the contralateral limb. Gap stiffness, gap strain, and failure properties were compared between cranial and medial plate positions. Limb constructs were axially loaded, cyclically through 4 conditions that allowed mediolateral or craniocaudal bending at walk and trot loads, before monotonic failure loading. The effects of plate position on mechanical variables were assessed using paired t-tests. Gap stiffness was greater for cranial plate constructs than medial plate constructs for axial loading with mediolateral bending, but lower with craniocaudal bending. However, in loading that facilitated craniocaudal bending the medial plate construct also had bending apparent in the mediolateral direction. Gap strains for the different conditions followed similar trends as stiffness. Cranial plate constructs had significantly higher monotonic stiffness, yield, and failure loads. The larger, cranially applied LCP was biomechanically superior to the smaller, medially applied LCP in our distal radial fracture gap model, however the medial plate was superior to the cranial plate in cyclic loading allowing craniocaudal bending. © Copyright 2013 by The American College of Veterinary Surgeons.

  15. Nanoparticles at liquid interfaces: rotational dynamics and angular locking.

    Science.gov (United States)

    Razavi, Sepideh; Kretzschmar, Ilona; Koplik, Joel; Colosqui, Carlos E

    2014-01-07

    Nanoparticles with different surface morphologies that straddle the interface between two immiscible liquids are studied via molecular dynamics simulations. The methodology employed allows us to compute the interfacial free energy at different angular orientations of the nanoparticle. Due to their atomistic nature, the studied nanoparticles present both microscale and macroscale geometrical features and cannot be accurately modeled as a perfectly smooth body (e.g., spheres and cylinders). Under certain physical conditions, microscale features can produce free energy barriers that are much larger than the thermal energy of the surrounding media. The presence of these energy barriers can effectively "lock" the particle at specific angular orientations with respect to the liquid-liquid interface. This work provides new insights on the rotational dynamics of Brownian particles at liquid interfaces and suggests possible strategies to exploit the effects of microscale features with given geometric characteristics.

  16. The dynamics of Cenozoic and Mesozoic plate motions

    OpenAIRE

    Lithgow-Bertelloni, C.; Richards, M. A.

    1998-01-01

    Our understanding of the dynamics of plate motions is based almost entirely upon modeling of present-day plate motions. A fuller understanding, however, can be derived from consideration of the history of plate motions. Here we investigate the kinematics of the last 120 Myr of plate motions and the dynamics of Cenozoic motions, paying special attention to changes in the character of plate motions and plate-driving forces. We analyze the partitioning of the observed surface velocity field into...

  17. The Clinical and Economic Impact of Generic Locking Plate Utilization at a Level II Trauma Center.

    Science.gov (United States)

    Mcphillamy, Austin; Gurnea, Taylor P; Moody, Alastair E; Kurnik, Christopher G; Lu, Minggen

    2016-12-01

    In today's climate of cost containment and fiscal responsibility, generic implant alternatives represent an interesting area of untapped resources. As patents have expired on many commonly used trauma implants, generic alternatives have recently become available from a variety of sources. The purpose of this study was to examine the clinical and economic impact of a cost containment program using high quality, generic orthopaedic locking plates. The implants available for study were anatomically precontoured plates for the clavicle, proximal humerus, distal radius, proximal tibia, distal tibia, and distal fibula. Retrospective review. Level II Trauma center. 828 adult patients with operatively managed clavicle, proximal humerus, distal radius, proximal tibia, tibial pilon, and ankle fractures. Operative treatment with conventional or generic implants. The 414 patients treated with generic implants were compared with 414 patients treated with conventional implants. There were no significant differences in age, sex, presence of diabetes, smoking history or fracture type between the generic and conventional groups. No difference in operative time, estimated blood loss or intraoperative complication rate was observed. No increase in postoperative infection rate, hardware failure, hardware loosening, malunion, nonunion or need for hardware removal was noted. Overall, our hospital realized a 56% reduction in implant costs, an average savings of $1197 per case, and a total savings of $458,080 for the study period. Use of generic orthopaedic implants has been successful at our institution, providing equivalent clinical outcomes while significantly reducing implant expenditures. Based on our data, the use of generic implants has the potential to markedly reduce operative costs as long as quality products are used. Therapeutic Level III.

  18. Dynamic Self-Locking of an OEO Containing a VCSEL

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Yu, Nan; Savchenkov, Anatoliy; Maleki, Lute

    2009-01-01

    A method of dynamic self-locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface-emitting laser (VCSEL) that is an active element in the frequency-control loop of an optoelectronic oscillator (OEO) designed to implement an atomic clock based on an electromagnetically- induced-transparency (EIT) resonance. This scheme can be considered an alternative to the one described in Optical Injection Locking of a VCSEL in an OEO (NPO-43454), NASA Tech Briefs, Vol. 33, No. 7 (July 2009), page 33. Both schemes are expected to enable the development of small, low-power, high-stability atomic clocks that would be suitable for use in applications involving precise navigation and/or communication. To recapitulate from the cited prior article: In one essential aspect of operation of an OEO of the type described above, a microwave modulation signal is coupled into the VCSEL. Heretofore, it has been well known that the wavelength of light emitted by a VCSEL depends on its temperature and drive current, necessitating thorough stabilization of these operational parameters. Recently, it was discovered that the wavelength also depends on the microwave power coupled into the VCSEL. This concludes the background information. From the perspective that led to the conception of the optical injection-locking scheme described in the cited prior article, the variation of the VCSEL wavelength with the microwave power circulating in the frequency-control loop is regarded as a disadvantage and optical injection locking is a solution of the problem of stabilizing the wavelength in the presence of uncontrolled fluctuations in the microwave power. The present scheme for dynamic self-locking emerges from a different perspective, in which the dependence of VCSEL wavelength on microwave power is regarded as an advantageous phenomenon that can be exploited as a means of controlling the wavelength. The figure schematically depicts

  19. Quantification of defects depth in glass fiber reinforced plastic plate by infrared lock-in thermography

    Energy Technology Data Exchange (ETDEWEB)

    Ranjit, Shrestha; Kim, Won Tae [Kongju National University, Cheonan (Korea, Republic of); Choi, Man Yong [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2016-03-15

    The increasing use of composite materials in various industries has evidenced the need for development of more effective nondestructive evaluation methodologies in order to reduce rejected parts and to optimize production cost. Infrared thermography is a noncontact, fast and reliable non-destructive evaluation technique that has received vast and growing attention for diagnostic and monitoring in the recent years. This paper describes the quantitative analysis of artificial defects in Glass fiber reinforced plastic plate by using Lockin infrared thermography. The experimental analysis was performed at several excitation frequencies to investigate the sample ranging from 2.946 Hz down to 0.019 Hz and the effects of each excitation frequency on defect detachability. The four point method was used in post processing of every pixel of thermal images using the MATLAB programming language. The relationship between the phase contrast with defects depth and area was examined. Finally, phase contrast method was used to calculate the defects depth considering the thermal diffusivity of the material being inspected and the excitation frequency for which the defect becomes visible. The obtained results demonstrated the effectiveness of Lock-in infrared thermography as a powerful measurement technique for the inspection of Glass fiber reinforced plastic structures.

  20. Surgical outcome of proximal femoral fractures using proximal femoral - locking compression plate

    Directory of Open Access Journals (Sweden)

    Prakash A. Sasnur

    2015-07-01

    Full Text Available Introduction: Proximal femoral fractures are complex fractures following devastating injuries in young and elderly population. Despite marked improvement in implant design, surgical technique and patient care these fractures are associated with high incidence of implant failure, refracture and varus collapse. Intramedullary nails are technically demanding and associated with high re-operation rates. The study was done to evaluate the outcome of proximal femoral fractures treated with proximal femur locking compression plate (PF-LCP. Methods: This study is conducted at Al Ameen Medical College and Hospital, Bijapur during the period Jan 2012 to March 2014.Pertrochanteric fractures especially unstable intertrochanteric & subtrochanteric fractures were included. Technical difficulties with the implant and operating time were quantified. Union of fracture site and implant related complications were followed up clinically and radiological. The Harris Hip Score was used to evaluate the functional outcome. Results: Thirty-two patients were available for final evaluation with average age of 55.4 years. The average operation time was 1 hour and 35 minutes with mean blood loss of 180ml. Union was achieved in all the cases with an average time of 17 weeks. Complications included one case of delayed union and three cases of varus collapse. Conclusion: PF-LCP achieves anatomical reduction and stable fixation with higher union rate and fewer complications.

  1. Atmospheric dynamics of Earth-like tidally locked aquaplanets

    CERN Document Server

    Merlis, Timothy M

    2010-01-01

    We present simulations of atmospheres of Earth-like aquaplanets that are tidally locked to their star, that is, planets whose orbital period is equal to the rotation period about their spin axis, so that one side always faces the star and the other side is always dark. As extreme cases illustrating the effects of slow and rapid rotation, we consider planets with rotation periods equal to one current Earth year and one current Earth day. The dynamics responsible for the surface climate (e.g., winds, temperature, precipitation) and the general circulation of the atmosphere are discussed in light of existing theories of atmospheric circulations. For example, as expected from the increasing importance of Coriolis accelerations relative to inertial accelerations as the rotation rate increases, the winds are approximately isotropic and divergent at leading order in the slowly rotating atmosphere but are predominantly zonal and rotational in the rapidly rotating atmosphere. Free-atmospheric horizontal temperature va...

  2. Minimally invasive proximal interphalangeal joint arthrodesis using a locking compression plate and tissue engineering in horses: A pilot study

    OpenAIRE

    SEO, Jong-Pil; Yamaga, Takashi; TSUZUKI, Nao; YAMADA, Kazutaka; HANEDA, Shingo; Furuoka, Hidefumi; Tabata, Yasuhiko; SASAKI, Naoki

    2014-01-01

    This pilot study assessed the efficacy of 2 minimally invasive techniques for proximal interphalangeal (PIP) joint arthrodesis in horses. The PIP joints of both forelimbs (n = 6) were stabilized with locking compression plates (LCP) using a minimally invasive technique (LCP technique). Subsequently, for 1 randomly selected PIP joint of each horse, surgical drilling (SurD) was performed and tissue engineering (TE) was applied (LCP/SurD/TE technique). Minimally invasive PIP joint arthrodesis wi...

  3. Radiation-Associated Fracture Nonunion of the Clavicle Treated with Locking Plate Fixation and Autologous Bone Grafting

    Directory of Open Access Journals (Sweden)

    Takahiro Niikura

    2012-01-01

    Full Text Available We describe a case of radiation-associated fracture nonunion of the clavicle, which was treated by locking plate fixation and autologous bone grafting. The patient was a 67-year old man who received 70 Gy radiation therapy to treat nasopharyngeal carcinoma. Eight years later, he suffered a pathological fracture of the right clavicle. One year after the fracture, surgical treatment was performed due to persistent pain and weakness. Radiographs demonstrated atrophic nonunion. Bone scan demonstrated hot uptake at both ends of the fractured bone. MRI demonstrated a formation of pseudoarthrosis with fluid collection and suggested bone marrow edema at both ends of the fracture fragments. In surgery, fibrous pseudoarthrosis tissue was excised and both ends of the fracture fragments were refreshed to identify bleeding. Open reduction and internal fixation using a 7-hole locking plate and autologous bone grafting were performed. Successful bony union was obtained 1 year postoperatively, and no adverse events were observed up to 52 months after the operation. Our case suggests that a locking plate provides sufficient fixation and autologous bone grafting is effective in enhancing bone healing in a radiation-associated fracture nonunion of the clavicle in which it is difficult to achieve bony union.

  4. Atmospheric dynamics of Earth-like tidally locked aquaplanets

    Directory of Open Access Journals (Sweden)

    Tapio Schneider

    2010-12-01

    Full Text Available We present simulations of atmospheres of Earth-like aquaplanets that are tidally locked to their star, that is, planets whose orbital period is equal to the rotation period about their spin axis, so that one side always faces the star and the other side is always dark. Such simulations are of interest in the study of tidally locked terrestrial exoplanets and as illustrations of how planetary rotation and the insolation distribution shape climate. As extreme cases illustrating the effects of slow and rapid rotation, we consider planets with rotation periods equal to one current Earth year and one current Earth day. The dynamics responsible for the surface climate (e.g., winds, temperature, precipitation and the general circulation of the atmosphere are discussed in light of existing theories of atmospheric circulations. For example, as expected from the increasing importance of Coriolis accelerations relative to inertial accelerations as the rotation rate increases, the winds are approximately isotropic and divergent at leading order in the slowly rotating atmosphere but are predominantly zonal and rotational in the rapidly rotating atmosphere. Free-atmospheric horizontal temperature variations in the slowly rotating atmosphere are generally weaker than in the rapidly rotating atmosphere. Interestingly, the surface temperature on the night side of the planets does not fall below ~240 K in either the rapidly or slowly rotating atmosphere; that is, heat transport from the day side to the night side of the planets efficiently reduces temperature contrasts in either case. Rotational waves and eddies shape the distribution of winds, temperature, and precipitation in the rapidly rotating atmosphere; in the slowly rotating atmosphere, these distributions are controlled by simpler divergent circulations. Both the slowly and rapidly rotating atmospheres exhibit equatorial superrotation. Systematic variation of the planetary rotation rate shows that the

  5. Dynamic localization and Bloch oscillations in the spectrum of a frequency mode-locked laser.

    Science.gov (United States)

    Longhi, Stefano

    2005-04-01

    It is shown that a frequency mode-locked laser with a sinusoidal sweep of modulation frequency around a mode-locking condition represents an ideal optical system for observing in the spectral domain the phenomena of dynamic localization and Bloch oscillations of electrons in an ideal solid placed in an external ac electric field.

  6. Study of proximal femoral locking compression plate in extra capsular fracture neck of femur

    Directory of Open Access Journals (Sweden)

    Ravi G.O.

    2015-12-01

    Results: In our study of 21 cases, cases 13 cases were intertrochanteric fracture and remaining 8 were subtrochanteric fracture with the mean age was 51.47 years. Minimum age was 19 years and maximum age was 85 years. 14 patients (67% were males and 7 patients (33% were females, 13 IX patients (62% had right-sided fracture and 8 patients (38% had left-sided fracture. with right side being more common side affected. The average duration of stay in the hospital was 25.31 days. The average follow up was 18 months [11 to 23 months]. Out of 21 patients in our study 16 patients (76% are able to sit cross-legged and can squat on ground without any problem. The functional results were graded according to Harris Hip Scoring, In our study, 10 patients (48%had excellent results, 8 patients (38%had good results, 2 patients (10%had poor result, and 1 failed case (5% as she is an elderly female of 85 years with limited activity both preoperatively due to physiological age and general weakness. Conclusions: In conclusion the potentiality of the Proximal Femoral Locking Compression Plate (PF-LCP in varied indications, shows its versatility. Although not free of complications our study has demonstrated excellent results. The procedure offers, faster mobilization, rapid return to activities of daily living, improves the quality of life and gave a long term solution in patients with extracapsular fracture neck of femur. Larger studies with longer follow up will further validate the procedure. [Int J Res Med Sci 2015; 3(12.000: 3726-3733

  7. OSTEOSYNTHESIS OF PROXIMAL HUMERAL END FRACTURES WITH FIXED-ANGLE PLATE AND LOCKING SCREWS: TECHNIQUE AND RESULTS

    Science.gov (United States)

    Cohen, Marcio; Amaral, Marcus Vinicius; Monteiro, Martim; Brandão, Bruno Lobo; Motta Filho, Geraldo Rocha

    2015-01-01

    Describe the results of proximal humeral fractures surgically treated with the Philos locking plate system. Method: Between March 2003 and October 2004 we prospectively reviewed 24 of 26 patients with proximal humerus fractures treated with a Philos plate. The mean follow-up time was 12 months and the mean age of patients was 57 years. Six patients had four-part proximal humerus fractures, 11 patients had three-part proximal humerus fractures, and nine patients had two-part proximal humerus fractures. Clinical evaluation was performed using the University of California at Los Angeles (UCLA) criteria. Results: The mean UCLA score was 30 points (17-34). All fractures showed union. Three patients showed fracture union at varus position. The mean UCLA score for these patients was 27 points. Conclusion: Osteosynthesis with Philos plate provides a stable fixation method with good functional outcome. PMID:26998460

  8. The Use of the String of Pearls Locking Plate System in the Stabilisation of a Comminuted Calcaneal Fracture in a Giant Breed Dog

    Directory of Open Access Journals (Sweden)

    A. B. Scrimgeour

    2011-01-01

    Full Text Available An eight-year-old male Pyrenean mountain dog was presented with a comminuted fracture of the right calcaneus following motor vehicle trauma. The fracture was stabilised with a plate-rod construct, using the String of Pearls locking plate system and an intramedullary pin. Healing was uncomplicated.

  9. Distraction osteogenesis using combined locking plate and Ilizarov fixator in the treatment of bone defect: A report of 2 cases

    Directory of Open Access Journals (Sweden)

    John Mukhopadhaya

    2017-01-01

    Full Text Available Distraction osteogenesis and bone transport has been used to reconstruct bone loss defect by allowing new bone to form in the gap. Plate-guided bone transport has been successfully described in literature to treat bone loss defect in the femur, tibia, and mandible. This study reports two cases of fracture of femur with segmental bone loss treated with locking plate fixation and bone transport with Ilizarov ring fixator. At the time of docking, when the transport segment is compressed with bone fragment, the bone fragment is fixed with additional locking or nonlocking screws through the plate. The bone defect size was 7 cm in case 1 and 8 cm in case 2 and the external fixation indexes were 12.7 days/cm and 14 days/cm. No shortening was present in either of our cases. The average radiographic consolidation index was 37 days/cm. Both cases achieved infection-free bone segment regeneration and satisfactorily functional outcome. This technique reduces the duration of external fixation during the consolidation phase, allows correction of length and alignment and provides earlier rehabilitation.

  10. EARLY RESULTS OF UNSTABLE DISTAL RADIUS FRACTURES- ORIF WITH LOCKING COMPRESSION PLATE VERSUS LIGAMENTOTAXIS WITH EXTERNAL FIXATORS

    Directory of Open Access Journals (Sweden)

    Mondeep Gayan

    2017-04-01

    Full Text Available BACKGROUND External Fixation (EF and Open Reduction and Internal Fixation (ORIF have been the traditional surgical modalities for unstable distal radius fractures. The Locking Compression Plates (LCP acting as “internal external fixators” are particularly valuable in difficult situations of fractures. We undertook a study to evaluate the outcome of unstable distal radius fractures treated with ORIF with LCP versus those treated by ligamentotaxis with external fixators. MATERIALS AND METHODS A comparative study was carried out in a tertiary care centre with 30 cases of unstable distal radius fractures (15 cases in each group. In one group, open reduction and internal fixation with distal radius volar locking compression plate was carried out and in the other group ligamentotaxis with external fixator was done. The patients were treated and followed up over a period of one and a half year between June 2011 to November 2012. The fractures were classified according to AO classification (Arbeitsgemeinschaft für Osteosynthesefragen: German for “Association for the Study of Internal Fixation” or AO. The functional results were evaluated at the end of 6 months according to Demerit point system of Gartland and Werley modified by Sarmiento (1975 and the anatomical results as per Lindstrom criteria (1959 modified by Sarmiento (1980. RESULTS Overall 86.66% (13 cases had good-to-excellent anatomical results in external fixator group as compared to 93.33% (14 cases in LCP group. The functional outcome was excellent in 80% (12 and good in 13.33% (2 cases in external fixator group as compared to 66.66% (10 excellent and 26.66% (4 good in LCP group. CONCLUSION Both open reduction and internal fixation with locking compression plate and ligamentotaxis with external fixators are good treatment modalities for unstable distal radius fractures. However, the choice should be guided by the fracture configuration, surgeons’ experience and patient’s profile.

  11. Mechanical assessment of local bone quality to predict failure of locked plating in a proximal humerus fracture model.

    Science.gov (United States)

    Röderer, Götz; Brianza, Stefano; Schiuma, Damiano; Schwyn, Ronald; Scola, Alexander; Gueorguiev, Boyko; Gebhard, Florian; Tami, Andrea

    2013-09-01

    The importance of osteoporosis in proximal humerus fractures is well recognized. However, the local distribution of bone quality in the humeral head may also have a significant effect because it remains unclear in what quality of bone screws of standard implants purchase. The goal of this study was to investigate whether the failure of proximal humerus locked plating can be predicted by the DensiProbe (ARI, Davos, Switzerland). A 2-part fracture with metaphyseal impaction was simulated in 12 fresh-frozen human cadaveric humeri. Using the DensiProbe, local bone quality was determined in the humeral head in the course of 6 proximal screws of a standard locking plate (Philos; Synthes GmbH, Solothurn, Switzerland). Cyclic mechanical testing with increasing axial loading until failure was performed. Bone mineral density (BMD) significantly correlated with cycles until failure. Head migration significantly increased between 1000 and 2000 loading cycles and significantly correlated with BMD after 3000 cycles. DensiProbe peak torque in all screw positions and their respective mean torque correlated significantly with the BMD values. In 3 positions, the peak torque significantly correlated with cycles to failure; here BMD significantly influenced mechanical stability. The validity of the DensiProbe was proven by the correlation between its peak torque measurements and BMD. The correlation between the peak torque and cycles to failure revealed the potential of the DensiProbe to predict the failure of locked plating in vitro. This method provides information about local bone quality, potentially making it suitable for intraoperative use by allowing the surgeon to take measures to improve stability.

  12. Application of anterior decompression and reconstruction using titanium mesh with locking plates in the management of cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    Maolin He; Zengming Xiao; Shide Li; Qianfen Chen

    2008-01-01

    Objective:To observe the clinical effect of anterior decompression and reconstruction using titanium mesh with locking plates in the treatment of cervical spondylotic myelopathy.Methods:One hundred and twenty patients with cervical spondylotic myelopathy were treated by anterior decompression and reconstruction using titanium mesh with locking plates.There were 66 men and 54 women ranges in age from 37 to 72 Years(mean age, 58.3 years).The mean Japanese orthopedic surgery association(JOA) scale was 9.6 points before operation.Patients were followed up clinically and radiographically.Results:Having stood surgery well, the operation time ranged between 60-100 min and bleeding during operation ranged between 20-200 ml.There were no case of postoperative infection, recurrent laryngeal nerve palsy, or esophageal or tracheal laceration or rupture.The average follow-up period was 14.3 months(range, 12 to 24 months) in 96 who were followed up.At the last follow-up visit the mean JOA scale had improved to 14.4 points, reflecting an improve ment of 4.8 points.The results were considered to be excellent in 87 patients, good in 25, fair in 6, and poor in 2.No hardware-related complications or adjacent segment degenerative changes were encountered during the follow-up periods.Stable bone union was observed in all cases and the average time required for fusion was 5.7 months.Conclusion:Titanium mesh filled with autologous bone graft can avoid the complications associated with harvesting bone from the iliac crest donor site.When combined with cervical anterior locking plate, it can obtain satisfatory clinical results for the treatment of cervical spondylotic myelopathy.

  13. Dynamic Response of Three-Layered Annular Plate with Imperfections

    Directory of Open Access Journals (Sweden)

    Pawlus Dorota

    2015-02-01

    Full Text Available This paper presents the imperfection sensitivity of annular plate with three-layered structure. The plate composed of thin elastic facings and a thicker elastic core is loaded in facing plane. The classical issue of a three-layered plate was solved for dynamic deflection problem using the approximation methods: orthogonalization and finite difference. The solution includes the axisymmetric and asymmetric plate modes of the dynamic stability loss. The evaluation of the rate of plate sensitivity to imperfection of plate preliminary geometry has been enriched by the analysis of plate models built of finite elements. The ABAQUS program has been used. The numerous calculation results in the form of deflection characteristics, buckling modes, values of critical parameters create the view of response of dynamic plate structure with different rate of imperfection and linear in time loading growth, too.

  14. Proximal humeral fractures: a biomechanical comparison of locking plate constructs in a cadaveric 3-part fracture model.

    Science.gov (United States)

    Rose, David M; Sutter, Edward G; Mears, Simon C; Gupta, Rohit R; Belkoff, Stephen M

    2010-11-01

    The purpose of our study was to biomechanically compare, under cyclic loading conditions, fracture site motion, humeral head collapse, and intra-articular hardware penetration in simulated 3-part osteoporotic proximal humeral fractures stabilized with 1 of 2 locking-plate constructs. We performed fixation on simulated 3-part proximal humeral fractures in 10 pairs of cadaveric osteoporotic humeri with a Hand Innovations S3 Proximal Humerus Plate (S3 plate) or an LCP Proximal Humerus Plate (LCP plate; 1 each for each pair). The specimens were potted, mounted on a materials testing machine, and subjected to 5000 cycles of abduction in the scapular plane, loading through the supraspinatus tendon. Interfragmentary displacement at 2 virtual points (the most medial aspect of the calcar and the most superior aspect of the osteotomy line between the greater tuberosity and humeral head) was measured using an optical tracking system. Humeral head rotation was also measured. We used a generalized linear latent and mixed model to check for an effect of cyclic loading and treatment on the parameters of interest (significance, P fracture site motion, it is unknown whether the magnitude of the motion is clinically significant.

  15. Clinical results of using the proximal humeral internal locking system plate for internal fixation of displaced proximal humeral fractures.

    Science.gov (United States)

    Norouzi, Masoud; Naderi, Mohammad Nasir; Komasi, Mehdi Hemmati; Sharifzadeh, Seyyed Reza; Shahrezaei, Mostafa; Eajazi, Alireza

    2012-05-01

    Proximal humerus fractures are accounting for 4-5% of all fractures with increasing incidence. Proximal Humeral Internal Locking System (PHILOS) plate is a new plate which permits early mobility and lowers the risk of complications. The aim of this study was to evaluate the functional outcome and the complication rate after using this plate. Between 2006-2008, 37 patients with displaced 2-, 3-, and 4-part fractures of the proximal humerus underwent surgery using PHILOS plate. The mean range of follow-up was 12 months. Twenty patients were aged 60 years and younger, and 17 were aged older than 60 years. The average American Shoulder and Elbow Surgeons (ASES) score at the final follow-up was 77.62. According to Michener and colleagues classification, 5.4% of patients had an excellent outcome, 72.9% were minimally functionally limited, 16.2% were moderately functionally limited, and 5.4% were maximally functionally limited. The average ASES score between patients 60 years and older and those 60 years and younger was not different significantly. One patient developed avascular necrosis of the humeral head, 2 patients developed an infection, and no patients developed a nonunion. Fixation with PHILOS plate can be considered a good method with high union rates for this kind of fracture, especially in the older population with osteoporotic bone.

  16. Extraarticular proximal tibial fractures repaired with multifunctional locking intramedullary nail and locking plate Extraarticular proximal tibial fractures repaired with multifunctional locking intramedullary nail and locking plate%多功能带锁髓内钉和钢板置入内固定修复关节外胫骨创伤性骨折

    Institute of Scientific and Technical Information of China (English)

    陈德明; 徐晓阳; 王蔚; 张力; 常乐

    2016-01-01

    BACKGROUND: Many researchers at home and abroad think that interlocking intramedul ary nails may be more suitable for comminuted fractures of the tibia with severe soft tissue injury. Plate fixation is more advantageous for distal tibial fractures. OBJECTIVE: To compare the effects of multifunctional locking intramedul ary nail and locking plate in treatment of extraarticular proximal tibial fractures. METHODS: 156 patients with extraarticular proximal tibial fractures were included and divided into intramedul ary nail group (n=78) and the locking plate group (n=78) according to repair method. Curative effects and healing time were compared between the two groups. At 3 months after treatment, Johner-Wruh tibial fracture scores were used to assess the repair effect in both groups. In addition, operation time, blood loss, healing time and complications were compared between the two groups.RESULTS AND CONCLUSION: Mean healing time was 9.3 months in the locking plate group and 9.2 months in the intramedul ary nail group. At 3 months after treatment, the repair effect was significantly better in the intramedul ary nail group than in the locking plate group (P < 0.05). Blood loss and time were less in the intramedul ary nail group than in the locking plate group (P < 0.05), and surgical difficulty was high. At 3 months after treatment, the incidence rates of tibia eversion/inversion, neurovascular injury and nonunion/infection were significantly lower in the intramedul ary nail group than in the locking plate group (P < 0.05). These findings confirmed that the multifunctional locking intramedul ary nailing for extraarticular proximal tibial fractures obtained reliable efficacy, exact effect, reduced blood loss and low incidence of complications. Thus, it is better than locking plate.%背景:国内外多数学者认为带锁髓内钉可能更适合于粉碎性且软组织损伤严重的胫骨骨折,而钢板内固定则对于胫骨远端骨折更有优势。目的:

  17. Dynamic buckling of stiffened plates subjected to explosion impact loads

    Science.gov (United States)

    Wang, J.; Guo, J.; Yao, X. L.; Zhang, A. M.

    2017-01-01

    The dynamic buckling characteristics and criteria of a ship's structural stiffened plate subjected to underwater explosion impact loads are investigated in this study. Using the structural deformations observed in the experiments of underwater explosions against a plated grillage model, the mode shapes of the dynamic buckling were obtained. Through the construction of a computational model of stiffened plates subjected to an underwater explosion shock wave, the impact load was theoretically calculated and transformed into a rectangular pulse. According to the different response patterns of stiffened plates under different impact loads, a dynamic buckling criterion for the stiffened plates subjected to an explosion shock wave was proposed. Additionally, the static buckling phenomenon in the stiffened plates was analysed based on the minimum excess principle. In combination with the dynamic buckling criterion, the effects of various stiffening configurations on the dynamic and static buckling loads are discussed. The calculation results show that when the equivalent rectangular pulse is 2-3 times that of the static buckling load, the responses of the stiffened plates under the original shock load and the equivalent rectangular pulse are virtually identical. The impact load amplitude is the primary influencing factor in the dynamic buckling of stiffened plates subjected to underwater explosive impact loads. The stiffened plate aspect ratio has a substantial influence on the dynamic load factor. The analytical method and results are presented, which can be used to design stiffened optimum hull structures to enhance the dynamic load carrying capacity to withstand underwater shock damage.

  18. Stability of unicortical locked fixation versus bicortical non-locked fixation for forearm fractures

    Institute of Scientific and Technical Information of China (English)

    Timothy J.Pater; Steve I Grindel; Gregory J.Schmeling; Mei Wang

    2014-01-01

    Locking plate fixation is being widely applied for fixation of forearm fractures and has many potential advantages, such as fixed angle fixation and improved construct stability, especially in osteoporotic bone. Biomechanical data comparing locking devices to commonly used Low Contact Dynamic Compression (LCDCP) plates for the fixation of forearm fractures has been lacking. The purpose of this study was to compare the fixation stability of a 3.5-mm unicortical locked plate with bicortical non-locked LCDCP plates. Six matched pairs of fresh frozen cadaveric forearms were randomly assigned to unicortical locked and bicortical unlocked groups. Non-destructive four-point bending and torsional test was performed on the ulna and radius separately, using a servohydraulic testing system to obtain construct stiffness of the intact specimens and specimens after osteotomy and plating. The specimens were then loaded to failure to test the fixation strength. The locked unicortical fixation showed significantly higher bending stiffness than the unlocked bicortical fixation, but with significantly lower stiffness and strength in torsion. Fixation strength was comparable between the two groups under bending, but significantly greater in the bicortical non-locked group under torsion. Findings from this study suggest that postoperative rehabilitation protocols may need modification to limit torsional loading in the early stage when using locked unicortical fixation. The study also points out the potential advantage of a hybrid fixation that combines locked unicortical and unlocked bicortical screws.

  19. Precision and Fast Wavelength Tuning of a Dynamically Phase-Locked Widely-Tunable Laser

    Science.gov (United States)

    Numata, Kenji; Chen, Jeffrey R.; Wu, Stewart T.

    2012-01-01

    We report a precision and fast wavelength tuning technique demonstrated for a digital-supermode distributed Bragg reflector laser. The laser was dynamically offset-locked to a frequency-stabilized master laser using an optical phase-locked loop, enabling precision fast tuning to and from any frequencies within a 40-GHz tuning range. The offset frequency noise was suppressed to the statically offset-locked level in less than 40 s upon each frequency switch, allowing the laser to retain the absolute frequency stability of the master laser. This technique satisfies stringent requirements for gas sensing lidars and enables other applications that require such well-controlled precision fast tuning.

  20. Polarization dynamic patterns of vector solitons in a graphene mode-locked fiber laser.

    Science.gov (United States)

    Han, Mengmeng; Zhang, Shumin; Li, Xingliang; Zhang, Huaxing; Yang, Hong; Yuan, Ting

    2015-02-09

    Multiple polarization dynamic patterns of vector solitons, including fundamental solitons, bunched solitons, loosely or tightly bound states and harmonic mode locking have been observed experimentally in an erbium-doped fiber ring laser with graphene as a saturable absorber. By carefully adjusting the pump power and the orientation of the intra-cavity polarization controller, either polarization rotation or polarization locked operation have all been achieved for the above vector solitons. This is the first time that high order harmonic mode locking of polarization rotation vector solitons has been achieved. The signal to noise ratio of our system was ~51 dB, which indicates that the laser operated with high stability.

  1. EVALUATION OF FUNCTIONAL OUTCOME AFTER OPEN REDUCTION AND INTERNAL FIXATION OF DISTAL FEMUR FRACTURES BY LOCKING COMPRESSION PLATE

    Directory of Open Access Journals (Sweden)

    L. Lokanadha Rao

    2016-09-01

    Full Text Available BACKGROUND In the supra and intercondylar fractures of femur particularly with intra articular extension, patient may develop stiffness of knee, shortening, rotational deformities, internal derangement of knee with instability, varus and valgus deformities which affect patient’s routine lifestyle. If these cases were treated with locking compression plate, the results obtained were successful, superior, timesaving providing early ambulation and least disability improving the functional outcome. MATERIALS AND METHODS This is a prospective interventional study. This study includes 25 supracondylar and intercondylar fractures of femur (both Muller’s Type ‘A’, Type B and Type ‘C’ fractures treated with open reduction and internal fixation by Locking Compression Plate in the Department of Orthopaedics, King George Hospital, Visakhapatnam from September 2013 to September 2015. There are 16 males and 9 females with age ranging from 20 to 80 years with an average of 44.6 years. Average age for males is 28.9 years and average age for females is 25 years. 18 fractures were due to road traffic accidents and 6 cases are due to fall from significant heights, 1 case due to simple fall from standing (osteoporosis. 15 cases were in right femur (60% and 10 cases were in left femur (40%. RESULTS 25 cases were included in the study. There is an increase in the rate of union, decreased time taken for union, increased knee range of motion, decreased time for weight-bearing, postoperative complications and duration for hospital stay. CONCLUSION LCP proved to be a good implant which could take the challenges like poor bone stock, severe comminution both metaphyseal and articular and prove successful. The locking head screws distally have prevented varus collapse, even in cases of osteoporosis. The Condylar LCP can be used in either an open or a minimally invasive manner.

  2. Compartment syndrome like picture in metaphyseal comminuted fracture of tibia treated by locking plate due to tight closure

    Directory of Open Access Journals (Sweden)

    Prafulla Herode

    2013-01-01

    Full Text Available A 22-year-old male came to casualty on 5 th May 2012 after a fall from motorcycle. He complained of excruciating pain and swelling over right knee. There was an open wound of 7 × 2 cm over supra-patellar region and diffuse swelling over knee joint with severe tenderness over proximal aspect of right tibia. X-ray showed intra-articular fracture of proximal tibia extending to diaphysis classified as type 6 by Schatzker classification for proximal tibia, with fibula shaft transverse fracture. The skin over the fracture was contused. Debridement with primary wound closure was done in emergency. Skeletal traction was applied through a lower tibial Steinman pin. Patient was operated after 15 days when wound healed and swelling subsided. Locking plate was applied on medial aspect using Minimally invasive percutaneous plate osteosysthesis (MIPPO technique. Post-operatively over 4 hours patient developed severe pain and swelling in operated leg which mimicked compartment syndrome. Suture removal was done immediately in the ward from the distal aspect, which relieved the symptoms but lead to exposure of the plate. A rotational flap was done to cover the plate in coordination with a plastic surgeon on the next day.

  3. Mechanical properties of Indonesian-made narrow dynamic compression plate.

    Science.gov (United States)

    Dewo, P; van der Houwen, E B; Sharma, P K; Magetsari, R; Bor, T C; Vargas-Llona, L D; van Horn, J R; Busscher, H J; Verkerke, G J

    2012-09-01

    Osteosynthesis plates are clinically used to fixate and position a fractured bone. They should have the ability to withstand cyclic loads produced by muscle contractions and total body weight. The very high demand for osteosynthesis plates in developing countries in general and in Indonesia in particular necessitates the utilisation of local products. In this paper, we investigated the mechanical properties, i.e. proportional limit and fatigue strength of Indonesian-made Narrow Dynamic Compression Plates (Narrow DCP) as one of the most frequently used osteosynthesis plates, in comparison to the European AO standard plate, and its relationship to geometry, micro structural features and surface defects of the plates. All Indonesian-made plates appeared to be weaker than the standard Narrow DCP because they consistently failed at lower stresses. Surface defects did not play a major role in this, although the polishing of the Indonesian Narrow DCP was found to be poor. The standard plate showed indications of cold deformation from the production process in contrast to the Indonesian plates, which might be the first reason for the differences in strength. This is confirmed by hardness measurements. A second reason could be the use of an inferior version of stainless steel. The Indonesian plates showed lower mechanical behaviour compared to the AO-plates. These findings could initiate the development of improved Indonesian manufactured DCP-plates with properties comparable to commonly used plates, such as the standard European AO-plates.

  4. 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.

  5. Close Intramedullary Interlocking Nailing Versus Locking Compression Plating In the Treatment of Closed Fracture Shaft of the Tibia.

    Science.gov (United States)

    Kundu, I K; Datta, N K; Chowdhury, A Z; Das, K P; Tarik, M M; Faisal, M A

    2016-07-01

    Fracture of tibial shaft is the commonest site of long bone fractures due to its superficial location involving young or middle-age people. Proper management is an important issue regarding the future effective movements. In this study patients were grouped in closed Intra medullary interlocking nailing and locking compression plating. Post-operative follow up at 2 weeks, 6 weeks, 12 weeks and 3 months thereafter up to 6 months were done. Each of the patients was evaluated clinically and radiologically by tucker criteria of Tuker et al. Patients were assessed for pain on full weight bearing and kneeling, shortening and range of motion of knee and ankle joints. Radiological assessment for union of fracture, alignment of fracture and angulations and position of nail and screws and infection were observed during follow up. A total number of 32 patients were selected but only 27 patients were available for follow up for a period of 6 months. They were grouped into Group A, consisting of 15 patients who took the treatment in the form of closed intramedullary interlocking nailing and Group B, consisting of 12 patients those underwent ORIF with locking compression plating. In both of the groups Motor Vehicle Accident was the main mechanism of trauma. Fracture involving the middle 3rd of the tibia is common in both the groups. During post-operative follow up, four patients in Group A complained anterior knee pain, one patient in Group B had superficial infection, most of the patients had no restriction of movement in the ankle and knee joints and a single patient in Group B showed 1.5cm shortening of the lower limb. Period of hospital stay and fracture union time were less in Group A, which was statistically significant. Both groups showed excellent result with minimum complications. So this study permits to conclude that close IM interlocking nailing and open reduction and internal fixation by locking compression plating is equally effective for the management of close

  6. The use of locking plates in proximal humeral fractures: Comparison of outcome by patient age and fracture pattern

    Directory of Open Access Journals (Sweden)

    Leonard Michael

    2009-01-01

    Full Text Available Purpose: This study was undertaken to evaluate the efficacy of a proximal humeral locking plate, and to specifically study the effect of patient age and fracture type on the outcome. Materials and Methods: Thirty-one cases of proximal humeral fractures fixed by using the proximal humeral interlocking (PHILOS plate were reviewed. Results: Average functional scores (minimum 18 months post operation per AO / ASIF fracture type were 25.3 for type A, 21.4 for type B, and 22.7 for type C. There was no statistically significant difference between the groups. The functional scores for patients over 65 years of age were significantly inferior (P = 0.03. At a final radiological review (mean 12 months post operation, 30 (96% of the patients demonstrated fracture union. Seven patients (22.5% required a second surgical procedure. Conclusion: We obtained both good functional results and bone healing with the PHILOS plate, irrespective of fracture type; the older patients had a poorer outcome. We caution the surgeons on the high potential for reoperations with its use.

  7. Minimally invasive proximal interphalangeal joint arthrodesis using a locking compression plate and tissue engineering in horses: a pilot study.

    Science.gov (United States)

    Seo, Jong-pil; Yamaga, Takashi; Tsuzuki, Nao; Yamada, Kazutaka; Haneda, Shingo; Furuoka, Hidefumi; Tabata, Yasuhiko; Sasaki, Naoki

    2014-11-01

    This pilot study assessed the efficacy of 2 minimally invasive techniques for proximal interphalangeal (PIP) joint arthrodesis in horses. The PIP joints of both forelimbs (n = 6) were stabilized with locking compression plates (LCP) using a minimally invasive technique (LCP technique). Subsequently, for 1 randomly selected PIP joint of each horse, surgical drilling (SurD) was performed and tissue engineering (TE) was applied (LCP/SurD/TE technique). Minimally invasive PIP joint arthrodesis with LCP demonstrated low postoperative infection rates. Gross and histological evaluations revealed considerable destruction of the articular cartilage in the LCP/SurD/TE-treated joints. In contrast, almost no destruction of the cartilage was observed in the LCP-treated joints. Our results suggest that the LCP technique alone is not sufficient for PIP joint arthrodesis and that the LCP/SurD/TE technique may be useful for PIP joint arthrodesis in horses.

  8. Bilateral traumatic proximal humerus fractures managed by open reduction and internal fixation with locked plates

    Institute of Scientific and Technical Information of China (English)

    Atin Jaiswal; Naiman Deepak Kachchhap; Rupak Chaterjee; Yashwant Singh Tanwar; Masood Habib; Satya Prakash Singh

    2013-01-01

    Fractures of the proximal humerus are uncommon in young patients.Although bilateral fracture of proximal humerus itself is rare,association with epilepsy and electrocution is frequent.Only one case of traumatic bilateral proximal humerus fracture has been reported in the literature.We report a rare case of bilateral traumatic displaced proximal humerus fractures in a 40 years old male patient,which was treated by means of open reduction and internal fixation with proximal humerus locked pates on both sides and obtained a good functional outcome.

  9. Bilateral traumatic proximal humerus fractures managed by open reduction and internal fixation with locked plates

    Directory of Open Access Journals (Sweden)

    Jaiswal Atin

    2013-12-01

    Full Text Available 【Abstract】Fractures of the proximal humerus are uncommon in young patients. Although bilateral fracture of proximal humerus itself is rare, association with epilepsy and electrocution is frequent. Only one case of traumatic bilateral proximal humerus fracture has been reported in the literature. We report a rare case of bilateral traumatic dis- placed proximal humerus fractures in a 40 years old male patient, which was treated by means of open reduction and internal fixation with proximal humerus locked pates on both sides and obtained a good functional outcome. Key words: Humeral fractures; Shoulder fractures; Fracture fixation, internal

  10. Bilateral traumatic proximal humerus fractures managed by open reduction and internal fixation with locked plates.

    Science.gov (United States)

    Jaiswal, Atin; Kachchhap, Naiman Deepak; Chaterjee, Rupak; Tanwar, Yashwant Singh; Habib, Masood; Singh, Satya Prakash

    2013-01-01

    Fractures of the proximal humerus are uncommon in young patients. Although bilateral fracture of proximal humerus itself is rare, association with epilepsy and electrocution is frequent. Only one case of traumatic bilateral proximal humerus fracture has been reported in the literature. We report a rare case of bilateral traumatic displaced proximal humerus fractures in a 40 years old male patient, which was treated by means of open reduction and internal fixation with proximal humerus locked pates on both sides and obtained a good functional outcome.

  11. Energy transfer in double plate system dynamics

    Institute of Scientific and Technical Information of China (English)

    Katica (Stevanovic) Hedrih

    2008-01-01

    The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component.

  12. Clinical evaluation of locking compression plate fixation for comminuted olecranon fractures

    NARCIS (Netherlands)

    Buijze, G.; Kloen, P.

    2009-01-01

    BACKGROUND: In patients managed with plate fixation for the treatment of an olecranon fracture, the placement of an axial intramedullary screw may obstruct the placement of bicortical screws in the ulnar shaft. To overcome this problem, unicortical screws can be applied with use of a contoured locki

  13. Screw augmentation reduces motion at the bone-implant interface: a biomechanical study of locking plate fixation of proximal humeral fractures.

    Science.gov (United States)

    Schliemann, Benedikt; Seifert, Robert; Rosslenbroich, Steffen B; Theisen, Christina; Wähnert, Dirk; Raschke, Michael J; Weimann, Andre

    2015-12-01

    Shear forces at the bone-implant interface lead to a loss of reduction after locking plate fixation of proximal humeral fractures. The aim of the study was to analyze the roles of medial support screws and screw augmentation in failure loads and motion at the bone-implant interface after locking plate fixation of proximal humeral fractures. Unstable 3-part fractures were simulated in 6 pairs of cadaveric humeri and were fixed with a DiPhos-H locking plate (Lima Corporate, Udine, Italy). An additional medial support screw was implanted in 1 humerus of every donor. The opposite humerus was stabilized with a medial support screw and additional bone cement augmentation of the 2 anteriorly directed head screws. Specimens were loaded in the varus bending position. Stiffness, failure loads, plate bending, and the motion at the bone-implant interface were evaluated using an optical motion capture system. The mean load to failure was 669 N (standard deviation [SD], 117 N) after fixation with medial support screws alone and 706 N (SD, 153 N) after additional head screw augmentation (P = .646). The initial stiffness was 453 N/mm (SD, 4.16 N/mm) and 461 N/mm (SD, 64.3 N/mm), respectively (P = .594). Plate bending did not differ between the 2 groups. However, motion at the bone-implant interface was significantly reduced after head screw augmentation (P Board of Trustees. Published by Elsevier Inc. All rights reserved.

  14. FUNCTIONAL OUTCOME OF LOCKING COMPRESSION PLATE OSTEOSYNTHESIS IN SCHATZKER’S TYPE V AND VI TIBIAL PLATEAU FRACTURES

    Directory of Open Access Journals (Sweden)

    Deependra

    2015-11-01

    Full Text Available : Tibial plateau fractures are the common injuries that may be associated with poor outcomes and a high rate of complications. The problem rise significantly in high energy trauma and severe soft tissue injuries. Early technique of osteosysnthesis were based on extensive surgical approach. Introduction of minimally invasive plate osteosynthesis using locking compression plate conserves the vascularity of the bone but also leads to the overall improvement in the values of bone healing. MATERIALS AND METHODS: Inclusion criteria for this study were patients of either sex, tibial plateau fractures Schatzker’s Type V and VI, age group 15 to 60 years and compounding upto Gustilo and Anderson’s Grade II and excluded the patients where the compounding was grade III and displacement <2mm. The fractures were treated applying LCP percutaneously either medially or laterally depending on the side of comminution. RESULTS: In our study conducted on 45 patients 4 lost to follow up in first 6 months with displaced tibial plateau overall the functional result using Rasmussen’s criteria was acceptable in all of the cases with an average score of 26.38. All the patients in our series showed union with average time for union being 13.3 weeks. DISCUSSION: Our study confirms that minimally invasive locking compression plate osteosynthesis is a viable alternative as a treatment for open tibial plateau fractures Gustilo and Anderson’s type I and II. The incidence of infection in our study wad 10% which is comparable with most of the series in literature that select the high energy tibial plateau fractures. None of the patients had nonunion only one had delayed union and does not required bone grafting as the metaphyseal area has a good blood supply. There were superficial infection in 4 cases which resolved to the dressing and antibiotic treatment within 3 weeks. The mean range motion at knee joint was 5 degree to 130 degree.(1 CONCLUSION: This paper reports the

  15. The treatment of AO type C fractures of the distal radius with dynamic external fixation combined with minimally invasive reset and bone gratting and locking compression plate%动力型外固定支架结合微创复位植骨与锁定钢板内固定治疗桡骨远端骨折的比较研究

    Institute of Scientific and Technical Information of China (English)

    付炳金; 朱晓东

    2014-01-01

    reset and bone grafting and open reduction combined with locking compression plate internal fixation .To evaluate the merit and demerit of the two methods .Methods From September 2010 to March 2014 , we choose 62 cases with AO type C2 and C3 fractures of the distal radius ,and make a retrospective study of these patients'fol-low -up data .32 cases were treated with dynamic external fixation combined with minimally invasive reset and bone grafting , 30 cases were treated with open reduction combined with locking compression plate internal fixation .Collected and sorted out the patients'X-ray measurement data ,the common surgery complications ,as well as the wrists'Gartland-Werley function scores ,for statistical analysis .Results 62 cases of distal radius fractures have received bone healing .After surgeries ,the com-mon surgery complications showed that ,in the external fixation group ,nail track infection 2 ,wrist joint pain 1 ,wrist joint stiffness 1;whilein the LCP group ,wound infection 2 ,wrist joint pain 2 .At 24 months after the treatments ,the wrists'Gart-land-Werley function scores showed that ,in the external fixation group ,excellent /good 28;whilein the LCP group ,excel-lent /good 28 .After statistical analysis ,The external fixation group and the LCP group was pointless to cast (P>0.05) .Con-clusions The treatment of AO type C2 and C3 fractures of the distal radius with dynamic external fixation combined with mini-mally invasive reset and bone grafting is an effective method .This method is simple ,less invasive .It can effectively correct the shortening deformity and angular deformity of the distal radius ,making an anatomical reduction of the distal radius fractures , and increasing the stability of the fractures .The treatment of AO type C2 and C3 fractures of the distal radius with locking com-pression plate is an effective method ,too .This surgery has a good reset effect ,and a high fixation strength .It can effectively avoid reset losing of the

  16. The Dynamics of Small-Sized Ensembles of the Phase-Locked Loops with Unidirectional Couplings

    Science.gov (United States)

    Aleshin, K. N.; V. Matrosov, V.; Shalfeev, V. D.

    2016-06-01

    We study collective dynamics of a small-sized chain of the unidirectionally coupled phase-locked loop. The conditions for the synchronous-regime existence are found, the asynchronous selfoscillation regimes and the transitions among them are studied, and the property of inheriting the structure of the parameter space of the chain when a new element is added to it is established.

  17. 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

  18. Polarization dynamics in dissipative soliton fiber lasers mode-locked by nonlinear polarization rotation.

    Science.gov (United States)

    Kong, Lingjie; Xiao, Xiaosheng; Yang, Changxi

    2011-09-12

    We numerically studied the polarization dynamics in dissipative soliton lasers mode-locked by nonlinear polarization rotation (NPR). It was found that the polarization states of the intracavity dissipative soliton vary with time across the pulse. Depending on output coupling ratios, the polarization states of the pulse peak before the polarizer can be either nearly circular or nearly linear polarizations. The polarization dependent component in NPR is found to play a role of spectral filter under high and medium output coupling. However, NPR may work as a weak optical limiter under low output coupling, when additional spectral filtering is necessary to maintain steady mode-locking state.

  19. Time Domain Dynamic Analysis of 1550nm Monolithic Two Sections Mode Locked MQW Laser

    OpenAIRE

    DUMAN, Çağlar; ÇAKMAK, Bülent

    2015-01-01

    In this study, time domain dynamic model of a mode locked two sections DBR laser was obtained. Sort duration and high power optical pulse generation from a semiconductor laser was examined by using obtained model. For this aim, while one of the laser sections was thought as reverse biased and so acted as a saturable absorber, other section thought as forward biased with a DC current and so acted as a gain section. A semiconductor laser biased this way can produce mode locked pulses by suitabl...

  20. Dynamics of a reinforced viscoelastic plate

    Directory of Open Access Journals (Sweden)

    Igor V. Andrianov

    2006-01-01

    Full Text Available Oscillations and static bending deformation of a viscoelastic reinforced plate are considered. Analytical solutions are derived. An asymptotic technique, based on the homogenization method, is used for this purpose. In addition, a special perturbation approach is employed. An example is given for the purpose of illustration. The approximate analytical expressions are shown to adequately meet the requirements of optimal structural design.

  1. Treatment of middle-third clavicle fractures using anterior plating with a dynamic compression plate (DCP).

    Science.gov (United States)

    Subramanian, Padmanabhan; Joshi, Meera; Shilston, Sophie; Wallace, Donald; Pearce, Oliver J

    2013-03-01

    Significantly displaced midshaft clavicle fractures can be managed operatively to restore anatomy and allow early mobilization. Several techniques have described using precontoured anatomically designed plates placed on the superior surface of the bone or reconstruction plates contoured by the surgeon placed either superiorly or anteriorly. We describe the use of the dynamic compression plate placed anteriorly on the clavicle in treating these fractures and discuss the relative advantages of this technique. We have a case series of 8 patients over a 2-year period, who were followed up and all went on to successful fracture union.

  2. Phase Locking Phenomena and Electroencephalogram-Like Activities in Dynamic Neuronal Systems

    Institute of Scientific and Technical Information of China (English)

    XU Xin-Jian; WANG Sheng-Jun; TANG Wei; WANG Ying-Hai

    2005-01-01

    @@ We study signal detection and transduction of dynamic neuronal systems under the influence of external noise,white and coloured. Based on simulations, we show explicitly phase locking phenomena between the output and the input of a single neuron and Electroencephalogram-like activities on neural networks with small-world connectivity. The numerical results prove that the dynamic neuronal system can be adjusted to an optimal sensitive state for signal processing in the presence of additive noise.

  3. Hierarchy, dimension, attractor and self-organization -- dynamics of mode-locked fiber lasers

    CERN Document Server

    Wei, Huai; Shi, Wei; Zhu, Xiushan; Norwood, Robert A; Peyghambarian, Nasser; Jian, Shuisheng

    2016-01-01

    Mode-locked fiber lasers are one of the most important sources of ultra-short pulses. However, A unified description for the rich variety of states and the driving forces behind the complex and diverse nonlinear behavior of mode-locked fiber lasers have yet to be developed. Here we present a comprehensive theoretical framework based upon complexity science, thereby offering a fundamentally new way of thinking about the behavior of mode-locked fiber lasers. This hierarchically structured frame work provide a model with and changeable variable dimensionality resulting in a simple and elegant view, with which numerous complex states can be described systematically. The existence of a set of new mode-locked fiber laser states is proposed for the first time. Moreover, research into the attractors' basins reveals the origin of stochasticity, hysteresis and multistability in these systems. These findings pave the way for dynamics analysis and new system designs of mode-locked fiber lasers. The paradigm will have a w...

  4. Structural Stability and Dynamics of FGM Plates Using an Improved 8-ANS Finite Element

    Directory of Open Access Journals (Sweden)

    Weon-Tae Park

    2016-01-01

    Full Text Available I investigate the vibration and buckling analysis of functionally graded material (FGM structures, using a modified 8-node shell element. The properties of FGM vary continuously through the thickness direction according to the volume fraction of constituents defined by sigmoid function. The modified 8-ANS shell element has been employed to study the effect of power law index on dynamic analysis of FGM plates with various boundary conditions and buckling analysis under combined loads, and interaction curves of FGM plates are carried out. To overcome shear and membrane locking problems, the assumed natural strain method is employed. In order to validate and compare the finite element numerical solutions, the reference results of plates based on Navier’s method, the series solutions of sigmoid FGM (S-FGM plates are compared. Results of the present study show good agreement with the reference results. The solutions of vibration and buckling analysis are numerically illustrated in a number of tables and figures to show the influence of power law index, side-to-thickness ratio, aspect ratio, types of loads, and boundary conditions in FGM structures. This work is relevant to the simulation of wing surfaces, aircrafts, and box structures under various boundary conditions and loadings.

  5. ELASTIC DYNAMIC ANALYSIS OF MODERATELY THICK PLATE USING MESHLESS LRPIM

    Institute of Scientific and Technical Information of China (English)

    Ping Xia; Shuyao Long; Hongxue Cui

    2009-01-01

    A meshless local radial point interpolation method (LRPIM) for solving elastic dy-namic problems of moderately thick plates is presented in this paper. The discretized system equation of the plate is obtained using a locally weighted residual method. It uses a radial basis function (RBF) coupled with a polynomial basis function as a trial function, and uses the quartic spline function as a test function of the weighted residual method. The shape function has the properties of the Kronecker delta function, and no additional treatment is done to impose essen-tial boundary conditions. The Newmark method for solving the dynamic problem is adopted in computation. Effects of sizes of the quadrature sub-domain and influence domain on the dynamic properties are investigated. The numerical results show that the presented method can give quite accurate results for the elastic dynamic problem of the moderately thick plate.

  6. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    2008-01-01

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  7. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  8. Dynamic Behaviors of Axially Moving Viscoelastic Plate with Varying Thicknessn

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yinfeng; WANG Zhongmin

    2009-01-01

    Structural components of varying thickness draw increasing attention these days due to economy and light-weight considerations. In view of the absence of research in vibration analysis of viscoelastic plate with varying thickness, this study devotes to investigate the dynamic behaviors of axially moving viscoelastic plate with varying thickness. Based on the thin plate theory and the two-dimensional viscoelastic differential constitutive relation, the differential equation of motion of the axially moving viscoelastic rectangular plate is derived, the plate constituted by Kelvin-Voigt model has linearly varying thickness in the y-direction. The dimensionless complex frequencies of axially moving viscoelastic plate with four edges simply supported are calculated by the differential quadrature method, curves of real parts and imaginary parts of the first three-order dimensionless complex frequencies versus dimensionless moving speed are obtained, the effects of the aspect ratio, thickness ratio, the dimensionless moving speed and delay time on the dynamic behaviors of the axially moving viscoelastic rectangular plate with varying thickness are analyzed. When other parameters keep constant, with the decrease of thickness ratio, the real parts of the first three-order natural frequencies decrease, and the critical divergence speeds of various modes decrease too, moreover, whether the delay time is large or small, the frequencies are all complex numbers.

  9. Size-Dependent Dynamic Behavior of a Microcantilever Plate

    Directory of Open Access Journals (Sweden)

    Xiaoming Wang

    2012-01-01

    Full Text Available Material length scale considerably affects the mechanical properties of microcantilever components. Recently, cantilever-plate-like structures have been commonly used, whereas the lack of studies on their size effects constrains the design, testing, and application of these structures. We have studied the size-dependent dynamic behavior of a cantilever plate based on a modified couple stress theory and the differential quadrature method in this note. The numerical solutions of microcantilever plate equation involving the size effect have been presented. We have also analyzed the bending and vibration of the microcantilever plates considering the size effect and discussed the dependence of the size effect on their geometric dimensions. The results have shown that (1 the mechanical characteristics of the cantilever plate show obvious size effects; as a result, the bending deflection of a microcantilever plate reduces whereas the natural frequency increases effectively and (2 for the plates with the same material, the size effect becomes more obvious when the plates are thinner.

  10. Additive fiber-cerclages in proximal humeral fractures stabilized by locking plates: no effect on fracture stabilization and rotator cuff function in human shoulder specimens.

    Science.gov (United States)

    Voigt, Christine; Hurschler, Christof; Rechi, Louise; Vosshenrich, Rolf; Lill, Helmut

    2009-08-01

    The effect of additive fiber-cerclages in proximal humeral fractures stabilized by locking plates on fracture stabilization and rotator cuff function is unclear. Here it was assessed in a human cadaver study. 24 paired human shoulder specimens were harvested from median 77-year-old (range 66-85) female donors. An unstable 3-part fracture model with an intact rotator cuff was developed. 1 specimen of each pair received an additive fiber-cerclage of the rotator cuff after plate fixation, and the other one received a plate fixation without an additive fiber-cerclage. Force-controlled hydraulic cylinders were used to simulate physiological rotator cuff tension, while a robot-assisted shoulder simulator performed 4 relevant cases of load: (1) axial loading at 0 degrees, (2) glenohumeral abduction at 60 degrees, (3) internal rotation at 0 degrees abduction, and (4) external rotation at 0 degrees abduction, and imitated hanging arm weight during loading without affecting joint kinematics. A 3-dimensional real-time interfragmentary motion analysis was done in fracture gaps between the greater tuberosity and the head, as well as subcapital. The capacity of the rotator cuff to strain was analyzed with an optical system. Interfragmentary motion was similar between the groups with and without fiber-cerclages, in both fracture gaps and in any of the cases of load. Cerclages did not impair the capacity of the rotator cuff to strain. INTERPRETATION; Provided that unstable 3-part fractures are reduced and stabilized anatomically by a locking plate, additive fiber-cerclages do not reduce interfragmentary motion. Additive fiber-cerclages may be necessary in locking plate osteosyntheses of multiple-fractured greater tuberosities or lesser tuberosity fractures that cannot be fixed sufficiently by the plate.

  11. Biomechanical Analysis Of The Proximal Femoral Locking Compression Plate: Do Quality Of Reduction And Screw Orientation Influence Construct Stability?

    Science.gov (United States)

    Zderic, Ivan; Oh, Jong-Keon; Stoffel, Karl; Sommer, Christoph; Helfen, Tobias; Camino, Gaston; Richards, R Geoff; Nork, Sean E; Gueorguiev, Boyko

    2017-08-22

    To investigate biomechanically in a human cadaveric model the failure modes of the Proximal Femoral Locking Compression Plate (PF-LCP) and explore the underlying mechanism. Twenty-four fresh-frozen paired human cadaveric femora with simulated unstable intertrochanteric fractures (AO/OTA 31-A3.3) were assigned to four groups with six specimens each for plating with PF-LCP. The groups differed in the quality of fracture reduction and plating fashion of the first and second proximal screws as follows: 1) anatomical reduction with on-axis screw placement; 2) anatomical reduction with off-axis screw placement; 3) malreduction with on-axis screw placement; 4) malreduction with off-axis screw placement. The specimens were tested until failure using a protocol with combined axial and torsional loading. Mechanical failure was defined as abrupt change in machine load-displacement data. Clinical failure was defined as 5° varus tilting of the femoral head as captured with optical motion tracking. Initial axial stiffness (N/mm) in groups 1 to 4 was 213.6±65.0, 209.5±134.0, 128.3±16.6 and 106.3±47.4, respectively. Numbers of cycles to clinical and mechanical failure were 16642±10468 and 8695±1462 in group 1, 14076±3032 and 7449±5663 in group 2, 8800±8584 and 4497±2336 in group 3 and 9709±3894 and 5279±4119 in group 4. Significantly higher stiffness as well as numbers of cycles to both clinical and mechanical failure were detected in group 1 in comparison to group 3, P≤0.044. Generally, malreduction led to significantly earlier construct failure. The observed failures were cut-out of the proximal screws in the femoral head, followed by either screw bending, screw loosening or screw fracture. Proper placement of the proximal screws in anatomically reduced fractures led to significantly higher construct stability. Our data also indicates that once the screws are placed off-axis (>5 degrees), the benefit of an anatomic reduction is lost.

  12. Dynamics of dual-polarization VCSEL-based optical frequency combs under optical injection locking.

    Science.gov (United States)

    Prior, E; de Dios, C; Criado, R; Ortsiefer, M; Meissner, P; Acedo, P

    2016-09-01

    The present experimental work studies the dynamics of dual-polarization optical frequency combs (OFCs) based on gain switching (GS) vertical-cavity surface-emitting laser (VCSEL) diodes under optical injection locking (OIL). This study presents two main results. First, we have obtained an overall comb formed by two orthogonally polarized sub-combs with comparable span and power. The overall comb shows enhanced optical span and flatness and high coherence between its modes. The second result is that we have been able to control the polarization state of the overall comb by tuning the polarization state of the injected light by locking the same single teeth of the comb. This produces an overall comb with single polarization that is parallel or orthogonal. These are novel findings that provide for the development of efficient and compact OFCs based on GS VCSEL sources with versatile polarization dynamics.

  13. Biomechanical evaluation of fracture fixation constructs using a variable-angle locked periprosthetic femur plate system.

    Science.gov (United States)

    Hoffmann, Martin F; Burgers, Travis A; Mason, James J; Williams, Bart O; Sietsema, Debra L; Jones, Clifford B

    2014-07-01

    In the United States there are more than 230,000 total hip replacements annually, and periprosthetic femoral fractures occur in 0.1-4.5% of those patients. The majority of these fractures occur at the tip of the stem (Vancouver type B1). The purpose of this study was to compare the biomechanically stability and strength of three fixation constructs and identify the most desirable construct. Fifteen medium adult synthetic femurs were implanted with a hip prosthesis and were osteotomized in an oblique plane at the level of the implant tip to simulate a Vancouver type B1 periprosthetic fracture. Fractures were fixed with a non-contact bridging periprosthetic proximal femur plate (Zimmer Inc., Warsaw, IN). Three proximal fixation methods were used: Group 1, bicortical screws; Group 2, unicortical screws and one cerclage cable; and Group 3, three cerclage cables. Distally, all groups had bicortical screws. Biomechanical testing was performed using an axial-torsional testing machine in three different loading modalities (axial compression, lateral bending, and torsional/sagittal bending), next in axial cyclic loading to 10,000 cycles, again in the three loading modalities, and finally to failure in torsional/sagittal bending. Group 1 had significantly greater load to failure and was significantly stiffer in torsional/sagittal bending than Groups 2 and 3. After cyclic loading, Group 2 had significantly greater axial stiffness than Groups 1 and 3. There was no difference between the three groups in lateral bending stiffness. The average energy absorbed during cyclic loading was significantly lower in Group 2 than in Groups 1 and 3. Bicortical screw placement achieved the highest load to failure and the highest torsional/sagittal bending stiffness. Additional unicortical screws improved axial stiffness when using cable fixation. Lateral bending was not influenced by differences in proximal fixation. To treat periprosthetic fractures, bicortical screw placement should be

  14. Nanoparticles at liquid interfaces: Rotational dynamics and angular locking

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, Sepideh; Kretzschmar, Ilona [Department of Chemical Engineering, City College of City University of New York, New York, New York 10031 (United States); Koplik, Joel [Department of Physics and The Benjamin Levich Institute for Physico-chemical Hydrodynamics, City College of City University of New York, New York, New York 10031 (United States); Colosqui, Carlos E., E-mail: carlos.colosqui@stonybrook.edu [Department of Mechanical Engineering, Stony Brook University, Stony Brook, New York 11794 (United States)

    2014-01-07

    Nanoparticles with different surface morphologies that straddle the interface between two immiscible liquids are studied via molecular dynamics simulations. The methodology employed allows us to compute the interfacial free energy at different angular orientations of the nanoparticle. Due to their atomistic nature, the studied nanoparticles present both microscale and macroscale geometrical features and cannot be accurately modeled as a perfectly smooth body (e.g., spheres and cylinders). Under certain physical conditions, microscale features can produce free energy barriers that are much larger than the thermal energy of the surrounding media. The presence of these energy barriers can effectively “lock” the particle at specific angular orientations with respect to the liquid-liquid interface. This work provides new insights on the rotational dynamics of Brownian particles at liquid interfaces and suggests possible strategies to exploit the effects of microscale features with given geometric characteristics.

  15. Dynamics of a Dispersion-Managed Passively Mode-Locked Er-Doped Fiber Laser Using Single Wall Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Norihiko Nishizawa

    2015-07-01

    Full Text Available We investigated the dynamics of a dispersion-managed, passively mode-locked, ultrashort-pulse, Er-doped fiber laser using a single-wall carbon nanotube (SWNT device. A numerical model was constructed for analysis of the SWNT fiber laser. The initial process of passive mode-locking, the characteristics of the output pulse, and the dynamics inside the cavity were investigated numerically for soliton, dissipative-soliton, and stretched-pulse mode-locking conditions. The dependencies on the total dispersion and recovery time of the SWNTs were also examined. Numerical results showed similar behavior to experimental results.

  16. This dynamic earth: the story of plate tectonics

    Science.gov (United States)

    Kious, W. Jacquelyne; Tilling, Robert I.

    1996-01-01

    In the early 1960s, the emergence of the theory of plate tectonics started a revolution in the earth sciences. Since then, scientists have verified and refined this theory, and now have a much better understanding of how our planet has been shaped by plate-tectonic processes. We now know that, directly or indirectly, plate tectonics influences nearly all geologic processes, past and present. Indeed, the notion that the entire Earth's surface is continually shifting has profoundly changed the way we view our world.People benefit from, and are at the mercy of, the forces and consequences of plate tectonics. With little or no warning, an earthquake or volcanic eruption can unleash bursts of energy far more powerful than anything we can generate. While we have no control over plate-tectonic processes, we now have the knowledge to learn from them. The more we know about plate tectonics, the better we can appreciate the grandeur and beauty of the land upon which we live, as well as the occasional violent displays of the Earth's awesome power.This booklet gives a brief introduction to the concept of plate tectonics and complements the visual and written information in This Dynamic Planet (see Further reading), a map published in 1994 by the U.S. Geological Survey (USGS) and the Smithsonian Institution. The booklet highlights some of the people and discoveries that advanced the development of the theory and traces its progress since its proposal. Although the general idea of plate tectonics is now widely accepted, many aspects still continue to confound and challenge scientists. The earth-science revolution launched by the theory of plate tectonics is not finished.

  17. Atmospheric circulation of tidally-locked exoplanets: a suite of benchmark tests for dynamical solvers

    CERN Document Server

    Heng, Kevin; Phillipps, Peter J

    2010-01-01

    The complexity of atmospheric modelling and its inherent non-linearity, together with the limited amount of data of exoplanets available, motivate model intercomparisons and benchmark tests. In the geophysical community, the Held-Suarez test is a standard benchmark for comparing dynamical core simulations of the Earth's atmosphere with different solvers, based on statistically-averaged flow quantities. In the present study, we perform analogues of the Held-Suarez test for tidally-locked exoplanets with the GFDL-Princeton Flexible Modeling System (FMS) by subjecting both the spectral and finite difference dynamical cores to a suite of tests, including the standard benchmark for Earth, a hypothetical tidally-locked Earth, a "shallow" hot Jupiter model and a "deep" model of HD 209458b. We find qualitative and quantitative agreement between the solvers for the Earth, tidally-locked Earth and shallow hot Jupiter benchmarks, but the agreement is less than satisfactory for the deep model of HD 209458b. Further inves...

  18. Continuum Modeling of the Dynamics of Externally Injection-locked Coupled Oscillator Arrays

    Science.gov (United States)

    Pogorzelski, Ronald J.; Maccarini, Paolo F.; York, Robert A.

    1999-01-01

    Mutually injection-locked arrays of electronic oscillators provide a novel means of controlling the aperture phase of a phased-array antenna, thus achieving the advantages of spatial power combining while retaining the ability to steer the radiated beam. In a number of design concepts, one or more of the oscillators are injection locked to a signal from an external master-oscillator. The behavior of such a system has been analyzed by numerical solution of a system of nonlinear differential equations which, due to its complexity, yields limited insight into the relationship between the injection signals and the aperture phase. In this paper, we develop a continuum model, which results in a single partial differential equation for the aperture phase as a function of time. Solution of the equation is effected by means of the Laplace transformation and yields detailed information concerning the dynamics of the array under the influence of the external injection signals.

  19. Simulating the frontal instability of lock-exchange density currents with dissipative particle dynamics

    Science.gov (United States)

    Li, Yanggui; Geng, Xingguo; Wang, Heping; Zhuang, Xin; Ouyang, Jie

    2016-06-01

    The frontal instability of lock-exchange density currents is numerically investigated using dissipative particle dynamics (DPD) at the mesoscopic particle level. For modeling two-phase flow, the “color” repulsion model is adopted to describe binary fluids according to Rothman-Keller method. The present DPD simulation can reproduce the flow phenomena of lock-exchange density currents, including the lobe-and-cleft instability that appears at the head, as well as the formation of coherent billow structures at the interface behind the head due to the growth of Kelvin-Helmholtz instability. Furthermore, through the DPD simulation, some small-scale characteristics can be observed, which are difficult to be captured in macroscopic simulation and experiment.

  20. Global Dynamic Numerical Simulations of Plate Tectonic Reorganizations

    Science.gov (United States)

    Morra, G.; Quevedo, L.; Butterworth, N.; Matthews, K. J.; Müller, D.

    2010-12-01

    We use a new numerical approach for global geodynamics to investigate the origin of present global plate motion and to identify the causes of the last two global tectonic reorganizations occurred about 50 and 100 million years ago (Ma) [1]. While the 50 Ma event is the most well-known global plate-mantle event, expressed by the bend in the Hawaiian-Emperor volcanic chain, a prominent plate reorganization at about 100 Ma, although presently little studied, is clearly indicated by a major bend in the fracture zones in the Indian Ocean and by a change in Pacific plate motion [2]. Our workflow involves turning plate reconstructions into surface meshes that are subsequently employed as initial conditions for global Boundary Element numerical models. The tectonic setting that anticipates the reorganizations is processed with the software GPlates, combining the 3D mesh of the paleo-plate morphology and the reconstruction of paleo-subducted slabs, elaborated from tectonic history [3]. All our models involve the entire planetary system, are fully dynamic, have free surface, are characterized by a spectacular computational speed due to the simultaneous use of the multi-pole algorithm and the Boundary Element formulation and are limited only by the use of sharp material property variations [4]. We employ this new tool to unravel the causes of plate tectonic reorganizations, producing and comparing global plate motion with the reconstructed ones. References: [1] Torsvik, T., Müller, R.D., Van der Voo, R., Steinberger, B., and Gaina, C., 2008, Global Plate Motion Frames: Toward a unified model: Reviews in Geophysics, VOL. 46, RG3004, 44 PP., 2008 [2] Wessel, P. and Kroenke, L.W. Pacific absolute plate motion since 145 Ma: An assessment of the fixed hot spot hypothesis. Journal of Geophysical Research, Vol 113, B06101, 2008 [3] L. Quevedo, G. Morra, R. D. Mueller. Parallel Fast Multipole Boundary Element Method for Crustal Dynamics, Proceeding 9th World Congress and 4th Asian

  1. Comparison and analysis of reoperations in two different treatment protocols for trochanteric hip fractures - postoperative technical complications with dynamic hip screw, intramedullary nail and Medoff sliding plate.

    Science.gov (United States)

    Paulsson, Johnny; Stig, Josefine Corin; Olsson, Ola

    2017-08-24

    In treatment of unstable trochanteric fractures dynamic hip screw and Medoff sliding plate devices are designed to allow secondary fracture impaction, whereas intramedullary nails aim to maintain fracture alignment. Different treatment protocols are used by two similar Swedish regional emergency care hospitals. Dynamic hip screw is used for fractures considered as stable within the respective treatment protocol, whereas one treatment protocol (Medoff sliding plate/dynamic hip screw) uses biaxial Medoff sliding plate for unstable pertrochanteric fractures and uniaxial Medoff sliding plate for subtrochanteric fractures, the second (intramedullary nail/dynamic hip screw) uses intramedullary nail for subtrochanteric fractures and for pertrochanteric fractures with intertrochanteric comminution or subtrochanteric extension. All orthopedic surgeries are registered in a regional database. All consecutive trochanteric fracture operations during 2011-2012 (n = 856) and subsequent technical reoperations (n = 40) were derived from the database. Reoperations were analysed and classified into the categories adjustment (percutaneous removal of the locking screw of the Medoff sliding plate or the intramedullary nail, followed by fracture healing) or minor, intermediate (reosteosynthesis) or major (hip joint replacement, Girdlestone or persistent nonunion) technical complications. The relative risk of intermediate or major technical complications was 4.2 (1.2-14) times higher in unstable pertrochanteric fractures and 4.6 (1.1-19) times higher in subtrochanteric fractures with treatment protocol: intramedullary nail/dynamic hip screw, compared to treatment protocol: Medoff sliding plate/dynamic hip screw. Overall rates of intermediate and major technical complications in unstable pertrochanteric and subtrochanteric fractures were with biaxial Medoff sliding plate 0.68%, with uniaxial Medoff sliding plate 1.4%, with dynamic hip screw 3.4% and with intramedullary nail 7.2%. The

  2. Static and dynamic buckling of thin-walled plate structures

    CERN Document Server

    Kubiak, Tomasz

    2013-01-01

    This monograph deals with buckling and postbuckling behavior of thin plates and thin-walled structures with flat wall subjected to static and dynamic load. The investigations are carried out in elastic range. The basic assumption here is the  thin plate theory. This method is used to determination the buckling load and postbuckling analysis of thin-walled structures subjected to static and dynamic load. The book introduces two methods for static and dynamic buckling investigation which allow for a wider understanding of the phenomenon. Two different methods also can allow uncoupling of the phenomena occurring at the same time and attempt to estimate their impact on the final result. A general mathematical model, adopted in proposed analytical-numerical method, enables the consideration of all types of stability loss i.e.local, global and interactive forms of buckling. The applied numerical-numerical method includes adjacent of walls, shear-lag phenomenon and a deplanation of cross-sections.

  3. Investigation of the nonlinear dynamics of a partially cracked plate

    Energy Technology Data Exchange (ETDEWEB)

    Israr, A [School of Engineering and Physical Sciences, Heriot Watt University - Dubai Campus, Block 2, Dubai International Academic City, P O Box 294345, Dubai (United Arab Emirates); Atepor, L, E-mail: a.israr@hw.ac.u, E-mail: katepor@yahoo.co [Department of Mechanical Engineering, James Watt South Building, University of Glasgow, Glasgow, G12 8QQ Scotland (United Kingdom)

    2009-08-01

    In this paper the nonlinear vibration of an aircraft panel structure modelled as an isotropic cracked plate and subjected to transverse harmonic excitation is considered for studying the dynamic response, both analytically and experimentally. A crack is arbitrarily located at the centre of the plate, consisting of a continuous line. This mathematical model is in the form of Duffing equation with a cubic nonlinear term. The perturbation method of multiple scales is used to solve the algebraic equation, and then investigated with the results of the direct integration within Mathematica{sup TM} and finite element analysis in ABAQUS for the first mode only. In addition, experimental measurements are also carried out to verify the dependence of the cracked plate's fundamental mode shape and resonance frequency on the vibration displacement amplitude. An extermely close agreement between these results is observed.

  4. Dynamics of multilayered orthotropic viscoelastic plates of Maxwell solids

    Directory of Open Access Journals (Sweden)

    P. Pal Roy

    1988-01-01

    Full Text Available This paper is concerned with a simplified dynamical analysis of orthotropic viscoelastic plates that are made up of an arbitrary number of layers each of which is a Maxwell type solid. This study includes the case where some or all the layers are themselves constituted by thinly laminated materials with couple stresses. The recurrence equations for the shear stresses are obtained for an arbitrary number of layers and then applied to plates with two or three layers. The viscoelastic damping effect is determined by the process of linearization and then illustrated by a plate composed of one, two or three layers. It is found that the damping increases with anisotropy and wave number. These results are shown by graphical representations.

  5. "Lock in accelerometry" to follow sink dynamics in shaken granular matter

    Science.gov (United States)

    Clement, Cecile; Sanchez-Colina, Gustavo; Alonso-Llanes, Laciel; Martinez-Roman, Etien; Batitsta-Leyva, Alfo-Jose; Toussaint, Renaud; Altshuler, Ernesto

    2015-04-01

    Understanding the penetration dynamics of intruders in granular beds is relevant not only for fundamental Physics, but also for geophysical processes and construction on granular soils in earthquake areas. Indeed a phenomenon named soil liquefaction can cause buildings to sink or tilt in areas separated of 1000 km from the epicentre in the worst cases. The damages on the constructions, the pipes and the roads may be huge. There is a conventional understanding of liquefaction from which scientists made theoretical and empirical laws for geotechnical use and building construction, but the dynamical penetration of buildings into the soil is still not well understood. While the penetration of intruders in 2D laboratory granular beds can be followed using video recording, it is useless in 3D beds of non-transparent materials such as common sand. Wireless accelerometry constitutes a natural alternative that has been used in very few occasions, however, it has never been used to quantify the penetration into horizontally shaken granular beds. Here we propose a method to quantify the sink dynamics of an intruder into laterally shaken, fluidized granular bed. We developped an embarked accelerometer small enough to fit into a modelized building. This sensor allows us to follow the intruder in realistic conditions namely buried in a 3D box of sand. Our method is based on the temporal correlations between the signals from a reference accelerometer fixed to the shaken granular bed, and the accelerometer deployed inside the intruder. We demonstrate that our method is able to determine the time interval of sinking of an intruder into shaken granular beds for both quasi-2D and 3D systems [1]. Due to its analogy with the working principle of a lock in amplifier, we call this technique Lock in accelerometry (LIA). In the experiments the intruder stops at a depth that we assume to be the beginning of the "jammed" granular phase. We are now developing numerical simulations based on a

  6. Tearing mode dynamics and locking in the presence of external magnetic perturbations

    Science.gov (United States)

    Fridström, R.; Munaretto, S.; Frassinetti, L.; Chapman, B. E.; Brunsell, P. R.; Sarff, J. S.

    2016-06-01

    In normal operation, Madison Symmetric Torus (MST) [R. N. Dexter et al., Fusion Technol. 19, 131 (1991)] reversed-field pinch plasmas exhibit several rotating tearing modes (TMs). Application of a resonant magnetic perturbation (RMP) results in braking of mode rotation and, if the perturbation amplitude is sufficiently high, in a wall-locked state. The coils that produce the magnetic perturbation in MST give rise to RMPs with several toroidal harmonics. As a result, simultaneous deceleration of all modes is observed. The measured TM dynamics is shown to be in qualitative agreement with a magnetohydrodynamical model of the RMP interaction with the TM [R. Fitzpatrick, Nucl. Fusion 33, 1049 (1993)] adapted to MST. To correctly model the TM dynamics, the electromagnetic torque acting on several TMs is included. Quantitative agreement of the TM slowing-down time was obtained for a kinematic viscosity in the order of νki n≈10 -20 m2/s. Analysis of discharges with different plasma densities shows an increase of the locking threshold with increasing density. Modeling results show good agreement with the experimental trend, assuming a density-independent kinematic viscosity. Comparison of the viscosity estimates in this paper to those made previously with other techniques in MST plasmas suggests the possibility that the RMP technique may allow for estimates of the viscosity over a broad range of plasmas in MST and other devices.

  7. Ultrafast non-equilibrium carrier dynamics in semiconductor laser mode-locking

    Science.gov (United States)

    Hader, J.; Scheller, M.; Laurain, A.; Kilen, I.; Baker, C.; Moloney, J. V.; Koch, S. W.

    2017-01-01

    Experimental and theoretical results on the mode-locking dynamics in vertical-external-cavity surface-emitting lasers with semiconductor and graphene saturable absorber mirrors are reviewed with an emphasis on the role of nonequilibrium carrier effects. The systems are studied theoretically using a fully microscopic many-body model for the carrier distributions and polarizations, coupled to Maxwell’s equations for the field propagation. Pump-probe measurements are performed with (sub-) 100 fs resolution. The analysis shows that the non-equilibrium carrier dynamics in the gain quantum-wells and saturable absorber medium significantly influences the system’s response and the resulting mode-locked pulses. The microscopic model is used to study the pulse build up from spontaneous emission noise and to determine the dependence of achievable pulse lengths and fluences on the amounts of saturable and non-saturable losses and the optical gain. The change of the group delay dispersion (GDD) on the pump level is examined and the dependence of the pulse lengths on the total amount of GDD is demonstrated experimentally. Theory-experiment comparisons are used to demonstrate the highly quantitative accuracy of the fully microscopic modeling.

  8. Teaching Earth Dynamics: What's Wrong with Plate Tectonics Theory?

    CERN Document Server

    Herndon, J M

    2005-01-01

    Textbooks frequently extol plate tectonics theory without questioning what might be wrong with the theory or without discussing a competitive theory. How can students be taught to challenge popular ideas when they are only presented a one-sided view? In just a few pages, I describe more than a century of geodynamic ideas. I review what is wrong with plate tectonics theory and with Earth expansion theory, and describe my new Whole-Earth Decompression Dynamics Theory, which unifies the two previous dominant theories in a self- consistent manner. Along the way, I disclose details of what real science is all about, details all too often absent in textbooks and classroom discussions. In these few pages, I only touch on highlights and just part the curtain a bit so that teachers might glimpse ways to bring to their students some of the richness and excitement of discovery that becomes evident when one begins to question prevailing, currently popular perceptions of our world.

  9. Treatment of comminuted proximal humeral fractures by locking plate%锁定钢板治疗肱骨近端粉碎性骨折

    Institute of Scientific and Technical Information of China (English)

    陈晓东; 王宇仁; 崔一民; 王栋梁; 王伟; 董海; 沈超; 何继业; 蒋雷声

    2008-01-01

    目的 了解锁定钢板治疗粉碎性肱骨近端骨折的疗效及相关手术技术.方法 2003年2月-2007年3月,采用锁定钢板治疗肱骨近端粉碎性骨折34例,其中21例采用肱骨近端锁定钢板(locking proximal humerus plate,LPHP),13例采用肱骨近端锁定系统(proximal humerus interlockingsystem,PHILOS).根据Neer分型,三部分骨折30例,四部分骨折4例.结果 术后32例获得12~36个月随访,平均18.6个月.2例失访.术后骨折均愈合,无内固定失效,骨折平均愈合时间为10周.根据Constant评分标准评定:优4例,良23例,可4例,差1例;优良率为84.4%.其中60岁以下Constant评分平均为83(77~90),60岁以上平均为72(30~86).三部分骨折评分平均为76(70~90),而四部分骨折平均为60(30~74).结论 锁定钢板是治疗肱骨近端粉碎性骨折的有效方法.肱骨近端内侧的有效支撑以及减少软组织剥离是手术成功的关键.%Objective To investigate the surgical techniques and evaluate the results of locking plate in treatment of comminuted proximal humeral fractures. Methods From February 2003 to March 2007, 34 cases of Comminuted proximal humeral fractures were treated using locking plate manufactured by Synthes (21 cases with locking proximal humerus plate, LPHP; 13 cases with proximal humerus interlocking system, PHILOS). There were 9 males and 25 females. The ages of this group ranged from 43 to 81 years, with an average of 64.7 years. According to Neer classification, there were 30 cases of three-part fractures, and 4 cases of four-part fractures. Results The follow-up period of 32 cases ranged from 12 months to 36 months, the average being 18.6 months. Two were lost for follow up. Bone union was achieved in all the cases, with the mean healing period of 10 weeks. According to Constant scoring, the excellent and good result rate was 84.4%. Conclusion Locking plate is an effective method for treating comminuted proximal humeral fractures. Mechanical

  10. Dynamic crack growth in a fiber-reinforced composite plate

    Institute of Scientific and Technical Information of China (English)

    LIU Kaixin; LIU Weifu; Zhang Jinxiang; LI Rong; ZHANG Guohua; FU Bin

    2005-01-01

    This paper reports an experiment on the failure of a precracked plate made of unidirectional glass-epoxy fiber-reinforced composites subjected to three-point bending impact load. In the experiment, the whole process of crack growth was recorded by using high-speed photographic technique, in which a transmitted light path was adopted. Moreover, a new phenomenon of dynamic fracture has been observed. Based on the results, some preliminary studies have been carried out on the rate and path of the crack growth, as well as the failure mode.

  11. Societal costs in displaced transverse olecranon fractures: using decision analysis tools to find the most cost-effective strategy between tension band wiring and locked plating.

    Science.gov (United States)

    Francis, Tittu; Washington, Travis; Srivastava, Karan; Moutzouros, Vasilios; Makhni, Eric C; Hakeos, William

    2017-09-15

    Tension band wiring (TBW) and locked plating are common treatment options for Mayo IIA olecranon fractures. Clinical trials have shown excellent functional outcomes with both techniques. Although TBW implants are significantly less expensive than a locked olecranon plate, TBW often requires an additional operation for implant removal. To choose the most cost-effective treatment strategy, surgeons must understand how implant costs and return to the operating room influence the most cost-effective strategy. This cost-effective analysis study explored the optimal treatment strategies by using decision analysis tools. An expected-value decision tree was constructed to estimate costs based on the 2 implant choices. Values for critical variables, such as implant removal rate, were obtained from the literature. A Monte Carlo simulation consisting of 100,000 trials was used to incorporate variability in medical costs and implant removal rates. Sensitivity analysis and strategy tables were used to show how different variables influence the most cost-effective strategy. TBW was the most cost-effective strategy, with a cost savings of approximately $1300. TBW was also the dominant strategy by being the most cost-effective solution in 63% of the Monte Carlo trials. Sensitivity analysis identified implant costs for plate fixation and surgical costs for implant removal as the most sensitive parameters influencing the cost-effective strategy. Strategy tables showed the most cost-effective solution as 2 parameters vary simultaneously. TBW is the most cost-effective strategy in treating Mayo IIA olecranon fractures despite a higher rate of return to the operating room. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  12. Development of the Gliding Hole of the Dynamics Compression Plate

    Science.gov (United States)

    Salim, U. A.; Suyitno; Magetsari, R.; Mahardika, M.

    2017-02-01

    The gliding hole of the dynamics compression plate is designed to facilitate relative movement of pedicle screw during surgery application. The gliding hole shape is then geometrically complex. The gliding hole manufactured using machining processes used to employ ball-nose cutting tool. Then, production cost is expensive due to long production time. This study proposed to increase productivity of DCP products by introducing forming process (cold forming). The forming process used to involve any press tool devices. In the closed die forming press tool is designed with little allowance, then work-pieces is trapped in the mould after forming. Therefore, it is very important to determine hole geometry and dimensions of raw material in order to success on forming process. This study optimized the hole sizes with both geometry analytics and experiments. The success of the forming process was performed by increasing the holes size on the raw materials. The holes size need to be prepared is diameter of 5.5 mm with a length of 11.4 mm for the plate thickness 3 mm and diameter of 6 mm with a length of 12.5 mm for the plate thickness 4 mm.

  13. Geoid Data and Implications for Plate Tectonic Dynamics

    Science.gov (United States)

    Richardson, R. M.; Coblentz, D. D.

    2013-12-01

    It has long been recognized that the motion of the mechanically rigid lithospheric plates of the earth are the surface expression of large-scale convection in the mantle. It is also accepted that the stresses driving plate motion are an amalgam of the basal tractions associated with this convection and long-wavelength density variations within the plates themselves. Parsing the relative contribution from these two sources to the geodynamics of the lithosphere continues to be an important topic of plate dynamics research. Because geoid anomalies are directly related to the local dipole moment of the density-depth distribution, they provide an ideal method for evaluating density variations within the lithosphere and the associated tectonic stresses. The main challenge with this approach is isolating the lithospheric geoid contribution from the full geoid (which is dominated by sources from deeper in the earth, namely the lower mantle). We address this issue by using a high-pass spherical harmonic filtering of the EGM2008-WGS84 geoid (which is complete to spherical harmonic degree and order 2159), with a cosine taper between orders 9 to 13 and 78 to 82 to produce a 'lithospheric' geoid. In the present study we focus on tectonic implications of the lithospheric geoid in three different areas: 1) passive continental margins where we have evaluated over 150 margin-transects spaced roughly every three degrees. The global average geoid anomaly associated with the transition from old oceanic lithosphere to the continent was found to 6-9 meters and appears to be insensitive to a range of geoid filtering degrees and orders; 2) The geoid highs associated with the mid-ocean ridges and the cooling oceanic lithospheric, where we have examined a number of geoid profiles across ridges and find that previous estimates of a geoid anomaly of 10-15 meters associated with ridges to be valid; and 3) continental regions which are characterized by both elevated geoid anomalies (e.g., the

  14. Dynamics of soliton explosions in passively mode-locked fiber lasers

    CERN Document Server

    Runge, Antoine F J; Erkintalo, Miro

    2015-01-01

    A soliton explosion is an instability whereby a dissipative soliton undergoes a sudden structural collapse, but remarkably returns back to its original shape after a short transient. We recently reported the first experimental observation of this effect in a fiber laser (A. F. J. Runge et al., Optica 2, 36 (2015)). Here, we expand on our initial work, presenting a more detailed experimental and numerical study of the characteristics and dynamics of soliton explosions in passively mode-locked fiber lasers. Specifically, we explore different cavity configurations and gain levels, observing and characterizing explosion events using spectral and temporal real-time single-shot techniques. Our results highlight that the explosion characteristics observed in experiments depend critically on the position in the cavity where the output coupler is located. Furthermore, we find that the frequency at which explosions occur can be controlled by adjusting the pump power. We also identify a new kind of ``partial'' explosion...

  15. Synchronous digitization for high dynamic range lock-in amplification in beam-scanning microscopy

    Science.gov (United States)

    Muir, Ryan D.; Sullivan, Shane Z.; Oglesbee, Robert A.; Simpson, Garth J.

    2014-01-01

    Digital lock-in amplification (LIA) with synchronous digitization (SD) is shown to provide significant signal to noise (S/N) and linear dynamic range advantages in beam-scanning microscopy measurements using pulsed laser sources. Direct comparisons between SD-LIA and conventional LIA in homodyne second harmonic generation measurements resulted in S/N enhancements consistent with theoretical models. SD-LIA provided notably larger S/N enhancements in the limit of low light intensities, through the smooth transition between photon counting and signal averaging developed in previous work. Rapid beam scanning instrumentation with up to video rate acquisition speeds minimized photo-induced sample damage. The corresponding increased allowance for higher laser power without sample damage is advantageous for increasing the observed signal content. PMID:24689588

  16. Synchronous digitization for high dynamic range lock-in amplification in beam-scanning microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Muir, Ryan D.; Sullivan, Shane Z.; Oglesbee, Robert A.; Simpson, Garth J., E-mail: gsimpson@purdue.edu [Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907 (United States)

    2014-03-15

    Digital lock-in amplification (LIA) with synchronous digitization (SD) is shown to provide significant signal to noise (S/N) and linear dynamic range advantages in beam-scanning microscopy measurements using pulsed laser sources. Direct comparisons between SD-LIA and conventional LIA in homodyne second harmonic generation measurements resulted in S/N enhancements consistent with theoretical models. SD-LIA provided notably larger S/N enhancements in the limit of low light intensities, through the smooth transition between photon counting and signal averaging developed in previous work. Rapid beam scanning instrumentation with up to video rate acquisition speeds minimized photo-induced sample damage. The corresponding increased allowance for higher laser power without sample damage is advantageous for increasing the observed signal content.

  17. Formation and removal of apical vapor lock during syringe irrigation: a combined experimental and Computational Fluid Dynamics approach

    NARCIS (Netherlands)

    Boutsioukis, C.; Kastrinakis, E.; Lambrianidis, T.; Verhaagen, B.; Versluis, M.; Sluis, van der L.W.M.

    2014-01-01

    Aim (i) To evaluate the effect of needle type and insertion depth, root canal size and irrigant flow rate on the entrapment of air bubbles in the apical part of a root canal (apical vapor lock) during syringe irrigation using experiments and a Computational Fluid Dynamics (CFD) model, (ii) to invest

  18. Formation and removal of apical vapor lock during syringe irrigation : a combined experimental and Computational Fluid Dynamics approach

    NARCIS (Netherlands)

    Boutsioukis, C.; Kastrinakis, E.; Lambrianidis, T.; Verhaagen, B.; Versluis, M.; van der Sluis, L. W. M.

    2014-01-01

    Aim(i) To evaluate the effect of needle type and insertion depth, root canal size and irrigant flow rate on the entrapment of air bubbles in the apical part of a root canal (apical vapor lock) during syringe irrigation using experiments and a Computational Fluid Dynamics (CFD) model, (ii) to investi

  19. 应用锁定钢板治疗股骨转子间骨折%Treatment of intertrochanteric fracture with proximal femoral lock plate

    Institute of Scientific and Technical Information of China (English)

    李志洲; 徐衍斌; 王再欣; 于欣; 周凤吉; 季晓风

    2012-01-01

    Objective To evaluate retrospectively the effect for treatment of intertrochanteric comminuted fracture with lock plate. Methods A retrospective analysis was conduced to investigate 237 cases of intertrochanteric comminuted fracture which were treated with femoral lock plate from April 2007 to February 2010 , we evaluated the bone union time and hip function of the 210 patients whom were well followed up for average 12.5months (from 6 to 34months). Results This operation is easy to manage, with the advantage of stable fixation, the average union time was 21 weeks (range 12 to 32 weeks). Superficial vein thrombosis in 12 cases, decubitus ulcer in 3 cases, pneumonia in 4 cases, varus deformation in 2 cases were found, 10 patients were changed to hip arthroplasty surgery. The end results were 161 excellent, 18 good, based on Harris hip scale. Conclusion Excellent clinical effects can be achieved if the patients are treated correctly, femoral lock plate may be a better option for the treatment of intertrochanteric comminuted fracture.%目的 回顾分析锁定钢板治疗股骨转子间粉碎性骨折疗效.方法 2007 年4 月~ 2010年2月应用锁定钢板治疗237 例转子间粉碎性骨折患者,回顾分析其中210 例获得随访患者临床疗效,平均随访12.5 个月( 6~34月),观察骨折愈合时间,髋关节功能恢复情况.结果 平均骨折愈合时间21周(12~32 周),发生浅静脉血栓12例,褥疮3例,肺内感染4例,髋内翻2 例,改行人工关节置换10例.按照Harris 评分髋关节功能优161 例,良18 例,可19例,差12 例.结论 应用锁定钢板治疗转子间粉碎性骨折,手术操作简单,固定稳定,能够获得良好的临床疗效,是治疗转子间粉碎性骨折的较好选择.

  20. Plate Motions Predicted from Global Dynamic Models and Seismic Tomography: The Problem of North American Plate Motion

    Science.gov (United States)

    Liu, S.; King, S. D.; Adam, C. M.

    2016-12-01

    Seismic tomography is a snapshot of the mantle convection system and provides important constraints on Earth's internal dynamics. An increasing number of global seismic tomography models along with various rheological structures have been used to compute mantle flow pattern and the resulting surface expressions, including dynamic topography and geoid. Accurately predicting the plate motion from the mantle dynamic models is a challenge particularly with the newest generation of seismic tomography models (e.g., S40RTS, SAVANI), especially for the North American plate which only has a little subduction along it's boundary. The difficulties include the uncertainty of the velocity-to-density scaling, discrepancies between different seismic tomography models, and the computational technology to solve for global mantle flow with observationally constrained high resolution models. We use the code ASPECT (Advanced Solver for Problems in Earth CovecTion) to make a series of tests to derive mantle flow pattern from different global seismic tomography models and rheological structures. We further make a quantitative statistical comparison between the modeled and observed plate motions in terms of flow magnitude, flow direction, and plateness within each plate area. We investigate how the velocity-to-density scaling, the features of seismic tomography models, and the lateral rheological structures of the lithosphere and upper mantle influence the modeled plate motions. We find that the velocity-to-density scaling mainly changes the flow magnitude and has little impact on the flow direction. The results of different seismic tomography models are similar broadly but can be quite different in some regions. The presence of lateral viscosity variations including stiff cratons, weak plate boundary zones, and high viscosity slabs along with density variations from seafloor age and subducting slabs can improve the fit to observed plate motions. With a very small fraction of subduction

  1. Fixation of complex proximal humeral fractures in elderly patients with a locking plate: A retrospective analysis of radiographic and clinical outcome and complications

    Institute of Scientific and Technical Information of China (English)

    Fabio Rodia; Emmanouil Theodorakis; Georgios Touloupakis; Angelo Ventura

    2016-01-01

    Purpose:The optimal surgical treatment of displaced type B and C fractures of the proximal humerus in the elderly remains controversial.Good clinical results have been reported by plating these fractures as well as a high rate of complications.Our retrospective study aims to evaluate clinical recovery and complications using the S3 locking plate in elderly patients.Methods:Fifty-one patients older than 65 years of age,with a complex proximal humeral fracture type B or C (AO classification system),were included.Patients have been followed up for a minimum of 12 months.We assessed callus formation,radiological results,clinical outcome (according to the Constant Shoulder Score System) and complications.Any difference in the clinical recovery among the 2 types of fracture pattern (B and C) was investigated.Results:The mean time of fracture healing was 12.4 weeks.The mean Constant score at 3,6 and 12 months was 68,73 and 75 respectively.No statistically significant difference in the clinical outcome was observed between the B and C fracture patterns (p > 0.05).We noticed an overall of 5 complications (9.8%).There was no need to revision any of the implants.Conclusion:Anatomic reduction and proper plate positioning are essential for minimizing implantrelated complications.In our experience the S3 angular stability system offers a proper osteosyntesis and a good clinical recovery with a low rate of complications.

  2. Dynamic initiation and propagation of cracks in unidirectional composite plates

    Science.gov (United States)

    Coker, Demirkan

    Dynamic crack growth along weak planes is a significant mode of failure in composites and other layered/sandwiched structures and is also the principal mechanism of shallow crustal earthquakes. In order to shed light on this phenomenon dynamic crack initiation and propagation characteristics of a model fiber-reinforced unidirectional graphite/epoxy composite plate was investigated experimentally. Dynamic fracture experiments were conducted by subjecting the composite plates to in-plane, symmetric and asymmetric, impact loading. The lateral shearing interferometric technique of coherent gradient sensing (CGS) in conjunction with high-speed photography was used to visualize the failure process in real time. It was found that mode-I cracks propagated subsonically with crack speeds increasing to the neighborhood of the Rayleigh wave speed of the composite. Also in mode-I, the dependence of the dynamic initiation fracture toughness on the loading rate was determined and was found to be constant for low loading rates and to increase rapidly above K˙dI>10 5 . The dynamic crack propagation toughness, KID, was observed to decrease with crack tip speed up to the Rayleigh wave speed of the composite. For asymmetric, mode-II, types of loading the results revealed highly unstable and intersonic shear-dominated crack growth along the fibers. These cracks propagated with unprecedented speeds reaching 7400 m/s which is the dilatational wave speed of the composite along the fibers. For intersonic crack growth, the interferograms, featured a shock wave structure typical of disturbances traveling with speeds higher than one of the characteristic wave speeds in the solid. In addition high speed thermographic measurements are conducted that show concentrated hot spots behind the crack tip indicating non-uniform crack face frictional contact. In addition, shear dominated dynamic crack growth is investigated along composite/Homalite interfaces subjected to impact loading. The crack

  3. Droplets sliding down inclined planes: unexpected dynamics on elastomer plates

    Science.gov (United States)

    Hourlier-Fargette, Aurelie; Antkowiak, Arnaud; Neukirch, Sebastien

    2016-11-01

    Droplet dynamics on an angled surface results from a competition between the weight of the droplet, capillary forces, and viscous dissipation inside the drop. The motion of droplets on stiff surfaces has been investigated for a long time, both experimentally and theoretically, while recent studies have shown the interesting physics underlying the sliding of droplets on soft surfaces. We focus on the dynamics of water-glycerol mixture droplets sliding down vertical plates of silicone elastomers, highlighting an unexpected behavior: the droplet dynamics on such a surface includes two regimes with different constant speeds. These results contrast with those found in the literature for droplets sliding on materials such as treated glass. We investigate the universality of this behavior on various elastomers, and study in detail the two regimes and the sharp transition observed between them. Different candidates can be responsible for the sudden speed change: bistability, chemical interaction with the substrate, softness of the material, etc. Our experiments to clarify the role of each of them reveal an unexpected link between microscopic phenomena at the scale of the polymer matrix and the macroscopic dynamics of a droplet.

  4. Spatiotemporal dynamics of a digital phase-locked loop based coupled map lattice system

    Science.gov (United States)

    Banerjee, Tanmoy; Paul, Bishwajit; Sarkar, B. C.

    2014-03-01

    We explore the spatiotemporal dynamics of a coupled map lattice (CML) system, which is realized with a one dimensional array of locally coupled digital phase-locked loops (DPLLs). DPLL is a nonlinear feedback-controlled system widely used as an important building block of electronic communication systems. We derive the phase-error equation of the spatially extended system of coupled DPLLs, which resembles a form of the equation of a CML system. We carry out stability analysis for the synchronized homogeneous solutions using the circulant matrix formalism. It is shown through extensive numerical simulations that with the variation of nonlinearity parameter and coupling strength the system shows transitions among several generic features of spatiotemporal dynamics, viz., synchronized fixed point solution, frozen random pattern, pattern selection, spatiotemporal intermittency, and fully developed spatiotemporal chaos. We quantify the spatiotemporal dynamics using quantitative measures like average quadratic deviation and spatial correlation function. We emphasize that instead of using an idealized model of CML, which is usually employed to observe the spatiotemporal behaviors, we consider a real world physical system and establish the existence of spatiotemporal chaos and other patterns in this system. We also discuss the importance of the present study in engineering application like removal of clock-skew in parallel processors.

  5. Development and clinical application of locking plate positioning connector%锁定钢板定位连接器的研制与临床应用

    Institute of Scientific and Technical Information of China (English)

    杨鹏; 翟睿; 史建民

    2012-01-01

    目的 设计一种锁定钢板的定位连接装置,探讨其在应用MIPPO技术治疗中的优越性.方法 将自制锁定钢板定位连接器应用于40例下肢骨折患者手术中,其中胫腓骨骨折18例,股骨近端骨折12例,股骨远端骨折10例.结果 40例手术均顺利完成,术中未发生定位偏差;切口长度7.3~16.5(12.2±2.24)cm,术中出血量80~310(110±25)ml,术后住院时间3~12(6±2.1)d.患者均获随访,时间6~26(12±2.4)个月.骨折均骨性愈合,时间5~7个月.1例术后出现腓浅神经麻痹.结论 锁定钢板定位连接器的应用能准确定位皮下钢板钉孔,减小手术切口和术中出血量,缩短患者住院时间,是锁定钢板微创手术中一个实用小工具.%Objective To design of a locking plate positioning and connecting device, and to discuss the application of MIPPO technology. Methods Self locking plate locating connector was used in 40 cases of lower limb fracture patients in operation, including 18 cases of tibia and fibula fractures, proximal femoral fracture in 12 cases, 10 cases of distal femoral fractures. Results 40 cases of laparoscopic operation were successful, with no positional deviation; operation incision length 7. 3 ~ 16. 5( 12. 2 ±2. 24 ) cm, intraoperative bleeding volume 80 ~310( 110 ±25 ) ml,postoperative hospital stay was 3~12(6±2. 1) days. All cases were followed up for 6 ~ 26( 12 ± 2. 4 ) months, the fractures were healed, 5 to 7 months; 1 case of postoperative superficial peroneal nerve palsy. Conclusions Application of locking plate locating connector can be accurately positioned subcutaneously steel nail hole, which can reduce the operation incision and bleeding in the operation, shorten the time of hospitalization. It is a locking plate of minimally invasive operation in a practical gadget.

  6. Hidden attractors in dynamical models of phase-locked loop circuits: Limitations of simulation in MATLAB and SPICE

    Science.gov (United States)

    Kuznetsov, N. V.; Leonov, G. A.; Yuldashev, M. V.; Yuldashev, R. V.

    2017-10-01

    During recent years it has been shown that hidden oscillations, whose basin of attraction does not overlap with small neighborhoods of equilibria, may significantly complicate simulation of dynamical models, lead to unreliable results and wrong conclusions, and cause serious damage in drilling systems, aircrafts control systems, electromechanical systems, and other applications. This article provides a survey of various phase-locked loop based circuits (used in satellite navigation systems, optical, and digital communication), where such difficulties take place in MATLAB and SPICE. Considered examples can be used for testing other phase-locked loop based circuits and simulation tools, and motivate the development and application of rigorous analytical methods for the global analysis of phase-locked loop based circuits.

  7. Outcomes and financial implications of intra-articular distal radius fractures: a comparative study of open reduction internal fixation (ORIF) with volar locking plates versus nonoperative management.

    Science.gov (United States)

    Toon, Dong Hao; Premchand, Rex Antony Xavier; Sim, Jane; Vaikunthan, Rajaratnam

    2017-02-02

    To evaluate the functional and radiographic outcomes, as well as the treatment costs, of closed displaced intra-articular distal radius fractures treated with either open reduction internal fixation (ORIF) with volar locking plates or nonoperative treatment with plaster cast immobilisation. A total of 60 patients (32 receiving ORIF, 28 receiving nonoperative treatment) with closed intra-articular distal radius fractures were included. The mean age was 52.1 and 57.4, respectively. Functional and radiographic assessments were carried out at 12 months post-injury. Patients' treatment costs, median salaries and lengths of medical leave were obtained. DASH and MAYO wrist score in the ORIF group did not differ significantly from those in the nonoperative group. Apart from superior ulnar deviation in the ORIF group (p = 0.0096), differences in the range of motion of the injured wrists were not significant. Similarly, there were no significant differences in grip strength and visual analog scale for pain. Volar tilt (p = 0.0399), radial height (p = 0.0087), radial inclination (p = 0.0051) and articular step-off (p = 0.0002) were all significantly superior in the ORIF group. There was a 37-fold difference in mean treatment costs between ORIF (SGD 7951.23) and nonoperative treatment (SGD 230.52). Our study shows no difference in overall functional outcomes at 12 months for closed displaced intra-articular distal radius fractures treated with either ORIF with volar locking plates or plaster cast immobilisation, and this is independent of radiographic outcome. A longer follow-up, nevertheless, is needed to determine whether the development of post-traumatic arthritis will have an effect on function. The vast difference in treatment costs should be taken into consideration when deciding on the treatment option. Level 3.

  8. The 2014 Iquique Chile earthquake: Preparatory breaking processes of a locked asperity and natural constraints for fluid migration along the plate interface

    Science.gov (United States)

    Moreno, M.; Li, S.; Angiboust, S.; Schurr, B.; Bedford, J. R.; Oncken, O.

    2015-12-01

    Variations in pore fluid pressure are of paramount importance in controlling fault stability. Recent studies have focused on investigating the underlying causes of pore fluid pressure, but natural constraints for lateral fluid migration have not yet been described. Here, we investigate the evolution of the plate interface kinematics and fluid pressure migration leading up to the Mw 8.1 Iquique earthquake. We present the deformation evolution of the last decade from a combination of ~40 continuous and ~70 survey-type GPS. The slip distribution of Iquique event covered areas that were previously intermediately to highly locked and enclosed by creeping interface zones. The seismicity recorded in the years before the mainshock tended to encircle the central locked patch (~40 km length asperity), which itself exhibited a low amount of seismicity. This earthquake was preceded by a series of foreshocks and transient deformation that was initiated by an Mw=6.7 event and which lasted for 16 days. The observed transient GPS signals can be explained by deformation due to foreshocks, indicating that slow slip was not a dominant factor in the stress build up that led to the mainshock. Foreshocks initiated at the edge of the asperity and migrated along the plate interface towards the mainshock hypocentre. The spatial and temporal proximity to the mainshock, as well as the migration pattern of events suggest that the foreshocks and mainshock were mechanically coupled. We suggest that the Mw 6.7 (that likely occurred on a splay fault) is responsible for a transient pore fluid pressure increase in the plate interface region, hence diminishing the effective normal stress on the interface. This segment of the plate interface, presumably mechanically weakened by near-lithostatic pore fluid pressures, was subsequently subjected to a propagation of foreshocks. We propose that the 16-days seismicity swarm could represent the lateral propagation of a fluid front through the place

  9. Hemiarthroplasty versus angle-stable locking compression plate osteosynthesis in the treatment of three- and four-part fractures of the proximal humerus in the elderly : design of a randomized controlled trial

    NARCIS (Netherlands)

    Verbeek, Paul A.; van den Akker-Scheek, Inge; Wendt, Klaus W.; Diercks, Ron L.

    2012-01-01

    Background: The optimal surgical management of dislocated three- and four-part fractures of the proximal humerus in elderly patients remains unclear. Most used techniques are hemiarthroplasty and angle-stable locking compression plate osteosynthesis. In the current literature there is no evidence av

  10. Dynamic Stability of Viscoelastic Plates with Finite Deformation and Shear Effects

    Institute of Scientific and Technical Information of China (English)

    李晶晶; 程昌钧; 等

    2002-01-01

    Based on Reddy's theory of plates with higher-order shear deformations and the Boltzmann superposition principles,the governing equations were established for dynamic stability of viscoelastic plates with finite deformations taking account of shear effects,The Galerkin method was applied to simplify the set of equations.The numerical methods in nonlinear dynamics were used to solve the simplified system.It could e seen that there are plenty of dynamic properties for this kind of viscoelastic plates under transverse harmonic loads.The influences of the transverse shear deformations and material parameter on the dynamic behavior of nonlinear viscoelatic plates were investigated.

  11. Orion锁定型颈椎前路钢板系统的临床应用%Clinical application of Orion anterior cervical locking plate system

    Institute of Scientific and Technical Information of China (English)

    郭澄水; 蒋学金; 陈新良; 韩国华; 孔祥飞

    2001-01-01

    Objective To evaluate the clinical application of Orion anterior cervical locking plate system in cervical injuries and cervical spondylous myelopathy. Methods 3 cervical spinal fractures and 2 cervical spondylous myelopathy were treated by anterior decompression, autografting and Orion plate fixation. Results 5 cases were followed up for 4~12 months. Bone graft was completely fused without complications of broken plate or loosening screw. Conclusion Orion plate can offer cervical stability after anterior decompression and bone grafting. It is easy to apply and suitable for the treatment of cervical fractures with spinal cord injuries.%目的探讨Orion锁定型颈椎前路钢板系统对颈椎骨折和脊髓型颈椎病手术固定的效果。方法对3例颈椎骨折合并高位截瘫和2例脊髓型颈椎病患者施行颈椎前路减压植骨融合及Orion钢板内固定。结果术后随访4~12个月,植骨已完全融合,无钢板断裂、螺钉松动等情况发生。结论 Orion锁定型颈椎前路钢板系统方法简单、容易掌握,内固定牢固,尤其适用于颈椎骨折伴高位截瘫患者的内固定治疗。

  12. Radio-over-fiber DSB-to-SSB conversion using semiconductor lasers at stable locking dynamics.

    Science.gov (United States)

    Hsieh, Kun-Lin; Hung, Yu-Han; Hwang, Sheng-Kwang; Lin, Chien-Chung

    2016-05-01

    In radio-over-fiber systems, optical single-sideband (SSB) modulation signals are preferred to optical double-sideband (DSB) modulation signals for fiber distribution in order to mitigate the microwave power fading effect. However, typically adopted modulation schemes generate DSB signals, making DSB-to-SSB conversion necessary before or after fiber distribution. This study investigates a semiconductor laser at stable locking dynamics for such conversion. The conversion relies solely on the nonlinear dynamical interaction between an input DSB signal and the laser. Only a typical semiconductor laser is therefore required as the key conversion unit, and no pump or probe signal is necessary. The conversion can be achieved for a broad tunable range of microwave frequency up to at least 60 GHz. In addition, the conversion can be carried out even when the microwave frequency, the power of the input DSB signal, or the frequency of the input DSB signal fluctuates over a wide range, leading to high adaptability and stability of the conversion system. After conversion, while the microwave phase quality, such as linewidth and phase noise, is mainly preserved, a bit-error ratio down to 10-9 is achieved for a data rate up to at least 8 Gb/s with a detection sensitivity improvement of more than 1.5 dB.

  13. Dynamic Analysis of Modifications to Simple Plate Tectonic Theory

    Science.gov (United States)

    Paczkowski, Karen

    A number of geological and geophysical observations suggest significant departures from simple, first-order plate tectonic theory. In this thesis we address the dynamic implications of some of these observations and propose generalized theories to explain their dynamics and conditions of formation. In Chapter 2, we develop a generalized theory and analytic model to predict the conditions under which large-volume removal of continental lithosphere can occur through the formation of drip instabilities. Using damage physics relevant for Earth, we find a large portion of the lithosphere may be mobilized and entrained into growing drip instabilities. For a critical amount of damage, the growth is accelerated sufficiently that large-volume drip instabilities may form within geologically feasible time frames. Our model suggests large-volume lithospheric drip instabilities may arise independently of tectonic settings through damage-assisted mobilization and entrainment of the highly viscous lithosphere. In Chapter 3, we develop a mechanical model independent of volcanism and thermal weakening to explain the initial formation and length scale of rifting and extension near convergent plate boundaries. We conduct a linear stability analysis of a simple viscous necking model, which includes the lithosphere's negative buoyancy, non-Newtonian rheology, and freely moving top surface, to determine which properties of the lithosphere govern the location of rifting. We find that the negative buoyancy of the lithosphere promotes the formation of rifting structures when simple Newtonian viscosities are present. However, localized weakening, introduced through a power law exponent, is required to generate realistic rifting length scales. Our model suggests that the initial location of rifting in the overriding plate at subduction zones is primarily due to the mechanical extension induced by rollback of the subducting slab. In Chapter 4, we propose a theory to explain the seismic

  14. Nonlinear dynamic buckling of stiffened plates under in-plane impact load

    Institute of Scientific and Technical Information of China (English)

    张涛; 刘土光; 赵耀; 罗家智

    2004-01-01

    This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stresses of stiffeners and in-plane displacement are neglected. Appling the Hamilton's principle, the motion equations of stiffened plates are obtained. The deflection of the plate is taken as Fourier series, and using Galerkin method the discrete equations can be deduced, which can be solved easily by Runge-Kutta method. The dynamic buckling loads of the stiffened plates are obtained form Budiansky-Roth criterion.

  15. DYNAMIC BUCKLING OF STIFFENED PLATES UNDER FLUID-SOLID IMPACT LOAD

    Institute of Scientific and Technical Information of China (English)

    张涛; 刘土光; 熊有伦; 张维衡

    2004-01-01

    A simple solution of the dynamic buckling of stiffened plates under fluid-solid impact loading is presented. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stresses of stiffeners and in-plane displacement are neglected. Applying the Hamilton' s principle, the motion equations of stiffened plates are obtained. The deflection of the plate is taken as Fourier series, and using Galerkin method,the discrete equations can be deduced, which can be solved easily by Runge-Kutta method.The dynamic buckling loads of the stiffened plates are obtained from Budiansky-Roth ( B-R )curves.

  16. The dynamic flexibility method in structural dynamics: Application to nonuniform beams and plates and to cavity-backed plates

    Science.gov (United States)

    Lee, Jinkyo

    1993-01-01

    Efficient and accurate analytical or semi-analytical solutions have been developed for the dynamics of one and two dimensional linear structures employing elemental dynamic flexibility formulation. This dissertation is divided into three parts. In the first, the elemental flexibility formulation is developed for Euler-Bernoulli beams having discontinuous section properties, which can be viewed as the synthesis of uniform beams, and the exactness of the solution is established. In the second, the elemental flexibility formulation is extended to thin rectangular plates having Levy boundary conditions, and conditions under which the exact solution can be achieved are presented. In the third, the structural-acoustic problem of Helmholtz fluid enclosed by a partially flexible cavity is posed and solved. Here, a concise analytical representation of the structural dynamics is used in conjunction with a boundary element approach for the fluid medium to give an efficient and accurate semi-analytical solution. All three sections are organized along similar lines. Following an introduction and review of the pertinent literature, the governing equations are derived and solved, a series of example problems is presented, the results from the examples are compared with similar results from the literature, and efficacy of the method when compared with other methods is discussed. This is followed by a general conclusions section and a series of appendices.

  17. Analysis of interlaminar stress and nonlinear dynamic response for composite laminated plates with interfacial damage

    Science.gov (United States)

    Zhu, F. H.; Fu, Y. M.

    2008-12-01

    By considering the effect of interfacial damage and using the variation principle, three-dimensional nonlinear dynamic governing equations of the laminated plates with interfacial damage are derived based on the general six-degrees-of-freedom plate theory towards the accurate stress analysis. The solutions of interlaminar stress and nonlinear dynamic response for a simply supported laminated plate with interfacial damage are obtained by using the finite difference method, and the results are validated by comparison with the solution of nonlinear finite element method. In numerical calculations, the effects of interfacial damage on the stress in the interface and the nonlinear dynamic response of laminated plates are discussed.

  18. Dynamic stiffness matrix of a rectangular plate for the general case

    Science.gov (United States)

    Banerjee, J. R.; Papkov, S. O.; Liu, X.; Kennedy, D.

    2015-04-01

    The dynamic stiffness matrix of a rectangular plate for the most general case is developed by solving the bi-harmonic equation and finally casting the solution in terms of the force-displacement relationship of the freely vibrating plate. Essentially the frequency dependent dynamic stiffness matrix of the plate when all its sides are free is derived, making it possible to achieve exact solution for free vibration of plates or plate assemblies with any boundary conditions. Previous research on the dynamic stiffness formulation of a plate was restricted to the special case when the two opposite sides of the plate are simply supported. This restriction is quite severe and made the general purpose application of the dynamic stiffness method impossible. The theory developed in this paper overcomes this long-lasting restriction. The research carried out here is basically fundamental in that the bi-harmonic equation which governs the free vibratory motion of a plate in harmonic oscillation is solved in an exact sense, leading to the development of the dynamic stiffness method. It is significant that the ingeniously sought solution presented in this paper is completely general, covering all possible cases of elastic deformations of the plate. The Wittrick-Williams algorithm is applied to the ensuing dynamic stiffness matrix to provide solutions for some representative problems. A carefully selected sample of mode shapes is also presented.

  19. 重建锁定接骨钢板治疗肩胛骨骨折的临床效果观察%Observation of clinical effect by reconstruction locking plate in the treatment of scapular fracture

    Institute of Scientific and Technical Information of China (English)

    魏树刚

    2015-01-01

    ObjectiveTo research and analyze clinical effect by reconstruction locking plate in the treatment of scapular fracture.MethodsA total of 68 scapular fracture patients were randomly divided into reconstruction fixation group and locking fixation group, with 34 cases in each group. The reconstruction fixation group received reconstruction locking plate for treatment, and the locking fixation group received T-type locking titanium plate internal fixation. Curative effects of the two groups were recorded and compared.ResultsThe reconstruction fixation group had total effective rate as 97.06%, and the locking fixation group had that as 70.59%. The reconstruction fixation group had obviously higher total effective rate than the locking fixation group, and their difference had statistical significance (P<0.05).ConclusionReconstruction locking plate provides precise effect in treating scapular fracture, and it is worthy of clinical promotion.%目的:研究分析采用重建锁定接骨钢板技术治疗肩胛骨骨折的临床效果。方法68例肩胛骨骨折患者随机分为重建固定组和锁定固定组,各34例。其中重建固定组给予重建锁定接骨钢板治疗,锁定固定组给予T型锁定钛板内固定治疗,分别记录两组患者的治疗效果,并比较。结果重建固定组总有效率为97.06%,锁定固定组总有效率为70.59%,重建固定组总有效率明显高于锁定固定组,差异具有统计学意义(P<0.05)。结论重建锁定接骨钢板技术治疗肩胛骨骨折效果明显,值得临床推广。

  20. Connecting the dots II: Phase changes in the climate dynamics of tidally locked terrestrial exoplanets

    CERN Document Server

    Carone, Ludmila; Decin, Leen

    2015-01-01

    We investigate 3D atmosphere dynamics for tidally locked terrestrial planets with an Earth-like atmosphere and irradiation for different rotation periods ($P_{rot}=1-100$ days) and planet sizes ($R_P=1-2 R_{Earth}$) with unprecedented fine detail. We could precisely identify three climate state transition regions that are associated with phase transitions in standing tropical and extra tropical Rossby waves. We confirm that the climate on fast rotating planets may assume multiple states ($P_{rot}\\leq 12$ days for $R_P=2 R_{Earth}$). Our study is, however, the first to identify the type of planetary wave associated with different climate states: The first state is dominated by standing tropical Rossby waves with fast equatorial superrotation. The second state is dominated by standing extra tropical Rossby waves with high latitude westerly jets with slower wind speeds. For very fast rotations ($P_{rot}\\leq 5$~days for $R_P=2 R_{Earth}$), we find another climate state transition, where the standing tropical and ...

  1. Dynamics of semi-superfluid fluxtubes in color-flavor locked quark matter

    CERN Document Server

    Alford, Mark G

    2016-01-01

    At very high densities, as for example in the core of a neutron star, matter may appear in the color-flavor locked (CFL) phase, which is a superfluid. This phase features topologically stable vortex solutions, which arise in a spinning superfluid as localized configurations carrying quanta of angular momentum. Despite the topological stability of these vortices they are not the lowest energy state of the system at neutron star densities and decay into triplets of semi-superfluid fluxtubes. In these proceedings we report on the progress of our numerical study in the Ginzburg-Landau approach, where we investigate lattices of semi-superfluid fluxtubes. The fluxtubes are obtained through controlled decay of global vortex configurations in the presence of a gauge field. Understanding the dynamics of semi-superfluid string configurations is important in the context of angular momentum transfer from a quark matter core of a neutron star beyond the core boundary, since not vortex-, but fluxtube pinning seems to be th...

  2. Chiral fermion dynamics in 2d magnetic vortices: Manifestation of momentum-spin-locking

    Science.gov (United States)

    Pötz, W.; Hammer, René

    2016-11-01

    The electronic surface-states of a topological insulator in the presence of an in-plane magnetization vortex M (ϕ)=M (cos(Φ+νϕ), sin(Φ+νϕ)) are investigated theoretically. For a general angle of magnetization Φ∈[0 ,2 π) and topological charge ν = 1, the modifications to the zero-mass single Dirac cone dispersion are treated exactly and the spectrum of bound eigenstates which forms in the energy window ±M cos(Φ) is derived. The space-time resolved dynamics of Dirac fermions in the presence of such vortices is studied numerically using a single-cone (2 + 1)D finite-difference scheme. In the continuous spectral region, Φ-dependent scattering of Dirac fermions at the vortex is observed. Depending on the type of vortex ( Φ, ν) and the impact parameter, the propagation direction of the Dirac fermion is changed: the magnetization of the vortex exerts a torque onto the fermion spin which, by momentum-spin locking associated with the helical Dirac states, results in an in-plane rotation of the propagation direction of the scattered Dirac fermion. In head-on collisions of a Gaussian wave-packet with ν = 1 vortices a Φ-dependent lensing effect is seen in our simulations. Depending on the direction of incidence, the vortex Φ=-π/2 , ν = 2 is identified as a coherent particle-beam splitter or "condenser" in head-on collisions.

  3. Linking mantle dynamics, plate tectonics and surface processes in the active plate boundary zones of eastern New Guinea (Invited)

    Science.gov (United States)

    Baldwin, S.; Moucha, R.; Fitzgerald, P. G.; Hoke, G. D.; Bermudez, M. A.; Webb, L. E.; Braun, J.; Rowley, D. B.; Insel, N.; Abers, G. A.; Wallace, L. M.; Vervoort, J. D.

    2013-12-01

    Eastern New Guinea lies within the rapidly obliquely converging Australian (AUS)- Pacific (PAC) plate boundary zone and is characterized by transient plate boundaries, rapidly rotating microplates and a globally significant geoid high. As the AUS plate moved northward in the Cenozoic, its leading edge has been a zone of subduction and arc accretion. The variety of tectonic settings in this region permits assessment of the complex interplay among mantle dynamics, plate tectonics, and surface processes. Importantly, the timescale of tectonic events (e.g., subduction, (U)HP exhumation, seafloor spreading) are within the valid bounds of mantle convection models. A record of changes in bathymetry and topography are preserved in high standing mountain belts, exhumed extensional gneiss domes and core complexes, uplifted coral terraces, and marine sedimentary basins. Global seismic tomography models indicate accumulation of subducted slabs beneath eastern New Guinea at the bottom of the upper mantle (i.e., 250-300 km). Preliminary global-scale backward advected mantle convection models, driven by density inferred from joint seismic-geodynamic tomography models, exhibit large-scale flow associated with these subducted slab remnants and predict the timing and magnitude (up to 1500 m) of dynamic topography change (both subsidence and uplift) since the Oligocene. In this talk we will explore the effects of large-scale background mantle flow and plate tectonics on the evolution of topography and bathymetry in eastern New Guinea, and discuss possible mechanisms to explain basin subsidence and surface uplift in the region.

  4. Dynamic Response of Stiffened Plates with Holes Subjected to Shock Waves and Fragments

    Institute of Scientific and Technical Information of China (English)

    刘彦; 张庆明; 黄风雷

    2004-01-01

    The power field of shock waves and fragments is analyzed and set up, and the damage modes of stiffened plates are put forward. According to the structural characters of the stiffened plates investigated and the properties of the shock waves and fragments, the experiments on the shock waves acting on the stiffened plates (penetrated and non-penetrated by fragments) are mainly conducted. The dynamic response rules of stiffened plates with holes under shock waves and fragments loading are obtained. The results show that the penetration of fragments into stiffened plates hardly affects their deformation produced by shock waves.

  5. 锁定加压钛板内固定治疗跟骨骨折%Application of locking compression plate in treatment of calcaneal fractures

    Institute of Scientific and Technical Information of China (English)

    董玉金; 童致虹; 张铁慧; 曾伟峰; 李靖年

    2013-01-01

    Objective To evaluate the clinical effect of the treatment for calcaneal fractures by locking compression plate.Methods From January 2008 to December 2011,30 patients with 40 calcaneal fractures were operated with locking compression plate.There were 25 males (33 feet) and 5 females (7 feet) with an average age of 44.8 years (range,22-60 years).Fifteen feet were on the left side,and 25 feet were on the right side.All patients had closed fractures,with complicated spinal injury in 2 patients.According to Sanders classification,20 feet were type Ⅱ[fractures,15 feet were type Ⅲ,and 5 feet were type Ⅳ.The lateral approach was adopted for all the patients in the treatment in which locking compression plate fixation was used but no external fixation.Early and suitable rehabilitation was carried out postoperatively.The patients could bear part of the loading six weeks after the operation and all the loading twelve weeks after the operation.The results were validated using the Anerican Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale.Results The patients were followed up for 8-20 months (average,12 months).Bone union occurred in all cases with roentgenographic evidence during 8-12 weeks postoperation (average,10 weeks).None of the patients had such complications as nerve injury or osteomyelitis.Incision dehiscence occurred in one case in which a little part of titanium plate and screw was exposed,but the incision was healed by dressing 1 month later.Two patients had subtalar arthritis and suffered from the pain while walking.Of the two patients,the pain was relieved for one after the operation of subtalar joint fusion,and the other was lost to the follow-up after he or she refused further treatment for economic reasons.According to AOFAS foot score standard,the effects of 20 cases were excellent,17 were good,and 3 were fair.The excellent and good rate was 92.5%.Conclusion The application of locking compression plate is an effective and satisfied

  6. A dynamic performance simulation model of flat-plate solar collectors for a heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    Arinze, E.A.; Schoenau, G.J.; Sokhansanj, S. (Saskatchewan Univ., Saskatoon, SK (Canada). College of Engineering); Adefila, S.S.; Mumah, S.M. (Ahmadu Bello Univ., Zaria (Nigeria). Dept. of Chemical Engineering)

    1993-01-01

    Flat-plate collectors are inherently exposed to time-varying meteorological and system parameters. Thus, dynamic modeling, rather than the commonly used steady-state models, is a more accurate approach for the design and performance evaluation of flat-plate solar collectors. The dynamic model presented in this study describes the fluid, plate and cover temperatures of the collector by three different differential equations. Taylor series expansion and the Runge-Kutta method are used in the solution of the differential equations. The accuracy of the dynamic model was tested by comparing the results predicted by the model with experimental performance data obtained for a liquid-cooled flat-plate solar collector with a corrugated transparent fiberglass cover. The predicted results by the dynamic model agreed favorably with the measured experimental data for the flat-plate solar collector. Experimentally determined collector temperatures varied by a maximum of [+-]3[sup o]C from values predicted by the model. (Author)

  7. Angular-stable locking plate fixation of tibial plateau fractures-clinical and radiological midterm results in 101 patients

    Directory of Open Access Journals (Sweden)

    Sven Mardian

    2015-01-01

    Full Text Available Background: Articular reconstruction and stable fixation of tibial plateau fractures and its various subtypes continue to represent a surgical challenge. Only few trials have studied results following angular stable plate fixation. The present study aimed to investigate the clinical, radiological, functional and quality of life results following tibial plateau fractures using angular stable plate fixation. Materials and Methods: 101 patients were retrospectively studied using functional (ROM; KSS; VAS, radiographic (osteoarthritis score, loss of reduction and quality of life (WOMAC; Lysholm scores. There were 46 males and 55 females. The average of patients was 51 years (range 22-77 years. Study groups were assigned according to the AO fracture classification. Results: Mean followup was 57 ± 30 months. Fracture type distribution revealed a significantly (P < 0.001 increased number of type B- (62.4% compared to C-fractures. Functional assessment showed a significantly better total KSS (84.1 ± 15.6 vs. 74.7 ± 18.0; P = 0.01 as well as ROM (active: 124°±17° vs. 116°±15°, P = 0.014; passive: 126°±18° vs. 118 ± 14°, P = 0.017 in the B-fracture group. VAS was found to be markedly higher (P = 0.0039 following type C-fractures. Rating osteoarthritis secondary to a tibial plateau fracture as a function of injury severity (r = 0.485; P < 0.001 and relating the loss of reduction to the grade of evolving osteoarthritis (r = 0.643;P < 0.001 a positive correlation was found. Quality of life showed significantly improved results for Lysholm score (P = 0.004 following B-fractures with low overall values for the WOMAC score. Conclusion: Presented data provide sufficient evidence that anatomic restoration of tibial plateau fractures with angular stable plate fixation result in decreased loss of reduction and declined incidence of posttraumatic osteoarthritis, thereby providing acceptable mid to long term outcome.

  8. Fixed vs dynamic plate complications following multilevel anterior cervical corpectomy and fusion with posterior stabilization.

    Science.gov (United States)

    Epstein, N E

    2003-07-01

    Comparison of fixed vs dynamic plate complications in cervical surgery. : New York, USA. Anterior cervical plate-related complications were evaluated following 66 anterior cervical corpectomy and fusion (ACF) with posterior stabilization (PWF) procedures performed in patients with ossification of the posterior longitudinal ligament (OPLL). Clinical data were comparable for both patient populations. Patients averaged between 52 and 53 years of age. The male to female ratio was approximately 2:1. Surgery addressed MR and CT documented multilevel OPLL in all patients accompanied by spondylosis and stenosis. Preoperatively average Nurick Grades ranged from 3.6 to 3.7. Anterior cervical corpectomies included an average of 2.6-3.0 vertebral bodies, while PWF covered seven levels. Fixed plates were applied in the initial 38 patients, while the latter 28 patients had dynamic plates (ABC, Aesculap, Tuttlingen, Germany) applied. Halo devices were used until fusion was documented on both X-ray and 2D-CT studies. Patients were followed-up for an average of 5.4 years in the fixed-plated groups, and 2.7 years in the dynamic-plated population. CT and dynamic X-ray confirmed that fusion occurred an average of 4.5-4.9 months postoperatively. Five (13%) fixed plates (Medtronic, Sofamor Danek, Memphis, TN, USA) failed warranting secondary surgery, while only one (3.6%) dynamic-plated patient developed a pseudarthrosis and required secondary posterior fusion. Higher failure rates follow multilevel ACF as compared with anterior diskectomy and fusion required to resect multilevel OPLL. Vaccaro et al observed a 9% failure rate following two-level ACFs and 50% failure rate following three-level ACFs performed with fixed plates. In this series, the plate extrusion rate was reduced to 3.6% when dynamic plates were applied.

  9. Analysis and Optimization of Locking Ring for Quick-opening Blind Plate Based on Ansys Workbench%基于Ansys Workbench的快开盲板锁环分析及优化

    Institute of Scientific and Technical Information of China (English)

    周天旭; 陈平; 陈水莲; 罗聪

    2013-01-01

    Ansys Workbench was used to optimize tilt angle of the locking ring in quick-opening blind plate so as to work out an optimum angle; and the relation curve between the locking ring size and the blind plate' s supporting was plotted,and the influence of locking ring size and tilt angle on the ring' s strength and stiffness was considered to propose details needing attention in the locking ring design.%利用Ansys Workbench对快开盲板锁环的倾斜角度进行了参数化设计,并优化出最佳角度.绘制出锁环尺寸对盲板支承状况和锁环应力的影响曲线.综合研究了锁环尺寸和倾斜角对锁环强度、刚度的影响,并提出了锁环设计中需要注意的细节.

  10. The efficiency of plate tectonics and nonequilibrium dynamical evolution of planetary mantles

    Science.gov (United States)

    Moore, W. B.; Lenardic, A.

    2015-11-01

    Consideration of the structure of dynamical equilibria in terrestrial planets using simplified descriptions of the relevant heat transport processes (rigid-lid convection, plate tectonics, and heat pipe volcanism) reveals that if the efficiency of plate tectonic heat transport decreases at higher mantle temperature, then it cannot govern quasi-equilibrium dynamical evolution, and the system is always evolving away from the plate tectonic regime. A planet on which plate tectonics is less efficient at higher temperature stays in heat pipe mode longer, spends less time undergoing plate tectonics, and has a low and ever-decreasing Urey number during this phase. These conclusions are based solely on the structure of the equilibria in a system with less efficient plate tectonics in the past and are independent of the mechanisms leading to this behavior. Commonly used quasi-equilibrium approaches to planetary thermal evolution are likely not valid for planets in which heat transport becomes less efficient at higher temperature.

  11. Dynamics of Shells and Fluid-Loaded Plates.

    Science.gov (United States)

    Wang, Zhang

    This thesis is composed of two parts. The first part is concerned with wave propagation on elastic structures in vacuum. An asymptotic approximation is obtained for the dispersion relation of flexural waves propagating in an infinite, flat plate, with material and/or geometric properties periodic in one direction. A matrix approach is proposed to investigate waves in circular cylindrical thin shells joined with circular plates. Both the general propagator matrix and S-matrix formalisms are presented, with emphasis on the latter. The second part is devoted to structures with ambient fluid loading. The Green's function for a fluid-loaded plate under line loading is expressed as a sum of five fluid-loaded plate waves and an acoustic wave with magnitude given by an infinite integral, similar to a branch cut integral. A scattering matrix approach is presented to solve wave propagation problems on fluid-loaded plates with attached ribs. The low frequency asymptotic dispersion relation for a fluid-loaded plate with infinite number of equally spaced identical ribs is derived, from which an equation of motion for the plate is inferred which is valid also at low frequencies.

  12. 肱骨近端锁定钢板治疗难复性肱骨近端骨折脱位18例体会%Treatment of irreducible proximal humerus fracture and dislocation with locking proximal humerus plate

    Institute of Scientific and Technical Information of China (English)

    沈爱东; 孙惠清; 杨惠光

    2010-01-01

    对肱骨近端锁定钢板(locking proximal humerus plate,LPHP)内固定治疗难复性肱骨近端骨折脱位临床资料进行回顾性分析.18例经7~12个月随访,骨折全部愈合.随访期间未发现肱骨头坏死病例.

  13. Fractures and fracture-dislocations of the proximal humerus: A retrospective analysis of 82 cases treated with the Philos(®) locking plate.

    Science.gov (United States)

    Erasmo, Rocco; Guerra, Giovanni; Guerra, Luigi

    2014-12-01

    To present the experience in a single institution of the management of 82 consecutive fractures and fracture-dislocations of the proximal humerus treated with the Proximal Humeral Internal Locking System (Philos(®)) plate. A total of 81 patients with 82 proximal humerus fractures (one patient had bilateral fracture) were treated at our institution with open reduction and internal fixation with Philos(®) plate from January 2008 to December 2012 and the clinico-radiological outcome was analysed. Twelve of these patients also had a dislocation of the proximal humerus. According to the Neer classification, there were seven two-part fractures, 40 three-part fractures and 35 four-part fractures. All patients received a similar physical therapy programme following internal fixation. Mean final follow-up was 32 months. Functional outcome was evaluated for each patient using the Constant-Murley score; radiographic evaluation was also conducted and complications were recorded. At the end of the follow-up period, the mean Constant-Murley score for the injured side was 75 points (range 42-92); results were graded as excellent for eight patients, good for 52, moderate for 17 and poor for five. Twenty-three patients (28%) had complications during the follow-up period. Reoperation was required in 12 patients. Complications included avascular necrosis of the humeral head in 10 patients (12%), varus positioning of the head in four patients (4.8%), impingement syndrome in three patients (3.6%), secondary screw perforation in three patients (3.6%), non-union of the fracture in two patients (2.4%) and infection in one patient (1.2%). Open reduction and internal fixation of proximal humeral fractures with the Philos(®) plate was associated with good clinical outcomes provided the correct surgical technique was used. To better evaluate the real incidence of complications, it is important to follow patients for more than one year after surgery as some complications may arise after

  14. 股骨近端外侧锁定钢板治疗Russell-Taylor Ⅱ型股骨转子下骨折%Femoral subtrochanteric fractures treated with proximal lateral femur locking Plate

    Institute of Scientific and Technical Information of China (English)

    胡孙君; 陈舰; 陈杰; 俞光荣; 张世民

    2012-01-01

    目的 探讨股骨近端外侧锁定钢板治疗股骨转子下骨折的治疗效果.方法 对28例Russell-Taylor Ⅱ型股骨转子下骨折患者采用股骨近端外侧锁定钢板固定.结果 28例均获得随访,时间10~24个月.根据髋关节Harris评分:优13例,良10例,中5例.结论 股骨近端外侧锁定钢板治疗股骨转子下骨折可以达到可靠的固定效果,骨折愈合较快,短期临床疗效良好.%Objective To study the outcome of subtrochanteric hip fractures treated by proximal lateral femur locking plate. Methods 28 elder patients with subtrochanteric hip fractures were treated with proximal lateral femur locking plate. Results All patients were followed up for 10 ~24 months. According to Hams index, there were 13 excellent cases, f 0 good and 5 fair. Conclusions The proximal lateral femur locking plate is the kind of stable and effective internal fixation of treating subtrochanteric hip fractures, and the clinical outcome is satisfied.

  15. 锁定加压钢板治疗骨折术后骨不连20例效果分析%Effect analysis of locking compression plate in the treatment of nonunion after fracture operation in 20 cases

    Institute of Scientific and Technical Information of China (English)

    曾雪松

    2016-01-01

    目的:观察使用锁定加压钢板(LCP)治疗20例骨折术后骨不连的临床效果。方法:对20例骨折术后骨不连患者给予锁定加压钢板方法治疗,观察疗效。结果:愈合率90.0%,平均愈合时间(7.2±0.3)个月。结论:使用锁定加压钢板治疗骨折术后骨不连的临床效果较好。%Objective:To observe the clinical effect of using locking compression plate in the treatment of nonunion after fracture operation in 20 cases.Methods:20 patients with nonunion after fracture operation were given locking compression plate method treatment.The curative effect was observed.Results:The healing rate was 90.0% ,and the average healing time was (7.2 ± 0.3) months.Conclusion:The clinical effect of using locking compression plate in the treatment of nonunion after fracture operation is better.

  16. ANALYSIS OF GLOBAL DYNAMICS IN A PAIAMETIICALLY EXCITED THIN PLATE

    Institute of Scientific and Technical Information of China (English)

    张伟

    2001-01-01

    The global bifurcations and chaos of a simply supported rectangular thin plate with parametric excitation are analyzed. The formulas of the thin plate are derived by yon Karman type equation and Galerkin's approach. The method of multiple scales is used to obtain the averaged equations. Based on the averaged equations, the theory of the normal form is used to give the explicit expressions of the normal form associated with a double zero and a pair of pure imaginary eigenvalues by Maple program. On the basis of the normal form, a global bifurcation analysis of the parametrically excited recta ngular thin plate is given by the global perturbation method developed by Kovacic and Wiggins. The chaotic motion of thin plate is also found by numerical simulation.

  17. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  18. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  19. EFFECT OF DAMAGE ON NONLINEAR DYNAMIC PROPERTIES OF VISCOELASTIC RECTANGULAR PLATES

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yu-fang; FU Yi-ming

    2005-01-01

    The nonlinear dynamic behaviors of viscoelastic rectangular plates including the damage effects under the action of a transverse periodic load were studied. Using the von Karman equations, Boltzmann superposition principle and continuum damage mechanics, the nonlinear dynamic equations in terms of the mid-plane displacements for the viscoelastic thin plates with damage effect were derived. By adopting the finite difference method and Newmark method, these equations were solved. The results were compared with the available data. In the numerical calculations, the effects of the external loading parameters and geometric dimensions of the plate on the nonlinear dynamic responses of the plate were discussed. Research results show that the nonlinear dynamic response of the structure will change remarkably when the damage effect is considered.

  20. Dynamic stress concentrations in thick plates with two holes based on refined theory

    Institute of Scientific and Technical Information of China (English)

    周伟平; 胡超; 刘殿魁

    2014-01-01

    Based on complex variables and conformal mapping, the elastic wave scat-tering and dynamic stress concentrations in the plates with two holes are studied by the refined dynamic equation of plate bending. The problem to be solved is changed to a set of infinite algebraic equations by an orthogonal function expansion method. As examples, under free boundary conditions, the numerical results of the dynamic moment concen-tration factors in the plates with two circular holes are computed. The results indicate that the parameters such as the incident wave number, the thickness of plates, and the spacing between holes have great effects on the dynamic stress distributions. The results are accurate because the refined equation is derived without any engineering hypothese.

  1. Studies on the Dynamic Buckling of Circular Plate Irradiated by Laser Beam

    Institute of Scientific and Technical Information of China (English)

    黄晨光; 段祝平

    2002-01-01

    The dynamic buckling of thin copper plate induced by laser beam, was analyzed with the numerical integration and disturbance methods of controlling equation. The buckling and post-buckling of thin plate were shown, with the consideration of the temperature distribution, inertia effect and initial deflection. At last, the buckling criterion about the circular plate was obtained and used to investigate the relation between the critical laser intensity and the ratio of thickness and diameter of the plate. The results fit the experimental observation and the FEM simulation very well, and benefit to the understanding of failure phenomenon of structures irradiated by laser beam.

  2. Nonlinear dynamic modeling of a helicopter planetary gear train for carrier plate crack fault diagnosis

    OpenAIRE

    Fan Lei; Wang Shaoping; Wang Xingjian; Han Feng; Lyu Huawei

    2016-01-01

    Planetary gear train plays a significant role in a helicopter operation and its health is of great importance for the flight safety of the helicopter. This paper investigates the effects of a planet carrier plate crack on the dynamic characteristics of a planetary gear train, and thus finds an effective method to diagnose crack fault. A dynamic model is developed to analyze the torsional vibration of a planetary gear train with a cracked planet carrier plate. The model takes into consideratio...

  3. 锁定加压钢板与DHS治疗股骨转子间骨折的对比研究%Comparative study of treatment of the femoral intertrochanteric fractures with locking compression Plate and DHS

    Institute of Scientific and Technical Information of China (English)

    罗福昌; 彭建强; 蔡汉周; 周经颖; 李中檀

    2008-01-01

    目的 探讨锁定加压钢板与DHS治疗股骨转子间骨折的疗效及适应证.方法 使用锁定加压钢板与DHS治疗股骨转子间骨折共102例,并对其在手术时间、术中出血量、术后引流、Parker髋关节功能评分、并发症等方而进行比较.结果 锁定加压钢板组在手术时间、手术期出血量、术后切口引流量、并发症等均较DHS组少,DHS组早期活动和负重时间明显早于锁定加压钢板组.结论 锁定加压钢板治疗股骨转子间骨折适用于所有类型的股骨转子间骨折,对于骨质疏松、粉碎性骨折患者尤为适合.DHS治疗股骨转子间骨折具有固定可靠、患者可早期活动和负重的优点,适用于Ⅰ、Ⅱ型股骨转子间骨折.%Objective To evaluate the effect and indications in the treatment of the femoral intertro-chanteric fractures with locking compression plate add DHS. Methods Treated femoral intertrochanteric fractures with locking compression plate and DHS for 102 cases at the same period, and its operation time, blood loss,the drainage volum,Parkerhip function score,complication in the 2 groups were compared. Results The group of locking compression plate in the blood loss, operation time, complication and the drainage volum were less than the group of DHS,the group of DHS in the early activities were more early than the group of locking compression plate. Conclusion Treatment of the femoral intertrochantefic fractures with locking compression plate is suitable treatment for all types of femoral intertroehanterie fractures, which is especially suitable treatment for the syntripsis and osteoporosis. Treatment of the femoral intertrochanteric fractures with DHS has the advantages of reliable fixation and early activities,which is suitable treatment for the types of Ⅰ and Ⅱ.

  4. Comparison of Locking Plate and PFNA for Intertrochanteric Fractures%锁定钢板与PFNA治疗股骨粗隆间骨折的对比分析

    Institute of Scientific and Technical Information of China (English)

    刘国龙; 窦庆寅; 韩同坤; 阳闽军

    2011-01-01

    Objective To compare the clinical effects of locking plate and PFNA in the treatment of intertrochanteric fractures. Methods A total of 138 cases of intertrochanteric fractures were treated with anatomical proximal femoral locking plate (locking plate group, n = 63) and modified proximal femoral intramedullary nails (PFNA group,n= 75) according to age and modified Evans classification. Perioperative indicators and degree of functional recovery of hip after surgery were compared between the two groups. Results All patients were followed up for 7-36 months. There were significant differences in cut size, amount of bleeding, reduction of neck shaft angle,and average healing time between locking plate group and PFNA group (P<0.05), but the differences in operation time and postoperative hip function were not significant between the two groups (P>0. 05). Conclusion PFNA is a better choice than proximal femoral anatomical locking plate in the treatment of intertrochanteric fractures due to smaller incisions,less blood loss and shorter time in bed.%目的 比较锁定钢板与改良股骨近端加锁髓内钉(PFNA)2种内固定方式治疗股骨粗隆间骨折的临床疗效.方法 根据不同年龄段和骨折分型,对138例股骨粗隆间骨折患者分别采用股骨近端解剖型锁定钢板(解剖型锁定钢板组,n=63)及PFNA(PFNA组,n=75)进行内固定.对2组围术期指标和术后髋关节功能恢复程度进行比较.结果 2组患者均获随访7~36个月.2组切口大小、出血量、颈干角减少、平均愈合时间比较,差异有统计学意义(P<0.05).2组骨折手术时间、术后髋关节功能比较,差异无统计学意义(P>0.05).结论 2种内固定方法 临床效果相当,但与股骨近端解剖型锁定钢板比较,PFNA创伤小、出血量少、卧床时间短.

  5. The importance of temporal stress variation and dynamic disequilibrium for the initiation of plate tectonics

    Science.gov (United States)

    Stamenković, V.; Höink, T.; Lenardic, A.

    2016-06-01

    We use 1-D thermal history models and 3-D numerical experiments to study the impact of dynamic thermal disequilibrium and large temporal variations of normal and shear stresses on the initiation of plate tectonics. Previous models that explored plate tectonics initiation from a steady state, single plate mode of convection concluded that normal stresses govern the initiation of plate tectonics, which based on our 1-D model leads to plate yielding being more likely with increasing interior heat and planet mass for a depth-dependent Byerlee yield stress. Using 3-D spherical shell mantle convection models in an episodic regime allows us to explore larger temporal stress variations than can be addressed by considering plate failure from a steady state stagnant lid configuration. The episodic models show that an increase in convective mantle shear stress at the lithospheric base initiates plate failure, which leads with our 1-D model to plate yielding being less likely with increasing interior heat and planet mass. In this out-of-equilibrium and strongly time-dependent stress scenario, the onset of lithospheric overturn events cannot be explained by boundary layer thickening and normal stresses alone. Our results indicate that in order to understand the initiation of plate tectonics, one should consider the temporal variation of stresses and dynamic disequilibrium.

  6. Dynamics of subduction and continental collision: Influence of the nature of the plate contact. Geologica Ultraiectina (284)

    NARCIS (Netherlands)

    De Franco, R.

    2008-01-01

    At convergent plate boundaries, the properties of the actual plate contact are important for the overall dynamics. Convergent plate boundaries both mechanically decouple and link tectonic plates and accommodate large amounts of strain. We investigate two fundamental physical states of the subduction

  7. A Transverse Dynamic Deflection Model for Thin Plate Made of Saturated Porous Materials

    Science.gov (United States)

    Feng-xi, Zhou; Xiao-lin, Cao

    2016-10-01

    In this article, a transverse dynamic deflection model is established for thin plate made of saturated porous materials. Based on the Biot's model for fluid-saturated porous media, using the Love-Kirchhoff hypothesis, the governing equations of transverse vibrations of fluid-saturated poroelastic plates are derived in detail, which take the inertial, fluid viscous, mechanical couplings, compressibility of solid, and fluid into account. The free vibration and forced vibration response of a simply supported poroelastic rectangular plate is obtained by Fourier series expansion method. Through numerical examples, the effect of porosity and permeability on the dynamic response, including the natural frequency, amplitude response, and the resonance areas is assessed.

  8. 股骨颈自锁钉板系统的研制及其生物力学结构测试%Design and biomechanical structure evaluation of self-locking screw plate system for femoral neck fracture

    Institute of Scientific and Technical Information of China (English)

    昌耘冰; 尹东; 李凭跃

    2004-01-01

    combines plate and screw through self-locking mechanism to form a stable mechanical structure inside the femoral neck, which can effectively antagonize the nocuous stress to fractured femoral neck.%背景:应用于股骨颈骨折的内固定器材种类繁多,但均存在较多的生物力学缺陷.目的:研制应用于股骨颈骨折的新型内固定器械并了解其生物力学特性.设计:随机对照的开放性实验.地点和对象:在第一军医大学生物力学重点实验室进行,12具新鲜人尸体股骨干标本为测试材料.干预:根据股骨颈骨折的病理和生物力学特点,设计由主钉,辅钉,自锁钢板组成的钉板系统(self-locking screw plate system,SLSP).分4组进行生物力学比较测试:①SLSP.②3枚空心加压钉(three compressive screws,TCS).③Hansson钉(Hansson pin,HP).④动力髋螺钉(Dynamic hip screw,DHS).主要观察指标:不同组内固定后股骨头的下沉位移(刚度)、水平位移(刚度)以及抗扭转强度和极限载荷.结果:上述4组固定在600 N纵向载荷时的下沉位移分别为:(4.25±0.20),(5.58±0.41),(5 87±0.35),(6.40±0.43)mm.水平位移分别为:(1.78±0.25),(2.41±0 04),(2.42±0.25),(2.79±0.31)mm.SLSP与各组之间均存在统计学差异(P<0.01).取等量扭矩1 N·m时的扭角比较,SLSP组的扭角分别较TCS组、HP组和DHS组小15%,35%和43%,差异有显著性意义(F=96.7,P<0.01).SLSP的极限载荷和位移分别为(3 830±66)N和(7.49±1.2)mm,其极限载荷明显高于其他3组.结论:采用SLSP系统进行股骨颈骨折内固定后,股骨头在下沉位移(刚度)、水平位移(刚度)以及抗扭转强度和极限载荷均高于其他3种固定形式.股骨颈自锁钉板系统通过自锁机制将钢板和螺钉两者有机地结合在一起,在股骨颈内构成稳定的力学结构,能有效地对抗股骨颈骨折后的有害应力.

  9. 锁定解剖钢板内固定治疗股骨转子间骨折%Treatment of trochanteric fractures with proximal femoral locking plates

    Institute of Scientific and Technical Information of China (English)

    徐荣华; 霍维玲; 吴昊; 陈明

    2011-01-01

    目的 探讨锁定解剖钢板内固定治疗股骨转子间骨折的临床疗效.方法 应用有限切开锁定解剖钢板内固定治疗股骨转子间骨折56例.结果 56例均获随访,时间3~24个月.全部骨性愈合,愈合时间3~6个月.有2例发生髋内翻,无骨不连、内固定断裂等并发症发生.结论 锁定解剖钢板治疗股骨转子间骨折切口小,手术时间短,出血量少,术后可早期功能锻炼,并发症少,尤其适用于老年骨质疏松患者.%Objective To investigate the clinical and radiographic results of proximal femoral locking plates( PFLPs ) for a minimally invasive method of treating intertrochanteric hip fractures.Methods A total of 56 patients with inter-trochanteric hip fractures were treated by limited open reduction and fixation with PFLPs.Results All the cases were followed up for 3 ~ 24 months and they all got bony union in 3 ~ 6 months.Coxa vara was found in 2 cases.No infection , pseudoarthrosis or implant failure was recorded.Conclusions PFLPs for intertrochanteric fractures is benificial for earlier functional exercise, shortening operating times, diminishing operating wound, less blood loss and little postoperative complications.It is especially of benefit to the old man with severe osteoporosis.

  10. A CLINICAL STUDY OF PROXIMAL FEMUR LOCKING COMPRESSION PLATE (LCP - PF IN THE MANAGEMENT OF COMMUNITED INTERTROCHANTERIC AND SUBTROCHANTERIC FRACTURES OF THE FEMUR

    Directory of Open Access Journals (Sweden)

    Hari Babu

    2015-10-01

    Full Text Available Fractures of proximal femur and hip are relatively common injuries in elderly individuals . The incidence of peritrochanteric and intertrochanteric fracture is also increasing among young population, who sustain high energy trauma Rigid Internal fixation and early mobilization has been the standard method of treatment. A combination of orthopaedic surgery and early postoperative physiotherapy and ambulation is the best approach. The overall goal in the treatment of hip fractures is to return the patient to pre - morbid level of function. AIMS & OBJECTIVE : To analyse the anatomical and f unctional outcome of the treatment with LCP - Proximal femur. METHODOLOGY : The present study consists of 12 adult patients of peritrochanteric factures of femur satisfying the inclusion criteria , treated with Proximal Femoral Locking Compression Plate at S. V. R. R . Govt . General Hospital, Tirupati during the period of nov 2013 to Oct 2015. INCLUSION CRITERIA : Age >18years , comminuted trochanteric and sub trochanteric fractures , Signed written informed consent . EXCLUSION CRITERIA: Inter trochanteric fractures involving piriformis fossa , Compound fractures . Pathological fractures . Any displacement of a femoral neck fracture . A ssociated malignancy. RESULTS : Average age incidence in the present study was 62.7 years. , Predominantly males (75% were affected. , Most cases occurred after a fall 10 (50% cases which was statistically significant , Right side involvement was more common. , Average post - operative stay was 13.5 days. , Out of the 12 cases, evaluated using Salvati - Wilson scoring : 3 cases (25% had good, 8 cases (66.67% fair, 1 case (8.33% had poor score , Average weight bearing time was14.5 weeks , Average union rate was 19.45 weeks.

  11. Kinematics to dynamics in the New Zealand plate-boundary zone

    Science.gov (United States)

    Lamb, S. H.

    2013-12-01

    New Zealand straddles the boundary between the Australian and Pacific plate, with a transition from subduction of Pacific oceanic lithosphere beneath North Island, to oblique continental collision in South Island. Cenozoic relative plate motion has resulted in a complex pattern of faulting and block rotation in a zone up to 250 km wide, with displacements on individual faults up to 100s of kilometres. Active deformation must be driven by a combination of plate-boundary forces and internal buoyancy forces. I use a compilation of seismic reflection/refraction studies and high quality receiver function analyses, together with simple Airy isostasy, to determine regional crustal and mantle structure. Integration of the vertical normal stress to the base of the deforming layer yields the buoyancy stress. Horizontal gradients of this can be compared with horizontal gradients of strain rate, using the method of England & Molnar (1997), in the context of a simple thin sheet model of deformation. Thus, if deformation is that of a Newtonian fluid, then appropriate combinations of the horizontal gradients of vorticity and dilatation are related to gradients of buoyancy stress by the fluid viscosity. However, the short term geodetic deformation is strongly biased by elastic strain accumulation related to locking on the plate interface, and cannot be used to determine the plate-boundary velocity field averaged over many seismic cycles (see Lamb & Smith 2013). Therefore, I derive here a velocity field for the plate-boundary zone, which is representative of deformation over tens of thousands of years. This is based on an inversion of fault slip, strain rate azimuth and paleomagnetic data, in the context of the short term relative plate motions, solved in a network of triangles spanning the plate-boundary, using the method of Lamb (2000). A comparison of gradients of buoyancy stress with the appropriate combinations of gradients of vorticity and dilatation shows that deformation in

  12. Numerical Simulations of Dynamic Behavior of Polyurea Toughened Steel Plates under Impact Loading

    Directory of Open Access Journals (Sweden)

    Chien-Chung Chen

    2014-01-01

    Full Text Available The objective of the work discussed herein is to develop a nonlinear 3D finite element model to simulate dynamic behavior of polyurea toughened steel plates under impact loading. Experimental and numerical work related to model development are presented. Material properties are incorporated into numerical models to account for strain-rate effects on the dynamic behavior of polyurea and steel. One bare steel plate and four polyurea toughened steel plates were tested under impact loading using a pendulum impact device. Displacement time-history data from experimental work was used to validate the numerical models. Details on material model construction, finite element model development, and model validation are presented and discussed. Results indicate that the developed numerical models can reasonably predict dynamic response of polyurea toughened steel plates under impact loading.

  13. Analysis of interlaminar stress and nonlinear dynamic response for composite laminated plates with interfacial damage

    Institute of Scientific and Technical Information of China (English)

    F. H. Zhu; Y. M. Fu

    2008-01-01

    By considering the effect of interfacial damage and using the variation principle, three-dimensional nonli-near dynamic governing equations of the laminated plates with interfacial damage are derived based on the general six-degrees-of-freedom plate theory towards the accurate stress analysis. The solutions of interlaminar stress and nonlinear dynamic response for a simply supported laminated plate with interfacial damage are obtained by using the finite dif-ference method, and the results are validated by compari-son with the solution of nonlinear finite element method. In numerical calculations, the effects of interfacial damage on the stress in the interface and the nonlinear dynamic response of laminated plates are discussed.

  14. DYNAMIC RESPONSE OF PLATES DUE TO MOVING VEHICLES USING FINITE STRIP METHOD

    Institute of Scientific and Technical Information of China (English)

    程远胜; 张佑啟; 区达光

    2002-01-01

    Dynamic response of beam-like structures to moving vehicles has been extensive-ly studied. However, the study on dynamic response of plates to moving vehicles has so farreceived but scant attention. A plate-vehicle strip for simulating the interaction between arectangular plate and moving vehicles was described. For the portion of strips that are in di-rect contact with the moving vehicles, the plate-vehicle strips were employed. Conventionalplate finite strips were used to model the portion of strips that are not directly under the ac-tion of moving vehicles. In the analysis, each moving vehicle is idealized as a one-foot dy-namic system with the unsprung mass and sprund mass interconnected by a spring and adashpot. The numerical results obtained from the proposed method agree well with availableresults.

  15. The Interpretation of Dynamic Contact Angles Measured by the Wilhelmy Plate Method

    Science.gov (United States)

    Ramé

    1997-01-01

    We present an analysis for properly interpreting apparent dynamic contact angles measured using the Wilhelmy plate method at low capillary numbers, Ca. This analysis removes the ambiguity in current dynamic measurements which interpret data with the same formula as static measurements. We properly account for all forces, including viscous forces, acting on the plate as it moves into or out of a liquid bath. Our main result, valid at O(1) as Ca --> 0, relates the apparent dynamic contact angle to material-dependent, geometry-independent parameters necessary for describing dynamic wetting of a system. The special case of the apparent contact angle = pi/2 was solved to O(Ca). This O(Ca) solution can guide numerical work necessary for higher Ca's and arbitrary values of the apparent contact angle. These results make the Wilhelmy plate a viable method for determining material parameters for dynamic spreading.

  16. Simulations of structural and dynamic anisotropy in nano-confined water between parallel graphite plates.

    Science.gov (United States)

    Mosaddeghi, Hamid; Alavi, Saman; Kowsari, M H; Najafi, Bijan

    2012-11-14

    We use molecular dynamics simulations to study the structure, dynamics, and transport properties of nano-confined water between parallel graphite plates with separation distances (H) from 7 to 20 Å at different water densities with an emphasis on anisotropies generated by confinement. The behavior of the confined water phase is compared to non-confined bulk water under similar pressure and temperature conditions. Our simulations show anisotropic structure and dynamics of the confined water phase in directions parallel and perpendicular to the graphite plate. The magnitude of these anisotropies depends on the slit width H. Confined water shows "solid-like" structure and slow dynamics for the water layers near the plates. The mean square displacements (MSDs) and velocity autocorrelation functions (VACFs) for directions parallel and perpendicular to the graphite plates are calculated. By increasing the confinement distance from H = 7 Å to H = 20 Å, the MSD increases and the behavior of the VACF indicates that the confined water changes from solid-like to liquid-like dynamics. If the initial density of the water phase is set up using geometric criteria (i.e., distance between the graphite plates), large pressures (in the order of ~10 katm), and large pressure anisotropies are established within the water. By decreasing the density of the water between the confined plates to about 0.9 g cm(-3), bubble formation and restructuring of the water layers are observed.

  17. Characterization of timing jitter spectra in free-running mode-locked lasers with 340 dB dynamic range over 10 decades of Fourier frequency

    CERN Document Server

    Jung, Kwangyun

    2014-01-01

    We demonstrate a method that enables accurate timing jitter spectral density characterization of free-running mode-locked laser oscillators over more than 10-decade of Fourier frequency from mHz to tens MHz range. The method is based on analyzing both the input voltage noise to the slave laser and the output voltage noise from the balanced optical cross- correlator (BOC), when two mode-locked lasers are synchronized in repetition rate by the BOC. As a demonstration experiment, timing jitter spectrum of a free-running mode-locked Er-fiber laser with a dynamic range of >340 dB is measured over Fourier frequency ranging from 1 mHz to 38.5 MHz (Nyquist frequency). The demonstrated method can resolve different noise mechanisms that cause specific jitter characteristics in free-running mode-locked laser oscillators for a vast range of time scales from 1000-s.

  18. 颈椎前路锁定钢板治疗颈椎疾病的疗效观察%Effectiveness of Anterior Cervical Locking Plate System in Cervical Surgery

    Institute of Scientific and Technical Information of China (English)

    任云峰; 熊鹰; 赵烽; 张仲子

    2011-01-01

    目的 观察颈椎前路减压、取髂骨植骨结合锁定型钢板系统内固定治疗颈椎疾病的临床疗效.方法 2001年3月至2008年3月采用该方法治疗颈椎疾病34例,并进行12 ~24个月后随访.结果 术前Frankel分级A-D级31例中,25例有1 ~2级的改善,6例无明显改善.植骨块融合良好,无严重并发症发生.结论 该方法具有固定牢靠、植骨融合率高、手术操作简单、手术并发症少等优点,是一种治疗颈椎疾病的良好方法.%Objective To evaluate the effectiveness of anterior decompression, bone grafting combined with locking plate system internal fixation for cervical spinal desease.Methods From March 2001 to March 2008 34 patients were operated with anterior decompression, bone grafting and locking plate system fixation, all the patients were followed up for 12 to 24 months.Results 25 patients of Frankel's A-D were improved by to 2 degree after operation,6 patients had no obvious improvement.There was no plate or screw breaking and loosening; no dislocation of graft bone, all the bones were fusion in 6 months.Conclusion Anterior decompression , bone grafting combined with locking plate system internal fixation can provide reliable stability for the fixation segments with higher bony fusion rate,less complications,and the operation was much simple and safe.It was a good choice for treatment of cervical spinal disease.

  19. UK DRAFFT - A randomised controlled trial of percutaneous fixation with kirschner wires versus volar locking-plate fixation in the treatment of adult patients with a dorsally displaced fracture of the distal radius

    Directory of Open Access Journals (Sweden)

    Brown Jaclyn

    2011-09-01

    Full Text Available Abstract Background Fractures of the distal radius are extremely common injuries in adults. However, the optimal management remains controversial. In general, fractures of the distal radius are treated non-operatively if the bone fragments can be held in anatomical alignment by a plaster cast or orthotic. However, if this is not possible, then operative fixation is required. There are several operative options but the two most common in the UK, are Kirschner-wire fixation (K-wires and volar plate fixation using fixed-angle screws (locking-plates. The primary aim of this trial is to determine if there is a difference in the Patient-Reported Wrist Evaluation one year following K-wire fixation versus locking-plate fixation for adult patients with a dorsally-displaced fracture of the distal radius. Methods/design All adult patients with an acute, dorsally-displaced fracture of the distal radius, requiring operative fixation are potentially eligible to take part in this study. A total of 390 consenting patients will be randomly allocated to either K-wire fixation or locking-plate fixation. The surgery will be performed in trauma units across the UK using the preferred technique of the treating surgeon. Data regarding wrist function, quality of life, complications and costs will be collected at six weeks and three, six and twelve months following the injury. The primary outcome measure will be wrist function with a parallel economic analysis. Discussion This pragmatic, multi-centre trial is due to deliver results in December 2013. Trial registration Current Controlled Trials ISRCTN31379280 UKCRN portfolio ID 8956

  20. A dynamic simulation of a flat-plate collector system

    Science.gov (United States)

    Annino, A.

    1983-04-01

    A numerical model for the performance of a flat plate solar collector array is presented, with account taken of thermal transients and calculation on a microcomputer. The system modeled consists of a flat plate array, the heat transfer fluid, an insulated storage tank, an exchange loop for heating a secondary fluid, and a load maintained by a pump. The one-dimensional analysis includes equations for the energy balances, with consideration given to heat losses to the outside. A function is defined for the total incident solar radiation, and behavior is simulated over the entire 24-hr day, weighted by the highest and lowest recorded temperatures. Good agreement has been found with experimental data.

  1. On Dynamic Transmitting Property of Circular Plate MR Clutch

    Science.gov (United States)

    Guo, Chongzhi; Guo, Jiangchuan; Guo, Yu; Ma, Ziyang

    This study focuses on the analysis of relationship between the current density and the torque of a circular plate Magneto-Rheological (MR) clutch. In order to get the expression of magnetic induction intensity, the Finite Element Method(FEM) is used for the magnetic analysis on the given geometry of circular plate MR clutch under different current density. With some reasonable assumptions, the discrete values of the magnetic induction intensity along some defined paths are obtained. The fitted expression of magnetic induction intensity is derived from discrete points and the analysis of these discrete data. Based on the expression and the Bingham model which is used to describe the constitutive characteristics of the MR fluids flow between two circular plates subject to an applied magnetic field induced by current density, the mathematical model to transmit the torque is established. From the model and the fit expression, the relationship of the torque and the current density is deduced. The numerical results show that the torque transferred under magnetic induction density by control current density is increased smoothly as the current density is increased except a very short time after initial start. Results also indicate that the torque can be controlled continuously by changing the current density. The analysis provides the theoretical foundation for the design of the MR clutch, and the equation of the torque provides the information by which the torque transmitted by the clutch can be manipulated accurately through adjusting the current density.

  2. The dynamic stiffness matrix of two-dimensional elements: application to Kirchhoff's plate continuous elements

    Science.gov (United States)

    Casimir, J. B.; Kevorkian, S.; Vinh, T.

    2005-10-01

    This paper describes a procedure for building the dynamic stiffness matrix of two-dimensional elements with free edge boundary conditions. The dynamic stiffness matrix is the basis of the continuous element method. Then, the formulation is used to build a Kirchhoff rectangular plate element. Gorman's method of boundary condition decomposition and Levy's series are used to obtain the strong solution of the elementary problem. A symbolic computation software partially performs the construction of the dynamic stiffness matrix from this solution. The performances of the element are evaluated from comparisons with harmonic responses of plates obtained by the finite element method.

  3. Non-stationary oscillations of sandwich plates under local dynamic loading

    NARCIS (Netherlands)

    Skvortsov, Vitaly; Krakhmalev, Sergey; Koysin, V.; Shipsha, Andrey

    2003-01-01

    The paper addresses the elastic response of composite sandwich panels to local dynamic loading. The plane and axisymmetric formulations are considered; no overall bending is assumed. The governing equations are derived using the static Lamé equations for the core and the plate Kirchoff-Love dynamic

  4. Rate equation dynamics of passively mode-locked quasi-continuous lasers: pulse stability and dynamic pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    New, G.H.C.; Orkney, K.E.; Nock, M.J.W.

    1976-09-01

    New theoretical results connected with the stability of multiple pulsing in a passively mode-locked quasicontinuous laser in the rate equation approximation are presented. Together with earlier results, these allow the number of pulses per cavity transit to be predicted and a qualitative estimate made of the pulse duration for any combination of parameters. The results are illustrated by computer evolutions.

  5. Two dimensional dynamic analysis of sandwich plates with gradient foam cores

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Lin; Xiao, Deng Bao; Zhao, Guiping [State Key Laboratory for Mechanical structure Strength and Vibration, School of AerospaceXi' an Jiaotong University, Xi' an (China); Cho, Chong Du [Dept. of Mechanical Engineering, Inha University, Inchon (Korea, Republic of)

    2016-09-15

    Present investigation is concerned about dynamic response of composite sandwich plates with the functionally gradient foam cores under time-dependent impulse. The analysis is based on a model of the gradient sandwich plate, in which the face sheets and the core adopt the Kirchhoff theory and a [2, 1]-order theory, respectively. The material properties of the gradient foam core vary continuously along the thickness direction. The gradient plate model is validated with the finite element code ABAQUS®. And the results show that the proposed model can predict well the free vibration of composite sandwich plates with gradient foam cores. The influences of gradient foam cores on the natural frequency, deflection and energy absorbing of the sandwich plates are also investigated.

  6. Static and Dynamic Structural Response of an Aircraft Wing with Damage Using Equivalent Plate Analysis

    Science.gov (United States)

    Krishnamurthy, T.; Tsai, Frank J.

    2008-01-01

    A process to generate an equivalent plate based on an optimization approach to predict the static and dynamic response of flight vehicle wing structures is proposed. Geometric-scale and frequency-scale factors are defined to construct an equivalent plate with any desired scale to use in simulation and wind tunnel experiments. It is shown that the stiffness and the displacements are scaled linearly with the geometric-scale factor, whereas the load is scaled as the square of the geometric-scale factor. The scaled stiffness of the reference flight vehicle is matched first to construct the equivalent plate. Then the frequency-scale factor is defined to scale the flight vehicle frequencies. The scaled flight vehicle frequencies are matched by placing arbitrary point masses along the equivalent plate geometry. Two simple stiffened-plate examples, one with damage and another without damage, were used to demonstrate the accuracy of the optimization procedure proposed. Geometric-scale factors ranging from 0.2 to 1.0 were used in the analyses. In both examples, the static and dynamic response of the reference stiffened-panel solution is matched accurately. The scaled equivalent plate predicted the first five frequencies of the stiffened panel very accurately. Finally, the proposed equivalent plate procedure was demonstrated in a more realistic typical aircraft wing structure. Two scale equivalent plate models were generated using the geometric-scale factors 1.0 and 0.2. Both equivalent plate models predicted the static response of the wing structure accurately. The equivalent plate models reproduced the first five frequencies of the wing structure accurately.

  7. Prospects of implant with locking plate in fixation of subtrochanteric fracture: experimental demonstration of its potential benefits on synthetic femur model with supportive hierarchical nonlinear hyperelastic finite element analysis

    Directory of Open Access Journals (Sweden)

    Latifi Mohammed

    2012-04-01

    Full Text Available Abstract Background Effective fixation of fracture requires careful selection of a suitable implant to provide stability and durability. Implant with a feature of locking plate (LP has been used widely for treating distal fractures in femur because of its favourable clinical outcome, but its potential in fixing proximal fractures in the subtrochancteric region has yet to be explored. Therefore, this comparative study was undertaken to demonstrate the merits of the LP implant in treating the subtrochancteric fracture by comparing its performance limits against those obtained with the more traditional implants; angle blade plate (ABP and dynamic condylar screw plate (DCSP. Materials and Methods Nine standard composite femurs were acquired, divided into three groups and fixed with LP (n = 3, ABP (n = 3 and DCSP (n = 3. The fracture was modeled by a 20 mm gap created at the subtrochanteric region to experimentally study the biomechanical response of each implant under both static and dynamic axial loading paradigms. To confirm the experimental findings and to understand the critical interactions at the boundaries, the synthetic femur/implant systems were numerically analyzed by constructing hierarchical finite element models with nonlinear hyperelastic properties. The predictions from the analyses were then compared against the experimental measurements to demonstrate the validity of each numeric model, and to characterize the internal load distribution in the femur and load bearing properties of each implant. Results The average measurements indicated that the constructs with ABP, DCPS and LP respectively had overall stiffness values of 70.9, 110.2 and 131.4 N/mm, and exhibited reversible deformations of 12.4, 4.9 and 4.1 mm when the applied dynamic load was 400 N and plastic deformations of 11.3, 2.4 and 1.4 mm when the load was 1000 N. The corresponding peak cyclic loads to failure were 1100, 1167 and 1600 N. The errors

  8. Dynamic Error Analysis Method for Vibration Shape Reconstruction of Smart FBG Plate Structure

    Directory of Open Access Journals (Sweden)

    Hesheng Zhang

    2016-01-01

    Full Text Available Shape reconstruction of aerospace plate structure is an important issue for safe operation of aerospace vehicles. One way to achieve such reconstruction is by constructing smart fiber Bragg grating (FBG plate structure with discrete distributed FBG sensor arrays using reconstruction algorithms in which error analysis of reconstruction algorithm is a key link. Considering that traditional error analysis methods can only deal with static data, a new dynamic data error analysis method are proposed based on LMS algorithm for shape reconstruction of smart FBG plate structure. Firstly, smart FBG structure and orthogonal curved network based reconstruction method is introduced. Then, a dynamic error analysis model is proposed for dynamic reconstruction error analysis. Thirdly, the parameter identification is done for the proposed dynamic error analysis model based on least mean square (LMS algorithm. Finally, an experimental verification platform is constructed and experimental dynamic reconstruction analysis is done. Experimental results show that the dynamic characteristics of the reconstruction performance for plate structure can be obtained accurately based on the proposed dynamic error analysis method. The proposed method can also be used for other data acquisition systems and data processing systems as a general error analysis method.

  9. Dynamic response of clamped corrugated sandwich plates subjected to underwater impulsive loads

    Science.gov (United States)

    Huang, Wei; Zhang, Wei; Ye, Nan; Li, Dacheng

    2017-01-01

    Corrugated sandwich plates are widely used in marine industry because such plates have high strength-to-weight ratios and blast resistance. The laboratory-scaled fluid-structure interaction experiments are performed to demonstrate the shock resistance of corrugated sandwich plates by quantifying the permanent transverse deflection at mid-span of the plates as a function of impulsive loadings per areal mass. Sandwich structures with 6mm-thick 3003 H18 aluminum corrugated core and 5A06 face sheets subjected to underwater impulsive loadings are studied experimentally in this paper. The dynamic deformations of plates are captured with the the 3D digital imaging correlation method (DIC). The results affirm the peak deflection during the processes of dynamic deformation and the residual maximum deflection for post-mortem plates show a linear trend with the impulses per areal mass, and show sensitivity to the change of impulses. Inhomogeneous deformation for corrugated sandwich plates are show uneven rather than the perfect parabolic shapes reported in previous studies. With the increasing of intensities for impulsive loadings, the failure modes can be observed more complicated from the initial plastic deformation to debonding and crack. This paper provides valid data to quantify the peak deflection, residual deflection and failure modes as functions of impulses and geometric parameters in the future work.

  10. The constraint method: A new finite element technique. [applied to static and dynamic loads on plates

    Science.gov (United States)

    Tsai, C.; Szabo, B. A.

    1973-01-01

    An approch to the finite element method which utilizes families of conforming finite elements based on complete polynomials is presented. Finite element approximations based on this method converge with respect to progressively reduced element sizes as well as with respect to progressively increasing orders of approximation. Numerical results of static and dynamic applications of plates are presented to demonstrate the efficiency of the method. Comparisons are made with plate elements in NASTRAN and the high-precision plate element developed by Cowper and his co-workers. Some considerations are given to implementation of the constraint method into general purpose computer programs such as NASTRAN.

  11. Seismic anisotropy: tracing plate dynamics in the mantle.

    Science.gov (United States)

    Park, Jeffrey; Levin, Vadim

    2002-04-19

    Elastic anisotropy is present where the speed of a seismic wave depends on its direction. In Earth's mantle, elastic anisotropy is induced by minerals that are preferentially oriented in a directional flow or deformation. Earthquakes generate two seismic wave types: compressional (P) and shear (S) waves, whose coupling in anisotropic rocks leads to scattering, birefringence, and waves with hybrid polarizations. This varied behavior is helping geophysicists explore rock textures within Earth's mantle and crust, map present-day upper-mantle convection, and study the formation of lithospheric plates and the accretion of continents in Earth history.

  12. Dynamic Correction Algorithm of Rolling Force in Plate Rolling

    Institute of Scientific and Technical Information of China (English)

    QIU Hong-lei; WANG Jun; HU Xian-lei; WANG Zhao-dong; WANG Guo-dong

    2005-01-01

    Based on the Shougang plat mill project, an on-line dynamic correction algorithm was analyzed. This algorithm can adjust model coefficients better because the reasonable correction is based on the measured and calculated rolling force. The results of application on site show that this on-line dynamic correction algorithm is effective.

  13. Dynamic Response of a Rigid Pavement Plate Based on an Inertial Soil.

    Science.gov (United States)

    Gibigaye, Mohamed; Yabi, Crespin Prudence; Alloba, I Ezéchiel

    2016-01-01

    This work presents the dynamic response of a pavement plate resting on a soil whose inertia is taken into account in the design of pavements by rational methods. Thus, the pavement is modeled as a thin plate with finite dimensions, supported longitudinally by dowels and laterally by tie bars. The subgrade is modeled via Pasternak-Vlasov type (three-parameter type) foundation models and the moving traffic load is expressed as a concentrated dynamic load of harmonically varying magnitude, moving straight along the plate with a constant acceleration. The governing equation of the problem is solved using the modified Bolotin method for determining the natural frequencies and the wavenumbers of the system. The orthogonal properties of eigenfunctions are used to find the general solution of the problem. Considering the load over the center of the plate, the results showed that the deflections of the plate are maximum about the middle of the plate but are not null at its edges. It is therefore observed that the deflection decreased 18.33 percent when the inertia of the soil is taken into account. This result shows the possible economic gain when taking into account the inertia of soil in pavement dynamic design.

  14. Dynamic Response of a Rigid Pavement Plate Based on an Inertial Soil

    Science.gov (United States)

    Gibigaye, Mohamed; Yabi, Crespin Prudence; Alloba, I. Ezéchiel

    2016-01-01

    This work presents the dynamic response of a pavement plate resting on a soil whose inertia is taken into account in the design of pavements by rational methods. Thus, the pavement is modeled as a thin plate with finite dimensions, supported longitudinally by dowels and laterally by tie bars. The subgrade is modeled via Pasternak-Vlasov type (three-parameter type) foundation models and the moving traffic load is expressed as a concentrated dynamic load of harmonically varying magnitude, moving straight along the plate with a constant acceleration. The governing equation of the problem is solved using the modified Bolotin method for determining the natural frequencies and the wavenumbers of the system. The orthogonal properties of eigenfunctions are used to find the general solution of the problem. Considering the load over the center of the plate, the results showed that the deflections of the plate are maximum about the middle of the plate but are not null at its edges. It is therefore observed that the deflection decreased 18.33 percent when the inertia of the soil is taken into account. This result shows the possible economic gain when taking into account the inertia of soil in pavement dynamic design. PMID:27382639

  15. Clinical analysis of humerus surgical neck fracture treated with locking proximal humerus plate%锁定钢板治疗肱骨外科颈骨折36例分析

    Institute of Scientific and Technical Information of China (English)

    袁展程

    2012-01-01

    Objective To study on the therapeutic effect of humerus surgical neck fracture treated with locking proximal humerus plate. Methods There were 36 cases of humerus surgical neck fracture were treated by locking proximal humerus plate. According to Neer classification, 6 cases had two -part fracture. 23 cases had three-part fracture and 7 cases four-part fracture. The function of shoulders was evaluated after treatment. Results According to the NEER criteria,the results were excellent in 19 cases, good in 12 cases, fair in 5 cases. The rate of excellent and good was 86. 1%. Conclusion Treatment of humerus surgical neck fracture with locking proximal humerus plate has stable internal fixation and less complications, bone fracture heals good. It can take functional exercise earlier.%目的 探讨锁定钢板治疗肱骨外科颈骨折的疗效.方法 应用肱骨近端锁定钢板治疗肱骨外科颈骨折36例,其中Neer分类二部分骨折6倒,三部分骨折23例,四部分骨折7例.治疗后评价肩关节功能.结果 术后所有患者随访4~12个月,按Neer评分标准判断:优19倒,良12例,可5例.总优良率为86.1%.结论 锁定钢板治疗肱骨外科颈骨折,内固定牢靠,骨折愈合良好,可早期功能锻炼,术后无严重并发症,是目前比较理想的治疗方法.

  16. 解剖型锁定钢板外固定治疗锁骨骨髓炎%Usage of anatomic locking plate as an external fixator for the treatment of clavicular osteomyelitis

    Institute of Scientific and Technical Information of China (English)

    叶文斌; 翟文亮; 丁真奇

    2011-01-01

    目的 探讨解剖型锁定钢板治疗锁骨骨髓炎的效果.方法 对14例锁骨骨髓炎患者进行病灶清除、灌洗,解剖型锁定钢板外固定治疗.根据ASES系统对肩关节功能进行综合评价.结果 14例均获随访,时间6~23(10±2.5)个月.均获得良好的愈合.肩关节功能评分平均为91.3分±3.2分.结论 解剖型锁定钢板可提供良好的外固定,用于锁骨骨髓炎病灶清除后固定确实、可行.%Objective To evaluate the effects of anatomic locking plate as an external fixator for the treatment of clavicular osteomyelitis.Methods 14 patients who had clavicular osteomyelitis and partially bone defect were treated by focus clearance and locking plate external fixation.At the last follow up, the shoulder function was evaluated according to the ASES system.Results Each of 14 patients ohtained healing, and was followed up for 6 ~ 23 months on average of( 10 ±2.5 ) months.and the average ASES score was ( 91.3 ±3.2 ).Conclusions It proves an excellent way hy using of anatomic locking plate as external fixation for clavicle osteomyelitis.

  17. 多轴锁定钢板内固定治疗复杂胫骨平台骨折临床观察%Clinical observation of multiaxis locking plate on treating complex tibial plateau fractures

    Institute of Scientific and Technical Information of China (English)

    周志华; 王修卓; 杨新

    2013-01-01

    Objective To explore multiaxis locking plate in the treatment of complex tibial plateau fractures fixed treatment effect. Methods 24 cases of complex fracture of tibial plateau were treated using multiaxis locking plate. Results 24 cases have been followed-up period was average of 12 months. (ranging from 6 months to 24 months), an According to Merchant score standard evaluation of knee joint function, excellent in 4 cases (16.6%), good in12 cases (50%),pretty good in 6 (25%) points, poor in 2 (8.4%). Conclusion Multiple spindle locking plate fixed in treatment of complex fracture of tibial plateau is widely used, the more stable after fixed, less postoperative complications, and is a good choice.%  目的探讨多轴锁定钢板内固定治疗复杂胫骨平台骨折的治疗效果。方法24例胫骨平台骨折患者采用多轴锁定钢板内固定治疗。结果24例均获随访,时间6个月~24个月,平均12个月。按Merchant评分标准评价膝关节功能,优4例(16.6%),良12例(50%),中6例(25%),差2例(8.4%)。结论多轴锁定钢板内固定治疗复杂胫骨平台骨折适用范围广,固定稳固,预后好,术后并发症少,可以作为复杂胫骨平台骨折的较佳治疗选择。

  18. Proximal femoral locking plate treatment of intertrochanteric fractures in older adults%股骨近端锁定板治疗老年人股骨粗隆间骨折

    Institute of Scientific and Technical Information of China (English)

    田学林; 朱冬承

    2014-01-01

    目的:探讨股骨近端锁定板治疗老年人股骨粗隆间骨折的疗效。方法选取我院老年人股骨粗隆间骨折患者88例为研究对象,对照组采取常规内固定,观察组采取股骨近端锁定板内固定,比较两组疗效。结果观察组治疗总有效率为95.45%;对照组治疗总有效率为68.18%。结论股骨近端锁定板治疗老年人股骨粗隆间骨折具有很好的临床效果,能有效促进患者恢复,提高其生活质量。%Objective To explore the proximal femoral locking plate curative effect for the treatment of intertrochanteric fractures in older adults. Methods Selected from 88 cases of patients with intertrochanteric fractures in older adults as the research object,control group,take regular internal fixation group take the proximal femoral locking plate internal fixation,compared two groups of therapeutic effect. Results Observation treatment group the total effective rate was 95.45%; The control group total effective rate was 68.18%. Conclusion Proximal femoral locking plate treatment of intertrochanteric fractures in older adults have very good clinical effect,can effectively promote the patient recover,improve the quality of life.

  19. Clinical efficacy of locking compression plate fixation in treatment of femoral intertrochanteric fracture%锁定加压钢板治疗股骨转子间骨折21例临床分析

    Institute of Scientific and Technical Information of China (English)

    杨岭; 聂磊; 孙湖山

    2012-01-01

    Objective: To investigate the effects of locking compression plate fixation in treatment of intertrochanteric fracture. Methods: Twenty-one cases with femoral intertrochanteric fracture were treated with locking compression plate fixation. Results: The fractures of all cases were recovered after 3-6 months. The complications of nails breakage and internal fixation loosening were not found. The function recovery of hip joint were good and no clear lower limb shortening deformity. Excellent and good effects in 13 and 8 cases were confirmed according to Harris standard. Conclusions: Treatmment of femoral intertrochanteric fracture with locking compression plate fixation is easy to install and fix, which is an effective method of operation with shorter operative time, less bleeding and goog hip joint function recovery.%目的:观察锁定加压钢板治疗股骨转子间骨折的疗效.方法:应用锁定加压钢板治疗股骨转子间骨折21例.结果:21例患者3~ 6个月骨折均愈合,未出现断钉、内固定松动等并发症,无明显髋内翻和下肢短缩畸形;Harris评分为优11例,良8例,可2例.结论:锁定加压钢板治疗股骨转子间骨折具有容易安装、固定可靠、手术时间短、出血量少、髋关节功能恢复优良率高等特点,是一种有效的手术方法.

  20. Dynamic Approach to Defend Against Distributed Denial of Service Attacks Using an Adaptive Spin Lock Rate Control Mechanism

    Directory of Open Access Journals (Sweden)

    V. P. Arunachalam

    2012-01-01

    Full Text Available Problem statement: The last decade has seen many prominent Distributed Denial of Service (DDoS attacks on high profile webservers. In this study, we deal with DDoS attacks by proposing a dynamic reactive defense system using an adaptive Spin Lock Rate control (D3SLR. D3SLR identifies malicious traffic flow towards a target system based on the volume of traffic flowing towards the victim machine. Approach: The proposed scheme uses a divide and conquer approach to identify the infected interface via which malicious traffic are received and selectively implements rate limiting based on the source of traffic flow towards victim and type of packet rather than a collective rate limiting on flow towards victim. Results: The results observed in simulation shows that D3SLR detects the onset of the attacks very early and reacts to the threat by rate limiting the malicious flow. The spin lock rate control adapts quickly to any changes in the rate of flow. Conclusion: D3SLR can be successfully implemented at critical points in the network as autonomous defense systems working independently to limit damage to the victim and also allows legitimate flows towards the target system with a higher degree of accuracy.

  1. A delay differential model of ENSO variability, Part 2: Phase locking, multiple solutions, and dynamics of extrema

    CERN Document Server

    Zaliapin, Ilya

    2010-01-01

    We consider a highly idealized model for El Nino/Southern Oscillation (ENSO) variability, as introduced in an earlier paper. The model is governed by a delay differential equation for sea surface temperature in the Tropical Pacific, and it combines two key mechanisms that participate in ENSO dynamics: delayed negative feedback and seasonal forcing. We perform a theoretical and numerical study of the model in the three-dimensional space of its physically relevant parameters: propagation period of oceanic waves across the Tropical Pacific, atmosphere-ocean coupling, and strength of seasonal forcing. Phase locking of model solutions to the periodic forcing is prevalent: the local maxima and minima of the solutions tend to occur at the same position within the seasonal cycle. Such phase locking is a key feature of the observed El Nino (warm) and La Nina (cold) events. The phasing of the extrema within the seasonal cycle depends sensitively on model parameters when forcing is weak. We also study co-existence of mu...

  2. 建立锁骨个性化锁定接骨板模型及有限元分析%Establishment of personalized locking clavicle plate model and finite element analysis

    Institute of Scientific and Technical Information of China (English)

    尹峰; 王晓东; 梁炜; 任龙韬

    2016-01-01

    BACKGROUND:The finite element analysis method is more accurate and fast to construct the three-dimensional model of the human skeleton and design the bone surgical medical instrument. OBJECTIVE:To establish locking plate model according to the clavicle model, analyze and evaluate stress distribution of locking plate of the finite element model under bending and torsion conditions. METHODS:Chest scan was carried out in a healthy young adult male by adopting 64-row spiral CT and his two-dimensional image data were gotten. The obtained data were analyzed with Mimics 10.0 software to establish the three-dimensional clavicle finite element model. The clavicle locking fixation plate model was established by applying the UG software. The locking fixation plate was evaluated by utilizing the abaqus software when the plate was bent while down to give force of 200 N, and twisted while 200 N•mm, to simulate the force and analyze the stress distribution of the locking plate. RESULTS AND CONCLUSION:Based on the original image parameters provided by CT, this experiment produced a three-dimensional model of the clavical titanium plate which fitted better to bones. This model can obtain a single individual, personalized plate by three-dimensional printing technology. The finite element analysis basical y can simulate the actual stress of the plate. For straight plate and“S”-shape plate, in lateral bending and axial torsion loads, the maximum stress distribution of the seven-hole titanium plate is located in the center of the center hole. During actual surgical procedures, clavicle fracture fragments and middle locking hole had stress superposition. If the titanium plate can avoid the stress concentration, it can effectively avoid the occurrence of the broken plate after implantation, provide theoretical guidance for clinical practice, and provide reference and technical route for biomechanical analysis of other types of titanium plate.%背景:应用有限元分析的方

  3. Hemiarthroplasty versus angle-stable locking compression plate osteosynthesis in the treatment of three- and four-part fractures of the proximal humerus in the elderly: design of a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Verbeek Paul A

    2012-02-01

    Full Text Available Abstract Background The optimal surgical management of dislocated three- and four-part fractures of the proximal humerus in elderly patients remains unclear. Most used techniques are hemiarthroplasty and angle-stable locking compression plate osteosynthesis. In the current literature there is no evidence available presenting superior results between hemiarthroplasty and angle-stable locking compression plate osteosynthesis in terms of speed of recovery, pain, patient satisfaction, functional outcome, quality of life or complications. Methods/Design A randomized controlled multicenter trial will be conducted. Patients older than 60 years of age with a dislocated three- or four-part fracture of the proximal humerus as diagnosed by X-rays and CT-scans will be included. Exclusion criteria are a fracture older than 14 days, multiple comorbidity, multitrauma, a pathological fracture, previous surgery on the injured shoulder, severely deranged function caused by a previous disease, "head-split" proximal humerus fracture and unwillingness or inability to follow instructions. Participants will be randomized between surgical treatment with hemiarthroplasty and angle-stable locking compression plate osteosynthesis. Measurements will take place preoperatively and 3 months, 6 months, 9 months, 12 months and 24 months postoperatively. Primary outcome measure is speed of recovery of functional capacity of the affected upper limb using the Disabilities of Arm, Shoulder and Hand score (DASH. Secondary outcome measures are pain, patient satisfaction, shoulder function, quality of life, radiological evaluation and complications. Data will be analyzed on an intention-to-treat basis, using univariate and multivariate analyses. Discussion Both hemiarthroplasty and angle-stable locking compression plate osteosynthesis are used in the current treatment of dislocated three-and four-part fractures of the proximal humerus. There is a lack of level-1 studies comparing

  4. High dynamic synchronization algorithm based on modified frequency-locked and phase-locked%基于改进锁频锁相的高动态同步算法

    Institute of Scientific and Technical Information of China (English)

    高玉龙; 王骐; 白旭; 沙学军

    2009-01-01

    针对卫星定位导航系统多谱勒频移大的特点,根据设计的实际系统推导出锁频锁相算法的理论表达式.对叉积算法得到的结果利用改进的平滑算法进行处理,降低了噪声方差.与此同时使锁频环和锁相环同时工作,加快了更新时间.对上述改进算法进行单片FPGA实现,采用NiosⅡ代替传统的DSP对算法的锁频锁相部分进行实现,增加了系统的稳定性和可靠性.通过实验验证,提出的改进算法解决了环路跟踪精度和动态性能不能兼顾的矛盾,各项技术指标达到或超过系统设计的要求.%Aiming at the characteristics of navigation satellite system,theoretical expressions of frequency-locked and phase-locked algorithm are gained according to practical system.The results of AFC algorithm are processed using modified smoothed algorithm,and its covariance is decreased.Simultaneously,Frequency-locked loop and cestas loop work synchronously,which shorten the update time of them.Above algorithm is realized using single FPGA,frequency-locked loop and phase-locked loop are imple-mented by NiosⅡ replacing conventional DSP,and these enhance stability and reliability of system.Some tests prove that contra-diction between tracking precision and dynamic performance is resolved basically.All required technical guideline of the system are achieved or exceeded.

  5. Higher-dimensional chaotic dynamics of a composite laminated piezoelectric rectangular plate

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; GAO MeiJuan; YAO MingHui; YAO ZhiGang

    2009-01-01

    The analysis on the chaotic dynamics of a six-dimensional nonlinear system which represents the averaged equation of a composite laminated piezoelectric rectangular plate is given for the first time. The theory of normal form and the energy-phase method are combined to investigate the higher-dimensional chaotic dynamics of the composite laminated piezoelectric rectangular plate. Firstly, the theory of normal form is used to reduce the six-dimensional averaged equation to the simpler normal form.Then, the energy-phase method is extended to analyze the global bifurcations and chaotic dynamics of a six-dimensional nonlinear system. The analysis results indicate that there exist the homoclinic bifurcation and Shilnikov type multi-pulse chaos for the composite laminated piezoelectric rectangular plate. Finally, numerical simulations are also used to investigate the nonlinear dynamic characteristics of the composite laminated piezoelectric rectangular plate. The results of numerical simulations also demonstrate that there exist the chaotic motions and the multi-pulse jumping orbits of the composite laminated piezoelectric rectangular plate.

  6. Higher-dimensional chaotic dynamics of a composite laminated piezoelectric rectangular plate

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The analysis on the chaotic dynamics of a six-dimensional nonlinear system which represents the averaged equation of a composite laminated piezoelectric rectangular plate is given for the first time. The theory of normal form and the energy-phase method are combined to investigate the higher-dimen-sional chaotic dynamics of the composite laminated piezoelectric rectangular plate. Firstly,the theory of normal form is used to reduce the six-dimensional averaged equation to the simpler normal form. Then,the energy-phase method is extended to analyze the global bifurcations and chaotic dynamics of a six-dimensional nonlinear system. The analysis results indicate that there exist the homoclinic bi-furcation and Shilnikov type multi-pulse chaos for the composite laminated piezoelectric rectangular plate. Finally,numerical simulations are also used to investigate the nonlinear dynamic characteristics of the composite laminated piezoelectric rectangular plate. The results of numerical simulations also demonstrate that there exist the chaotic motions and the multi-pulse jumping orbits of the composite laminated piezoelectric rectangular plate.

  7. Innovation and Lock-in

    DEFF Research Database (Denmark)

    Cantner, Uwe; Vannuccini, Simone

    2016-01-01

    , especially when innovation is concerned. Also, we address the question if lock-in is a well-defined concept at all. To offer a fresh view on lock-in and to tackle the issues just raised, we employ the replicator dynamics model. By making a parallel between monopolization in the replicator dynamics...... and the occurrence of lock-ins, we show that the convergence of a system to a given outcome can be reversed, under certain conditions. We highlight the need for a more precise demarcation of the conceptual boundaries of lock-in and path dependence, both from the formal and the empirical side, and suggest...

  8. In-plane dynamic stiffness matrix for a free orthotropic plate

    Science.gov (United States)

    Ghorbel, O.; Casimir, J. B.; Hammami, L.; Tawfiq, I.; Haddar, M.

    2016-03-01

    The aim of this paper is to describe a procedure for computing the dynamic stiffness matrix relative to the in-plane effect for an orthotropic rectangular plate. The dynamic stiffness matrix is calculated for free edge boundary conditions. The formulation is based on strong solutions for the equations of motion for an orthotropic plate obtained with the Levy series and a Gorman decomposition of the free boundary conditions. The results obtained for the in-plane harmonic response are validated by the Finite Element Method.

  9. Late Miocene Pacific plate kinematic change explained with coupled global models of mantle and lithosphere dynamics

    DEFF Research Database (Denmark)

    Stotz, Ingo Leonardo; Iaffaldano, Giampiero; Davies, DR

    2017-01-01

    and the consequent subduction polarity reversal. The uncertainties associated with the timing of this event, however, make it difficult to quantitatively demonstrate a dynamical association. Here, we first reconstruct the Pacific plate's absolute motion since the mid-Miocene (15 Ma), at high-temporal resolution....../lithosphere system to test hypotheses on the dynamics driving this change. These indicate that the arrival of the OJP at the Melanesian arc, between 10 and 5 Ma, followed by a subduction polarity reversal that marked the initiation of subduction of the Australian plate underneath the Pacific realm, were the key...

  10. Clinical Comparison of Locking Proximal Humerus Plate and Conventional Plate in Treatment of Proximal Humerus Fractures%肱骨近端加压锁定钢板与传统钢板治疗肱骨近端骨折的疗效比较

    Institute of Scientific and Technical Information of China (English)

    孙跃先; 尹威; 于晶

    2015-01-01

    Objective To compare the efficacy of proximal humerus locking plate and conventional plate in treatment of proximal humerus fractures.Methods66 patients with proximal humeral fracture were divided into two groups. The observation group used locking proximal humerus plate,control group used conventional plate. compared the effect of two groups.ResultsThe Neer score, excelent rate and complication rate of the observation group were significantly better than control group (P<0.05).ConclusionThe proximal humerus locking plate can promote the healing of fractures,and less complications.%目的:探讨肱骨近端加压锁定钢板和传统钢板治疗肱骨近端骨折的效果。方法选择将我院收治的66例肱骨近端骨折患者随机平分为2组。观察组行加压锁定钢板术,对照组行传统钢板术。比较两组临床疗效。结果观察组Neer评分、优良率及并发症发生率优于对照组(P<0.05)。结论肱骨近端加压锁定钢板治疗肱骨近端骨折有利于骨折的快速愈合,且并发症少。

  11. Dynamic subduction process of local plate revealed by Ibaraki earthquake sequence of 1982 in Japan

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The kinematics and dynamics of plate tectonics are frontalsubjects in geosciences and the strong earthquake oc-curred along the plate boundary result directly from plate movement. By analyzing Ibaraki earthquake sequence, it has been found that the focal fault plane shows a special image of grading expansion along the direction of strike and adjustment along the dip direction respectively. With the consideration of strike, dip and slip directions of focal mechanism, we have confirmed that Ibaraki earthquake belongs to a thrust fault earthquake occurred under the Japan Trench. The cause of the earthquake sequence is discussed in the paper. The study on the temporal-spatial distribution of the earthquake sequence with a time-scale between the year-scale spatial geodetic data and the second-scale moment tensor of the strong earthquake has indicated the dynamic process of Pacific Plate sub-duction under the Eurasia Plate. According to the average slip distance of earthquake and the velocity of plate movement, it is predicted that a strong earthquake might occur in recent years.

  12. Effects of multiple resistive shells and transient electromagnetic torque on the dynamics of mode locking in reversed field pinch plasmas

    Science.gov (United States)

    Guo, S. C.; Chu, M. S.

    2002-11-01

    The effects of multiple resistive shells and transient electromagnetic torque on the dynamics of mode locking in the reversed field pinch (RFP) plasmas are studied. Most RFP machines are equipped with one or more metal shells outside of the vacuum vessel. These shells have finite resistivities. The eddy currents induced in each of the shells contribute to the braking electromagnetic (EM) torque which slows down the plasma rotation. In this work we study the electromagnetic torque acting on the plasma (tearing) modes produced by a system of resistive shells. These shells may consist of several nested thin shells or several thin shells enclosed within a thick shell. The dynamics of the plasma mode is investigated by balancing the EM torque from the resistive shells with the plasma viscous torque. Both the steady state theory and the time-dependent theory are developed. The steady state theory is shown to provide an accurate account of the resultant EM torque if (dω/dt)ω-2≪1 and the time scale of interest is much longer than the response (L/R) time of the shell. Otherwise, the transient theory should be adopted. As applications, the steady state theory is used to evaluate the changes of the EM torque response from the resistive shells in two variants of two RFP machines: (1) modification from Reversed Field Experiment (RFX) [Gnesotto et al., Fusion Eng. Des. 25, 335 (1995)] to the modified RFX: both of them are equipped with one thin shell plus one thick shell; (2) modification from Extrap T2 to Extrap T2R [Brunsell et al., Plasma Phys. Controlled Fusion 43, 1457 (2001)]: both of them are equipped with two thin shells. The transient theory has been applied numerically to study the time evolution of the EM torque during the unlocking of a locked tearing mode in the modified RFX.

  13. Modeling and Chaotic Dynamics of the Laminated Composite Piezoelectric Rectangular Plate

    Directory of Open Access Journals (Sweden)

    Minghui Yao

    2014-01-01

    Full Text Available This paper investigates the multipulse heteroclinic bifurcations and chaotic dynamics of a laminated composite piezoelectric rectangular plate by using an extended Melnikov method in the resonant case. According to the von Karman type equations, Reddy’s third-order shear deformation plate theory, and Hamilton’s principle, the equations of motion are derived for the laminated composite piezoelectric rectangular plate with combined parametric excitations and transverse excitation. The method of multiple scales and Galerkin’s approach are applied to the partial differential governing equation. Then, the four-dimensional averaged equation is obtained for the case of 1 : 3 internal resonance and primary parametric resonance. The extended Melnikov method is used to study the Shilnikov type multipulse heteroclinic bifurcations and chaotic dynamics of the laminated composite piezoelectric rectangular plate. The necessary conditions of the existence for the Shilnikov type multipulse chaotic dynamics are analytically obtained. From the investigation, the geometric structure of the multipulse orbits is described in the four-dimensional phase space. Numerical simulations show that the Shilnikov type multipulse chaotic motions can occur. To sum up, both theoretical and numerical studies suggest that chaos for the Smale horseshoe sense in motion exists for the laminated composite piezoelectric rectangular plate.

  14. Supercontinent Pangea, Mantle Dynamics, and Reference Frame of Global Plate Motions

    Science.gov (United States)

    Zhong, S.; Rudolph, M. L.; Liu, X.

    2014-12-01

    Arguably the most important and challenging goal in geodynamics is to understand the two-way dynamics between tectonic plates and mantle convection. While it has long been recognized that the present-day degree-2 mantle structure as imaged seismically is closely related to the plate motions (Hager and O'Connell, 1981) and their history (500 Ma (Torsvik et al., 2014), although its statistical significance has been challenged (Austermann et al., 2013). The proposals of the spatially stable Africa and Pacific LLSVPs and of the LIP eruptions along their edges have also been exploited in attempts to build global plate motion models since the Pangea assembly by providing a plate motion reference frame or inferring true polar wander (TPW) corrections to the plate motions (Torsvik et al., 2014). Second, mantle dynamics studies indicate that degree-1 mantle convection, which is expected with realistic lithospheric and mantle viscosity, may be needed for assembly of a supercontinent (e.g., Pangea) (Zhong et al., 2007). This suggests that the present degree-2 mantle structure may have been formed only after the Pangea assembly from an initially degree-1 structure - a scenario that is consistent with convection calculations with a proxy plate motion model that considers Pangea process (Zhang et al., 2010). In this presentation, in addition to critically reviewing these arguments, we will discuss calculations of long-wavelength geoid for the mantle with thermochemical piles and LLSVPs and their potential effects on TPW determinations and hence reconstruction of plate motion (i.e., net lithospheric rotation). We will also present additional calculations of mantle structure evolution using different plate motion history models.

  15. Dynamic Analysis of the Titanium Alloy Plate under Thermal-acoustic Loadings

    Directory of Open Access Journals (Sweden)

    Zou Xuefeng

    2015-01-01

    Full Text Available Hypersonic vehicles structures suffer complex combined loadings generally. For the thin-walled structures and thermal protection systems of the aircraft, high temperature and intensity acoustic loadings are the significant factors that leading to their break. The object of this paper is typical simply supported titanium alloy plate, the finite element method was adopted to calculate the critical thermal buckling temperature the ordinal coupling method and Newmark method were adopted to calculate the thermal-acoustic dynamic response. Based on the FEM analysis, the power spectrum densities (PSD of center point was presented. Research results show that the thermal buckling of the typical simply supported titanium alloy plate occurs easily because of the low critical thermal buckling temperature, dynamic response of the thermal buckled plate suffering acoustic loads performs strong nonlinear characteristics and complex forms of exercise.

  16. Dynamically slow processes in supercooled water confined between hydrophobic plates

    Energy Technology Data Exchange (ETDEWEB)

    Franzese, Giancarlo [Departamento de Fisica Fundamental, Universidad de Barcelona, Diagonal 647, Barcelona 08028 (Spain); Santos, Francisco de los, E-mail: gfranzese@ub.ed, E-mail: fdlsant@ugr.e [Departamento de Electromagnetismo y Fisica de la Materia, Universidad de Granada, Fuentenueva s/n, 18071 Granada (Spain)

    2009-12-16

    We study the dynamics of water confined between hydrophobic flat surfaces at low temperature. At different pressures, we observe different behaviors that we understand in terms of the hydrogen bond dynamics. At high pressure, the formation of the open structure of the hydrogen bond network is inhibited and the surfaces can be rapidly dried (dewetted) by formation of a large cavity with decreasing temperature. At lower pressure we observe strong non-exponential behavior of the correlation function, but with no strong increase of the correlation time. This behavior can be associated, on the one hand, to the rapid ordering of the hydrogen bonds that generates heterogeneities and, on the other hand, to the lack of a single timescale as a consequence of the cooperativity in the vicinity of the liquid-liquid critical point that characterizes the phase diagram at low temperature of the water model considered here. At very low pressures, the gradual formation of the hydrogen bond network is responsible for the large increase of the correlation time and, eventually, the dynamical arrest of the system, with a strikingly different dewetting process, characterized by the formation of many small cavities.

  17. Proximal humerus comminuted fracture of the plate fixation in the treatment of locking application%肱骨近端粉碎性骨折应用锁定钢板内固定治疗的临床分析

    Institute of Scientific and Technical Information of China (English)

    叶鹏

    2014-01-01

    Objective:To study the comminuted fractures of the proximal humerus locking plate internal fixation treatment.Methods:A retrospective analysis of 22 cases of proximal humerus fractures in our hospital patient data.Results:Patients with fractures healed,the average healing time of 22W frac-ture,the excellent and good rate was 81.8%.Conclusion:the use of locking plate fixation for comminuted fractures of the proximal humerus,effect.%目的:研究分析肱骨近端粉碎性骨折应用锁定钢板内固定治疗效果。方法:回顾性分析我院收治的22例肱骨近端粉碎性骨折患者的资料。结果:患者骨折愈合良好,骨折平均愈合时间为22w,优良率为81.8%。结论:采用锁定钢板内固定治疗肱骨近端粉碎性骨折,效果显著。

  18. Growth plate cartilage shows different strain patterns in response to static versus dynamic mechanical modulation.

    Science.gov (United States)

    Kaviani, Rosa; Londono, Irene; Parent, Stefan; Moldovan, Florina; Villemure, Isabelle

    2016-08-01

    Longitudinal growth of long bones and vertebrae occurs in growth plate cartilage. This process is partly regulated by mechanical forces, which are one of the underlying reasons for progression of growth deformities such as idiopathic adolescent scoliosis and early-onset scoliosis. This concept of mechanical modulation of bone growth is also exploited in the development of fusionless treatments of these deformities. However, the optimal loading condition for the mechanical modulation of growth plate remains to be identified. The objective of this study was to evaluate the effects of in vitro static versus dynamic modulation and of dynamic loading parameters, such as frequency and amplitude, on the mechanical responses and histomorphology of growth plate explants. Growth plate explants from distal ulnae of 4-week-old swines were extracted and randomly distributed among six experimental groups: baseline ([Formula: see text]), control ([Formula: see text]), static ([Formula: see text]) and dynamic ([Formula: see text]). For static and dynamic groups, mechanical modulation was performed in vitro using an Indexed CartiGen bioreactor. A stress relaxation test combined with confocal microscopy and digital image correlation was used to characterize the mechanical responses of each explant in terms of peak stress, equilibrium stress, equilibrium modulus of elasticity and strain pattern. Histomorphometrical measurements were performed on toluidine blue tissue sections using a semi-automatic custom-developed MATLAB toolbox. Results suggest that compared to dynamic modulation, static modulation changes the strain pattern of the tissue and thus is more detrimental for tissue biomechanics, while the histomorphological parameters are not affected by mechanical modulation. Also, under dynamic modulation, changing the frequency or amplitude does not affect the biomechanical response of the tissue. Results of this study will be useful in finding optimal and non-damaging parameters

  19. TWO-MODE GALERKIN APPROACH IN DYNAMIC STABILITY ANALYSIS OF VISCOELASTIC PLATES

    Institute of Scientific and Technical Information of China (English)

    张能辉; 程昌钧

    2003-01-01

    The dynamic stability of viscoelastic thin plates with large deflections was investigated by using the largest Liapunov exponent analysis and other numerical and analytical dynamic methods. The material behavior was described in terms of the Boltzmann superposition principle. The Galerkin method was used to simplify the original integropartial-differential model into a two-mode approximate integral model, which further reduced to an ordinary differential model by introducing new variables. The dynamic properties of one-mode and two-mode truncated systems were numerically compared. The influence of viscoelastic properties of the material, the loading amplitude and the initial values on the dynamic behavior of the plate under in-plane periodic excitations was discussed.

  20. Application of long PHILOS locking compression plate for treatment of proximal humerus long segment fractures%应用长PHILOS接骨板治疗肱骨近端长节段骨折

    Institute of Scientific and Technical Information of China (English)

    郑继会; 苑娜; 胡思斌; 孙宏辉; 赵爱军; 刘道阔

    2013-01-01

    目的 探讨长PHILOS接骨板治疗肱骨近端长节段骨折的疗效.方法 应用长PHILOS接骨板结合MIPO技术治疗22例肱骨近端长节段骨折患者.结果 患者均获随访,时间8~36个月,骨折全部愈合.按照Neer肩关节功能评分标准:优12例,良8例,可2例.结论 应用长PHILOS接骨板结合MIPO技术治疗肱骨近端长节段骨折固定可靠,可以早期功能锻炼,术后功能恢复满意,是治疗肱骨近端长节段骨折有效的方法.%Objective To explore the treatment effeet of long proximal humeral internal locking system ( PHILOS )for proximal humeral long segment fractures. Methods 27 cases of proximal humeral long segment fractures were treated with long PHILOS locking compression plate combined with MIPO technology. Results All patients were followed up for 8 ~ 36 months, all fractures were union. By Neer shoulder scoring system, 12 cases were excellent, 8 good, and 2 fair. Conclusions Applying long PHILOS locking compression plate combined with MIPO technology in treatment of proximal humeral long segment fractures provides a stable fixation and earlier rehabilitation. It is an effective method for proximal humeral long segment fractures.

  1. Computational Fluid Dynamics and Experimental Study of Lock-in Phenomenon in Vortex-Induced Motions of a Cell-Truss Spar

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; YANG Jian-min; L(U) Hai-ning

    2009-01-01

    Spar platforms could be subject to vortex-induced-motions (VIM) in certain current conditions. Lock-in is a phenomenon which occurs in a range of reduced velocities in VIM. In this paper, a new concept of spar platform called cell-truss spar is studied using both computational fluid dynamics (CFD) and model test to investigate the VIM of the spar under different reduced velocities. The unique configuration of the cell-truss spar is carefully considered, and the unsteady flow around the spar is calculated and visualized in CFD simulations. A physical model with a scale ratio of 1:100 of the cell-truss spar is fabricated, and model tests are carried out in the current-generating ocean engineering basin. Many important parameters in VIM of the cell-truss spar are obtained, the occurrence of lock-in phenomenon is successfully simulated, and the mechanism and rules of lock-in are analyzed.

  2. Lithosphere-mantle coupling and the dynamics of the Eurasian Plate

    NARCIS (Netherlands)

    Warners-Ruckstuhl, K.N.; Govers, R.; Wortel, R.

    2012-01-01

    Mechanical equilibrium of tectonic plates implies that lithospheric edge and body forces are balanced by forces arising from interaction with the underlying mantle. We use this quantitative physical relation to integrate existing modelling approaches of lithosphere dynamics and mantle flow into a ne

  3. Analysis of amelioration of neurological function on cervical degeneration disease after treatment with cervical spine locking plate%颈椎带锁钢板内固定术对颈椎退变性疾病神经功能改善的分析

    Institute of Scientific and Technical Information of China (English)

    赖志军; 谢惠缄; 谢唏衷; 肖建如

    2002-01-01

    Objective To discuss the clinical effect of treatment with anterior decompression, bone graft and cervical locking plate fixation for cervical degeneration disease.Method 23 patients with cervical spondylotic myelopathy and cervical ossification of the posterior longitudinal ligament have undergone the treatment of anterior cervical spine locking plate fusion.Neurological signs and symptoms were evaluated before and after surgery, and mean follow up time was 11.3 months.Result In all cases,radiography demonstrated a solid bony fusion.Additional general complications include a large wound hematoma in one and hoarseness in one.All patients' neurological function were improved.Conclusion The clinical effect of treatment with anterior decompression, bone graft and cervical locking plate fixation for cervical degeneration disease is satisfactory.

  4. Dynamic Stationary Response of Reinforced Plates by the Boundary Element Method

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Facundo Sanches

    2007-01-01

    Full Text Available A direct version of the boundary element method (BEM is developed to model the stationary dynamic response of reinforced plate structures, such as reinforced panels in buildings, automobiles, and airplanes. The dynamic stationary fundamental solutions of thin plates and plane stress state are used to transform the governing partial differential equations into boundary integral equations (BIEs. Two sets of uncoupled BIEs are formulated, respectively, for the in-plane state (membrane and for the out-of-plane state (bending. These uncoupled systems are joined to form a macro-element, in which membrane and bending effects are present. The association of these macro-elements is able to simulate thin-walled structures, including reinforced plate structures. In the present formulation, the BIE is discretized by continuous and/or discontinuous linear elements. Four displacement integral equations are written for every boundary node. Modal data, that is, natural frequencies and the corresponding mode shapes of reinforced plates, are obtained from information contained in the frequency response functions (FRFs. A specific example is presented to illustrate the versatility of the proposed methodology. Different configurations of the reinforcements are used to simulate simply supported and clamped boundary conditions for the plate structures. The procedure is validated by comparison with results determined by the finite element method (FEM.

  5. Study on rigid-flexible coupling dynamics of hub-plate system

    Institute of Scientific and Technical Information of China (English)

    ZHAO Feiyun; XIE Yongcheng; ZHANG Ming; HE Yinbiao

    2007-01-01

    Dynamic modeling of a rotating flexible hubplate system is investigated by using Jourdain's variation principle in which the finite element method (FEM) is used as discretization method for a flexible plate. Different from the previous modeling of a plate with a prescribed large overall motion, the coupling between large overall motion of the system and elastic deformation of the flexible plate is taken into account in the proposed coupling model. The quadratic terms are included in the strain-displacement expression,such that the dynamic stiffening terms are included. Simulation of a rotating hub-plate system indicates that the linear model based on linear strain-displacement assumption may lead to erroneous results in the case of high rotation speed. Conservation of energy verifies the validity of the proposed model. Furthermore, frequency analysis of a hub-plate system shows the difference between the frequencies of the system with free and prescribed large overall motion, and parameter analysis of the system reveals the coupling characteristics of the rotational motion and the deformation.

  6. 肱骨近端解剖锁定钢板与解剖钢板治疗肱骨Neer三、四部分骨折的疗效比较%Comparison of proximal humerus locking plate and anatomical plate for Neer three-and four-part of proximal humeral fractures

    Institute of Scientific and Technical Information of China (English)

    朱豪东; 蔡新新; 郭云峰; 郑柏生; 周卓谦

    2015-01-01

    目的:探讨肱骨近端解剖钢板与肱骨近端解剖锁定钢板治疗老年肱骨近端 Neer三、四部分骨折的功能及疗效差异。方法收集有完整随访资料的151例老年Neer 三、四部分骨折患者,按手术方式分为肱骨近端解剖钢板组(A 组,65例)和肱骨近端解剖锁定钢板组(B 组,86例),在随访过程采用Constant 评分及Neer 评分评价并比较两组疗效。结果 B 组平均愈合时间显著短于A 组(P<0.05)。两组的术后1年和术后2年功能比较:B 组Neer 评分的疼痛、功能、活动度及总分均显著优于 A 组(P<0.05);B 组 Constant 评分的疼痛、日常生活活动、主动活动及总分显著优于 A 组(P<0.05)。结论肱骨近端解剖钢板与肱骨近端解剖锁定钢板均可用于老年Neer 三、四部分骨折,但解剖锁定钢板愈合更快,功能恢复更好,临床推荐优先使用。%Objective To investigate the effect of proximal humerus locking plate and proximal humerus anatomical plate on complex 3- and 4-part fractures of the proximal humerus (Neer classification) in the elders. Methods 151 cases of proximal humeral fractures were included in the study and divided into proximal humerus anatomical plate group (A group, n=65 cases) and proximal humerus locking plate group (B group, n=86 cases) according to different operation methods. The patients of A group underwent fracture fixation by anatomical plate and those in B group received fracture fixation by locking proximal humerus plate. The treatment effect was evaluated in two groups and compared between two groups by Neer score and Constant score. Results The mean humerus healing time of B group was significant superior to A group (P<0.05). Neer score, constant score, pain , function , activity and total score of shoulder in B group were significant superior to those in A group in 1 year and 2 years after operation (P<0.05). Conclusion Proximal humerus

  7. Effect of a weak layer at the base of an oceanic plate on subduction dynamics

    Science.gov (United States)

    Carluccio, Roberta; Kaus, Boris

    2017-04-01

    The plate tectonics model relies on the concept of a relatively rigid lithospheric lid moving over a weaker asthenosphere. In this frame, the lithosphere asthenosphere boundary (LAB) is a first-order discontinuity that accommodates differential motions between tectonic plates and the underlying mantle. Recent seismic studies have revealed the existence of a low velocity and high electrical conductivity layer at the base of subducting tectonic plates. This thin layer has been interpreted as being weak and slightly buoyant and was suggested to affect the dynamics of subducting plates. However, geodynamically, the role of a weak layer at the base of the lithosphere remains poorly studied, especially at subduction zones. Therefore, we here use numerical models to investigate the first-order effects of a weak buoyant layer at the LAB on subduction dynamics. We employ both 2-D and 3-D models in which the slab and mantle are either linear viscous or have a more realistic temperature-dependent visco-elastic-plastic rheology. Results show that a weak layer affects the dynamics of the plates, foremost by increasing the subduction speed. The impact of this effect depends on the thickness of the layer and the viscosity contrast between the mantle and the weak layer. For moderate viscosity contrasts (1000), it can also change the morphology of the subduction itself, perhaps because this changes the overall effective viscosity contrast between the slab the and the mantle. For thinner layers, the overall effect is reduced. Yet, if seismological observations are correct that suggests that this layer is 10 km thick and partially molten, such that the viscosity is 1000 times lower than that of the mantle, our models suggest that this effect should be measurable. Some of our models also show a pile-up of weak material in the bending zone of the subducting plate, consistent with recent seismological observations.

  8. This Dynamic Planet: World map of volcanoes, earthquakes, impact craters and plate tectonics

    Science.gov (United States)

    Simkin, Tom; Tilling, Robert I.; Vogt, Peter R.; Kirby, Stephen H.; Kimberly, Paul; Stewart, David B.

    2006-01-01

    Our Earth is a dynamic planet, as clearly illustrated on the main map by its topography, over 1500 volcanoes, 44,000 earthquakes, and 170 impact craters. These features largely reflect the movements of Earth's major tectonic plates and many smaller plates or fragments of plates (including microplates). Volcanic eruptions and earthquakes are awe-inspiring displays of the powerful forces of nature and can be extraordinarily destructive. On average, about 60 of Earth's 550 historically active volcanoes are in eruption each year. In 2004 alone, over 160 earthquakes were magnitude 6.0 or above, some of which caused casualties and substantial damage. This map shows many of the features that have shaped--and continue to change--our dynamic planet. Most new crust forms at ocean ridge crests, is carried slowly away by plate movement, and is ultimately recycled deep into the earth--causing earthquakes and volcanism along the boundaries between moving tectonic plates. Oceans are continually opening (e.g., Red Sea, Atlantic) or closing (e.g., Mediterranean). Because continental crust is thicker and less dense than thinner, younger oceanic crust, most does not sink deep enough to be recycled, and remains largely preserved on land. Consequently, most continental bedrock is far older than the oldest oceanic bedrock. (see back of map) The earthquakes and volcanoes that mark plate boundaries are clearly shown on this map, as are craters made by impacts of extraterrestrial objects that punctuate Earth's history, some causing catastrophic ecological changes. Over geologic time, continuing plate movements, together with relentless erosion and redeposition of material, mask or obliterate traces of earlier plate-tectonic or impact processes, making the older chapters of Earth's 4,500-million-year history increasingly difficult to read. The recent activity shown on this map provides only a present-day snapshot of Earth's long history, helping to illustrate how its present surface came to

  9. 锁定接骨板与解剖接骨板治疗老年肱骨近端骨折的比较%Comparison of Locking Plate and Anatomical Plate in Treatment of Elderly Patients with Proximal Humerus Fractures

    Institute of Scientific and Technical Information of China (English)

    潘捷; 黄吉利; 龙德生

    2011-01-01

    Objective:To compare the effects of locking plate and anatomical plate on elderly patients with proximal humerus fractures.Methods:The proximal humerus locking plate and ana-tomical plate were used to treat 56 cases of proximal humeral fractures.Operative time(min),blood loss(mL),postoperative pain score(score),postoperative joint function score(score) were compared of two treatment methods.Results:56 patients were followed up for 6 months to 18 months,average of 12 months.Locking plate group blood loss(134.55±30.67)mL were less than the anatomical plate group(178.69±50.73)mL;operation time(79.65±20.37)min were less than anatomical plate group(96.87±30.63)min;postoperative pain VAS score(1.35±0.22)points were less than anatomical plate group(2.27±1.23)points;postoperative shoulder function Neer score(94.53±8.54)points and Constant score(90.26±10.37)points were higher than anatomical plate group.Differences were statistically significant(P0.05).Conclusion:The treatment to proximal humerus fractures in aged patients with locking plate has more advantage than anatomical plate.%目的:对比锁定接骨板与解剖接骨板治疗老年肱骨近端骨折的效果.方法:应用肱骨近端锁定接骨板及解剖接骨板治疗肱骨近端骨折56例.比较两种治疗方法在手术时间、术中出血量、术后疼痛评分、术后关节功能评分(score)等方面的差异.结果:56例均获随诊,随诊时间6~18个月,平均12个月.锁定接骨板组术中出血量(134.55±30.67)mL少于解剖接骨板组(178.69±50.73)mL;手术时间(79.65±20.37)min短于解剖接骨板组(96.87±30.63)min;术后疼痛VAS评分(1.35±0.22)分低于解剖接骨板组(2.27±1.23)分;术后肩关节功能Neer评分(94.53±8.54)分及Constant评分(90.26±10.37)分均高于解剖接骨板组.差异均有统计学意义(P〈0.05).结论:锁定接骨板治疗老年

  10. Complex dynamics of functionally graded plates with thermal load in 1:2 internal resonance

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Complex dynamics of the simply-supported functionally graded(FG)rectangular plates with thermal load is investigated.Based on Reddy’s third-order shear deformation theory and the von Karman nonlinear strain-displacement relations,ordinary differential equations(ODEs)of the plate’s transversal oscillation are derived by using Hamilton’s principle and Galerkin’s approach.Solutions’classification of the equations in 1:2 internal resonance is analyzed.Particular results of a simplysupported aluminum-alumina rectangular FG plate are given.Effects of temperature and volume fraction on the responses’ stabilities are discussed.

  11. ANALYSIS OF NONLINEAR DYNAMIC RESPONSE FOR VISCOELASTIC COMPOSITE PLATE WITH TRANSVERSE MATRIX CRACKS

    Institute of Scientific and Technical Information of China (English)

    FuYiming; LiPing'en; ZhengYufang

    2004-01-01

    Based on the Schapery three-dimensional viscoelastic constitutive relationship with growing damage, a damage model with transverse matrix cracks for the unidirectional fibre reinforced viscoelastic composite plates is developed. By using Karman theory, the nonlinear dynamic governing equations of the viscoelastic composite plates under transverse periodic loading are established. By applying the finite difference method in spatial domain and the Newton-Newmark method in time domain, and using the iterative procedure, the integral-partial differential governing equations are solved. Some examples are given and the results are compared with available data.

  12. Nonlinear dynamic modeling of a helicopter planetary gear train for carrier plate crack fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    Fan Lei; Wang Shaoping; Wang Xingjian; Han Feng; Lyu Huawei

    2016-01-01

    Planetary gear train plays a significant role in a helicopter operation and its health is of great importance for the flight safety of the helicopter. This paper investigates the effects of a planet carrier plate crack on the dynamic characteristics of a planetary gear train, and thus finds an effec-tive method to diagnose crack fault. A dynamic model is developed to analyze the torsional vibra-tion of a planetary gear train with a cracked planet carrier plate. The model takes into consideration nonlinear factors such as the time-varying meshing stiffness, gear backlash and viscous damping. Investigation of the deformation of the cracked carrier plate under static stress is performed in order to simulate the dynamic effects of the planet carrier crack on the angular displacement of car-rier posts. Validation shows good accuracy of the developed dynamic model in predicting dynamic characteristics of a planetary gear train. Fault features extracted from predictions of the model reveal the correspondence between vibration characteristic and the conditions (length and position) of a planet carrier crack clearly.

  13. Nonlinear dynamic modeling of a helicopter planetary gear train for carrier plate crack fault diagnosis

    Directory of Open Access Journals (Sweden)

    Fan Lei

    2016-06-01

    Full Text Available Planetary gear train plays a significant role in a helicopter operation and its health is of great importance for the flight safety of the helicopter. This paper investigates the effects of a planet carrier plate crack on the dynamic characteristics of a planetary gear train, and thus finds an effective method to diagnose crack fault. A dynamic model is developed to analyze the torsional vibration of a planetary gear train with a cracked planet carrier plate. The model takes into consideration nonlinear factors such as the time-varying meshing stiffness, gear backlash and viscous damping. Investigation of the deformation of the cracked carrier plate under static stress is performed in order to simulate the dynamic effects of the planet carrier crack on the angular displacement of carrier posts. Validation shows good accuracy of the developed dynamic model in predicting dynamic characteristics of a planetary gear train. Fault features extracted from predictions of the model reveal the correspondence between vibration characteristic and the conditions (length and position of a planet carrier crack clearly.

  14. Dynamic Hip Screw Compared to Condylar Blade Plate in the Treatment of Unstable Fragility Intertrochanteric Fractures

    Directory of Open Access Journals (Sweden)

    CK Yong

    2009-05-01

    Full Text Available Dynamic hip screw (DHS fixation is considered standard treatment for most intertrochanteric fractures. However, excessive sliding at the fracture site and medialisation of femoral shaft may lead in fixation failure. In contrast, fixed- angled 95° condylar blade plate (CBP has no effective dynamic capacity and causes little bone loss compared to DHS. We compared the outcome of 57consecutive unstable intertrochanteric fragility fractures treated with these two fixation methods. CBP instrumentation is more difficult requiring longer incision, operating time and higher surgeon- reported operative difficulty. The six month post-operative mortality rate is 16%. Post-operative Harris hip scores were comparable between the two methods. Limb length shortening more than 20 mm was 6-fold more common with DHS. In elderly patients with unstable intertrochanteric fragility fractures, fixed angled condylar blade plate appears to be a better choice than dynamic hip screws for preventing fixation failures.

  15. Prediction for Dynamic Characteristics of Ring-Plate Planetary Indexing Cam Mechanism

    Institute of Scientific and Technical Information of China (English)

    SONG Yimin; TIAN Guangcai; ZHANG Jun; LIU Mingtao; LIU Jianping

    2009-01-01

    This paper is aimed to propose an approach to predict the dynamic characteristics of ring-plate planetary indexing cam mechanism, which is a novel type of indexing mechanism that employs internal planetary transmis-sion structure. Firstly, the geometry and structure of the mechanism are discussed and the kinematic practicability is simulated with virtual prototype design. Then a 3D finite element model of the ring-plate planetary indexing cam mechanism is developed with the commercial software of MATLAB and ANSYS. Through the finite element analysis, the natural frequencies and the corresponding mode shapes are predicted in one motion cycle. On the basis of the virtual prototype design and finite element analysis, an experimental prototype is made and tested to validate the prediction of the dynamic characteristics. The agreement between experimental results and the finite element analysis testifies that the finite element model developed is applicable to the prediction of the dynamic characteris-tics of this type of mechanism.

  16. UNCONVENTIONAL HAMILTON-TYPE VARIATIONAL PRINCIPLES FOR DYNAMICS OF REISSNER SANDWICH PLATE

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei-jiang; LUO En; SHE Hui

    2006-01-01

    According to the basic idea of classical yin-yang complementarity and modern dual-complementarity, in a simple and unified way proposed by Luo(1987), some unconventional Hamilton-type variational principles for dynamics of Reissner sandwich plate can be established systematically. The unconventional Hamilton-type variation principle can fully characterize the initial-boundary-value problem of this dynamics. In this paper, an important integral relation is given, which can be considered as the generalized principle of virtual work in mechanics. Based on this relation, it is possible not only to obtain the principle of virtual work in dynamics of Reissner sandwich plate, but also to derive systematically the complementary functionals for five-field, two-field and one-field unconventional Hamilton-type variational principles by the generalized Legender transformations. Furthermore, with this approach, the intrinsic relationship among the various principles can be explained clearly.

  17. Design and Dynamics Simulation of a Novel Double-Ring-Plate Gear Reducer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A patented double-ring-plate gear reducer was designed and its dynamic performance was simulated. One unique characteristic of this novel drive is that the phase angle difference between two parallelogram mechanisms is a little less than 180 degree and four counterweights on two crankshafts are designed to balance inertia forces and inertia moments of the mechanisms. lts oper ating principle, advantages, and design issues were discussed. An elasto-dynamics model was presented to acquire its dynamic response by considering the elastic deformations of ring-plates,gears, bearings, etc. The simulation results reveal that compared with housing bearings, planetary bearings work in more severe conditions. The fluctuation of loads on gears and bearings indicates that the main reason for reducer vibration is elastic deformations of the system rather than inertia forces and inertia moments of the mechanisms.

  18. Innovation and Lock-in

    DEFF Research Database (Denmark)

    Cantner, Uwe; Vannuccini, Simone

    2016-01-01

    , especially when innovation is concerned. Also, we address the question if lock-in is a well-defined concept at all. To offer a fresh view on lock-in and to tackle the issues just raised, we employ the replicator dynamics model. By making a parallel between monopolization in the replicator dynamics...... that further structural features - for example users heterogeneity - may play a relevant role in affecting the outcome of dynamic allocation and competition processes....

  19. The interpretation of crustal dynamics data in terms of plate motions and regional deformation near plate boundaries

    Science.gov (United States)

    Solomon, Sean C.

    During our participation in the NASA Crustal Dynamics Project under NASA contract NAS-27339 and grant NAG5-814 for the period 1982-1991, we published or submitted for publication 30 research papers and 52 abstracts of presentations at scientific meetings. In addition, five M.I.T. Ph.D. students (Eric Bergman, Steven Bratt, Dan Davis, Jeanne Sauber, Anne Sheehan) were supported wholly or in part by this project during their thesis research. Highlights of our research progress during this period include the following: application of geodetic data to determine rates of strain in the Mojave block and in central California and to clarify the relation of such strain to the San Andreas fault and Pacific-North American plate motions; application of geodetic data to infer post seismic deformation associated with large earthquakes in the Imperial Valley, Hebgen Lake, Argentina, and Chile; determination of the state of stress in oceanic lithosphere from a systematic study of the centroid depths and source mechanisms of oceanic intraplate earthquakes; development of models for the state of stress in young oceanic regions arising from the differential cooling of the lithosphere; determination of the depth extent and rupture characteristics of oceanic transform earthquakes; improved determination of earthquake slip vectors in the Gulf of California, an important data set for the estimation of Pacific-North American plate motions; development of models for the state of stress and mechanics of fold-and-thrust belts and accretionary wedges; development of procedures to invert geoid height, residual bathymetry, and differential body wave travel time residuals for lateral variations in the characteristic temperature and bulk composition of the oceanic upper mantle; and initial GPS measurements of crustal deformation associated with the Imperial-Cerro Prieto fault system in southern California and northern Mexico. Full descriptions of the research conducted on these topics may be

  20. Layerwise mechanics and finite element for the dynamic analysis of piezoelectric composite plates

    Science.gov (United States)

    Saravanos, Dimitris A.; Heyliger, Paul R.; Hopkins, Dale A.

    1996-01-01

    Laminate and structural mechanics for the analysis of laminated composite plate structures with piezoelectric actuators and sensors are presented. The theories implement layerwise representations of displacements and electric potential, and can model both the global and local electromechanical response of smart composite laminates. Finite-element formulations are developed for the quasi-static and dynamic analysis of smart composite structures containing piezoelectric layers. Comparisons with an exact solution illustrate the accuracy, robustness and capability of the developed mechanics to capture the global and local response of thin and/or thick laminated piezoelectric plates. Additional correlations and numerical applications demonstrate the unique capabilities of the mechanics in analyzing the static and free-vibration response of composite plates with distributed piezoelectric actuators and sensors.

  1. 微创锁定接骨板治疗老年肱骨近端复杂骨折%Minimally invasive locking proximal humerus plate in treatment of complex proximal humerus fractures in the elderly

    Institute of Scientific and Technical Information of China (English)

    陈烁; 徐若男; 蔡筱松; 刘宏滨

    2012-01-01

    目的 探讨微创肱骨近端锁定接骨板(LPHP)治疗老年肱骨近端复杂骨折的临床疗效.方法 回顾分析采用微创LPHP治疗24例老年肱骨近端复杂骨折.按Neer分型,3部分骨折14例;4部分骨折10例.结果 24例经9 ~39个月随访,无一例发生内固定松动、断裂,全部骨折均愈合.肩关节功能按照Constant评分标准,功能优12例,良9例,中3例,优良率87.5%.结论 微创LPHP内固定治疗肱骨近端复杂骨折固定可靠,骨折愈合率高,可行早期功能锻炼,功能恢复好,尤其适用于治疗老年骨质疏松患者.%Objective To study surgical treatment of complex proximal humeral fracture in the elderly with minimally invasive locking proximal humerus plate. Methods 24 cases of complex fractures of the proximal humerus treated with minimally invasive locking proximal humerus plate were retrospectively analysed. According to Neer classification,there were 14 cases with three-part fractures and 10 cases with four-part fractures. Results The follow-up ranged from 9 months to 39 months, all cases experienced bone union, without internal fixation loosing and breakdown. By Constant scoring system,there were 12 excellent cases,9 good cases and 3 fair cases. The excellent and good rate was 87. 5%. Conclusion Application of minimally invasive locking proximal humerus plate can resuh in more reliable fixation. Higher bone union rate, earlier rehabilitation and better functional recover in treatment of complex fractures of the proximal humerus, especially in the elderly.

  2. 肱骨近端解剖锁定钢板治疗肱骨外科颈骨折的效果观察%Observation on effect of surgical neck fractures of humerus by locking proximal humerus plate fixation

    Institute of Scientific and Technical Information of China (English)

    陈兆平

    2014-01-01

    目的:探究肱骨近端解剖锁定钢板治疗肱骨外科颈骨折的临床效果。方法选取近3年到我院就诊的肱骨外科颈骨折患者120例,给予患者肱骨近端解剖锁定钢板治疗,观察其临床效果并定期随访,评价其肩关节功能。结果所有患者均顺利完成手术,术中未出现神经、血管损伤,住院期间和随访期间均未发生感染等并发症,术后切口都是Ⅰ期愈合,按照 neer 评定标准,优良率达92.5%。结论肱骨近端解剖锁定钢板治疗肱骨外科颈骨折,具有固定可靠、效果良好、并发症少、操作简单等优点,适合临床推广应用。%objective To explore the effect of surgical neck fractures of humerus by locking proximal humerus plate fixation. Methods choced 120 patients with surgical neck fractures of humerus which was cheated in our hospital in the last three years, treated the patients with locking proximal humerus plate fixation, then observed the clinical effect and evaluated the function of shoulders after regular follow-up. Results all patients completed the surgery smoothly, no case of blood vessels and nerve damage, and no infection occurred during hospitalization and the follow up period, all the patients got recovered in Ⅰ period and the excellent and good rate was 92.5%. Conclusions surgical neck fractures of humerus by locking proximal humerus plate fixation, has the advantages of reliable fixation, good effect, less complications and simple operation, it is suitable for clinical application.

  3. 锁定钢板治疗肱骨近端骨折30例临床分析%Clinical analysis of locking plate in treatment of proximal humerus fractures 30 cases

    Institute of Scientific and Technical Information of China (English)

    肖锦春

    2011-01-01

    Objective To investigate the effect of locking compression plate (LCP) in treatment of complex proximal humeral fractures. Methods The proximal humerus locking plate in treatment of proximal humerus fractures, 30 cases classified according to Neers, two - part fracture in 12 cases, three - part fractures in 16 cases, four - part fractures in 2 cases. Results The group of 30 cases of surgical patients were 6 to 13 months follow -up, average 11.5 months, all fractures healed within 12 months. According to Neer shoulder function assessment criteria; excellent in 18 cases, good in 8 cases, effective in 4 cases, the whole group of excellent and good rate was 86. 7%. Conclusions Treatment of proximal humeral locking plate fixation of proximal humeral fractures, reliable, fewer complications, and early functional exercises, results were satisfactory, especially for elderly patients with osteoporosis is particularly applicable.%目的 探讨应用锁定加压接骨板(LCP)治疗肱骨近端复杂骨折的疗效.方法 应用肱骨近端锁定钢板治疗肱骨近端骨折30例,根据Neers分类,二部分骨折12例,三部分骨折16例,四部分骨折2例.结果 本组30例手术患者均获得6~13个月的随访,平均11.5个月,骨折12个月内全部愈合.按Neer肩关节功能评分标准评定:优18例,良8例,可4例,全组优良率86.7%.结论 肱骨近端锁定钢板治疗肱骨近端骨折固定可靠,并发症少,可早期进行功能锻炼,疗效满意,特别是对于老年骨质疏松的患者尤为适用.

  4. Analysis of the Effect of Locking Compression Plate Internal Fixation for Aged Fractures of Humerus%老年肱骨远端骨折锁定加压钢板内固定手术疗效分析

    Institute of Scientific and Technical Information of China (English)

    冯波

    2015-01-01

    Objective To study the analysis of the distal humerus fractures in elderly patients with locking compression plate fixation for the treatment of clinical effect.Methods 34 cases of elderly patients with distal humerus fractures were selected in May 2014 to May 2012 in our hospital, all patients were treated with locking compression plate fixation surgery, all patients were observed fracture healing effect. ResultsAll patients were followed, including fracture healing excellent in 19 cases, good in 13 cases, good in 13 cases, medium in 1 cases, and poor in 1 cases, the treatment rate of 94.1% excellent, and all the patients were not there wound infection, delayed union and nonunion and other complications.Conclusion Locking compression plate ifxation distal humeral fractures in elderly patients can promote fracture healing, the effect is signiifcant.%目的:研究分析老年肱骨远端骨折患者采用锁定加压钢板内固定术治疗的临床效果。方法选择我院2012年5月~2014年5月收治的34例老年肱骨远端骨折患者,所有患者均采用锁定加压钢板内固定手术治疗,观察所有患者的骨折愈合效果。结果对所有患者进行随访,其中骨折愈合优19例、良13例、可1例、差1例,其治疗优良率达94.1%;且所有患者均未出现伤口感染、骨折延迟愈合和骨不连等并发症。结论锁定加压钢板内固定术治疗老年肱骨远端骨折能够促进患者骨折愈合,效果显著。

  5. 肱骨近端锁定接骨板治疗老年肱骨近端骨折%Proximal humerus locking plate fixation in the treatment of proximal humeral fracture

    Institute of Scientific and Technical Information of China (English)

    杨志; 陈记明

    2015-01-01

    目的:探讨应用肱骨近端锁定接骨板内固定治疗老年肱骨近端骨折的手术疗效。方法:回顾分析应用肱骨近端锁定接骨板内固定治疗21例老年肱骨近端骨折患者的临床资料,Neer分型,三部分骨折17例,四部分骨折4例。结果:通过术后(13.5±1.2)个月随访。骨折愈合时间3~8个月;根据Neer肩关节功能评分标准进行评定,优12例,良6例,可2例,差1例,优良率85.7%。结论:肱骨近端锁定接骨板治疗老年肱骨近端骨折内固定牢靠,局部创伤小,骨折愈合时间短,关节功能恢复满意,是老年肱骨近端骨折理想的治疗方法。%Objective:To explore the operation effect of the proximal humerus locking plate fixation in the treat-ment of proximal humeral fracture. Methods:a retrospective analysis of the proximal humerus locking plate fixation in the treatment of 21 cases of senile proximal humeral fractures in patients with clinical data, The Neer type, the three part fractures in 17 cases, 4 cases of four part fractures. Results:the patients were followed up for 10~18 months, av-erage 13.2 months. Fracture healing time of 3~8 months; shoulder joint function were evaluated according to Neer score standard, excellent in 12 cases, good in 6 cases, 2 cases, poor in 1 cases, the excellent and good rate was 85.7%. Conclusion:the proximal humerus locking plate in the treatment of senile proximal humeral fracture internal fixation is the ideal treatment of senile proximal humeral fracture , with few local trauma, short fracture healing time, and satis-factory joint function recovery.

  6. 锁定钢板治疗肱骨近端骨折术后并发症的相关因素分析%Correlative factor analysis of complications in proximal humerus fractures treated with locking plates

    Institute of Scientific and Technical Information of China (English)

    韦盛旺; 赵友明; 杨杰; 郭晓山; 陈华; 杨翔; 陈林

    2012-01-01

    目的 探讨应用锁定钢板治疗肱骨近端骨折发生术后并发症的相关因素.方法 回顾性分析80例(并发症组29例,无并发症组51例)行锁定钢板(LPHP或PHILOS)治疗肱骨近端骨折患者资料,应用Logistic回归分析研究各因素与术后并发症的关系.结果 单因素分析示,并发症组在年龄、术后内侧皮质缺损、肱骨颈干角复位不佳等方面与无并发症组比较,差异有统计学意义(P <0.05);Logistic回归分析发现术后内侧皮质缺损和肱骨颈干角复位不佳是发生术后并发症的独立预测因素.结论 影响锁定钢板治疗肱骨近端骨折术后并发症的相关因素较多,其中术后内侧皮质缺损及肱骨颈干角复位不佳是主要因素.%Objective To explore the correlative factors affecting the complications in proximal humerus fractures treated with locking plates. Methods Eighty patients (29 cases with complications and 51 cases without) with proximal humerus fractures were treated by locking plates (LPHP or PHILOS) and were retrospectively analyzed. And logistic regression analysis was used to find main factors. Results The univariate analysis showed that age, the integrity of the medial humerus wall postoperatively and head-shaft angle had a significant association with complications encountered in proximal humerus fractures treated with locking plate fixation (P<0.05). The multiple stepwise logistic regression showed that the postoperative integrity of the medial humerus wall and head-shaft angle were key factors affecting the complications. Conclusion The integrity of the medial humerus wall and head-shaft angle are the main factors affecting the complications.

  7. 微创经皮钢板固定技术结合锁定钢板治疗胫骨粉碎性骨折%MIPPO Technology Combined with Locking Plate in the Treatment of Comminuted Fracture of Tibia

    Institute of Scientific and Technical Information of China (English)

    邵安泽; 岳洋; 潘长军; 顾飞; 吴瑞; 聂玮

    2015-01-01

    目的:观察微创经皮钢板固定(MIPPO)技术闭合复位结合锁定钢板治疗胫骨粉碎性骨折的临床效果.方法:采用MIPPO技术闭合复位结合锁定钢板治疗胫骨粉碎性骨折24例,男17例女7例,年龄23~65岁,平均42.4岁,胫骨中上段骨折15例,胫骨中下段9例.结果:24例患者均获得随访,时间6~14m,平均9.6m,术后采用Johner-Wruhs关节功能评定标准,24例患者优21例,良2例,中1例.结论:运用MIPPO技术闭合复位结合锁定钢板治疗胫骨粉碎性骨折能有效的降低软组织创伤,减少血运破坏,骨折愈合时间短等优点,是治疗胫骨粉碎性骨折的一种有效办法.%Objective: To investigate the use of closed reduction MIPPO technology combined with locking plate in the treatment of tibial comminuted fracture of the clinical effect. Methods:The use of closed reduction MIPPO technology combined locking plate in the treatment of comminuted fracture of the tibia in 24 cases, including 17 males and 7 females, aged 23~65 years, mean 42.4 years, the upper tibia 15 cases of fracture of tibia in nine cases the next segment.Results:24 patients were followed up for 6~14m, average 9.6m, after using Johner-Wruhs joint function evaluation standard, the results were excellent in 21 cases, good in 2 cases, 1 case.Conclusion:Closed reduction MIPPO technology combined with the locking plate in the treatment of comminuted fracture of the tibia with a soft tissue trauma, less blood supply destruction, reliable fixation, fracture healing time is short, etc., it is an effective way to treat comminuted fracture of the tibia.

  8. Curative effect analysis of proximal femoral locking compression plate femoral subtrochanteric comminuted fracture%近端锁定加压钢板治疗股骨转子下骨折疗效分析

    Institute of Scientific and Technical Information of China (English)

    杨治涛; 郑锐

    2014-01-01

    Objective:To explore the proximal femoral locking compression plate fixation of intertrochanteric frac-ture surgery. Methods:14 cases clinical data of intertrochanteric fractures proximal femoral locking compression plate fixation in our hospital were retrospective analyzed. Results:Follow-up time for 8 to 18 months.Fracture healing time of 12-18 weeks, mean (14.2±2.6)weeks, the healing rate of 100%.good rate of 92.8%.Conclusion:proximal femoral locking compression plate fixation of intertrochanteric fracture trauma, shorter operative time, reliable fixation, fracture healing, joint function recovered satisfactorily, clinical efficacy, suitable for different age groups subtrochanteric fracture, femur subtrochanteric fractures more satisfactory method of treatment.%目的:探讨股骨近端锁定加压钢板在股骨转子下粉碎性骨折治疗中的手术效果。方法:回顾分析14例股骨转子下粉碎性骨折患者应用股骨近端锁定加压钢板内固定治疗的临床资料。结果:随访时间8~18个月,患者全部愈合,愈合时间为12~18周,平均为(14.2±2.6)周,优良率92.8%。结论:股骨近端锁定加压钢板治疗股骨转子下粉碎性具有骨折创伤小,手术时间短,固定可靠,骨折愈合快,关节功能恢复满意,临床疗效好,适用于不同年龄组股骨转子下骨折,是较为理想的治疗方法。

  9. High-Frequency Dynamic Analysis of Plates in Thermal Environments Based on Energy Finite Element Method

    Directory of Open Access Journals (Sweden)

    Di Wang

    2015-01-01

    Full Text Available The energy density governing equation to analyze the high-frequency dynamic behavior of plates in thermal environments is derived in this paper, in which the thermal effects are considered to change the membrane stress state and temperature dependent material properties of plates. Then the thermal effects on the energy reflection and transmission coefficients are dealt with hereof. Based on the above, an EFEM (energy finite element method based approximate approach for the energy analysis of coupled plates under nonuniform thermal environments is proposed. The approach could be conducted by three steps: (1 thermal analysis, (2 thermal stress analysis, and (3 forming element matrixes, joint matrixes, and the whole EFEM formulation for the energy analysis. The same mesh model is used for all the three steps. The comparison between EFEM results and classical modal superposition method results of simply supported plates in various uniform thermal environments and coupled plates in nonuniform thermal environments demonstrated that the derived energy governing equation and the proposed approach described well the smooth time- and locally space-averaged energy density. It is found that the distributions and levels of energy density are affected by thermal effects, and the variation trends are related to exciting frequency.

  10. Nonlinear dynamics of angle-ply composite laminated thin plate with third-order shear deformation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An asymptotic perturbation method is presented based on the Fourier expansion and temporal rescaling to investigate the nonlinear oscillations and chaotic dynamics of a simply supported angle-ply composite laminated rectangular thin plate with parametric and external excitations.According to the Reddy’s third-order plate theory,the governing equations of motion for the angle-ply composite laminated rectangular thin plate are derived by using the Hamilton’s principle.Then,the Galerkin procedure is applied to the partial differential governing equation to obtain a two-degrees-of-freedom nonlinear system including the quadratic and cubic nonlinear terms.Such equations are utilized to deal with the resonant case of 1:1 internal resonance and primary parametric resonance-1/2 subharmonic resonance.Furthermore,the stability analysis is given for the steady-state solutions of the averaged equation.Based on the averaged equation obtained by the asymptotic perturbation method,the phase portrait and power spectrum are used to analyze the multi-pulse chaotic motions of the angle-ply composite laminated rectangular thin plate.Under certain conditions the various chaotic motions of the angle-ply composite laminated rectangular thin plate are found.

  11. An Unstructured Finite Volume Method for Impact Dynamics of a Thin Plate

    Institute of Scientific and Technical Information of China (English)

    Weidong Chen; Yanchun Yu

    2012-01-01

    The examination of an unstructured finite volume method for structural dynamics is assessed for simulations of systematic impact dynamics.A robust display dual-time stepping method is utilized to obtain time accurate solutions.The study of impact dynamics is a complex problem that should consider strength models and state equations to describe the mechanical behavior of materials.The current method has several features.1) Discrete equations of unstructured finite volume method naturally follow the conservation law.2)Display dual-time stepping method is suitable for the analysis of impact dynamic problems of time accurate solutions.3) The method did not produce grid distortion when large deformation appeared.The method is validated by the problem of impact dynamics of an elastic plate with initial conditions and material properties.The results validate the finite element numerical data.

  12. Treatment of proximal humeral fractures with interlocking intramedullary nail versus locking plate%锁定钢板与交锁髓内钉治疗肱骨近端骨折的疗效分析

    Institute of Scientific and Technical Information of China (English)

    徐小东; 张殿英; 付中国; 王天兵; 陈建海; 杨明; 芦浩

    2014-01-01

    Background Proximal humeral fracture is usually seen in elder citizens with osteoporosis,and such a fracture in younger patients mainly results from high-energy inj ury.Surgical procedure is often adopted for patients with unstable or obviously displaced fracture.Open reduction and locking plate fixation or closed reduction and interlocking intramedullary nail fixation are two common treatment methods for proximal humeral fracture.In this paper,retrospective analysis was conducted to compare the clinical curative effects between locking plate and intramedullary nail in the treatment of proximal humeral fracture.Methods General data:From January 2012 to May 2013,38 patients with full information in our department were randomly selected in the retrospective analysis, including 13 male and 25 female,aged from 20 to 86,and the mean age was 66.5 ± 16.9 years. According to the different treatment methods,the patients were divided into the locking plate group (24 cases)and the interlocking intramedullary nail group (14 cases).All patients had unilateral closed fractures treated with locking plate or interlocking intramedullary nail,including 22 cases on the left side and 17 cases on the right side.28 patients were injured from low energy falls and 10 cases were from high energy trauma like skiing,motor accidents,etc.According to Neer classification,7 cases of two-part fracture,1 1 cases of three-part fracture and 6 cases of four-part fracture were in the locking plate group,and 8 cases of two-part fracture,5 cases of three-part fracture and 1 case of four-part fracture were in the interlocking intramedullary nail group.In the meanwhile,on the basis of AO classification,4 type 11-A cases,14 type 11-B cases and 6 type 11-C cases were in the locking plate group,and 7 type 1 1-A cases,6 type 1 1-B cases and 1 type 1 1-C case were in the interlocking intramedullary group.PHILOS plate of Synthes,Inc.and TRIGEN intramedullary nail of Smith &Nephew,Inc.were used in the operation

  13. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    Science.gov (United States)

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  14. Clinical outcomes of proximal humeral internal locking system self-locking plates in treatment of proximal humeral fractures%肱骨近端内固定系统自锁钢板治疗肱骨近端骨折疗效分析

    Institute of Scientific and Technical Information of China (English)

    唐康来; 许建中; 谭晓康; 吴雪晖; 徐格; 龚继承; 汪华清; 谢肇; 马树枝; 王序全

    2008-01-01

    目的 介绍肱骨近端内固定系统(proximal humeral internal locking system,PHILOS)白锁钢板治疗肱骨近端骨折的方法并分析其疗效. 方法 本组男19例,女16例;年龄29~92岁,平均53.5岁.所有骨折均按Neer分型标准进行分类,其中二部分骨折19例,三部分骨折15例,四部分骨折1例.手术采用胸人肌-三角肌间隙入路,均采用PHILOS自锁钢板进行固定.术后对所有患者进行平均18.9个月(6~46个月)的临床随访,主要包括X线片和Constant功能评分. 结果 X线片证实所有肱骨近端骨折均得到良好的复位并完全骨性愈合,愈合时间8~12周.最近一次Constant-Murley功能评分:平均89.5分(82~94分).随访期间未发生钢板松动、肱骨头缺血性坏死和需肱关节创伤性关节炎等并发症. 结论 PHILOS自锁钢板是治疗肱骨近端骨折的好方法,具有操作方便、固定可靠、疗效确切及并发症少的优势.%Objective To evaluate the clinical results of proximal humeral internal locking sys-tem(PHILOS)self-locking plates in treatment of proximal humeral fractures. Methods There were 35 patients including 19 males and 16 females(at mean age of 53.5 years,ranging from 29 to 92 years)with proximal humeral fractures treated with PHILOS plate.According to the Neer's classification sys-tem,there were two-part fractures in 19 patients,three-part fractures in 15 and four-part fractures in 1.Surgery was performed with PHILOS serf-locking plate via dehopectoral approach.All patients were fol-lowed up for mean 18.9 months(6-46 months)and evaluated by using Constant score and X-rays. Re-suits X-rays proved that all fractures got good reduction and complete healing during 8-12 weeks.The latest Constant scores was mean 89.5 points(82-94 points).There were no complications including plate loosing.humenral head necrosis or gleno-humeral ioint osteoarthritis. Conclusion PHILOS plate is a good choice for treatment of proximal humeral fractures

  15. A biomechanical evaluation of a Hybrid Dynamic Compression Plate and a CastLess Arthrodesis Plate for pancarpal arthrodesis in dogs.

    Science.gov (United States)

    Meeson, Richard L; Goodship, Allen E; Arthurs, Gareth I

    2012-08-01

    To determine mechanical differences between two plates with different requirements for supplementary casting after pancarpal arthrodesis (PCA): the Veterinary Instrumentation Hybrid Dynamic Compression Plate (HDCP), and the OrthoMed CastLess Arthrodesis Plate (CLP). In vitro mechanical analysis. HDCP(n = 10), CLP(10). Single-cycle load to failure using a materials-testing machine and cyclic loading between 38 and 380 N ± 5% to simulate estimated in vivo loads until failure or 10(6) cycles. Single-cycle to failure: bending stiffness was significantly higher for the HDCP(2269 ± 175 N/mm) than CLP(1754 ± 88 N/mm; P Bending structural stiffness was higher for the HDCP(3.8 ± 0.3 Nm(2) ) versus CLP(2.9 ± 0.2 Nm(2) ; P= .0022). A difference between the 2 plates for bending strength was not demonstrated; HDCP= 13.9 ± 1.4 Nm, CLP13.2 ± 0.5 Nm (P= .24). Cyclic Loading: no failures occurred with either plate type when plates were cycled to 10(6) cycles. There is no mechanical advantage in bending resistance afforded by the CLPover the HDCP. Fatigue failure of either plate during the convalescent period of an estimated 150,000-250,000 cycles is unlikely. Based on the bending performance, there is no evidence to support the use of the CLPover the HDCPfor castless PCA. © Copyright 2012 by The American College of Veterinary Surgeons.

  16. A Dynamic Multinode Model for Component-Oriented Thermal Analysis of Flat-Plate Solar Collectors

    OpenAIRE

    Reiter, Christoph N.; Christoph Trinkl; Wilfried Zörner; Hanby, Vic I.

    2015-01-01

    A mathematical model of a flat-plate solar collector was developed on the basis of the physical principles of optics and heat transfer in order to determine collector’s component temperatures as well as collector efficiency. In contrast to many available models, the targeted use of this dynamic model is the detailed, theoretical investigation of the thermal behaviour of newly developed or adjusted collector designs on component level, for example, absorber, casing, or transparent cover. The d...

  17. 锁定加压钢板在治疗桡骨远端不稳定骨折中的应用%Locking Compression Plate Fixation for Intraarticular and Unstable Distal Radial Fractures

    Institute of Scientific and Technical Information of China (English)

    张珂; 刘其明; 赵庆华; 李峰; 王予治; 孙羽

    2012-01-01

      目的:探讨锁定加压钢板(locking compression plate,LCP)治疗不稳定型桡骨远端骨折(distal radial fractures,DRF)的效果.方法:分析自2006年1月~2012年5月我院采用锁定加压钢板治疗桡骨远端不稳定骨折20例患者临床资料,其中男12例,女8例;年龄18~66岁,平均年龄44.6岁.按AO桡尺骨远端骨折分型,B2、3型(部分关节面骨折,掌背侧骨块)6例;Cl型(完全关节内骨折,干骺端骨折)7例;C2型(完全关节内骨折,干骺端粉碎骨折)5例;C3型2例.部分患者初期手法复位固定治疗失败.掌侧入路切开复位,LCP内固定治疗.结果:术后门诊随访2~36个月.桡骨远端骨折均完全愈合,按改良的Mcbirde评分和纽约骨科医院腕关节功能评估标准,优良率为85℅(17/20).结论:对桡骨远端不稳定性骨折,掌侧LCP是一种安全有效的治疗方法.%  Objective:To investigate the locking compression plate (locking compression plate,LCP) the effect of the treatment of unstable distal radial fracture (distal radial fractures,DRF). Methods: Analysis from January 2006 to May 2012 using locking compression plate for treatment of distal radius unstable fracture of the clinical data of 20 patients,including 12 males and 8 females; age 18-66 years,mean age 44.6 years old. Radius and ulna in remote according to the AO fracture classification,B2,3 (partial articular fractures,palm dorsal bone) six cases: Cl (complete articular fractures of the metaphyseal fracture) 7 cases; C2,type (full intra-articular fracture,metaphyseal comminuted fracture) 5 cases; C3 type 2 patients. Fixed treatment failure in some patients early manipulative reduction. Volar open reduction and internal fixation in the LCP.Results: Folowed-up from 2 to 36 months,Distal radius fractures are completely healed,the improved Mcbirde score and the New York Orthopaedic Hospital,wrist function evaluation criteria, excellent rate of 85 ℅ (17/20). Conclusion:Volar LCP

  18. 肱骨近端锁定加压钢板治疗肱骨近端骨折的疗效%The effect of proximal humeral locking plate in treating proximal humeral fractures

    Institute of Scientific and Technical Information of China (English)

    曾勉东; 谢景开; 杨波; 张志; 尹飚

    2013-01-01

    [ Objective ] To evaluate and observe functional outcome of locking proximal humeral plate ( LPHP) used for fixation of the proximal humerus fractures in elderly. [ Method] Retrospective analysis from December 2009 to December 2011,41 patients with an acute proximal humerus fracture were managed with locking proximal humeral plate osteosynthesis after open reduction,15cases were males, 28case were females, with age of 49 to 82(mean 67. 5). According to Neer classification, 12 cases were two-part fracture,22 cases were three-part fracture,7 cases were four-part fracture. [Result] All of them were with the mean follow-up of ranged 8-28 months (mean 14 months),healing at the last review. Functional score standard of Neer was used for evaluating the shoulder function, 13 cases were excellent,21 cases were good,4 cases were morderate,3 cases were poor,the excellent and good results rate was 82.9%. [ Conclusion] Locking proximal humeral plate osteosynthesis leads to satisfactory functional outcomes in proximal humerus fractures, which is a less complications, early functional exercise, effective therapeutic method.%[目的]观察、评价肱骨近端锁定加压钢板(locking proximal humeral plate,LPHP)治疗复杂性老年肱骨近端骨折的疗效.[方法]回顾性分析2009年12月~2011年12月41例老年肱骨近端二部分以上骨折采用骨折切开复位结合锁定钢板内固定治疗的疗效,其中男13例,女28例,年龄49 ~ 82岁(平均67.5岁).按Neer分类法:2部分骨折12例,3部分骨折22例,4部分骨折7例.[结果]41例均获随访,随访时间8~ 28个月(平均14个月),骨折均得到了愈合,随访肩关节功能按Neer功能评分标准,优13例,良21例,可4例,差3例,优良率达82.9%.有1例发生肱骨头缺血坏死,2例发生肩峰撞击综合征.[结论]锁定钢板针治疗老年性肱骨近端骨折固定可靠,并发症少,骨折愈合良好,便于早期功能锻炼,是一种有效的治疗方法.

  19. Clinical analysis of 24 cases of fracture of anatomical plate in the treatment of tibial locking%解剖锁定钢板治疗胫骨平台骨折24例临床分析

    Institute of Scientific and Technical Information of China (English)

    和尧虎; 王玲智; 李晓波; 杨慧斌; 马龙

    2015-01-01

    Objective To investigate the choice of different approach, anatomic locking plate fixation in thetreatment of different types of tibial plateau fractures.Methods from 2010-01-2013-06, 24 cases of tibial plateau fracture by patellar, anterior lateral incision, anterior medial incision, anterior lateral incision combined with small incision or patellar medial posterior median longitudinal incision. Simple proximal lateral tibiaanatomical locking plate , or with"T"type, rear locking reconstruction plate internal fixation.Results in this group, 24 cases got follow-up, 6 months to 30 months, average 15 months. After 6 to 12 months, all fractures healed, no loosening of the internal fixation of fracture,one case of superficial infection, Staphylococcus epidermidis infection by VSD culture, negative pressure suction a week, anti infection, skin grafting for 4 weeks.A case of sural total nerve damage, weak foot dorsiflexed. Using the Rasmussen function evaluation:excellent in 14 cases, good in 7 cases, 2 cases, poor in 1 cases. Excellent rate was 87.5%.Conclusion Choose a different approach,anatomic locking plate fixation in the treatment of different types of tibial plateau fractures, early functional exercise, is an effective method.%目的:探讨解剖锁定钢板内固定治疗胫骨平台骨折的疗效。方法2010年1月—2013年6月,对24例胫骨平台骨折患者采取髌旁前外侧切口、前内侧切口、前外侧切口加后内侧小切口或髌正中纵行切口,单纯胫骨近端外侧解剖锁定钢板或加内、后侧“T”形锁定、重建钢板复位内固定。结果本组24例均获得随访,时间6个月~30个月,平均15个月。术后6个月~12个月骨折全部愈合,内固定无松动断裂,其中1例切口浅表感染,培养表皮葡萄球菌感染,经负压封闭引流术(VSD)负压吸引1周,抗感染、植皮4周痊愈。1例腓总神经损伤,足背伸无力。采用Rasmussen功能评定标准:优14

  20. A STUDY OF SURGICAL MANAGEMENT OF DIAPHYSEAL FRACTURES OF HUMERUS BY DYNAMIC COMPRESSION PLATE OSTEOSYNTHESIS

    Directory of Open Access Journals (Sweden)

    Kuppa

    2015-01-01

    Full Text Available AIMS AND OBJECTIVES: To study the fractures, mechanism of injury, union rates and functional results of humeral shaft fractures treated with open reduction and internal fixation with dynamic compression plate. RESULTS: In present study, 25 patients of diaphyseal fractures of humerus, surgically managed by dynamic compression plate & screws, between O ctober 2012 to S eptember 2014 in government general hospital attached to kurnool medical college were included. The average age of the patient is 38.9 years, road traffic accidents being the most common mode of accident with 72%, middle third fractures were commonest with 80%, transverse fractures were the commonest with 52%, anterolateral approach was used in 88%, union achieved in 88% with mean time for union 15.56 weeks, iatrogenic radial nerve palsy in 4%, postoperative infection in 4%, full range of movements in 80%, with 8% nonunion . CONCLUSION : By the analysis of the data collected in the present study, dynamic compression plate & screws remains the implant of choice in the management of diaphyseal fractures of humerus.

  1. CAD-CAM plates versus conventional fixation plates for primary mandibular reconstruction: A biomechanical in vitro analysis.

    Science.gov (United States)

    Rendenbach, Carsten; Sellenschloh, Kay; Gerbig, Lucca; Morlock, Michael M; Beck-Broichsitter, Benedicta; Smeets, Ralf; Heiland, Max; Huber, Gerd; Hanken, Henning

    2017-09-01

    CAD/CAM reconstruction plates have become a viable option for mandible reconstruction. The aim of this study was to determine whether CAD/CAM plates provide higher fatigue strength compared with conventional fixation systems. 1.0 mm miniplates, 2.0 mm conventional locking plates (DePuy Synthes, Umkirch, Germany), and 2.0 mm CAD/CAM plates (Materialise, Leuven, Belgium/DePuy Synthes) were used to reconstruct a polyurethane mandible model (Synbone, Malans, CH) with cortical and cancellous bone equivalents. Mastication was simulated via cyclic dynamic testing using a universal testing machine (MTS, Bionix, Eden Prairie, MN, USA) until material failure reached a rate of 1 Hz with increasing loads on the left side. No significant difference was found between the groups until a load of 300 N. At higher loads, vertical displacement differed increasingly, with a poorer performance of miniplates (p = 0.04). Plate breakage occurred in miniplates and conventional locking plates. Screw breakage was recorded as the primary failure mechanism in CAD/CAM plates. Stiffness was significantly higher with the CAD/CAM plates (p = 0.04). CAD/CAM plates and reconstruction plates provide higher fatigue strength than miniplates, and stiffness is highest in CAD/CAM systems. All tested fixation methods seem sufficiently stable for mandible reconstruction. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  2. 49 CFR 236.779 - Plate, top.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plate, top. 236.779 Section 236.779 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top. A metal plate secured to a locking bracket to prevent the cross locking from being forced out of the...

  3. Dynamic effects of plate-buoyancy subduction at Manila Trench, South China Sea

    Science.gov (United States)

    Jiang, L.; Zhan, W.; Sun, J.; Li, J.

    2015-12-01

    Bathymetric map of SCS plate shows two subducting buoyancies, the fossil ridge and the oceanic plateau, which are supposed to impact slab segmentation into the north from Taiwan to 18°N, and the south from 17°N to Mindoro. Hypocenter distribution show that slab dip angle turns lower southwards from 45° to 30° in the north segment, and relatively equals ~45° in the south segment at the depth of 100km. Moreover, volcano distribution can be segmented into Miocene WVC, Quaternary EVC in the north and combined SVC in the south (Fig. A). We found that WVC and SVC mostly locate in a parallel belt ~50km apart to Manila trench, however EVC turn father southwards from 50km to 100km (Fig. B). Above characters congruously indicate that SCS plate kept equal dip angle in Miocene; then the north segment shallowed at 18°N and developed northwards in Quaternary, resulting in lower dip angle than the invariant south segment. To check the transformation of slab dip angle from 45° to 30° between 17~18°N, focal mechanism solution nearby 17°N are found 90° in rake and dip angle, strike parallel to the fossil ridge, indicating a slab tear located coincident with the ridge, where is a weak zone of higher heat flow and lower plate coupling ratio than the adjacent zones and slab can be easily tore as an interface for SCS plate segmentation. Subduction of the two buoyancies within SCS plate is supposed as influential dynamic factor: It caused the trench retreat rate reduced, forming a cusp and a flat convex of Manila trench shape; Moreover, the buoyancies resisted subduction, resulting in shear stress heterogeneity of SCS plate, in consequence the fossil ridge as a fragile belt potentially became stress concentration zone that easily tore; Then the buoyant oceanic plateau might lead to shallowing of the northern SCS plate. To examine the hypothesis, dynamic effects of the two subducting buoyancies are being respectively investigated based on numerical models. (Grt. 41376063, 2013

  4. Locking intrameduilar nail and locking plate in treatment of proximal humerus fractures:a comparative study%锁定型髓内针和锁定型钢板治疗肱骨近端骨折的对比研究

    Institute of Scientific and Technical Information of China (English)

    朱以明; 鲁谊; 姜春岩

    2008-01-01

    目的 对比肱骨近端锁定型髓内针或肱骨近端锁定型钢板治疗肱骨近端骨折的疗效,并探究两种内固定物各自的特点. 方法 54例新鲜肱骨近端二部分外科颈骨折患者,分为髓内针同定组(26例)和锁定犁钢板同定组(28例),两组在平均年龄比例、性别比例、优势侧受累比例方面差异尤统计学意义.最终随访时进行洋细肩关节体检,拍摄肩关节X线片以评价愈合的情况,并应用疼痛的视觉评分(VAS),美国肩肘外科医师评分(ASES),Constant-Murley评分,以及简单肩关节功能问卷(SST)评估患者肩关节功能,对比两组的结果. 结果 所有骨折均在术后8周内初步愈合.随访过程中两组均未出现感染、肱骨头坏死.钢板组患者并发症率较髓内针组高.两组的肩关节功能恢复情况均比较令人满意.两组间在术后患肢平均主动前屈上举、主动体侧外旋、主动内旋体侧内旋活动度、Constant-Murley评分、SST评分方面差异无统计学意义.但钢板组在最终患者的肩关节ASES评分、VAS评分和平均冈上肌肌力等方而优于髓内针组. 结论 两种内固定物均可较满意地治疗肱骨近端二部分外科颈骨折.锁定型髓内针创伤较小,而锁定型钢板在术后功能恢复方面更具优势.%Objective To compare the results of locking intramedullar nail and Locking plate in treating proximal humerus fractures and discuss features of each instrument. Methods A total of 54 patients with fresh two-part surgical neck fracture of proximal humerus were divided into intramedullar nail fixation group(26 patients)and locking plate fixation group(128 patients).with no statistical difference upon age,gender and dominate hand involvement in two groups.At final follow-up,physical examination and X-ray films were used to evaluate fracture healing of shoulder ioint.In the meantime,VAS score,ASES score,Constant-Murley score,UCLA and SST questionnaire were used to

  5. Dynamic response of geometrically nonlinear, elastic rectangular plates under a moving mass loading by inclusion of all inertial components

    Science.gov (United States)

    Rofooei, Fayaz R.; Enshaeian, Alireza; Nikkhoo, Ali

    2017-04-01

    Dynamic deformations of beams and plates under moving objects have extensively been studied in the past. In this work, the dynamic response of geometrically nonlinear rectangular elastic plates subjected to moving mass loading is numerically investigated. A rectangular von Karman plate with various boundary conditions is modeled using specifically developed geometrically nonlinear plate elements. In the available finite element (FE) codes the only way to distinguish between moving masses from moving loads is to model the moving mass as a separate entity. However, these procedures still do not guarantee the inclusion of all inertial effects associated with the moving mass. In a prepared finite element code, the plate elements are developed using the conventional nonlinear methods, i.e., Total Lagrangian technique, but all inertial components associated with the travelling mass are taken into account. Since inertial components affect the mass, damping, and stiffness matrices of the system as the moving mass traverses the plate, appropriate time increments shall be selected to avoid numerical instability. The dynamic response of the plate induced by the moving mass is evaluated and compared to previous studies. Also, unlike the existing FE programs, the different inertial components of the normal contact force between the moving mass and the plate are computed separately to substantiate the no-separation assumption made for the moving mass. Also, it is observed that for large moving mass velocities, the peak plate deformation occurs somewhere away from the plate center point. Under the two extreme in-plane boundary conditions considered in this study, it is shown that if the geometrical nonlinearity of plate is accounted for, the deformations obtained would be less than the case with classical linear plate theory.

  6. 外侧锁定板与内侧支持接骨板联合治疗C2及C3型股骨髁间骨折%Internal Fixation of Femoral Intercondylar Fracture with Lateral Locking Plate and Medial Buttress Plate

    Institute of Scientific and Technical Information of China (English)

    周建刚; 孟维春; 曹骏敏; 蒋臻欢

    2011-01-01

    Objective:To investigate the clinical effects of the treatment of type C2 and C3 femoral intercondylar fractures using locking plate and buttress plate. MethodS:From 2007 to 2010,18 cases of femoral intercondylar fractures were treated with lateral locking plates and medial buttress plates. According to Osteosynthe stfragen (AO) fracture classification, the fractures were classified as type C2 in 12 cases and type C3 in 6 cases. Medial and lateral approaches were used in the operation. After reduction,buttress plates were placed medially and locking plates were inserted laterally. There was no additional external fixation device postoperatively. Results: All the cases were followed up for an average of 8. 3 months and they all got bony union in 12-22 weeks. According to the criteria of Lysholm Knee Score, the result was as follows: 8 excellent, 8 good and 2 fair. The excellent and good rate was 89%. Conclusions: Open reduction and internal fixation with locking and buttress plates in the treatment of type C2 and C3 femoral intercondylar fracture has the advantage of a low rate complication, stable fixation and rapid bone union,and presents good clinical outcome.%目的:探讨外侧锁定板结合内侧支持接骨板治疗股骨髁间C2及C3型骨折的可行性.方法:采用外侧锁定板结合内侧支持接骨板治疗股骨髁间骨折患者18例.按AO分型:C2型12例,C3型6例,手术均采用内、外侧联合入路,骨折解剖复位后分别在外侧放置髁支持钢板,内侧放置普通钢板固定,术后不予外固定.结果:所有患者获得随访,平均随访时间为8.3个月,骨折均愈合,愈合时间12~22周.膝关节功能Lysholm评分:优8例,良8例,可2例,优良率为89%.结论:切开复位外侧锁定板结合内侧支持接骨板内固定治疗C2及C3股骨髁间型骨折并发症少、固定牢固、骨折愈合快,能获得良好的临床效果.

  7. 多轴锁定钢板治疗复杂胫骨平台骨折的初步疗效分析%Multiaxial locking plates for treatment of complex tibiai plateau fractures

    Institute of Scientific and Technical Information of China (English)

    郭永飞; 刘岩; 苟三怀; 曹振羽; 陈爱民; 欧阳跃平; 张伟; 侯春林

    2009-01-01

    目的 报告多轴锁定钢板治疗复杂胫骨平台骨折的方法及初步疗效. 方法 2006年7月至2007年6月,采用开放复位、多轴锁定钢板内固定治疗复杂胫骨平台骨折25例,闭合性骨折21例,开放性骨折4例;骨折按Schatzker分型:Ⅳ型6例,Ⅴ型16例,Ⅵ型3例;根据影像学测量结果及HSS评分标准进行临床效果评定.结果 所有患者术后获得7~15个月(平均10.5个月)随访,骨折4~6个月后骨折均获骨性愈合,术后6个月膝关节HSS评分78~96分,平均88.4分.发生皮瓣坏死1例,切口局部感染1例,无一例发生内固定松动、断裂或骨折复位丢失现象.术后1周、3个月及6个月的内翻角和后倾角比较差异无统计学意义(P>0.05). 结论胫骨平台多轴锁定钢板操作简便,锁定螺钉置入角度选择性高,内固定稳定性好,避免了原始及继发复位的丢失,是手术治疗复杂胫骨平台骨折安全、有效的内固定方法.%Objective To report clinical effects of multiaxial locking plates in the treatment of the complex tibial plateau fractures. Methods From July 2006 to June 2007, 25 cases of complex tibial plateau fractures, 18 males and 7 females, were treated with surgical reduction and internal fixation using multiaxial locking plates. The mean age of the patients was 32.8(20 to 56) years. There were 21 closed fractures and 4 open ones. According to Schatzker classification, 6 cases were of type Ⅳ, 16 of type Ⅴ, and 3 of type Ⅵ. The follow-up period lasted 10.5(7 to 15) months on average. The knee functions in all the patients were assessed according to radiological manifestations and HSS scoring. Results All fractures united at 4 to 6 months postoperatively and the average HSS score after half a year was 88.4 (78 to 96). Skin flap necrosis was found in 1 case and incision infection in another. No loosening or rupture of the fixator, or reduction failure was observed. Conclusions The multiaxial locking plate is an

  8. 颈椎前路蝶形钢板内固定系统的研制及临床应用%Design and preliminary clinical application of anterior cervical butterfly-like locking plate fixation system

    Institute of Scientific and Technical Information of China (English)

    金大地; 瞿东滨; 陈建庭; 江建明; 王吉兴; 朱青安

    2001-01-01

    Objective To evaluate the biomechanical stability and the preliminary clinical efficacy of self-designed anterior cervical butterfly-like locking plate fixation system. Methods The anterior cervical fixation system is composed of one butterfly-like plate and three types of screw made of titanium alloy(TC4,Ti6Al4V) on the basis of unicortical screw fixation and point contact plate fixation principle. Biomechanical stability analyses of the system and Orion locking plate system (Sofamor - Danek Corp) were performed in fresh cervical spine specimens from fourteen young male cadavers. 61 patients with cervical disorders were stabilized with the fixation system. The mean age of the patients during surgery was 48.2 years (range 18 to 68 years). The diagnosis included spondylosis in 26 cases, cervical intervertebral disk protrusion 14, fracture and/or dislocation 18 and tuberculosis 3. Results This anterior butterfly-like cervical plate fixation system holds similar biomechanical stability effects as Orion system. Of 61 cases received the plate fixation system after anterior decompression and autologous interbody fusion, 48 were followed-up for six to ten months, and showed solid interbody fusion in three to four months. No early complications such as implant loosening or failure related to the fixation system were noted. Conclusion The anterior cervical plate fixation system can provide sufficient biomechanical stability to cervical spine after anterior decompression surgery.%目的研制颈椎前路蝶形钢板内固定系统,评价其生物力学稳定性,并进行临床初步应用观察.方法该系统包括蝶形钢板及三种不同用途的螺钉,采用单皮质螺钉固定及点接触原理,由医用钛合金材料(TC4)制成.采用14具青年男性尸体的新鲜颈椎标本,利用脊柱三维运动分析系统,比较蝶形钢板固定与Orion钢板固定对失稳颈椎的稳定作用.临床上应用于颈椎患者的治疗61例,其中颈椎病26例,颈椎间

  9. Study of Dynamic Buckling of FG Plate Due to Heat Flux Pulse

    Directory of Open Access Journals (Sweden)

    Czechowski L.

    2015-02-01

    Full Text Available The paper deals with a FEM analysis of dynamic buckling of functionally graded clamped plates under heat flux loading with huge power. The materials of structures as well as their properties are varying in each layer across the plate thickness formulated by the power law distribution. The heat flux was applied evenly to the whole ceramic surface. The analysis was developed in the ANSYS 14.5 software. The duration of the heat flux loading equal to a period of natural fundamental flexural vibrations of given structures was taken into consideration. To implement large deflections of structures, the Green-Lagrange nonlinear-displacement equations and the incremental Newton-Raphson algorithm were applied. An evaluation of the dynamic response of structures was carried out on basis of the Budiansky-Hutchinson criterion. The studies were conducted for different volume fraction distributions and different shapes of the heat flux loading. The computation results of the heat flux versus maximal plate deflection are shown and discussed.

  10. Operative treatment of proximal humeral fractures with T incision and MIPPO locking compression plate%T形切口下微创锁定钢板治疗肱骨近端骨折疗效探讨

    Institute of Scientific and Technical Information of China (English)

    韩立强; 江汉; 肖联平; 杨国跃; 江毅; 张殿英

    2014-01-01

    目的:回顾性分析 T 形切口下微创锁定钢板治疗肱骨近端骨折的疗效。方法自2011年1月至2013年8月,我院收治肱骨近端骨折患者35例,分类方法采用 AO 分型,其中11-A2型7例,11-A3型12例,11-B1型8例,11-B2型6例,11-C1型2例,均采用T型切口下锁定钢板手术治疗,术后2~3d开始肩关节被动活动锻炼,逐渐增加活动范围,术后2 周开始肩关节摆动锻炼,术后3周开始肩关节锻炼,并采用 Neer肩关节功能评分。结果本组 3 5例患者手术切口均一期愈合,所有患者均得到随访,随访时间5~16个月,平均13.1个月,骨折均骨性愈合,术后未发现腋神经损害表现,未发现退钉、钢板松动。Neer肩关节功能评分:优19例,良10例,可6例。结论 T 形切口下微创锁定钢板治疗肱骨近端骨折具有创伤小、功能恢复快、临床疗效佳的优点,尤其适于 AO 分型的A2、A3型和B型骨折的治疗。%Background With the aging of population,the proximal humerus fractures are becoming more and more common.The displaced proximal humeral fractures often result in long-term disability.For the instability and displacement of the fracture,the operation treatment is of the best effect so far.At present,the locking plate has been widely used in the treatment of proximal humerus fractures,and has already achieved good clinical results.This paper retrospectively analysis the functional effect of minimally invasive locking plate in the treatment of proximal humeral fractures in our hospital with T shape incision.Methods Thirty-five cases in our hospital suffered from proximal humeral fractures were included in this study (16 males,19 females,aged 31-72 years old)during the past years.The average age was 56.3 years old.Fifteen cases were injured on the left side,20 cases were injured on the right side.All the fractures were fresh.The cause of injury:20 cases were living accident,6 cases were of high falling inj ury,9 cases were of traffic

  11. Experimental demonstration of change of dynamical properties of a passively mode-locked semiconductor laser subject to dual optical feedback by dual full delay-range tuning.

    Science.gov (United States)

    Nikiforov, O; Jaurigue, L; Drzewietzki, L; Lüdge, K; Breuer, S

    2016-06-27

    In this contribution we experimentally demonstrate the change and improvement of dynamical properties of a passively mode-locked semiconductor laser subject to optical feedback from two external cavities by coupling the feedback pulses back into the gain segment. Hereby, we tune the full delay-phase of the pulse-to-pulse period of both external cavities separately and demonstrate the change of the repetition rate, timing jitter, multi-pulse formation and side-band suppression for the first time for such a dual feedback configuration. In addition, we thereby confirm modeling predictions by achieving both a good qualitative and quantitative agreement of experimental and simulated results. Our findings suggest a path towards the realization of side-band free all-optical photonic oscillators based on mode-locked lasers.

  12. Free Vibration Analysis for Dynamic Stiffness Degradation of Cracked Cantilever Plate

    Directory of Open Access Journals (Sweden)

    Oday. I. Abdullah

    2005-01-01

    Full Text Available In the present work a dynamic analysis technique have been developed to investigate and characterize the quantity of elastic module degradation of cracked cantilever plates due to presence of a defect such as surface of internal crack under free vibration. A new generalized technique represents the first step in developing a health monitoring system, the effects of such defects on the modal frequencies has been the main key quantifying the elasticity modulii due to presence any type of un-visible defect. In this paper the finite element method has been used to determine the free vibration characteristics for cracked cantilever plate (internal flaws, this present work achieved by different position of crack. Stiffness reduction in term of elastic material properties is analyzed through a parametric study of crack density factor. Results are given for Young’s modulus and shear modulus variation with respects the vibrational characteristics.

  13. Synchronized molecular-dynamics simulation for the thermal lubrication of a polymeric liquid between parallel plates

    CERN Document Server

    Yasuda, Shugo

    2015-01-01

    The Synchronized Molecular-Dynamics simulation which was recently proposed by authors [Phys. Rev. X {\\bf 4}, 041011 (2014)] is applied to the analysis of polymer lubrication between parallel plates. The rheological properties, conformational change of polymer chains, and temperature rise due to the viscous heating are investigated with changing the values of thermal conductivity of the polymeric liquid. It is found that at a small applied shear stress on the plate, the temperature of polymeric liquid only slightly increases in inverse proportion to the thermal conductivity and the apparent viscosity of polymeric liquid is not much affected by changing the thermal conductivity. However, at a large shear stress, the transitional behaviors of the polymeric liquid occur due to the interplay of the shear deformation and viscous heating by changing the thermal conductivity. This transition is characterized by the Nahme-Griffith number $Na$ which is defined as the ratio of the viscous heating to the thermal conducti...

  14. Dynamic buckling analysis of delaminated composite plates using semi-analytical finite strip method

    Science.gov (United States)

    Ovesy, H. R.; Totounferoush, A.; Ghannadpour, S. A. M.

    2015-05-01

    The delamination phenomena can become of paramount importance when the design of the composite plates is concerned. In the current study, the effect of through-the-width delamination on dynamic buckling behavior of a composite plate is studied by implementing semi-analytical finite strip method. In this method, the energy and work integrations are computed analytically due to the implementation of trigonometric functions. Moreover, the method can lead to converged results with comparatively small number of degrees of freedom. These features have made the method quite efficient. To account for delamination effects, displacement field is enriched by adding appropriate terms. Also, the penetration of the delamination surfaces is prevented by incorporating an appropriate contact scheme into the time response analysis. Some selected results are validated against those available in the literature.

  15. Femoral Locking Compression Plate (LCP)for the Subtrochanteric Fractures in Children%股骨锁定加压钢板(LCP)在儿童股骨转子下骨折中的应用

    Institute of Scientific and Technical Information of China (English)

    蔡文全; 覃佳强; 南国新; 王忠良; 宿玉玺; 张德文

    2014-01-01

    Objetive To study the clinical effect of the femoral locking compression plate (LCP)in children femoral subtrochanteric fracture. Methods 22 cases of femoral subtrochanteric fracture in children diagnosed in our hospital from February 201 0 to December 201 2 were analyzed retrospectively,including 1 6 ca-ses of male,6 cases of female,with an average age of 8.5.Results All of the 22 cases received follow-ups ranging from 6 to 48 months (27 months in average);osseous healing was found in all these 22 cases of frac-ture,without broken nails,nail,loose steel plate,broken board or coax vara,articular dyskinesia,etc. Con-clusion Application of femoral locking compression plate (LCP)for children femoral subtrochanteric fractures can effectively improve the deficiencies of the traditional conservative treatments including traction,k-wire,ti-tanium elastic nail fixation and other therapies,and can achieve a better effect through early functional exercise to reduce joint rigidity.%目的:探讨股骨锁定加压钢板(LCP)对儿童股骨转子下骨折的临床疗效。方法回顾性分析本院2010年2月至2012年12月收治的22例股骨转子下骨折患儿临床资料,其中男16例,女6例,平均年龄8.5岁。结果22例均获得随访,随访时间6~48个月,平均27个月,22例均骨性愈合,无断钉、脱钉、钢板松动、断板及髋内翻、关节活动障碍等并发症发生。结论股骨锁定加压钢板(LCP)对于儿童股骨转子下骨折可以有效改善传统保守牵引、克式针、弹性髓内钉固定及其他治疗方法的不足,可早期进行功能锻炼,减少关节僵直,效果良好。

  16. The biomechanics of point contact-dynamic compression plate and its effects on bone perfusion

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu-feng; LI Qi-hong; GU Zu-chao; WANG Ai-min

    2006-01-01

    Objective: To compare the mechanical properties of point contact-dynamic compression plate (PC-DCP) and its effects on cortical bone perfusion with that of dynamic compression plates (DCP) in goat tibiae.Methods: Twenty pairs of matched fresh goat tibiae were used. A transverse fracture model was established.The fractures with a 3mm interspace between the fracture ends were subject to fixations with the DCPs and the PCDCPs respectively, then the four-points bending tests and the torsion tests were conducted to compare the mechanical properties of the PC-DCP with that of DCP. Another 13sexually mature goats underwent fixations with the DCPs and the PC-DCPs, respectively, at the mid-shafts of the intact bilateral tibiae. Ischemic zones were observed at four time points (1 day, 2, 6, and 12 weeks after operation)using disulphine blue staining technique.Results: There were no significant differences in mechanical properties, such as bend- and torsionresistance, between the DCPs and the PC-DCPs. One day,2, and 6 weeks after operation, on the side of DCP fixation, outer cortical bone iscbemia under the plate persisted, and this condition did not reverse until 12 weeks after operation. However, on the side of PC-DCP fixation,cortical bone ischemia occurred only in the periphery of the screw holes and at the contact sites of the PC NUTs 1 day after operation, and it disappeared at 2 weeks after operation.Conclusions: The PC-DCP has similar biomechanical properties of the DCP, but is less detrimental to local bone blood circulation than the conventional plates.

  17. Analysis on locking proximal hummers plate for treatment of proximal humeral fractures in elderly%肱骨近端锁定钢板治疗老年肱骨近端骨折的疗效分析

    Institute of Scientific and Technical Information of China (English)

    杜区成; 戴小玲; 柯文坤; 李明

    2014-01-01

    Objective:To investigate the locking plate minimally invasive treatment of proximal humeral fractures in elderly patient’s clinical efficacy and safety. Methods: The elderly in our hospital and proximal hummers fracture patients were randomly divided into control and treatment groups. All patients received the same preoperative therapy, the control group received conventional steel surgical treatment, the use of steel plate or intramedullary nail fixation; patients treated with minimally invasive surgery locking plate line , groups of patients received the same postoperative treatment and care. Results: The patients treated with surgery time is slightly lower than the control group , but the difference was not statistically significant (P>0.05), while patients treated with fracture healing time and blood loss were lower than the control group, the difference was statistically significant (P0.05);treatment group patients total efficiency (84.4%) was higher (59.4%) , the difference was statistically significant (P<0.05);patients treated with various common adverse events were lower than the control group, the difference was statistically significant (P<0.05). Conclusion:Using locking plate for treatment of proximal humeral fractures in elderly patients clinical effects, adverse reactions, worthy of promotion.%目的:探讨锁定钢板微创治疗老年肱骨近端骨折患者的临床效果和安全性。方法:将老年肱骨近端骨折患者并随机分为对照组和治疗组。所有患者接受相同的术前治疗后,对照组接受常规钢板手术治疗,使用钢板或髓内钉固定;治疗组患者使用微创锁定钢板行微创手术治疗,两组患者接受相同的术后治疗和护理。结果:治疗组患者手术时间稍低于对照组,其差异无统计学意义(t=7.766,P>0.05),而治疗组患者的骨折愈合时间和术中出血量均低于对照组,其差异有统计学意义(t=8.439,t=12.380;P<0.05);治疗

  18. Dynamics and roles of phragmoplast microfilaments in cell plate formation during cytokinesis of tobacco BY-2 cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan; ZHANG WenJie; BALUSKA Frantisek; MENZEL Diedrik; REN HaiYun

    2009-01-01

    The phragmoplast is a special apparatus that functions in establishing a cell plate in dividing plant cells.It is known that microfilaments (MFs) are involved in constituting phragmoplast structure, but the dynamic distribution and role of phragmoplast MFs are far from being understood. In this study, the precise structure and dynamics of MFs during the initiation and the late lateral expansion of the phragmoplast were observed by using a tobacco BY-2 cell line stably expressing the microfilament reporter construct GFP-f ABD2. Three-dimensional imaging showed that the phragmoplast MFs were initiated by two populations of MFs emerging between the reconstituting daughter nuclei at anaphase, which migrated to the mid-zone and gave rise to two layers of microfilament arrays. FM4-64 stained vesicles accumulated and fused with the cell plate between the two populations of MFs. The two layers of microfilament arrays of phragmoplast with ends overlapped always surrounded the centrifugally expanding cell plate. Partial disruption of MFs at metaphase by low concentration of latrunculin B resulted in the inhibition of the cell plate consolidation and the blockage of cell plate lateral expansion,whereas high concentration of latrunculin B restrained the progression of the cell cycle. Treating the cell after the initiation of phragmoplast led to the cease of the expansion of the cell plate. Our observations provide new insights into the precise structure and dynamics of phragmoplast MFs during cytokinesis and suggest that dynamic phragmoplast MFs are important in cell plate formation.

  19. Generalized equations of finite difference method in the problems of dynamic load calculation for thin bending plates

    Directory of Open Access Journals (Sweden)

    Gabbasov Radek Fatykhovich

    Full Text Available Bending plate is widely used in the construction of large-span structures. Its advantage is light weight, industrial production, low cost and easy installation. Implementing the algorithm for calculating bending plates in engineering practice is an important issue of the construction science. The generalized equations of finite difference method is a new trend in the calculation of building construction. FDM with generalized equation provides additional options for an engineer along with other methods (FEM. In the article the algorithm for dynamic calculation of thin bending plates basing on FDM was developed. The computer programs for dynamic calculation were created on the basis of the algorithm. The authors come to the conclusion that the more simple equations of FDM can be used in case of solving the impulse load problems in dynamic load calculation of thin bending plate.

  20. Exploring the self-mode-locked dynamics of cryogenic diode-pumped Nd:YLF lasers: switching of orthogonal polarizations

    Science.gov (United States)

    Huang, T. L.; Y Cho, C.; Liang, H. C.; Huang, K. F.; Chen, Y. F.

    2017-08-01

    The self-mode-locked output for cryogenic Nd:YLF laser at the temperature range of 90 K to 290 K is thoroughly investigated. Linearly polarized self-mode-locked lasing at 1047 nm (1053 nm) with a repetition rate up to 1.59 GHz and a pulse width as short as 52 ps can be realized at temperatures above 155 K (below 135 K). Orthogonally polarized self-mode-locked operation can be observed at temperatures near 145 K. During dual-polarization operation, it is found that the polarized component with higher output power is the fundamental transverse mode, whereas the other component with lower output power becomes the high-order transverse mode. The dominant polarized component can be either π- or σ-polarization, depending on the fine adjustment of the cavity.

  1. Long-time dynamics of two classes of beam and plate equations

    OpenAIRE

    2016-01-01

    In this thesis we will discuss the well-posedness and long-time dynamics of curved beam and thermoelastic plates. First, we considered the Bresse system with nonlinear damping and forcing terms. For this model we show the Timoshenko system as a singular limit of the Bresse system as the arch curvature l goes to 0 and under suitable assumptions on the nonlinearity we prove the existence of a smooth global attractor with finite fractal dimension and exponential attractors as well. We also compa...

  2. Dynamical Analysis of Long Fiber-Reinforced Laminated Plates with Elastically Restrained Edges

    Directory of Open Access Journals (Sweden)

    Liz G. Nallim

    2012-01-01

    Full Text Available This paper presents a variational formulation for the free vibration analysis of unsymmetrically laminated composite plates with elastically restrained edges. The study includes a micromechanics approach that allows starting the study considering each layer as constituted by long unidirectional fibers in a continuous matrix. The Mori-Tanaka method is used to predict the mechanical properties of each lamina as a function of the elastic properties of the components and of the fiber volume fraction. The resulting mechanical properties for each lamina are included in a general Ritz formulation developed to analyze the free vibration response of thick laminated anisotropic plates resting on elastic supports. Comprehensive numerical examples are computed to validate the present method, and the effects of the different mechanical and geometrical parameters on the dynamical behavior of different laminated plates are shown. New results for general unsymmetrical laminates with elastically restrained edges are also presented. The analytical approximate solution obtained in this paper can also be useful as a basis to deal with optimization problems under, for instance, frequency constraints.

  3. Using Plate Finite Elements for Modeling Fillets in Design, Optimization, and Dynamic Analysis

    Science.gov (United States)

    Brown, A. M.; Seugling, R. M.

    2003-01-01

    A methodology has been developed that allows the use of plate elements instead of numerically inefficient solid elements for modeling structures with 90 degree fillets. The technique uses plate bridges with pseudo Young's modulus (Eb) and thickness (tb) values placed between the tangent points of the fillets. These parameters are obtained by solving two nonlinear simultaneous equations in terms of the independent variables rlt and twallt. These equations are generated by equating the rotation at the tangent point of a bridge system with that of a fillet, where both rotations are derived using beam theory. Accurate surface fits of the solutions are also presented to provide the user with closed-form equations for the parameters. The methodology was verified on the subcomponent level and with a representative filleted structure, where the technique yielded a plate model exhibiting a level of accuracy better than or equal to a high-fidelity solid model and with a 90-percent reduction in the number of DOFs. The application of this method for parametric design studies, optimization, and dynamic analysis should prove extremely beneficial for the finite element practitioner. Although the method does not attempt to produce accurate stresses in the filleted region, it can also be used to obtain stresses elsewhere in the structure for preliminary analysis. A future avenue of study is to extend the theory developed here to other fillet geometries, including fillet angles other than 90 and multifaceted intersections.

  4. 肱骨近端交锁髓内钉和锁定接骨板治疗肱骨近端骨折的生物力学研究%Biomechanical investigation on current fixation options for proximal humerus fractures:locked intramedullary nail and locked plate

    Institute of Scientific and Technical Information of China (English)

    周君琳; 赵会; 秦永超; 陆铁

    2016-01-01

    Background Proximal humeral fracture is a common fracture in elderly patients with osteoporosis,locking plate and intramedullary nail fixation are the most popular methods for its surgical treatment at present.There are advantages and disadvantages for both methods of internal fixation treatment.Currently,the choice of internal fixation method is a problem faced by traumatic orthopedic doctors. In this study we used proximal humeral locking plate or interlocking intramedullary nail for fracture fixation in vitro human samples with anticorrosive treatment tosimulate theload condition of shoulder joint after internal fixation,measured and calculated the axial load and stiffness of the fracture model,and discussed the fixed strength of the two internal fixation devices.We also analyzed the characteristics of these two kinds of internal fixation methods from the perspective of biomechanics.Methods (1)Selection of humeralsamples.A total of 36 humeralsamples with antiseptic treatment wereselected from 18 specimens of 60-85 years old,including 14 male samplesand 22 female samples.The X-ray films of the samples were taken to exclude congenital deformity,fracture and tumor.We appliedUnigamma X-ray Plus bone mineral density instrument to measure bone mineral density (humeral head area were unified delimited),results in each group were recorded for variance analysis.(2)Construction of fracture model with internal fixation.According to Neerclassification and the method introduced by Kwon,we produced three-partproximal humeral fracture model.We cut the humeral head with a oscillating saw at the surgical neck plane,the thickness of saw blade was 1 mm,confirmed the position of intertubercular sulcus on the osteotomy plane,then saw the bone along intertubercular sulcus to the distal humerus, thedirection is perpendicular to the osteotomy plane,until to the base of the lesser tubercle level,cut the greater tuberosity from proximal humerusat the base of lesser tuberosity

  5. 锁定钢板治疗老年肱骨外科颈骨折%Locking Plate in the Treatment of Surgical Neck Fractures of Humerus in Elderly Patients

    Institute of Scientific and Technical Information of China (English)

    胡北

    2015-01-01

    Objective To study the analysis of proximal humerus locking plate in the treatment of humerus surgical neck fracture healing. Methods This study selected 50 cases of elderly patients with humerus surgical neck fracture were from our hospital in October 2013~December 2014 during hospitalization in patients undergoing surgery, to select al of the old age patients with humerus surgical neck fracture treated by those who did the same personnel row locking plate, postoperative fol ow-up for 9 months. Statistical treatment ef ect. Results Al patients with postoperative wound infection, not fracture malunion or don't heal as wel as the internal fixation of fracture, loose;To recover the shoulder function evaluation standard reference Neer criteria for evaluation the curative ef ect of al of the patients;Its specific function recovery is:23 cases, 19 cases, 6 cases, 2 cases, fine rate was 84%. Conclusion Locking proximal humeral plate treatment has a good treatment and humerus surgical neck fracture fixed ef ects, and joint function recovered wel and fracture end good healing of fracture, fewer complications, early functional exercise can help patients and restore injured limb function, is a good surgical treatment method, is worthy of clinical promotion.%目的探讨分析肱骨近端锁定钢板治疗老年肱骨外科颈骨折的临床治疗效果。方法本次研究选取的50例老年肱骨外科颈骨折患者均来自我院2013年10月~2014年12月的住院接受手术治疗的患者,对选取的所有老年肱骨外科颈骨折患者均由同一手术组人员行锁定钢板手术治疗,术后进行随访9个月。统计治疗效果。结果术后所有患者都未发生伤口感染、骨折畸形愈合或不愈合以及内固定断裂、松动;对于肩关节功能的恢复评价标准参照Neer评分标准对所有患者的疗效进行评定;其具体功能恢复情况为:优23例,良19例,可6例,差2例,优良率为84%。结论肱骨近

  6. 锁定板微创治疗肱骨近端骨折短期临床观察%Early Clinical Observation of Minimally Invasive Treatment of Proximal Humerus Fractures with the Locking Proximal Humerus Plate

    Institute of Scientific and Technical Information of China (English)

    王胜利; 肖亮; 郭庆功

    2013-01-01

    Objective:The aim of this paper was to evaluate early results of proximal humerus fractures with the locking proximal humerus plate. Method:In this paper we retrospectively reviewed the records and radiographs of 36 patients(25 males and 11 females)with proximal humerus fractures. These cases were treated with the locking proximal humerus plate. The fractures were reduced by the transdeltoid lateral approach using minimally invasive surgery. Passive and active exercises were initiated on the second postoperative day. The results were assessed using the Constant-Murley shoulder scoring system. Result:All cases were followed up. The average time of follow-up was 15 months(range 12 to 17 months). Radiographically,union was observed in the most cases at the end of 10 weeks. In one case non union was observed and it was grafted with an autogenous graft. Acording to Constant-Murley should scoring system,the results were very good in 22 cases,good in 9 cases,mean in 4 cases,poor in 1 cases. Conclusion:It is an effective technique to minimally invasive treatment of proximal humerus fractures with the locking proximal humerus plate to deal with proximal humerus fractures.%  目的:评估运用肱骨近端锁定加压钢板微创治疗肱骨近端骨折的短期疗效。方法:本文回顾了36例运用肱骨近端锁定加压钢板治疗肱骨近端骨折患者的病案和影像资料。且本组病例均采用三角肌外侧微创外科入路反向置入钢板。术后第2天开始进行被动及主动功能锻炼。肩关节功能按照 Constant-Murley 肩关节评分标准进行评估。结果:所有患者均获得随访,平均15个月。后10周通过 X 线片观测多数病例的骨折愈合情况。仅1例发现不愈合后行自体骨移植术。根据 Constant-Murley 肩关节评分标准,优22例,良9例,中4例,差1例。结论:肱骨近端锁定加压钢板微创技术是治疗肱骨近端骨折的一种有效方法,可获得满意短期疗效。

  7. Nursing of Intertrochanteric Fracture with Osteoporosis by Proximal Femoral Locking Compression Plate%骨质疏松性股骨转子间骨折患者锁定加压钢板固定治疗的护理

    Institute of Scientific and Technical Information of China (English)

    王秀

    2011-01-01

    Objective To evaluate the nursing measures of intertrochanteric fracture and osteoporosis by proximal femoral locking compression plate.Methods Twenty-nine patients with the intertrochanteric fracture and osteoporosis by proximal femoral locking compression plate were reviewed for the psychological nursing, dietary nursing and effects of rehabilitation and training before and after treatment from February 2006 through October 2009.Results The postoperative follow ranged from 6 to 36 months(mean 18.31±6.43 months).The postoperative ambulation ranged from 3 to 15 days(mean 9.00±2.42 days).The time of fracturehealing ranged from 12-30 weeks(mean 14.85±2.21 weeks).Deep vein thrombosis of the lower extremity and minor coax vara occurred in one ant two patients respectively.The good and excellent rate of postoperative function was 93.10% according to Sander's standard.Conclusion Proximal femoral locking compression plate is effective for the intertrochanteric fracture with osteoporosis, which has the advantages of minimal invasiveness and little blood loss.It is especially suitable for elder patients.Positive psychological interventions, proper rehabilitation, routine follow up, and anti- osteoporosis treatment play essential roles in lessening bed time and improving the postoperative life quality.%目的 探讨骨质疏松性股骨转子间骨折患者股骨近端锁定加压钢板内固定手术前后的护理措施.方法 回顾性总结2006年2月至2009年10月29例采用股骨近端锁定加压钢板内固定手术治疗骨质疏松性股骨转子间骨折患者的心理护理、饮食护理、术前后康复训练及效果.结果 29例患者术后随访6~36个月,平均(18.31±6.43)个月.术后离床时间3~15 d,平均(9.00±2.42)d;骨折愈合时间12~30周,平均(14.85±2.21)周.出现下肢深静脉血栓1例,轻度髋内翻2例.按照Sander评分标准,优良率为93.10%.结论 股骨近端锁定加压钢板是治疗骨质疏松性股骨转子间

  8. Volar locking compression plate combined with artificial bone grafting for treatment of comminuted distal radial fracture%掌侧锁定加压接骨板结合人工骨植骨治疗桡骨远端骨折

    Institute of Scientific and Technical Information of China (English)

    周凯龙; 王培吉

    2014-01-01

    目的 探讨应用掌侧锁定加压接骨板(LCP)结合人工骨植骨治疗桡骨远端粉碎性骨折的临床疗效.方法 2011年1月至2013年8月期间在我院行掌侧LCP结合人工骨植骨,治疗A3、C2、C3型桡骨远端粉碎性骨折45例.术前及术后测量掌倾角、尺偏角、桡骨轴向短缩及关节面台阶程度.结果 所有患者均获得6~18个月的随访,平均12个月,骨折均获得骨性愈合,人工骨无不良反应;各影像学数据较术前均有明显改善;按Gartland-Werley评分标准评定,A3型优良率为94.4%、C2型优良率为87.5%、C3型优良率为81.8%.结论 应用掌侧LCP结合人工骨植骨治疗A3、C2、C3型桡骨远端粉碎性骨折,能够恢复桡骨长度,获得坚强内固定.%Objective To investigate the clinical results of the application of volar locking compression plate combined with artificial bone grafting in the treatment of comminuted distal radial fractures.Methods From January 2011 to August 2013,45 cases of type A3,type C2 and type C3 comminuted distal radial fractures were treated with volar locking compression plate combined with artificial bone grafting.All the cases were closed fractures with radial shortening or articular surface collapse.Volar tilt angle,radial inclination angle,axial shortening of the radius and extent of joint surface step deformity were measured both pre and post operatively.Results All the patients were follow-up for 6 to 18 months,with an average of 12 months.Bone union was noted in all the cases.There was no adverse reaction to the artificial bone grafts.Radiographic parameters were significantly improved.The clinical results were evaluated using the Gartland-Werley wrist score and rated as excellent and good in 94.4% of type A3 fractures,87.5% of type C2 fractures,and 81.8% of type C3 fractures.Conclusion Applying volar locking compression plate combined with artificial bone grafting can achieve rigid fixation and restore radial length in

  9. Tratamento das fraturas femorais subtrocantéricas com placas de bloqueio lateral da parte proximal do fêmur The treatment of femoral subtrochanteric fractures with the proximal lateral femur locking plates

    Directory of Open Access Journals (Sweden)

    Sun-Jun Hu

    2012-12-01

    Full Text Available OBJETIVO: Estudar o desfecho de fraturas subtrocantéricas de quadril tratadas com placa de bloqueio lateral da parte proximal do fêmur. MÉTODO: Revisamos retrospectivamente os resultados clínicos de 48 casos de fraturas subtrocantéricas tratadas com placas de bloqueio lateral da parte proximal do fêmur de janeiro de 2008 a maio de 2010. Registrou-se o progresso da consolidação da fratura, assim como a ocorrência de complicações. A função da articulação do quadril foi avaliada pelo índice social de Harris e o escore de mobilidade de Parker-Palmer, um ano após a cirurgia. RESULTADO: Quarenta e cinco pacientes foram acompanhados até a união da fratura ou a revisão da cirurgia. Entre os 45 pacientes, 43 atingiram a união da fratura sem outra intervenção. Trinta e oito fraturas consolidaram sem perda da posição no acompanhamento de um ano. Não houve casos de perfuração da cabeça do fêmur pelo parafuso. O escore médio do índice social de Harris foi 86,5 ± 9,8 (73 ~95. A média do escore de mobilidade de Parker e Palmer foi 7,4 ± 2,1 (3~ 9. CONCLUSÃO: A placa de bloqueio lateral da parte proximal do fêmur é o tipo de fixação interna estável e efetiva para tratar as fraturas subtrocantéricas de quadril e tem a vantagem de fixação estável, em especial em fratura da parede lateral do fêmur. Nível de evidência IV, Série de Casos.OBJECTIVE: To study the outcome of subtrochanteric hip fractures treated by using a proximal lateral femur locking plate. METHOD: We retrospectively reviewed the clinical results of 48 cases of femoral subtrochanteric fractures treated with proximal lateral femur locking plates from Jan 2008 to May 2010. The progress of fracture healing, as well as the occurrence of complications, was recorded. The function of the hip joint was evaluated by Harris social index and the Parker and Palmer mobility score at 1 year after the operation. RESULT: 45 patients were followed up until fracture

  10. Treatment of long unstable femoral intertrochanteric fractures with locking plate and cable rope%锁定钢板及缆绳联合治疗老年长段粗隆骨折

    Institute of Scientific and Technical Information of China (English)

    杨玉宝; 阚金庆; 高忠礼; 李林

    2012-01-01

    目的:探讨锁定钢板和缆绳治疗老年长段粗隆间骨折的临床疗效.方法:自2004年6月至2010年6月治疗26例老年长段粗隆间骨折,男16例,女10例;年龄50~65岁,平均(58.23±4.45)岁.车祸伤22例,其中10例合并其他复合伤;坠落伤4例.Evans分型:I型21(顺转子型),其中Ia型8例,Ib型10例,Ic型2例,Id型1例;Hrd型(逆转子型)5例.26例中均采用锁定钢板及缆绳固定治疗,髋关节功能根据Harris评分.结果:26例均获得随访,时间9~18个月,平均15个月.手术顺利,术后7~14d下地无负重功能锻炼,6周逐渐负重功能锻炼,12周后逐渐完全负重.髋关节功能Harris评分,疼痛(39.79±6.54)分,功能(31.08±9.45)分,畸形及活动(3.85±0.46)分,总分(77.31±13.97)分;结果优10例,良13例,可3例.结论:锁定钢板及缆绳适合治疗老年长段涉及粗隆Evans分型的各种类型骨折,尤其是骨质疏松患者取得较好临床效果.%Objective: To investigate clinical effect of long unstable femoral intertrochanteric fractures with locking plate and cable rope. Methods: From June 2004 to June 2010, twenty-six elderly patients with long unstable femoral intertrochanteric fractures were treated locking plate and cable rope fixation, included 16 males and 10 females with an average age of (58.23?4.45) years ranging from 50 to 65 years. There were 22 cases for traffic accident, 10 of them for traffic accident with other injury; 4 cases for falling injury. According to Evans classification, 21 cases were in type I, among them 8 in type la, 10 in type Ib, 2 in type Ic, 1 in type Id; the other 5 cases were type Hrd. Hip function scores were recorded to evaluate the treatment outcomes by Harris hip function score system. Results: Twenty-six cases were followed-up for 9 to 18 months (means 15 months). The operations were successful. All the patients received functional training for walking without weight loading from 7 to 14 days after operation , and walking

  11. Features of Three- and Four-Part Proximal Humeral Fractures and Outcome of Internal Fixation Using the Philos® Locking Plate

    Directory of Open Access Journals (Sweden)

    Ali Sadighi

    2017-03-01

    Full Text Available Background: Proximal humeral fractures are among common types of fractures and remain a challenging issue for surgical management. This study aimed to assess the clinical outcomes and complication rates of three- vs. four-part proximal humeral fractures, treated with internal fixation using the Philos® plate. Material and Methods: In this cohort study, a total of 30 consecutive patients with three-part or four-part proximal humeral fractures based on the Neer classification were included. Surgical treatment was performed with open reduction and internal fixation using the Philos® plate. The constant score was evaluated 6 months later in follow-up. The P<0.05 was considered significant. Results: Four-part fractures were mainly caused by trauma from above, while insults of opposite direction were responsible for more than half of 3 part fractures (P=0.01. Open fractures were only observed in patients with a four-part fracture (P=0.018. No significant differences were noticed regarding gender, cause, and side of the fracture. The presence of other fractures, fracture of the implant, reduction loss, avascular necrosis (AVN of humerus head, rotator cuff injury, and revision surgery were significantly higher in patients with four-part fractures. The mean constant score was 81.40±11.61 and 65.09±16.09 for three-part and four-part fractures, respectively (P=0.006. Conclusion: Open reduction and internal fixation with Philos® plate yield acceptable results in both types of fractures, however, the prognosis of this intervention is poorer four-part fractures.

  12. The experience of humerus surgical neck fracture with proximal humeral locking plate%锁定钢板治疗肱骨外科颈骨折临床疗效研究

    Institute of Scientific and Technical Information of China (English)

    曾强

    2013-01-01

    目的探讨肱骨近端锁定钢板(LPHP)治疗肱骨外科颈骨折的临床疗效。方法将78例肱骨外科颈骨折患者随机分为两组,试验组采用LPHP治疗,对照组采用克氏针内固定治疗,对比两组的治疗效果。结果试验组骨折愈合时间为(6.20±0.95)个月,快于对照组的(7.44±0.98)个月(P<0.05)。试验组患者Neer评分的总优良率为87.50%,显著高于对照组的65.79%(P<0.05)。结论肱骨近端锁定钢板固定治疗肱骨外科颈骨折疗效肯定,值得进一步推广。%Objective To investigate the therapeutic effect of humerus surgical neck fracture with proximal humeral locking plate. Methods 78 patients of humerus surgical neck fracture were randomly divided into two groups. The experimental group was treated by LPHP treatment. The control group was treated by Kirschner. Then comparing to the therapeutic effect of the two groups. Results Fracture healing time of the experimental group was (6.20±0.95) months. It was faster than the control group (7.44±0.98) months (P < 0.05). Neer score excellent and good rate of the experimental group was 87.50%, significantly higher than 65.79% of the control group (P<0.05). Conclusion The efficiency that proximal humeral locking plate was used to treat humerus surgical neck fracture is certain. So it is worthy of future promotion.

  13. Treatment of unstable femoral intertrochanteric fractures with locking proximal femoral plate%锁定接骨板治疗不稳定性股骨转子间骨折

    Institute of Scientific and Technical Information of China (English)

    侯振海; 施建国; 姚远; 叶虹; 郑隆宝; 倪志明; 姚军

    2009-01-01

    Objective To investigate the efficacy of locking proximal femoral plate (LPFP) in treatment of unstable femoral intertrochanteric fractures. Methods A total of 32 patients with unstable femoral intertrochanteric fractures were operated via Watson-Jones approach. According to the Evans classification, there were 16 patients with type Ⅲ fractures, 10 with type Ⅳ fractures and 6 with type Ⅴ fractures. The data of bone healing time and hip function scores according to Harris hip function score system were recorded for evaluating treatment outcomes. Results All the patients were followed up for an average 12.5 months, which showed fracture union within mean 10.4 weeks. There were no hip varus deformation, internal fixation failure and avaacular necrosis of femoral head, with total excellence rate of 84% according to Harris hip function score system. Conclusions LPFP is characterized by correspondence with configuration of proximal femur, stable fixation, less disturb to blood supply of femoral head, and hence is an effective treatment method for unstable femoral intertrochanteric fractures.%目的 总结股骨近端锁定接骨板(locking proximal femoral plate,LPFP)治疗不稳定性股骨转子间骨折的临床疗效. 方法股骨不稳定性转子间骨折32例,根据Evans分型:Ⅲ型16例,Ⅳ型10例,Ⅴ型6例.采用LPFP固定.观察骨折愈合情况,参照Harris髋关节评分系统评定术后患髋功能. 结果全部32例患者获得平均12.5个月随访,所有骨折均愈合.无髋内翻及内固定失败,无股骨头缺血性坏死.按Harris髋关节评分标准:优良率84%. 结论 LPFP具有符合股骨近端解剖形态、固定牢靠、对股骨头血供干扰小等优点,是一种较好的固定不稳定性股骨转子间骨折的内置物.

  14. Modeling and numerical simulation of static and dynamic behavior of multilayered plates with interface effects

    Directory of Open Access Journals (Sweden)

    Zaki Smail

    2014-04-01

    Full Text Available In Multilayered structures the interface effects have a wide range of applications in aerospace, automotive and especially in civil engineering. The design and construction of these structures and the account for interface effects require special expertise in modeling, simulation and implementation. Many studies in this case were conducted to address these issues. The objective of this work is the modeling and numerical simulation of static and dynamic behaviors of beams and plates multilayered structures with different types of interfaces. The focus was on the prediction of the behavior of stresses; shears and displacements depending on thickness. The interface can be elastic or viscoelastic of small or large thickness. The state space method has been developed for this purpose. Various types of rolled arbitrary number of isotropic or anisotropic layers structures were considered. The three-dimensional behavior is obtained for different types of static and dynamic loading. The results were compared with those based on the model of Stroh and on the various existing theories of beams and plates. The methodological approach, developed here, will be applied to thick structures, functionally graded, bimorph or multilayer structures and possibly piezoelectric or viscoelastic layered structures with interface effect

  15. Dynamics of a Grain-Filled Ball on a Vibrating Plate

    Science.gov (United States)

    Pacheco-Vázquez, F.; Ludewig, F.; Dorbolo, S.

    2014-09-01

    We study experimentally how the bouncing dynamics of a hollow ball on a vibrating plate is modified when it is partially filled with liquid or grains. Whereas empty and liquid-filled balls display a dominant chaotic dynamics, a ball with grains exhibits a rich variety of stationary states, determined by the grain size and filling volume. In the collisional regime, i.e., when the energy injected to the system is mainly dissipated by interparticle collisions, an unexpected period-1 orbit appears independently of the vibration conditions, over a wide range. This is a self-regulated state driven by the formation and collapse of a granular gas within the ball during one cycle. In the frictional regime (dissipation dominated by friction), the grains move collectively and generate different patterns and steady modes: oscillons, waves, period doubling, etc. From a phase diagram and a geometrical analysis, we deduce that these modes are the result of a coupling (synchronization) between the vibrating plate frequency and the trajectory followed by the particles inside the cavity.

  16. NON-LINEAR DYNAMIC BEHAVIOR OF THERMOELASTIC CIRCULAR PLATE WITH VARYING THICKNESS SUBJECTED TO NON- CONSERVATIVE LOADING

    Institute of Scientific and Technical Information of China (English)

    WANG Zhongmin; GAO Jingbo; LI Huixia; LIU Hongzhao

    2008-01-01

    The non-linear dynamic behaviors of thermoelastic circular plate with varying thickness subjected to radially uniformly distributed follower forces are considered. Two coupled non-linear differential equations of motion for this problem are derived in terms of the transverse deflection and radial displacement component of the mid-plane of the plate. Using the Kantorovich averaging method, the differential equation of mode shape of the plate is derived, and the eigenvalue problem is solved by using shooting method. The eigencurves for frequencies and critical loads of the circular plate with unmovable simply supported edge and clamped edge are obtained. The effects of the variation of thickness and temperature on the frequencies and critical loads of the thermoelastic circular plate subjected to radially uniformly distributed follower forces are then discussed.

  17. Effect of nanostructure on rapid boiling of water on a hot copper plate: a molecular dynamics study

    Science.gov (United States)

    Fu, Ting; Mao, Yijin; Tang, Yong; Zhang, Yuwen; Yuan, Wei

    2016-08-01

    Molecular dynamic simulations are performed to study the effects of nanostructure on rapid boiling of water that is suddenly heated by a hot copper plate. The results show that the nanostructure has significant effects on energy transfer from solid copper plate to liquid water and phase change process from liquid water to vapor. The liquid water on the solid surface rapidly boil after contacting with an extremely hot copper plate and consequently a cluster of liquid water moves upward during phase change. The temperature of the water film when it separates from solid surface and its final temperature when the system is at equilibrium strongly depend on the size of the nanostructure. These temperatures increase with increasing size of nanostructure. Furthermore, a non-vaporized molecular layer is formed on the surface of the copper plate even continuous heat flux is passing into water domain through the plate.

  18. Clinical Effect of Fixation of the Older Osteoporosis Fractures of Humeral Surgical Neck Using the Locking Plate-Philos%Philos系统治疗老年骨质疏松性肱骨外科颈骨折

    Institute of Scientific and Technical Information of China (English)

    齐新文; 王兆杰; 邝立鹏; 陈军平; 俞华威; 安荣泽

    2011-01-01

    Objective To investigate the clinical effect of inter fixation of the older osteoporosis fractures of humeral surgical neck using the locking plate-Philos (Proximal humeral internal locking system) via the deltopctoral-groove approach. Methods Reduction and locking plate-Philos fixation were done via deltopctoral-groove approach on 23 cases with the older osteoporosis humeral surgical neck fractures from March 2008 to December 2010. Bone graft was applicated on 19 of 23 cases and the rotator cuff was repaired simultaneously if damaged. The medicine of anti-osteoporosis and promoting fractures healing were applied after be in hospital. Shoulder joint passive exercises was performed at 2 days after Operation.actived exercises were done gradually 2 weeks after operation. According to Neer classification.there were 4 cases of two parts fracture. 13 cases of three parts fractures and 6 cases of four parts fractures. Results The postoperative radiographs verified good position of plate and screws,with satisfactory fracture reduction and no neurovascular injury (such as axillery nerve and humeral artery) happened. Fat liquefaction happened on 4 cases. Follow-up for 6~24 months (average 9. 8 months) showed no necrosis of humeral head.no delayed-union and un-union happen, 2 cases heterotopic ossification. According to Constant Score: the rate of excellent good was 82. 6%. After 6 months,the bone mineral density SD value of patients were higher than the first BMD SD value, but this was not statistically significant (P>0. 05). Conclusion Locking plate-Philos can firmly fixe the fractures of humeral surgical neck and possessed such advantages as assistance of reduction,early exercises and less disturbance of the blood supply. This plate showed good results for fractures of humeral surgical neck.especially communited fractures and older osteoporosis patients.%目的 探讨经肌间隙入路应用Philos系统治疗老年骨质疏松性肱骨外科颈骨折的疗效.方法

  19. 前路经寰枕寰枢关节锁定钛板螺钉内固定系统的匹配性研究%Compatible study of anterior occiput to axis transarticular locking plate system

    Institute of Scientific and Technical Information of China (English)

    李明; 蔡贤华; 黄卫兵; 张中

    2015-01-01

    目的:观察新型前路经枕寰枢关节锁定钛板螺钉内固定系统与枕颈复合体的匹配性,探讨此内固定系统临床应用的可行性。方法对枕颈部CT扫描数据进行三维重建,并通过数字化模拟手术进行解剖学匹配实验。通过观察钛板枢椎椎体前表面的切合性及螺钉的走行,测量经关节螺钉的理想钉道参数,评估此内固定系统与枕颈复合体的匹配性。结果钛板与枢椎椎体前表面相匹配;经关节螺钉均穿过寰枕关节及寰枢关节进入枕骨髁,无穿出骨质者,螺钉均未损伤舌下神经管。椎体固定螺钉均位于枢椎椎体骨质内,未进入椎管及椎间隙。经关节螺钉钉道理想钉道参数与内固定系统实际钉道参数差异无统计学意义。结论前路经寰枕寰枢关节锁定钛板螺钉内固定系统与枕颈复合体解剖学匹配性较好,具有临床应用可行性。%Objective To investigate the feasibility of anterior occiput to axis transarticular locking plate system through analyzing its compatibility with the occipital cervical complex. Methods Thirty health cases were selected from the date of head-neck CT examination randomly. 3D models of occipital cervical complex were reconstructed on the date. The anatomical compatibility was assessed between the systems and the 30 cases through surgical simulation by computer via digital technology. The morphological compatibility between the titanium plate and the surface of the axis as well as the screw trajectory were observed. The ideal screw trajectory parameters of trans- articular screws were measured so that the compatibility could be assessed. Results There was a morphological match between the titanium plate and the surface of the axis. All the trans-articular screws passed through the atlanto-occipital articulation and the atlanto-axial articulation, without piercing the bones or going into the hypoglossal canal. The fixed screws were in the

  20. Biomechanical and clinical researches of cervical spine locking plate for treatment of cervical bursting fracture%颈椎前路带锁钢板治疗颈椎爆裂骨折的试验及临床研究

    Institute of Scientific and Technical Information of China (English)

    陈福文; 周密; 贾连顺; 张树明; 王剑平; 宋迪煜; 朱方正; 朱泽兴

    2012-01-01

    Objective To evaluate the stability and clinical feasibility of cervical spine locking plate (CSLP)for the treatment of cervical fractures. Methods Six fresh cadaver cervical specimens (from C2-6) were used for test. The normal three -dimension motions of C3_5 segments were measured on a three-dimensional spinal motion test machine. Then C4 bursting fracture models were built to measure the range of motions (ROM). Iliac bony grafts were implanted and the ROM were tested once more. Finally the injured segments were fixed with AO cervical spine locking plate to measure the ROM. Thirty-two cases of lower cervical spine fractures were treated surgically with anterior decompression and fusion, and were internally fixed with CSLP. Results After bony implantation and CSLP fixation, the ROM of cervical spines in flexion/extension, left/right bending, and left/right axial rotation reduced significantly. Compared with normal ROM, flexion/extension and left/right bending were reduced significantly while left/right axial rotation didn't change significantly. After 6-48 months follow-up, all fracture were reduced completely and implanted bone was fused. Postoperative X-ray showed plates and screws were in their correct position, no loosening and breakage of both plates and screws was found. Conclusion CSLP is an ideal fixation apparatus for treatment of cervical fracture in cervical spine and can restore stability in three-dimensional ROM.%目的 评价颈椎前路带锁钢板固定系统(CSLP)治疗颈椎骨折的稳定性及临床有效性.方法 将6具新鲜成人颈椎标本(C2~6)置于脊柱三维测量仪上测定C3~5节段的ROM,制造C4爆裂骨折,测定其三维运动变化后分别进行植骨、植骨+CSLP固定,并重复测量其三维运动.对32例下颈椎骨折行前路减压融合,并以CSLP进行内固定治疗.结果 植骨+CSLP固定后在屈伸、侧弯、旋转方向较损伤后明显下降,与正常值相比,屈伸和侧弯运动均明显减少,但

  1. Two kinds of locking plate for treatment of proximal humerus fractures in the elderly%两种锁定钢板置入内固定治疗老年肱骨近端骨折

    Institute of Scientific and Technical Information of China (English)

    陈立; 赵弟庆; 杨广忠; 陈刚

    2013-01-01

    背景:肱骨近端内固定锁定系统(proximal humeral internal locking system,PHILOS)和肱骨近端锁定钢板(locking proximal humerus plate,LPHP)均作为内固定锁定钢板,用于治疗肱骨近端骨折疗效显著,但目前尚不能肯定PHILOS和LPHP治疗老年肱骨近端骨折哪个更具优势?  目的:探讨比较PHILOS和 LPHP这两种锁定板治疗老年肱骨近端骨折的近期疗效。  方法:回顾性分析具有完整随访资料的61例老年肱骨近端骨折患者,根据不同治疗方法分为 LPHP 治疗组(n=27)和PHILOS治疗组(n=34)。均根据Neer分类,LPHP组二部分骨折7例,三部分骨折11例,四部分骨折9例;PHILOS组二部分骨折9例,三部分骨折14例,四部分骨折11例。记录手术时间、出血量、引流量,观察骨折愈合时间、功能恢复、并发症,并进行统计学分析。  结果与结论:61例患者全部获得随访,随访时间12-36个月(平均20.6个月),PHILOS组和LPHP组手术时间、出血量、引流量,观察骨折愈合时间、功能恢复、并发症比较,差异并无显著性意义(P>0.05)。PHILOS和LPHP治疗老年肱骨近端骨折均可获得良好的效果,随访1年时优良率分别为81.5%,82.4%;具有固定可靠、并发症少、满意率高等优点,两种锁定板目前具有较高的临床应用价值,是治疗移位和不稳定老年肱骨近端骨折有效的切开复位内置物。%BACKGROUND:Proximal humeral internal locking system (PHILOS) and locking proximal humerus plate (LPHP) are both new types of internal fixation plates, and have satisfactory effects in the treatment of proximal humerus fractures. However, which is better? OBJECTIVE:To compare the short-term efficacy of PHILOS and LPHP in the treatment of elderly patients with proximal humeral fractures. METHODS:The fol ow-up data of 61 elderly patients with proximal humeral fractures were retrospectively analyzed. The patients

  2. Anterior cervical locking plate combined with bone graft for cervical vertebral fractures%颈前路带锁钢板联合植骨手术治疗颈椎骨折

    Institute of Scientific and Technical Information of China (English)

    王家明

    2011-01-01

    目的探讨和评价颈前路带锁钢板联合钛网植骨治疗颈椎损伤的应用价值。方法自2003年6月至2009年5月经住院手术的13例颈椎骨折的患者行颈椎前路椎体次全切除术减压,同时带锁钢板内固定联合钛网植骨或自体髂骨植骨融合。结果全部病例得到随访,平均18个月,内固定牢靠无松脱,植骨融合,椎体高度无丢失。结论颈前路带锁钢板联合钛网植骨可即刻恢复节段高度,重建节段稳定性,手术操作简单,并发症少,解决了颈椎损伤重建的难题。%Objective To evaluate the efficacy of anterior cervical locking plate combined with bone graft for cervical vertebral fractures. Methods Totally 13 patients with cervical vertebral fracture hospitalized from June 2003 to May 2009 were treated with internal fixation of steel plate combined with fusion of titanium mesh or iliac bone autograft after the resection of anterior cervical vertebra. Results All cases were followed up for an average of 18 months. The internal fixation was stable, the bone graft fusion was well and the height of vertebra body was close to normal. Conclusion The operation can be used to recover the height and stability of vertebra body. It is an easy operation with few complications and it is conducive to the reconstruction of injured cervical vertebra.

  3. Construction of semi-dynamic model of subduction zone with given plate kinematics in 3D sphere

    Science.gov (United States)

    Morishige, M.; Honda, S.; Tackley, P. J.

    2010-09-01

    We present a semi-dynamic subduction zone model in a three-dimensional spherical shell. In this model, velocity is imposed on the top surface and in a small three-dimensional region around the shallow plate boundary while below this region, the slab is able to subduct under its own weight. Surface plate velocities are given by Euler's theorem of rigid plate rotation on a sphere. The velocity imposed in the region around the plate boundary is determined so that mass conservation inside the region is satisfied. A kinematic trench migration can be easily incorporated in this model. As an application of this model, mantle flow around slab edges is considered, and we find that the effect of Earth curvature is small by comparing our model with a similar one in a rectangular box, at least for the parameters used in this study. As a second application of the model, mantle flow around a plate junction is studied, and we find the existence of mantle return flow perpendicular to the plate boundary. Since this model can naturally incorporate the spherical geometry and plate movement on the sphere, it is useful for studying a specific subduction zone where the plate kinematics is well constrained.

  4. Dynamics Simulation Analysis of Solar Array Ground Deployment and Locking%太阳翼地面展开锁定的动力学仿真分析

    Institute of Scientific and Technical Information of China (English)

    王晛; 陈天智; 柴洪友

    2011-01-01

    A simulation model for solar array ground deployment and locking is proposed with the combination of ADAMS and PATRAN/NASTRAN, based on the ADAMS's function of dynamics analysis of the flexible body. The flexibility of yoke and panels is considered at the beginning of the deployment. Concerning all the ground factors, the ground deployment and locking process is simulated constantly, and the dynamics properties, such as the impact load on solar array drive assembly, are obtained. Ground experiment has demonstrated effectiveness of the proposed approach. Then,the simulation results of solar array space deployment and locking are presented.Finally, the effects of the air resistance, the friction of the suspension system and other factors on the impact load are investigated with the simulation model.%利用ADAMS软件的柔体动力学计算功能,将ADAMS和PATRAN/NASTRAN软件联合,建立太阳翼地面展开及锁定仿真模型,从太阳翼展开初始就考虑连接架和基板的弹性,以及地面各影响因素的影响,对太阳翼地面展开锁定过程进行连续的仿真计算,得到了对驱动机构的冲击载荷等动力学性能.分析方法得到了试验的验证.其后,给出了太阳翼空间展开锁定仿真结果.最后,利用仿真模型,分析了空气阻力、吊挂装置摩擦阻力等因素对太阳翼地面展开及锁定冲击载荷的影响.

  5. Y型锁定钢板置入治疗成人肱骨髁间骨折36例%Y-type locking plate for intercondylar fractures of the adult hunmerus in 36 cases

    Institute of Scientific and Technical Information of China (English)

    程煜方; 魏忠民; 黄方敏; 张克良; 李子熙

    2011-01-01

    背景:肱骨髁间骨折是一种复杂的关节内骨折,骨折端的显露及固定均比较困难.目的:观察经尺骨鹰嘴截骨入路Y型解剖型锁定钢板治疗肱骨髁间骨折的效果.方法:采用尺骨鹰嘴截骨入路,Y型解剖型锁定钢板治疗肱骨髁间骨折36例,男22例,女14例,年龄19-76岁,平均47岁,按AO/OTA分型:C1型8例,C2型15例,C3型13例.结果与结论:32例获得随访,随访时间为10~26个月.用改良的Cassebaum评分标准评分,优15例,良13例,中3例,差1例,优良率89.6%.尺骨鹰嘴截骨入路切口无一例感染,骨折愈合时间为2.5~4.5个月,平均3.5个月.固定后钢板未出现松动现象.结果显示用尺骨鹰嘴截骨入路Y型解削型锁定钢板治疗肱骨髁间骨折,显露范围广,固定牢靠,能有效防止骨折不愈合,可指导患者早期在CPM机上进行肘关节功能锻炼,肘关节功能恢复良好,是治疗肱骨髁间骨折的有效方法.%BACKGROUND: Jnlercondylar fracture of the humerus is a hind of complex intra-articular fractures. Fracture exposure andfixation are difficult.OBJECTIVE: To explore the surgical effect of Y-type locking plate through the approach of olecranon osterolomy onintercondylar fracture of Ihe adult humerus.METHODS: Thirty-six adult patients with intercondylar fractures of the hunmerus were treated with Y-type locking plale Ihroughthe approach of olecranon osterotomy. Including 22 mates and 14 females, aged 19-76 years. Averagely47year. According lothe AO/OTA dassificaiton. Type C1 fracture was found in 8 cases, type C2 in 15, and type C3 in 13.RESULTS AND CONCLUSION: Thirty-two cases received a follow-up of 10-26 months. According to Cassebaum scale, thefunction of the elbow showed excellent in 15 cases, good in 13 cases, fair in 3 cases and poor in 1 case, and the excellent-goodrate was 89.6%. No infection occurred. The mean time for fracture healing was 2.4 to 4.5 months, averagely 3.5 months. Thetechnique of Y-type locking plate for

  6. A nonlinear analytical model for the squeeze-film dynamics of parallel plates subjected to axial flow

    Energy Technology Data Exchange (ETDEWEB)

    Piteau, Ph. [CEA Saclay, DEN, DM2S, SEMT, DYN, CEA, Lab Etud Dynam, F-91191 Gif Sur Yvette (France); Antunes, J. [ITN, ADL, P-2686 Sacavem Codex (Portugal)

    2010-07-01

    In this paper, we develop a theoretical model to predict the nonlinear fluid-structure interaction forces and the dynamics of parallel vibrating plates subjected to an axial gap flow. The gap is assumed small, when compared to the plate dimensions, the plate width being much larger than the length, so that the simplifying assumptions of 1D bulk-flow models are adequate. We thus develop a simplified theoretical squeeze-film formulation, which includes both the distributed and singular dissipative flow terms. This model is suitable for performing effective time-domain numerical simulations of vibrating systems which are coupled by the nonlinear unsteady flow forces, for instance the vibro-impact dynamics of plates with fluid gap interfaces. A linearized version of the flow model is also presented and discussed, which is appropriate for studying the complex modes and linear stability of flow/structure coupled systems as a function of the average axial gap velocity. Two applications of our formulation are presented: (1) first we study how an axial flow modifies the rigid-body motion of immersed plates falling under gravity; (2) then we compute the dynamical behavior of an immersed oscillating plate as a function of the axial gap flow velocity. Linear stability plots of oscillating plates are shown, as a function of the average fluid gap and of the axial flow velocity, for various scenarios of the loss terms. These results highlight the conditions leading to either the divergence or flutter instabilities. Numerical simulations of the nonlinear flow/structure dynamical responses are also presented, for both stable and unstable regimes. This work is of interest to a large body of real-life problems, for instance the dynamics of nuclear spent fuel racks immersed in a pool when subjected to seismic excitations, or the self-excited vibro-impact motions of valve-like components under axial flows. (authors)

  7. 长型肱骨近端锁定钢板治疗肱骨近端并肱骨干骨折★%Long proximal humeral locking compression plate treats proximal humerus and humeral shaft fractures

    Institute of Scientific and Technical Information of China (English)

    吴旭; 黄强; 蔡丰; 郭震; 姚勐炜; 杨安礼; 刘亮

    2013-01-01

    BACKGROUND:The domestic and international literatures have confirmed that the internal fixation of long proximal humeral locking compression plate has satisfactory effect on the treatment of proximal humerus fractures. OBJECTIVE:To investigate the clinical effect of internal fixation of long proximal humeral locking compression plate on the treatment of proximal humerus and humeral shaft fractures. METHODS:Sixteen cases with the proximal humerus and humeral shaft fractures were treated with long proximal humeral locking compression plate internal fixation, including seven males and nine females, aged 45-83 years old (average 71 years old). According to the Neer classification of proximal humerus, five cases had two parts of fracture, eight cases had three parts of fracture, and three cases had four parts of fracture;and according the AO classification of humeral shaft, five cases were classified as A1, six cases as B1, two cases as B2, two cases as C1 and one case as C3. Postoperatively, Constant-Murley scoring system was employed to evaluate the function of shoulder joint, and then the percentage was calculated for the corresponding evaluation. Modified Hospital for Special Surgery scoring system was adopted to evaluate the function of elbow joint. RESULTS AND CONCLUSION:Al cases were fol owed-up for 12-24 months (average 14.9 months), and al the cases had bone union in 8-17 weeks (average 12.1 weeks) after operation. Postoperatively, two cases suffered from fat liquoring, but healed after dressing. One case had the symptoms of radial nerve paralysis, one case had subacromial impingement syndrome and improved after treatment. No complications such as screw loosening, screw cut out or humeral head ischemic necrosis were observed. After treated for 12 months, the Constant-Murley score on fracture side was 76.87 in average (ranged 65-90), which was 83.41%in average (ranged 71.4%-93.8%) to the normal side, the clinical outcomes on shoulder were excel ent or good in

  8. 120°儿童髋锁定加压钢板治疗儿童股骨转子下骨折%120° locking compression paediatric hip plate for femoral subtrochanteric fractures in children

    Institute of Scientific and Technical Information of China (English)

    尤瑞金; 杨德育; 黄飞; 吕宏升; 苏在权

    2016-01-01

    [目的]探讨120°儿童髋锁定加压钢板(120°Locking compression paediatric hip plate,120°LCP PHP)治疗儿童股骨转子下骨折的临床疗效.[方法] 2010年10月~2014年5月采用120°LCP PHP治疗儿童股骨转子下骨折16例.[结果]本组患儿术后随访24 ~36个月,平均(27.3±3.2)个月.无1例发生神经血管损伤、骨折端再移位、再骨折、髋内翻、骨髓炎、股骨头坏死及骨骺发育异常.骨折骨性愈合时间为8~13周,平均(10.1±1.4)周,无骨不愈合.于术后18~32周取出内固定物,平均(25.3±3.4)周.早期Beaty评分及远期Theologis评分皆为满意,术后2年Sanders髋关节评分为57 ~ 60分,平均(58.7±2.1)分,都为优,优良率为100%.[结论]120°LCP PHP治疗儿童股骨转子下骨折,具有符合儿童股骨转子下解剖及生物力学特点、固定牢固、避免损伤骨骺、骨折愈合快、并发症少、适应证广、可早期功能锻炼等优点.但存在需要切开复位、损伤相对较大、出血较多、二次手术切开取出内固定物、费用较高、切口瘢痕影响美观等缺点.%[Objective] To investigate the clinical efficacy of 120° locking compression paediatric hip plate in treatment of femoral subtrochanteric fractures in children.[Method] Sixteen skeletally immature idolescents with femoral subtrochanteric fractures were treated with 120° locking compression paediatric hip plate in our department from September 2010 to May 2014.[Result]Patients were followed up for average 27.3 ± 3.2 months (range,24 months to 36 months,average 27.3 ± 3.2 months).No complication was found,such as neurovascular injury,fracture re-displacement,re-fracture,varus deformities,osteomyelitis,osteonecrosis and epiphyseal dysplasia.Bone fracture healing time was 8 to 13 weeks,with an average of 10.1 ± 1.4 weeks,without nonunion being noted.The internal fixation was removed at 18 to 32 weeks after surgery (average 25.3 ± 3.4 weeks).Satisfactory outcomes had

  9. 后外侧锁定接骨板治疗大块后踝骨折的疗效分析%Efficacy of Posterolateral Locking Plate in the Treatment of Large Posterior Malleolar Fracture

    Institute of Scientific and Technical Information of China (English)

    胥正锋; 尹望平; 倪妙忠; 吴荣博

    2014-01-01

    目的:探讨经后外侧入路应用锁定接骨板治疗大块后踝骨折的临床疗效。方法:2010年1月-2012年6月经后外侧入路应用锁定接骨板内固定治疗后踝大块骨折患者23例,其中男性15例,女性8例;年龄32~78岁,平均年龄43.7岁;受伤至手术时间5~12d,平均7.3d。术前以石膏或跟骨牵引术固定患肢,待患肢肿胀消退后,采用后外侧入路锁定接骨板治疗后踝骨折。根据美国足踝外科协会(American Orthopedic Foot and Ankle Society ,AOFAS )的踝与后足评分标准评价踝关节功能。结果:所有患者均获得随访,随访时间14~22个月,平均17.4个月。23例患者均获得骨性愈合,无内固定松动或断裂;X线片示骨折愈合时间为术后11~21周,平均14.7周;完全负重时间为15~25周,平均17.1周;术后12个月AOFAS评分为73~94分,平均83.4分。1例患者术后第7天出现伤口浅表感染,经换药及敏感抗生素治疗后愈合,其他患者伤口愈合良好。结论:采用后外侧入路锁定接骨板治疗能在直视下对后踝进行有效复位和妥当固定,用于治疗后踝大块骨折时疗效良好。%Objective:To investigate the clinical efficacy of posterolateral locking plate in the treatment of large posterior malle-olar fracture .Methods :From January 2010 to June 2012 ,23 patients with large posterior malleolar fractures were treated by posterolateral locking plate ,including 15 males and 8 females ,all of whom aged from 32 to 78 years with an average age of 43 .7 years .The average time from injury to operation was 7 .3 days ,which ranged from 5 to 12 days .Calcaneal traction fixa-tion or plaster was performed on the injured limb before operation .Once that swelling reduced ,all patients were treated by posterolateral locking plate and were assessed with the ankle hindfoot clinical rating system of the American Orthopaedic Foot and Ankle Society (AOFAS

  10. Improved non-dimensional dynamic influence function method for vibration analysis of arbitrarily shaped plates with clamped edges

    Directory of Open Access Journals (Sweden)

    Sang-Wook Kang

    2016-03-01

    Full Text Available A new formulation for the non-dimensional dynamic influence function method, which was developed by the authors, is proposed to efficiently extract eigenvalues and mode shapes of clamped plates with arbitrary shapes. Compared with the finite element and boundary element methods, the non-dimensional dynamic influence function method yields highly accurate solutions in eigenvalue analysis problems of plates and membranes including acoustic cavities. However, the non-dimensional dynamic influence function method requires the uneconomic procedure of calculating the singularity of a system matrix in the frequency range of interest for extracting eigenvalues because it produces a non-algebraic eigenvalue problem. This article describes a new approach that reduces the problem of free vibrations of clamped plates to an algebraic eigenvalue problem, the solution of which is straightforward. The validity and efficiency of the proposed method are illustrated through several numerical examples.

  11. Study of transient flow in fuel element of tubular plates. Accident: Shaft locking of primary cooling pump without opening the emergency gate; Estudio del regimen transitorio en el elemento combustible de placas tubulares. Accidente: Agarrotamiento de la bomba. No se abre la compuerta

    Energy Technology Data Exchange (ETDEWEB)

    Aguilas, F.; Moneva, M. A.; Garcia Ramirez, L.; Lopez Jimenez, J.; Diaz Diaz, J.

    1971-07-01

    It is analysed the thermal distribution of a fuel element of tubular plates irradiated in the JEN-1 reactor in the case of shaft locking of the primary cooling pump without opening the emergency gate. The fuel element hottest channel is studied in the position of maximum neutronic flux for three reactor power levels: 3 Hw (maximum reactor power), 2 Mw and 1 Hw. (Author) 8 refs.

  12. Saturation and Dynamic Range of Microchannel Plate-Based X-Ray Imagers

    Energy Technology Data Exchange (ETDEWEB)

    ,

    2012-05-04

    This paper describes recent advances in Monte Carlo simulations of microchannel plate (MCP)–based x-ray detectors, a continuation of ongoing work in this area. A Monte Carlo simulation model has been developed over the past several years by National Security Technologies, LLC (NSTec). The model simulates the secondary electron emission process in an MCP pore and includes the effects of gain saturation. In this work we focus on MCP gain saturation and dynamic range. We have performed modeling and experimental characterizations of L/D = 46, 10-micron diameter, MCP-based detectors. The detectors are typically operated by applying a subnanosecond voltage pulse, which gates the detector on. Agreement between the simulations and experiment is very good for a variety of voltage pulse waveforms ranging in width from 150 to 300 ps. The results indicate that such an MCP begins to show nonlinear gain around 5 × 10^4 electrons per pore and hard saturation around 105 electrons per pore. The simulations show a difference in MCP sensitivity vs voltage for high flux of photons producing large numbers of photoelectrons on a subpicosecond timescale. Simulations and experiments both indicate an MCP dynamic range of 1 to 10,000, and the dynamic range depends on how the voltage is applied.

  13. The coupling of mechanical dynamics and induced currents in plates and surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Weissenburger, D.W.; Bialek, J.M.

    1986-10-01

    Significant mechanical reactions and deflections may be produced when electrical eddy currents induced in a conducting structure by transformer-like electromotive forces interact with background magnetic fields. Additional eddy currents induced by structural motion through the background fields modify both the mechanical and electrical dynamic behavior of the system. The observed effects of these motional eddy currents are sometimes referred to as magnetic damping and magnetic stiffness. This paper addresses the coupled structural deformation and eddy currents in flat plates and simple two-dimensional surfaces in three-space. A coupled system of equations has been formulated using finite element techniques for the mechanical aspects and a mesh network method for the electrical aspects of the problem.

  14. Phase-locked stereoscopic PIV measurements of the turbulent swirling flow in a dynamic model of a uniflow-scavenged two-stroke engine cylinder

    DEFF Research Database (Denmark)

    Ingvorsen, Kristian Mark; Meyer, Knud Erik; Walther, Jens Honore

    2013-01-01

    turbulence models. In the present work, the flow in a dynamic scale model of a uniflow-scavenged cylinder is investigated experimentally. The model has a transparent cylinder and a movable piston driven by a linear motor. The flow is investigated using phase-locked stereoscopic particle image velocimetry......It is desirable to use computational fluid dynamics for the optimization of in-cylinder processes in large two-stroke low-speed uniflowscavenged marine diesel engines. However, the complex nature of the turbulent swirling in-cylinder flow necessitates experimental data for validation of the used...... (PIV) and time resolved laser Doppler anemometry (LDA). Radial profiles of the phase-averaged mean velocities are computed from the velocity fields recorded with PIV and the validity of the obtained profiles is demonstrated by comparison with reference LDA measurements. Radial profiles are measured...

  15. A dynamic cell adhesion surface regulates tissue architecture in growth plate cartilage.

    Science.gov (United States)

    Romereim, Sarah M; Conoan, Nicholas H; Chen, Baojiang; Dudley, Andrew T

    2014-05-01

    The architecture and morphogenetic properties of tissues are founded in the tissue-specific regulation of cell behaviors. In endochondral bones, the growth plate cartilage promotes bone elongation via regulated chondrocyte maturation within an ordered, three-dimensional cell array. A key event in the process that generates this cell array is the transformation of disordered resting chondrocytes into clonal columns of discoid proliferative cells aligned with the primary growth vector. Previous analysis showed that column-forming chondrocytes display planar cell divisions, and the resulting daughter cells rearrange by ∼90° to align with the lengthening column. However, these previous studies provided limited information about the mechanisms underlying this dynamic process. Here we present new mechanistic insights generated by application of a novel time-lapse confocal microscopy method along with immunofluorescence and electron microscopy. We show that, during cell division, daughter chondrocytes establish a cell-cell adhesion surface enriched in cadherins and β-catenin. Rearrangement into columns occurs concomitant with expansion of this adhesion surface in a process more similar to cell spreading than to migration. Column formation requires cell-cell adhesion, as reducing cadherin binding via chelation of extracellular calcium inhibits chondrocyte rearrangement. Importantly, physical indicators of cell polarity, such as cell body alignment, are not prerequisites for oriented cell behavior. Our results support a model in which regulation of adhesive surface dynamics and cortical tension by extrinsic signaling modifies the thermodynamic landscape to promote organization of daughter cells in the context of the three-dimensional growth plate tissue.

  16. [Experience with Poly Ether Ether Ketone (PEEK) cages and locking plate for anterior cervical fusion in the treatment of spine trauma without cord injury].

    Science.gov (United States)

    Delépine, F; Jund, S; Schlatterer, B; de Peretti, F

    2007-12-01

    The purpose of this study was to determine whether spinal fusion using radiotransparent cages can be an appropriate treatment for traumatic injury of the cervical spine. This series included 30 patients aged 17-84 years (average 46 years) treated between October 1999 and June 2003 for traumatic injury of the cervical spine without neurological deficit or cord injury. There were two bifocal cases so that the study concerned 32 fusions. Injuries were: tear drop (n=1), serious flexion sprain (n=8), biarticular dislocation (n=4), serous hyperextension sprain (n=4), dislocation-fracture (n=1), uniarticular fracture (n=7), fracture-separation of the facet joints (n=4), post-traumatic herniation (n=3). For each injury, we measured pre and postoperatively and at last follow-up: the intersomatic angle, anterior displacement, and height of the intersomatic space at the center of the intervertebral disc. All x-rays were read twice, by two independent investigators. In the event of disagreement, the x-rays were read again by a senior surgeon and the main author of this article. Anterior fusion was achieved using a Poly Ether Ether Ketone (PEEK) (32%) and knitted carbon (68%) cage (cologne, Ostapek, Nexis) filled with cancellous bone harvested percutaneously from the iliac crest. The cage was associated with an anterior titanium plate fixation (Senegas, Euros and Orion, Medtronic). A posterior approach was associated if further stability was required (n=4 fusions). All patients were reviewed at minimum five months follow-up. Intersomatic fusion was verified on the standard x-rays (plus stress images and computed tomography at three months). Fusion was considered to be achieved if continuous bone lines crossed the graft and angle measurements remained stable, with the cage in the same position on successive examinations. One patient died from lung cancer five months after spinal fusion. All other patients survived with a mean follow-up of 24 months. Fusion was achieved in all

  17. A new technique for insertion of barrel plate over dynamic hip/compression lag screw:a case report

    Institute of Scientific and Technical Information of China (English)

    Sameer Naranje; Vivek Trikha

    2012-01-01

    Dynamic hip/compression screw (DHS/DCS) is one of the most commonly performed surgeries in orthopaedic practice.Sliding barrel plate over the DHS/DCS lag screw is one of the very crucial and at times uncomfortable and time consuming steps of DHS/DCS surgery especially when it comes to inexperienced surgeons and residents.Also in developing countries where not all standard instrumentation is always available,this crucial step becomes more time consuming.Here we present a case report of 58-year-old male patient with intertrochanteric fracture,in which we used a new device for insertion of barrel plate over DHS/DCS lag screw and found that a small DHS/DCS lag screw extension (sliding jig of barrel plate)can be very helpful to slide barrel plate over the DHS/DCS lag screw.

  18. Comparison of the Clinical Efficacy of the Proximal Humerus Pressure Plate With Traditional Steel Locking Proximal Humeral Fractures%比较肱骨近端加压锁定钢板与传统钢板治疗肱骨近端骨折的临床疗效

    Institute of Scientific and Technical Information of China (English)

    杜杰; 廖彦生; 袁春晓

    2016-01-01

    目的:探讨肱骨近端加压锁定钢板与传统钢板治疗肱骨近端骨折的临床疗效。方法将78例肱骨近端骨折患者随机分为观察组(n=39)和对照组(n=39),观察组采取肱骨近端加压锁定钢板治疗,对照组应用传统钢板治疗,比较两组患者治疗效果。结果观察组并发症发生率、骨折愈合时间均优于对照组(P<0.05)。结论与传统钢板治疗方案相比,肱骨近端加压锁定钢板治疗肱骨近端骨折的临床效果更佳。%Objective To investigate the clinical efficacy of proximal humeral locking plate and the pressure plate of traditional treatment of proximal humeral fractures. Methods 78 cases of proximal humerus fractures were randomized into two groups (n=39) and control group (n=39), the observation group was taken the pressure locking proximal humerus plate treatment, control group was taken conventional plating treatment, compared outcomes in two groups.ResultsThe incidence of complications, healing time were better than the control group (P<0.05).Conclusion Compared with the traditional steel regimen, the clinical effect of locking proximal humerus plate for treatment of pressure proximal humerus fractures is better.

  19. Comparison of the efficacy of double locking plate and Y plate in the treatment of type C inter-condylar humeral fracture%双锁定钢板与Y型钢板治疗C型肱骨髁间骨折的疗效对比

    Institute of Scientific and Technical Information of China (English)

    汪文录; 王春喜

    2016-01-01

    目的:比较双锁定钢板与 Y 型钢板内固定治疗 C 型肱骨髁间骨折的临床效果。方法选择2011年12月至2014年10月 C 型肱骨髁间骨折患者32例,随机分为观察组(双锁定钢板组)和对照组(Y 型钢板组),每组16例,观察组患者给予双锁定钢板内固定治疗,对照组患者给予 Y 型钢板内固定治疗,比较两组患者的手术时间、术中出血量、住院时间及肘关节功能。结果两组患者手术时间、术中出血量、住院时间比较差异均未见统计学意义(P ﹥0.05);观察组患者肘关节功能恢复优10例,良4例,可1例,差1例,优良率为87.50%;对照组患者肘关节功能恢复优7例,良4例,可3例,差2例,优良率为68.75%;观察组患者肘关节功能恢复优良率高于对照组(P ﹤0.05)。结论双锁定钢板治疗 C 型肱骨髁间骨折可提供坚强的内固定,有利于患者术后肘关节功能恢复,减少并发症。%Objective To compare the clinical effect of double locking plate and Y plate internal fixation in treatment of type C intercondylar humeral fractures. Methods From November 2011 to Octo-ber 2014,the 32 cases of type C intercondylar humeral fractures were randomly divided into two groups, the observation group(double locking plate group)and the control group(Y plate group),with 16 cases in each group. The observation group was treated by double locking plate internal fixation,and the control group was treated by Y plate internal fixation. The operation time,bleeding volume and hospitalization time and elbow joint function were compared between the two groups. Results By follow-up of 12 -24 months(mean,15. 6 months)for 32 cases,there was no significant difference in operation time, bleeding volume and hospitalization time between the two groups(P ﹥ 0. 05). In the observation group, the function of elbow joint was excellent in 10 cases,good in 4 cases,fair in 1 case,poor in 1 case

  20. Clinical Analysis of the Treatment of Proximal Humeral Locking Plate of Proximal Humerus Fractures in Elderly%肱骨近端锁定钢板治疗老年肱骨近端骨折的临床分析

    Institute of Scientific and Technical Information of China (English)

    施云东

    2015-01-01

    Objective To evaluate and observe functional outcome of locking proximal humeralplate(LPHP)used for fixationof the proximal humerus fractures in elderly.Methods In 108 cases of proximal humerus in elderly hospital in April 2011 to April 2014 received fractures were targeted,according to neer classification of fractures were classified in some patients,including 48 cases of fracture type Ⅱ,Ⅲ fracture 50 cases,ⅳ fractures in 10 cases. Al patients underwent treatment of proximal humeral locking plate by neer scores were assessed for treatment effect.Results After treatment,al patients 4 to 10 months of folow-up,results showed that al patients have received bone fractures healed and no deformity occurs in good overal healing rate of 98.1 percent, fracture healing time of 9 to 11 weeks,in al cases no complications of infection,nerve injury.Conclusion Locking proximal humeral plateosteosynthes is leads to satisfactory functional outcomes in proximal humerus fractures,which is aless complications,early functional exercise,effective therapeutic method.%目的:对肱骨近端锁定钢板治疗老年肱骨近端骨折的临床分析效果进行分析。方法以我院2011年4月~2014年4月接收的108例老年肱骨近端骨折患者为对象,根据Neer分型对患者骨折部分进行分型,其中Ⅱ型骨折48例,Ⅲ型骨折50例,Ⅳ型骨折10例。所有患者均行肱骨近端锁定钢板治疗,通过Neer评分对患者治疗效果进行评定。结果治疗后对所有患者进行4~10个月的随访,结果显示所有患者骨折情况均得到愈合,且无畸形发生,在总体愈合优良率方面达98.1%;骨折愈合时间9~11周;所有病例均未产生感染、神经损伤等并发症。结论肱骨近端锁定钢板治疗老年肱骨近端骨折不仅愈合率高,且康复时间短,较少发生术后并发症,对复位丢失情况能够有效防止,使板下血运和骨折愈合得到保护。

  1. 肱骨近端复杂骨折老年患者手术治疗临床分析%Curative Effect of Locking Proximal Humeral Plate and Proximal Humerus Locking Fixation System for the Treatment of Proximal Humeral Fractures in the Elderly Patients

    Institute of Scientific and Technical Information of China (English)

    阮艺; 程廷雄; 聂运修; 翁永前

    2014-01-01

    目的 研究肱骨近端锁定内固定系统(proximal humerus internal locking system,PHILOS)、肱骨近端锁定钢板(locking proximal humerus plate,LPHP)对于肱骨近端复杂骨折老年患者的治疗效果.方法 将作者医院2010-07/2012-07月收治的92例老年肱骨近端复杂骨折的患者作为研究对象,随机分为PHILOS组、LPHP组,每组各46例,比较两组的治疗效果.结果 与LPHP组相比PHILOS组手术时间较短、术中出血量相对少,骨折愈合时间短,两组相比差异具有统计学意义(P<0.01);两组患者术后,疼痛症状改善,日常生活逐渐恢复,关节活动能力提高;PHILOS组上述指标的改善程度优于LPHP组(P<0.01);PHILOS组治愈率为97.83%高于LPHP组的80.43%(x2=7.1805,P<0.01);两组并发症的发生情况比较差异具无统计学意义(x2= 1.0110,P=0.3417).结论 PHILOS与LPHP相比骨折愈合时间短、患者术后疼痛减轻、运动功能恢复快,且治愈率高;对于治疗老年肱骨近端复杂骨折具有一定的临床意义.

  2. A study of ground-structure interaction in dynamic plate load testing

    Science.gov (United States)

    Guzina, Bojan B.; Nintcheu Fata, Sylvain

    2002-10-01

    A mathematical treatment is presented for the forced vertical vibration of a padded annular footing on a layered viscoelastic half-space. On assuming a depth-independent stress distribution for the interfacial buffer, the set of triple integral equations stemming from the problem is reduced to a Fredholm integral equation of the second kind. The solution method, which is tailored to capture the stress concentrations beneath footing edges, is highlighted. To cater to small-scale geophysical applications, the model is used to investigate the near-field effects of ground-loading system interaction in dynamic geotechnical and pavement testing. Numerical results indicate that the uniform-pressure assumption for the contact load between the composite disc and the ground which is customary in dynamic plate load testing may lead to significant errors in the diagnosis of subsurface soil and pavement conditions. Beyond its direct application to non-intrusive site characterization, the proposed solution can be used in the seismic analysis of a variety of structures involving annular foundation geometries.

  3. A refractive tilting-plate technique for measurement of dynamic contact angles.

    Science.gov (United States)

    Smedley, Gregory T; Coles, Donald E

    2005-06-01

    The contact angle is a critical parameter in liquid interface dynamics ranging from liquid spreading on a solid surface on earth to liquid motion in partially filled containers in space. A refractive tilting-plate technique employing a scanning laser beam is developed to conduct an experimental study of a moving contact line, with the intention of making accurate measurements of the contact angle. The technique shows promise as an accurate and potentially fully automated means to determine the velocity dependence of the contact angle at the intersection of the interface between two transparent fluids with a transparent solid surface. Ray tracing calculations are included to reinforce the measurement concept. The principal experiments were conducted at speeds ranging from 0.05 to 1.00 mm/s, both advancing and receding, using an immiscible liquid pair (nonane/formamide) in contact with glass. The contact angle was found to depend for practical purposes only on the sign of the velocity and not on its magnitude for the range of velocities studied. Other observations revealed a bimodal behavior of the contact line that depends on which liquid first contacts the glass, with resulting drift in the dynamic contact angle with time.

  4. Application of the R-Functions Theory to Problems of Nonlinear Dynamics of Laminated Composite Shallow Shells and Plates: Review

    OpenAIRE

    2016-01-01

    A review of studies performed using the R-functions theory to solve problems of nonlinear dynamics of plates and shallow shells is presented. The systematization of results and studies for the problems of free and parametric vibrations and for problems of static and dynamic stability is fulfilled. Expansion of the developed original method of discretization for nonlinear movement equations on new classes of nonlinear problems is shown. These problems include researches of vibratio...

  5. 背侧双锁定加压钢板治疗桡骨远端伸直型不稳定骨折%Dorsal double locking compression plate for treatment of stretched unstable distal radial fractures

    Institute of Scientific and Technical Information of China (English)

    伏治国; 张曦; 董启榕; 盛永华; 高俊

    2013-01-01

    Objective To evaluate the outcome of dorsal double locking compression plate (LCP) in treatment of stretched unstable distal radial fractures.Methods Fourteen cases of stretched unstable distal radial fractures were treated by reduction and internal fixation using straight or L-shaped anatomic LCP via dorsal approach.Wrist functional exercise was conducted immediately after operation.Follow up was made after operation to assess motion pain,functional score of wrist,and complication incidence at postoperative 12 weeks,24 weeks,and 1 year.Results Follow-up was lasted for 5-24 months.At postoperative 12 weeks,24 weeks and 1 year,mean visual analogue scale (VAS) was (1.88 ±0.26) points,(0.87 ± 0.14) points and (0.37 ± 0.06) points respectively and wrist functional score (Gartland-Werley score) was (6.45 ± 1.72) points,(2.73 ± 0.52) points and (2.10 ± 0.31) points respectively.According to Garfland-Werley score in the latest follow-up,the results were excellent in 10 cases,good in two,and fair in two.Besides,one case was combined with myotenositis of extensor pollicis longus muscle tendon and another case with myotenositis of extensor tendon.Conclusion Dorsal double LCP is one of the effective methods for stretched unstable distal radial fractures that can reconstruct anatomical structure of the wrist efficiently and attain satisfactory functional recovery,with no obvious pain.%目的 评价背侧双锁定加压钢板(locking compression plate,LCP)对桡骨远端伸直型不稳定骨折的治疗效果. 方法 14例桡骨远端伸直型不稳定骨折,采用背侧入路,骨折复位后用解剖型直形和“L”形LCP固定.术后早期开始腕关节动能锻炼.随访评价术后12,24周、1年的活动痛和腕关节功能评分及并发症的发生率. 结果 随访5~24个月,术后12,24周,1年活动时的视觉模拟评分(visual analogue scale,VAS)分别为(1.88±0.26)分、(0.87±0.14)分、(0.37±0.06)分;腕关节功

  6. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures.

    Science.gov (United States)

    Seybold, Dominik; Citak, Mustafa; Königshausen, Matthias; Gessmann, Jan; Schildhauer, Thomas A

    2011-10-01

    Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft für Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures.

  7. Finite element analysis of bridge combined fixation system and the locking plate-screw system on the application for femoral fractures%桥接组合式内固定系统与锁定接骨板钉系统在股骨骨折应用中的有限元分析

    Institute of Scientific and Technical Information of China (English)

    熊鹰; 李群辉; 柳百炼; 赵烽; 王大兴; 张仲子

    2012-01-01

    背景:桥接组合式内固定系统在人体骨折固定上,与锁定钢板相比效果如何,有待实验证实.目的:比较桥接组合式内固定系统与金属锁定接骨板钉系统固定股骨干骨折的生物力学特性.方法:对两种固定方式的有限元模型进行模拟加载,了解各模型中骨与内固定的应力分布和应变特点,并对结果加以分析.结果与结论:爬楼梯时接骨板锁定螺钉上的应力比步态时增48.6%,达到480 MPa,最大应力出现在中间锁定螺钉上.桥接系统中间联接棒上的最大应力比步态时大34.1%,最大值为373.9 MPa,出现在联接棒中间略远端附近;骨折区域上的应力桥接组合式内固定系统小于金属锁定接骨板钉系统.提示桥接组合式内固定系统较金属锁定接骨板钉系统具有更好的生物力学性能,固定更牢靠、利于骨折生长,是骨折内固定的一种更好选择.%BACKGROUND: The effect of the bridge combined fixation system for the fixation of bone fracture compared with locking plate system needs to be confirmed by experiment. OBJECTIVE: To compare the biomechanical properties of bridge combined fixation system and locking plate-screw system for the fixation of femoral fractures. METHODS: We used the finite element analysis method to analyze biomechanical characters of the femoral fractures fixed with the locking plate-screw system and bridge combined fixation system, such as the stress distribution and the strain characteristics of bone and fixation. RESULTS AND CONCLUSION: The stress on the locking plate screw when climbing stairs was increased for 48.6% compared with walking, the stress was 480 MPa and the maximum stress was on the middle of the locking plate-screw screws. The maximum stress on the middle of the bridge system when climbing was 34.1% larger than that when walking, the maximum stress was 373.9 MPa and occurred near the distal connection rod. The stress on the fracture area of bridge combined

  8. Effects of finiteness on the thermo-fluid-dynamics of natural convection above horizontal plates

    Science.gov (United States)

    Guha, Abhijit; Sengupta, Sayantan

    2016-06-01

    A rigorous and systematic computational and theoretical study, the first of its kind, for the laminar natural convective flow above rectangular horizontal surfaces of various aspect ratios ϕ (from 1 to ∞) is presented. Two-dimensional computational fluid dynamic (CFD) simulations (for ϕ → ∞) and three-dimensional CFD simulations (for 1 ≤ ϕ cases, with the complex three-dimensional solutions revealed here. The present computational study establishes the region of a high-aspect-ratio planform over which the results of the similarity theory are approximately valid, the extent of this region depending on the Grashof number. There is, however, a region near the edge of the plate and another region near the centre of the plate (where a plume forms) in which the similarity theory results do not apply. The sizes of these non-compliance zones decrease as the Grashof number is increased. The present study also shows that the similarity velocity profile is not strictly obtained at any location over the plate because of the entrainment effect of the central plume. The 3-D CFD simulations of the present paper are coordinated to clearly reveal the separate and combined effects of three important aspects of finiteness: the presence of leading edges, the presence of planform centre, and the presence of physical corners in the planform. It is realised that the finiteness due to the presence of physical corners in the planform arises only for a finite value of ϕ in the case of 3-D CFD simulations (and not in 2-D CFD simulations or similarity theory). The presence of physical corners is related here to several significant aspects of the solution - the conversion of in-plane velocity to out-of-plane velocity near the diagonals, the star-like non-uniform distribution of surface heat flux on heated planforms, the three-dimensionality of the temperature field, and the complex spatial structure of the velocity iso-surfaces. A generic theoretical correlation for the Nusselt

  9. Using paleomagnetism to expand the observation time window of plate locking along subduction zones: evidence from the Chilean fore-arc sliver (38°S - 42°S)

    Science.gov (United States)

    Hernandez-Moreno, Catalina; Speranza, Fabio; Di Chiara, Anita

    2017-04-01

    fore-arc sliver undergoing CW rotations is a function of plate coupling along the subduction zone interface. Zones of high coupling enhance stress normal to the LOFZ, induce high LOFZ strength, and yield a wide deformation zone characterized by CW rotations. Conversely, low coupling imply a weak LOFZ, a lack of CW rotations, and a fore arc entirely dominated by CCW rotations related to sinistral fault kinematics. Our locking inferences are in good agreement with those recently derived by GPS analysis and indicate that seismotectonic segment coupling has remained virtually unchanged during the last 5Ma.

  10. ANALYSIS ON DYNAMIC CHARACTERISTICS FOR FERROMAGNETIC CONDUCTING PLATES IN A TRANSVERSE UNIFORM MAGNETIC FIELD

    Institute of Scientific and Technical Information of China (English)

    Zheng Xiaojing; Liu Xin'en

    2000-01-01

    In this paper, a set of basic equations for free vibration of ferromagnetic conducting plates in a transverse magnetic field are presented, in which the coupled effects of magnetization and eddy current on the mechanical behavior of the plate are included. Based on the quantitative analyses on the vibration frequency and the values of the critical magnetic field for several supporting conditions of the plate, the effects of the conductivity, the magnetic permeability, the thickness of the plate and supporting conditions on the vibration frequency of the plate and the crifcal magnetic field are discussed.

  11. Deeply trapped electrons in imaging plates and their utilization for extending the dynamic range

    Science.gov (United States)

    Ohuchi, Hiroko; Kondo, Yasuhiro

    2010-09-01

    The absorption spectra of deep centers in an imaging plate (IP) made of BaFBr 0:85I 0:15:Eu 2+ have been studied in the ultraviolet region. Electrons trapped in deep centers are considered to be the cause of unerasable and reappearing latent images in IPs over-irradiated with X-rays. Deep centers showed a dominant peak at around 320 nm, followed by two small peaks at around 345 and 380 nm. By utilizing deeply trapped electrons, we have attempted to extend the dynamic range of an IP. The IP was irradiated by 150-kV X-rays with doses from 8.07 mGy to 80.7 Gy. Reading out the latent image by the stimulation of Eu 2+ luminescence with a 633-nm He-Ne laser light from a conventional Fuji reader showed a linear relationship with irradiated dose up to 0.8 Gy, but then becoming non-linear. After fully erasing with visible light, unerasable latent images were read out using 635-nm semi-conductor laser light combined with a photon-counting detection system. The dose-response curve so obtained gave a further two orders of magnitude extending the dynamic range up to 80.7 Gy. Comprehensive results indicate that electrons supplied from deep centers to the F centers provided the extended dynamic range after the F centers became saturated. Based on these facts, a model of the excitation of deeply trapped electrons and PSL processes is proposed.

  12. Deeply trapped electrons in imaging plates and their utilization for extending the dynamic range

    Energy Technology Data Exchange (ETDEWEB)

    Ohuchi, Hiroko, E-mail: hiroko@mail.pharm.tohoku.ac.j [Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Kondo, Yasuhiro [Ishinomaki Senshu University, 1 Shinmito Minamisakai Ishinomaki-shi, Miyagi 986-8580 (Japan)

    2010-09-21

    The absorption spectra of deep centers in an imaging plate (IP) made of BaFBr{sub 0:85}I{sub 0:15}:Eu{sup 2+} have been studied in the ultraviolet region. Electrons trapped in deep centers are considered to be the cause of unerasable and reappearing latent images in IPs over-irradiated with X-rays. Deep centers showed a dominant peak at around 320 nm, followed by two small peaks at around 345 and 380 nm. By utilizing deeply trapped electrons, we have attempted to extend the dynamic range of an IP. The IP was irradiated by 150-kV X-rays with doses from 8.07 mGy to 80.7 Gy. Reading out the latent image by the stimulation of Eu{sup 2+} luminescence with a 633-nm He-Ne laser light from a conventional Fuji reader showed a linear relationship with irradiated dose up to 0.8 Gy, but then becoming non-linear. After fully erasing with visible light, unerasable latent images were read out using 635-nm semi-conductor laser light combined with a photon-counting detection system. The dose-response curve so obtained gave a further two orders of magnitude extending the dynamic range up to 80.7 Gy. Comprehensive results indicate that electrons supplied from deep centers to the F centers provided the extended dynamic range after the F centers became saturated. Based on these facts, a model of the excitation of deeply trapped electrons and PSL processes is proposed.

  13. Lost Treasures: Locks

    Directory of Open Access Journals (Sweden)

    Semra SARAÇOĞLU ÇELİK

    2015-03-01

    Full Text Available Locks have been widely used in our daily life. In this paper an attempt is made to study the history of locks and to give the kinds of locks and samples from past to present: Ancient Egypt, Chinese, Iran, Roman, Turk-Islam Locks. Ancient locks relied on the pin tumbler principle that many of today's locks use. Many early Roman Keys were made to be worn as rings, because clothing of Romans did not have pockets. It is hoped that this article can simulate more research and publications regarding the development of ancient locks.

  14. Locking of metacarpophalangeal joints in a patient with acromegaly

    Energy Technology Data Exchange (ETDEWEB)

    Tani, Y.; Tanaka, N.; Isoya, Eiji [Dept. of Orthopaedic Surgery, Soseikai General Hospital, Kyoto (Japan)

    1999-11-01

    A 39-year-old man with acromegaly exhibited locking of metacarpophalangeal (MCP) joints of both index fingers. Large osteophytes were found at the metacarpal heads by radiography and computerized tomography (CT). Magnetic resonance (MR) images revealed hypertrophy of volar plates. We suggest that these characteristic acromegalic features caused locking of MCP joints. Surgery was required on one of the joints to release the locking. (orig.)

  15. High-content imaging with micropatterned multiwell plates reveals influence of cell geometry and cytoskeleton on chromatin dynamics.

    Science.gov (United States)

    Harkness, Ty; McNulty, Jason D; Prestil, Ryan; Seymour, Stephanie K; Klann, Tyler; Murrell, Michael; Ashton, Randolph S; Saha, Krishanu

    2015-10-01

    Understanding the mechanisms underpinning cellular responses to microenvironmental cues requires tight control not only of the complex milieu of soluble signaling factors, extracellular matrix (ECM) connections and cell-cell contacts within cell culture, but also of the biophysics of human cells. Advances in biomaterial fabrication technologies have recently facilitated detailed examination of cellular biophysics and revealed that constraints on cell geometry arising from the cellular microenvironment influence a wide variety of human cell behaviors. Here, we create an in vitro platform capable of precise and independent control of biochemical and biophysical microenvironmental cues by adapting microcontact printing technology into the format of standard six- to 96-well plates to create MicroContact Printed Well Plates (μCP Well Plates). Automated high-content imaging of human cells seeded on μCP Well Plates revealed tight, highly consistent control of single-cell geometry, cytoskeletal organization, and nuclear elongation. Detailed subcellular imaging of the actin cytoskeleton and chromatin within live human fibroblasts on μCP Well Plates was then used to describe a new relationship between cellular geometry and chromatin dynamics. In summary, the μCP Well Plate platform is an enabling high-content screening technology for human cell biology and cellular engineering efforts that seek to identify key biochemical and biophysical cues in the cellular microenvironment.

  16. Dynamic and buckling analysis of a thin elastic-plastic square plate in a uniform temperature field

    Institute of Scientific and Technical Information of China (English)

    Shifu Xiao; Bin Chen

    2005-01-01

    The nonlinear models of the elastic and elasticlinear strain-hardening square plates with four immovably simply-supported edges are established by employing Hamilton's Variational Principle in a uniform temperature field. The unilateral equilibrium equations satisfied by the plastically buckled equilibria are also established. Dynamics and stability of the elastic and plastic plates are investigated analytically and the buckled equilibria are investigated by employing Galerkin-Ritz's method. The vibration frequencies, the first critical temperature differences of instability or buckling, the elastically buckled equilibria and the extremes depending on the final loading temperature difference of the plastically buckled equillibria of the plate are obtained. The results indicate that the critical buckling value of the plastic plate is lower than its critical instability value and the critical value of its buckled equilibria turning back to the trivial equilibrium are higher than the value. However, three critical values of the elastic plate are equal. The unidirectional snap-through may occur both at the stress-strain boundary of elasticity and plasticity and at the initial stage of unloading of the plastic plate.

  17. The oscillations of ship lock bottom

    Directory of Open Access Journals (Sweden)

    N.Yu. Kuzmin

    2012-06-01

    Full Text Available The article deals with the dynamic characteristics of the ship lock. The accurate design relations intended to study the natural and forced vibrations of the bottom of the ship lock are provided. The degree of filling of the lock, as well as the added mass of water is considered. The various coupling conditions of the bottom and walls of buildings are taken into account. A concrete example of the calculation is given.An exact, in the framework of the adopted design scheme, solution of the problem of the own and forced vibrations of the bottom of the ship lock is found. The frequency of the first five tones of vibrations and the associated mass of liquid according to thickness of the structure and coupling conditions of the bottom and sides of the lock are analyzed. A significant effect of liquids on low-frequency part of the spectrum and the dynamic response of the bottom is determined.

  18. The proximal humerus pressure locking plate clinical efficacy for treatment of proximal humeral fractures with traditional steel%肱骨近端加压锁定钢板与传统钢板治疗肱骨近端骨折的临床疗效比较

    Institute of Scientific and Technical Information of China (English)

    唐拥军

    2013-01-01

      目的对肱骨近端加压锁定钢板和传统钢板应用于肱骨近端骨折的效果加以对比分析。方法随机选择我院2009年5月~2011年5月肱骨近端骨折患者56名,分成A、B组,A组治疗组33名患者,B组对照组23名患者,分别给予加压锁定钢板和传统钢板方法加以医治。结果经医治,A组患者Neer功能分数高于B组,有效率高于B组,并发症概率低于B组患者。结论肱骨近端加压锁定钢板应用于肱骨近端骨折,效果较好。%Objective Pressurized locking plates and traditional steel to contrast analysis applied to the effect of proximal humerus fractures of the proximal humerus. Methods Random selection in our hospital from May 2009 to May 2011 proximal humeral fractures in 56 patients, divided into A, group B, group A treatment group of 33 patients, 23 patients of the B group, the control group were given pressurized locking plate andconventional plate method to be healed. Results A group of patients after healing the Neer function scores higher than group B, there are more efficient than group B, the complication probability lower than that in group B patients. Conclusion Pressurize the proximal humeral locking plate is applied to the proximal humerus fractures, better.

  19. Supercontinents, mantle dynamics and plate tectonics: A perspective based on conceptual vs. numerical models

    Science.gov (United States)

    Yoshida, Masaki; Santosh, M.

    2011-03-01

    The periodic assembly and dispersal of supercontinents through the history of the Earth had considerable impact on mantle dynamics and surface processes. Here we synthesize some of the conceptual models on supercontinent amalgamation and disruption and combine it with recent information from numerical studies to provide a unified approach in understanding Wilson Cycle and supercontinent cycle. Plate tectonic models predict that superdownwelling along multiple subduction zones might provide an effective mechanism to pull together dispersed continental fragments into a closely packed assembly. The recycled subducted material that accumulates at the mantle transition zone and sinks down into the core-mantle boundary (CMB) provides the potential fuel for the generation of plumes and superplumes which ultimately fragment the supercontinent. Geological evidence related to the disruption of two major supercontinents (Columbia and Gondwana) attest to the involvement of plumes. The re-assembly of dispersed continental fragments after the breakup of a supercontinent occurs through complex processes involving 'introversion', 'extroversion' or a combination of both, with the closure of the intervening ocean occurring through Pacific-type or Atlantic-type processes. The timescales of the assembly and dispersion of supercontinents have varied through the Earth history, and appear to be closely linked with the processes and duration of superplume genesis. The widely held view that the volume of continental crust has increased over time has been challenged in recent works and current models propose that plate tectonics creates and destroys Earth's continental crust with more crust being destroyed than created. The creation-destruction balance changes over a supercontinent cycle, with a higher crustal growth through magmatic influx during supercontinent break-up as compared to the tectonic erosion and sediment-trapped subduction in convergent margins associated with supercontinent

  20. Dynamic behavior of an injection-locked quantum-dash Fabry-Perot laser at zero-detuning.

    Science.gov (United States)

    Pochet, M; Naderi, N A; Terry, N; Kovanis, V; Lester, L F

    2009-11-09

    This work investigates the behavior of a zero-detuned optically-injected quantum-dash Fabry-Perot laser as the injected field ratio is increased from near-zero to levels resulting in stable locking. Using a normalized model describing optically-injected semiconductor lasers, variations in the slave laser's free-running characteristics are shown to have a strong impact on the coupled system's behavior. The theoretical model is verified experimentally using a high resolution spectrometer. It is found that the quantum-dash laser has the technological advantage of a low linewidth enhancement factor at low bias currents that suppresses undesirable Period-2 and chaotic behavior. Such observations suggest that optically-injected quantum-dash lasers can be used as an enabling component for tunable photonic oscillators.

  1. Three dimensional finite element of new assembly locking compression plate%新型组合式锁定加压钢板生物力学性能的三维有限元分析

    Institute of Scientific and Technical Information of China (English)

    周江军; 余专一; 程球新; 肖春林; 赵敏; 罗飞; 吕仁发; 杨俊; 付美清; 史柏娜; 雷雪

    2016-01-01

    目的:通过有限元分析的方法观察新型组合式锁定加压钢板(NALCP)与传统锁定加压钢板(LCP)固定股骨粉碎性骨折的应力分布情况。方法采用64排螺旋CT对一名健康成年男性股骨进行层厚为0.625 mm扫描,获得股骨CT数据,通过Mimics、Geomagic等逆向工程软件获得股骨有限元模型,模拟股骨中段粉碎性骨折,分别采用NALCP和LCP两种钢板模拟手术固定,加以缓慢行走单腿股骨载荷及扭转载荷,分析两种不同固定方式钢板及股骨的应力分布情况。结果两种载荷情况下, NALCP与LCP骨折断端区域钢板应力分布变化趋势基本一致,应力分布均匀。缓慢行走载荷NALCP主钢板最大应力值为5.292×102 Mpa,滑槽钢板部件最大应力值为9.388×102 Mpa,骨折块最大位移为1.428 mm,LCP钢板最大应力值为6.485×102 Mpa,骨折块最大位移2.633 mm;扭转载荷NALCP主钢板最大应力值为6.172×102 Mpa,滑槽钢板部件最大应力值为1.059×103 Mpa,骨折块最大位移为1.495 mm,LCP钢板最大应力值为1.059×103 Mpa,骨折块最大位移为2.103 mm。结论 NALCP既能够为骨干粉碎性骨折提供坚强的力学稳定性,又能为骨折断端保证足够的力学刺激,促进骨愈合。%Objective To investigate the stress distribution of new assembly locking compression plate(NALCP)and conventional locking compression plate(LCP)in the fixation for femoral comminuted fracture by finite element analysis(FEA). Methods The femur of a healthy male adult received 64⁃slice spiral CT scanning with 0.625 mm slice thickness,and the femur CT data was obtained. The femur finite element models were established by reverse engineering softwares,such as Mimics and Geomagic,to simulate the middle femoral comminuted fracture. The models received simulated fixation by using NALCP and LCP,respectively. Loads were applied on the two models to simulate a person slowly walking by

  2. Effect of Rheology on Mantle Dynamics and Plate Tectonics in Super-Earths

    Science.gov (United States)

    Tackley, P. J.; Ammann, M. W.; Brodholt, J. P.; Dobson, D. P.; Valencia, D. C.

    2011-12-01

    The discovery of extra-solar "super-Earth" planets with sizes up to twice that of Earth has prompted interest in their possible lithosphere and mantle dynamics and evolution. Simple scalings [1,2] suggest that super-Earths are more likely than an equivalent Earth-sized planet to be undergoing plate tectonics. Generally, viscosity and thermal conductivity increase with pressure while thermal expansivity decreases, resulting in lower convective vigor in the deep mantle, which, if extralopated to the largest super-Earths might, according to conventional thinking, result a very low effective Rayleigh number in their deep mantles and possibly no convection there. Here we evaluate this. (i) As the mantle of a super-Earth is made mostly of post-perovskite we here extend the density functional theory (DFT) calculations of post-perovskite activation enthalpy of [3] to a pressure of 1 TPa. The activation volume for diffusion creep becomes very low at very high pressure, but nevertheless for the largest super-Earths the viscosity along an adiabat may approach 10^30 Pa s in the deep mantle, which would be too high for convection. (ii) We use these DFT-calculated values in numerical simulations of mantle convection and lithosphere dynamics of planets with up to ten Earth masses. The models assume a compressible mantle including depth-dependence of material properties and plastic yielding induced plate-like lithospheric behavior, solved using StagYY [4]. Results confirm the likelihood of plate tectonics and show a novel self-regulation of deep mantle temperature. The deep mantle is not adiabatic; instead internal heating raises the temperature until the viscosity is low enough to facilitate convective loss of the radiogenic heat, which results in a super-adiabatic temperature profile and a viscosity increase with depth of no more than ~3 orders of magnitude, regardless of what is calculated for an adiabat. It has recently been argued [5] that at very high pressures, deformation

  3. The dynamics of plate tectonics and mantle flow: from local to global scales.

    Science.gov (United States)

    Stadler, Georg; Gurnis, Michael; Burstedde, Carsten; Wilcox, Lucas C; Alisic, Laura; Ghattas, Omar

    2010-08-27

    Plate tectonics is regulated by driving and resisting forces concentrated at plate boundaries, but observationally constrained high-resolution models of global mantle flow remain a computational challenge. We capitalized on advances in adaptive mesh refinement algorithms on parallel computers to simulate global mantle flow by incorporating plate motions, with individual plate margins resolved down to a scale of 1 kilometer. Back-arc extension and slab rollback are emergent consequences of slab descent in the upper mantle. Cold thermal anomalies within the lower mantle couple into oceanic plates through narrow high-viscosity slabs, altering the velocity of oceanic plates. Viscous dissipation within the bending lithosphere at trenches amounts to approximately 5 to 20% of the total dissipation through the entire lithosphere and mantle.

  4. A Dynamic Multinode Model for Component-Oriented Thermal Analysis of Flat-Plate Solar Collectors

    Directory of Open Access Journals (Sweden)

    Christoph N. Reiter

    2015-01-01

    Full Text Available A mathematical model of a flat-plate solar collector was developed on the basis of the physical principles of optics and heat transfer in order to determine collector’s component temperatures as well as collector efficiency. In contrast to many available models, the targeted use of this dynamic model is the detailed, theoretical investigation of the thermal behaviour of newly developed or adjusted collector designs on component level, for example, absorber, casing, or transparent cover. The defined model is based on a multinode network (absorber, fluid, glazing, and backside insulation containing the relevant physical equations to transfer the energy. The heat transfer network covers heat conduction, convection, and radiation. Furthermore, the collector optics is defined for the plane glazing and the absorber surface and also considers interactions between them. The model enables the variation of physical properties considering the geometric parameters and materials. Finally, the model was validated using measurement data and existing efficiency curve models. Both comparisons proved high accuracy of the developed model with deviation of up to 3% in collector efficiency and 1 K in component temperatures.

  5. Computational Fluid Dynamics Uncertainty Analysis Applied to Heat Transfer over a Flat Plate

    Science.gov (United States)

    Groves, Curtis Edward; Ilie, Marcel; Schallhorn, Paul A.

    2013-01-01

    There have been few discussions on using Computational Fluid Dynamics (CFD) without experimental validation. Pairing experimental data, uncertainty analysis, and analytical predictions provides a comprehensive approach to verification and is the current state of the art. With pressed budgets, collecting experimental data is rare or non-existent. This paper investigates and proposes a method to perform CFD uncertainty analysis only from computational data. The method uses current CFD uncertainty techniques coupled with the Student-T distribution to predict the heat transfer coefficient over a at plate. The inputs to the CFD model are varied from a specified tolerance or bias error and the difference in the results are used to estimate the uncertainty. The variation in each input is ranked from least to greatest to determine the order of importance. The results are compared to heat transfer correlations and conclusions drawn about the feasibility of using CFD without experimental data. The results provide a tactic to analytically estimate the uncertainty in a CFD model when experimental data is unavailable

  6. Investigation on Dynamic Propagation Characteristics of In-Plane Cracks in PVB Laminated Glass Plates

    Directory of Open Access Journals (Sweden)

    Xiaoqing Xu

    2016-01-01

    Full Text Available Polyvinyl butyral (PVB laminated glass has been widely used as an important component of mechanical and construction materials. Cracks on PVB laminated glass are rich in impact information, which contribute to its impact resistance design. In this paper, a three-dimensional (3D numerical simulation model describing PVB laminated glass under impact loading is firstly established and validated qualitatively and quantitatively compared with the corresponding experimental results recorded by the high-speed photography system. In the meantime, the extended finite element method (XFEM is introduced to analyze the crack propagation mechanism of laminated glass based on dynamic stress intensity factors (DSIFs and propagations of stress waves. Parametric studies are then carried out to investigate the influence of five critical parameters, that is, plate dimension, crack length, impact energy, glass properties, and PVB properties, on crack propagation characteristics of laminated glass. Results show that the interaction between crack tip and stress waves as well as the propagations of stress waves corresponds to the fluctuations of DSIFs at crack tip. Both the structure and material variables are proven to play a very important role in glass cracking DSIFs and thus govern the crack propagation behavior. Results may provide fundamental explanation to the basic crack propagation mechanism on radial cracks in PVB laminated glass under impact loading conditions, thus to instruct its impact design improvement.

  7. Humeral shaft fractures treated by dynamic compression plates, Ender nails and interlocking nails.

    Science.gov (United States)

    Chao, Ting-Cheng; Chou, Wen-Ying; Chung, Jui-Chang; Hsu, Chien-Jen

    2005-04-01

    Between January 1991 and December 2002, we treated 92 acute, displaced, closed humeral shaft fractures (AO classification type A). We used three fixation methods: dynamic compression plates (DCP) in 36 patients, Ender nails (EN) in 32 patients and interlocking nails (ILN) in 24 patients. The patients were followed for a minimum of 24 months. At one year, all fractures except two (one DCP/one ILN) had united. Patients treated with EN had shorter mean operation time, 51 (35-110) min; less mean blood loss, 70 (30-170) ml and shorter mean hospital stay, 5.8 (3-12) days. There were three iatrogenic radial nerve palsies: two in the DCP group and one in the ILN group. There was one wound infection. There were three cases with impingement of the shoulder but range of motion was restored after nail removal. For patients with multiple trauma or high operative risk, EN fixation served as a safer and faster procedure. ILN fixation offered a stable fixation via a smaller incision but more fracture comminution might happen.

  8. The Fluid-Solid Interaction Dynamics between Underwater Explosion Bubble and Corrugated Sandwich Plate

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2016-01-01

    Full Text Available Lightweight sandwich structures with highly porous 2D cores or 3D (three-dimensional periodic cores can effectively withstand underwater explosion load. In most of the previous studies of sandwich structure antiblast dynamics, the underwater explosion (UNDEX bubble phase was neglected. As the UNDEX bubble load is one of the severest damage sources that may lead to structure large plastic deformation and crevasses failure, the failure mechanisms of sandwich structures might not be accurate if only shock wave is considered. In this paper, detailed 3D finite element (FE numerical models of UNDEX bubble-LCSP (lightweight corrugated sandwich plates interaction are developed by using MSC.Dytran. Upon the validated FE model, the bubble shape, impact pressure, and fluid field velocities for different stand-off distances are studied. Based on numerical results, the failure modes of LCSP and the whole damage process are obtained. It is demonstrated that the UNDEX bubble collapse jet local load plays a more significant role than the UNDEX shock wave load especially in near-field underwater explosion.

  9. 普通接骨板与锁定接骨板治疗成人闭合性跟骨关节内骨折疗效对比%Clinical analysis of open reduction and internal fixation with unlocking plate or locking plate for treatment of adult in-tra-articular calcaneal fractures

    Institute of Scientific and Technical Information of China (English)

    曲绍东; 杨占辉; 史宏伟; 石明国; 张立军; 贾文杰; 苏庆军

    2015-01-01

    Objective To analyze the effect of open reduction and internal fixation (ORIF) with unlocking plate or locking plate for treatment of adult intra-articular calcaneal fracture. Methods 68 cases of calcaneal fracture,including 72 feet in 56 males (4 males were bilateral) and 12 females,with the average age of 35 years (ranging from 18 to 71), were en-rolled. According to Sanders' classification,15 feet were classified as type Ⅱ,46 feet were classified as type Ⅲ, and 11 feet were classified as type Ⅳ. 44 feet were treated with unlocking plate for calcaneal fracture in group A , 28 feet were treated with locking plate for calcaneal fracture in group B. The cases of existing ipsilateral lower limb fracture, ipsilateral vascular injury, and ipsilateral lower limb open injury were excluded. Results The wounds of 64 feet healed piemarily,5 feet were delayed healing. The soft tissue coloboma of 3 feet delayed until pedicle flap transfered. The B(o)hler angle of two groups were significantly different between preoperation and postoperation, but there were no significant differences in B(o)hler angle between two groups. 64 feet in 63 cases were followed up for 12~26 months. According to the AOFAS Ankle-Hindfoot Scale ,49 feet scored 90~100 points,13 feet scored 75~89 points and 2 feet scored 50~74 points. The excellent and good rate was 96.9%. Conclusion ORIF with unlocking plate or locking plate are all effective methods to treat the calcaneal fracture , there are no significant dif-ferences in curative effect between the two methods.%目的 分析普通接骨板与锁定接骨板治疗成人闭合性跟骨骨折的临床疗效. 方法 本组跟骨骨折68例(72足),男56例,女12例,4例男性为双侧. 年龄18~71岁,平均35岁. 应用Sanders分型,其中Ⅱ型15足,Ⅲ型46足,Ⅳ型11足.其中应用非锁定跟骨接骨板治疗44足(A组),应用锁定跟骨接骨板治疗28足(B组).排除术前合并同侧下肢骨折、同侧血管损伤及同

  10. Periodic and chaotic dynamics of composite laminated piezoelectric rectangular plate with one-to-two internal resonance

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; YAO ZhiGang; YAO MingHui

    2009-01-01

    The bifurcations and chaotic dynamics of a simply supported symmetric cross-ply composite lami-nated piezoelectric rectangular plate are studied for the first time, which are simultaneously forced by the transverse, in-plane excitations and the excitation loaded by piezoelectric layers. Based on the Reddy's third-order shear deformation plate theory, the nonlinear governing equations of motion for the composite laminated piezoelectric rectangular plate are derived by using the Hamilton's principle. The Galerkin's approach is used to discretize partial differential governing equations to a two-degree-of-freedom nonlinear system under combined the parametric and external excitations. The method of multiple scales is employed to obtain the four-dimensional averaged equation. Numerical method is utilized to find the periodic and chaotic responses of the composite laminated piezoelectric rectangular plate. The numerical results indicate the existence of the periodic and chaotic responses in the aver-aged equation. The influence of the transverse, in-plane and piezoelectric excitations on the bifurca-tions and chaotic behaviors of the composite laminated piezoelectric rectangular plate is investigated numerically.

  11. Periodic and chaotic dynamics of composite laminated piezoelectric rectangular plate with one-to-two internal resonance

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The bifurcations and chaotic dynamics of a simply supported symmetric cross-ply composite lami- nated piezoelectric rectangular plate are studied for the first time, which are simultaneously forced by the transverse, in-plane excitations and the excitation loaded by piezoelectric layers. Based on the Reddy’s third-order shear deformation plate theory, the nonlinear governing equations of motion for the composite laminated piezoelectric rectangular plate are derived by using the Hamilton’s principle. The Galerkin’s approach is used to discretize partial differential governing equations to a two-degree- of-freedom nonlinear system under combined the parametric and external excitations. The method of multiple scales is employed to obtain the four-dimensional averaged equation. Numerical method is utilized to find the periodic and chaotic responses of the composite laminated piezoelectric rectangular plate. The numerical results indicate the existence of the periodic and chaotic responses in the aver- aged equation. The influence of the transverse, in-plane and piezoelectric excitations on the bifurca- tions and chaotic behaviors of the composite laminated piezoelectric rectangular plate is investigated numerically.

  12. 3D-FEM and histomorphology of mandibular reconstruction with the titanium functionally dynamic bridging plate.

    Science.gov (United States)

    Schuller-Götzburg, P; Pleschberger, M; Rammerstorfer, F G; Krenkel, C

    2009-12-01

    Biomechanical investigation of the mandible is difficult due to the complex geometrical structure. A three-dimensional finite element model of the mandible and masticatory muscles was produced with approximately 23,000 hexahedral elements. On this model, mesial and distal portions of the jaw were resected and bridged with a buccal and/or caudally positioned bridging plate. The plate was fixed caudal or buccal to the mandible. The defect was left as it was or reconstructed with an exactly fitting transplant defined as bone. The jaw was loaded at a predefined point. The changes in stresses and deformations of bone, the transplant and the bridging plate were analysed. In the caudally positioned bridging plate, finite element analysis showed lesser stresses around the fixation screws of the bridging plate. During reconstruction of the lateral defect, the buccal (ramus)-caudal (corpus) position of the bridging plate showed fewer stresses and deformations than purely buccal positioning. The caudal position of the bridging plate has biomechanical advantages and facilitates fixation of the plate, and fixation of a bone graft on the jaw stumps. Histomorphological investigations, 12 weeks and 7 years after reconstruction, show partial osseous integration or transformation of autologous iliac crest transplants.

  13. On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate cam mechanism

    Science.gov (United States)

    Fan, Hui Ching; Yan, Hong Sen

    2012-03-01

    Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower's residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.

  14. 抗生素骨水泥被覆锁定钢板在膜诱导技术治疗胫骨创伤后骨感染中的运用%Application of antibiotic cement-coated locking plates in induced membrane technique for treating post-traumatic tibial osteomyelitis

    Institute of Scientific and Technical Information of China (English)

    余鑫; 贾硕; 吴宏日; 喻胜鹏; 谢肇

    2017-01-01

    Objective To investigate the clinical outcome of post-traumatic tibial osteomyelitis treated by induced membrane technique combined with the antibiotic cement-coated locking plate.Methods A restrospective case series analysis was made on 71 cases of post-traumatic tibial osteomyelitis treated by induced membrane technique from September 2014 to September 2014.There were 55 males and 16 females, aged 18-60 years(mean, 37.4 years).Mean length of bone defect following debridement was 4.5 cm(range, 4-11 cm).Antibiotic cement-coated locking plates were used to provide the stability of the bone defects after one-stage debridement.Bone grafting and exchanging the plates with ntramedullary nails were done during the second-stage surgery.Parameters were monitored dynamically after operation to evaluate infection recurrence and bone healing, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), clinical features(sinus formation, redness and swelling, warmth and pain) and X-ray films of the involved limbs.Results All patients were followed up for 13-25 months (mean, 19.5 months).There was no sign of recurring infection and CRP and ESR were normal in all cases after the first stage surgery.However, four cases (6%) had recurrent infection with sinus exudates and their CRP and ESR were abnormal after the second stage surgery, and further treatments were carried out on these patients.Follow-up showed bony union in all patients within mean 5.5 months (range, 4-6 months).Conclusion Induced membrane technique with antibiotic cement-coated locking plates for treatment of post-traumatic tibial osteomyelitis can shorten bone healing time and decrease infection recurrent rate without obvious impact on osteogenic activity.%目的 探讨在膜诱导技术治疗胫骨创伤后骨感染中使用抗生素骨水泥被覆锁定钢板的临床疗效. 方法 采用回顾性病例系列研究分析2014年9月-2015年9月运用膜诱导技术治疗的

  15. Lithospheric Rheology Constrained by Loading of the Hawaiian Islands and its Implications for the Dynamics of Plate Tectonics

    Science.gov (United States)

    Zhong, S.; Watts, A. B.

    2013-12-01

    Lithospheric rheology is important for understanding crustal and lithospheric dynamics, and the conditions for plate tectonics. For example, numerical modeling studies suggest that plate tectonics emerge from the dynamics of mantle convection when a small coefficient of friction (significantly to match the observations, together with frictional coefficient in the range from 0.1 to 0.7. However, the small coefficient of friction weakens the shallow part of the lithosphere so much that it causes the minima in strain rate and stress to occur at too large depths to be consistent with the depth distribution of seismicity at Hawaii. Our results therefore suggest that the coefficient of friction is between 0.25 and 0.7. Finally, maximum lithospheric stress under Hawaiian loads is about 100-200 MPa for models that match the observations, and this stress may be viewed as the largest lithospheric stress on the Earth.

  16. A counterexample of the Euler condition:the Appell-Hamel dynamical system on a horizontally moving plate

    Institute of Scientific and Technical Information of China (English)

    Xu Shan-Shan; Li Shu-Min; Berakdax Jamal

    2009-01-01

    As a counterexample of the Euler condition for nonholonomic constraint problems [H.C.Shen,Acta Phys.Sin.54,2468 (2005)],we investigate the Apell-Hamel dynamical system on a horizontally moving plate.The inconsistency of the results with Newton mechanics suggests that the Euler condition is not a universal model for nonlinear nonholonomic systems.This is attributed to the fact that the virtual displacements so obtained are not normal to the constraint forces.

  17. Treatment of intertrochanteric and subtrochanteric femur fractures with indirect reduction and submuscular reversed polyaxial locking plate fixation%间接复位、经皮股骨髁万向锁定板倒置治疗股骨转子间及转子下骨折

    Institute of Scientific and Technical Information of China (English)

    张智长; 王韬; 陆男吉; 罗从风; 曾炳芳

    2011-01-01

    目的 探讨间接复位、经皮股骨髁万向锁定板倒置治疗股骨转子间及转子下骨折治疗效果.方法 对28例股骨转子间及转子下骨折患者,均采用牵引床间接复位、穿皮股骨髁万向锁定板倒置固定.结果 28例均获得随访,时间5~11个月.骨折愈合时间为3~6个月.无肢体短缩、髋内翻等并发症.结论 对外侧壁粉碎或反斜行骨折、髓腔过细不适合髓内固定、假体周围骨折等股骨转子间及转子下骨折,采用间接复位、股骨髁万向锁定板倒置固定效果良好.%Objective To evaluate the clinical effects of treating intertrochanteric and subtrochanteric femur fractures with indirect reduction and submuscular reversed polyaxial locking plate fixation.Methods 28 patients of intertrochanteric and subtrochanteric femur fractures were treated by indirect reduction and submuscular reversed polyaxial locking plate fixation.Results All 28 patients were followed up for 5 ~ 11 months.Fractures healed at 3 ~ 6 months.No complications as limb shortening, or varus deformity was found.Conclusions For patients with fractures with trochanteric extension,reverse obliquity fractures , subtrochanteric fractures associated with indwelling intramedullary hardware, patients with intramedullary canals too small for intramedullary nailing, indirect reduction and submuscular reversed polyaxial locking plate is effective.

  18. Minimally invasive percutaneous compression plating versus dynamic hip screw for intertrochanteric fractures: a randomized control trial

    Institute of Scientific and Technical Information of China (English)

    Cheng Qiang; Huang Wei; Gong Xuan; Wang Changdong; Liang Xi; Hu Ning

    2014-01-01

    Objective:Intertrochanteric femur fracture is a common injury in elderly patients.The dynamic hip screw (DHS) has served as the standard choice for fixation; however it has several drawbacks.Studies of the percutaneous compression plate (PCCP) are still inconclusive in regards to its efficacy and safety.By comparing the two methods,we assessed their clinical therapeutic outcome.Methods:Atotal of 121 elderly patients with intertrochanteric femur fractures (type AO/OTA 31.A 1-A2,Evans type 1) were divided randomly into two groups undergoing either a minimally invasive PCCP procedure or a conventional DHS fixation.Results:The mean operation duration was significantly shorter in the PCCP group (55.2 min versus 88.5 min,P<0.01).The blood loss was 156.5 ml±18.3 ml in the PCCP group and 513.2 ml±66.2 ml in the DHS group (P<0.01).Among the patients treated with PCCP,3.1% needed blood transfusions,compared with 44.6% of those that had DHS surgery (P<0.01).The PCCP group displayed less postoperative complications (P<0.05).The mean American Society of Anesthesiologists score and Harris hip score in the PCCP group were better than those in the DHS group.There were no significant differences in the mean hospital stay,mortality rates,or fracture healing.Conclusion:Due to several advantages,PCCP has the potential to become the ideal choice for treating intertrochanteric fractures (type AO/OTA 31.A1-A2,Evans type 1),particularly in the elderly.

  19. Clinical Analysis on Locking Plate Combining Bone Grafting in Treating with Fracture of Surgical Neck of Humerus%锁定钢板联合植骨治疗老年性肱骨外科颈骨折临床分析

    Institute of Scientific and Technical Information of China (English)

    张坤和; 黄黎; 王理德

    2014-01-01

    Objective To explore clinical efficacy of locking plate combining bone grafting in treating the senile with fracture of surgical neck of humerus and to provide references for future clinical treatment. Methods 180 patients with fracture of surgical neck of humerus admitted by this Hospital were selected as research subjects, who were divided into the research group and the control group on different treatment methods with 90 cases in each group. The patients in the research group underwent locking plate combining bone grafting treatment, and patients in the control group underwent locking plate treatment. Results The comparison and difference between intra-operative duration and postoperative healing time of patients in two groups were statistically significant (P <0.05).Conclusions The locking plate combining bone grafting in treating the senile with fracture of surgical neck of humerus delivers remarkable clinical efficacy, and patients are greatly recovered.%目的:探究钢板联合植骨治疗老年肱骨外科颈骨折的临床效果,为后期临床治疗提供参考。方法选取我院收入的肱骨骨折患者180例为研究对象,根据治疗方式的不同分为研究组与对照组各90例。研究组行锁定钢板联合植骨治疗,对照组行锁定钢板治疗。结果两组患者在手术及术后愈合时间比较,差异具有统计学意义(P<0.05)。结论锁定钢板联合植骨治疗老年性肱骨外科颈骨折的临床效果显著,患者恢复好。

  20. Using closed reduction and minimally invastive locking plate fixation to treat distal radius fractures%闭合复位微创锁定钢板内固定治疗桡骨远端骨折

    Institute of Scientific and Technical Information of China (English)

    明立功; 明朝戈; 王自方; 王新德; 孟维娜; 王慧

    2016-01-01

    目的:探讨采用闭合复位微创接骨板固定术(minimally invasive plate osteosynthesis, MIPO )置入锁定加压接骨板(locking compression plate, LCP)内固定治疗桡骨远端骨折的手术技巧及疗效。方法自2010年以来,在桡骨远端解剖学基础上,采用远端腕关节横弧形切口、近端纵行小切口MIPO技术置入LCP内固定治疗桡骨远端骨折12例。结果12例患者术后获12~25个月(平均15个月)随访。骨折愈合时间6~12周,平均8周。采用AO组织建议的Garland and Werley评分方法,对本组的疗效进行评估。优10例,良1例,可1例,优良率91.7%。12例平均手术时间为(55±15) min,术中平均失血量为(35±10) mL,术后平均住院时间为(7±2) d。无一例发生医源性正中神经损伤,所有患者伤口均Ⅰ期愈合。结论采用小切口MIPO技术置入LCP内固定治疗桡骨远端骨折,具有骨折愈合快、并发症少、功能恢复快的优点,临床效果良好。%Objective To describe the surgical skill and the effect of using closed reduction MIPO technology into LCP internal fixation for the treatment of distal radius fractures. Methods Since from 2010, based on the anatomy of distal radius, 12 cases with distal radius fractures were treated by using MIPO technology into LCP internal fixation, by which applying horizontal arc incision of distal wrist joint and longitudinal small incision of proximal of wrist joint. Results 12 cases were followed-up from 12 to 24 months (average 15 months), bone union time from 6 to 12 weeks (average 8 weeks). The scoring methods used Garland and Werley, the results showed excellent in 10 cases, good in 1 case, fair in 1 case, with an excellent and good rate of 91.7%. The mean operative time was (55 ±15) min in 12 cases, mean intraoperative blood lose was (35 ±10) mL, the average hospitallization time was (7 ±2) d. None of the iatrogenic injury of the median nerve, all

  1. Analysis of the Outcomes of Anatomical Lock Plate for C Type Distal Humerus Fracture%解剖锁定接骨板治疗C型肱骨远端骨折的疗效分析

    Institute of Scientific and Technical Information of China (English)

    朱前拯; 刘成刚; 段亚景; 杨雨润; 杨欢; 陈星佐; 王立强; 陈瀛; 杨连发; 林朋

    2015-01-01

    目的:观察解剖锁定接骨板治疗C型肱骨远端骨折以及术后规范化康复的疗效。方法2009年12月至2013年6月使用解剖锁定接骨板治疗17例C型肱骨远端骨折患者,其中男性6例,女性11例;年龄24~84岁,平均51.2岁。损伤原因:低能量损伤9例(低能量组);高能量损伤8例(高能量组)。受伤至手术时间为1~30d,平均8.4d。术后患者开始规范化肘关节功能康复治疗。末次随访时记录患侧肘关节活动范围并采用M ayo肘关节功能评分。结果所有患者术后获9~48个月(平均18.59个月)随访,所有骨折均愈合,1例合并尺骨鹰嘴截骨处延迟愈合。末次随访时,肘关节伸直15.0°±10.2°,屈曲103.2°±16.3°,活动范围88.2°±22.8°。M EPS评分(83.9±19.2)分,优良率76.5%(13/17)。高能量组与低能量组MEPS评分分别为(71.9±22.5)分和(94.6 ± 4.9)分,差异有统计学意义( P=0.025)。结论 A O解剖锁定接骨板治疗C型肱骨远端骨折的疗效肯定,高能量损伤患者的预后较差,初始损伤因素影响患者肘关节功能恢复,规范化的康复治疗有助于肘关节功能恢复。%Background Among AO types ,C type distal humerus fracture is a very complicated intra‐articular fracture .The distal humerus metaphysis and the articular surface are easy to get severe smash ,which add more difficulties to the treatment .C type distal humerus fracture is complicated with bone defects ,soft tissue injury ,nerve injury ,osteoporosis and other symptoms ,which add to the unsteady fixation and can lead to adverse impacts to prognosis .AO distal humerus lock plates are paralleled plates that vertically fix the internal fracture .It designs to be anatomical plastotype and the distal point is fixed with the 2 .7mm screws .It is more flexible and convenient to use in the operation , and can effectively prevent the

  2. Fixation of displaced proximal humeral fractures with proximal humeral internal locking plate in the elderly%肱骨近端锁定型钉板治疗老年人移位的肱骨近端骨折

    Institute of Scientific and Technical Information of China (English)

    纪泉; 文良元; 薛庆云; 赵立连; 黄公怡

    2011-01-01

    Objective To investigate the treatment effect of the proximal humeral internal locking system (PHIL()S) on the elderly patients with displaced proximal humeral fractures.Methods From Feb 2004 to Mar 2007, 36 patients (mean age: 72.2 years) with proximal humeral fractures were treated with PHILOS plate fixation which included 14 cases with 2-part, 17 cases with three-part and 5 cases with four-part fractures according to Neer classification. Operation time,intraoperative blood loss, blood transfusion, perioperative complications and function evaluation of the operated shoulder joint were calculated with 14.5 months follow-up at average.Results The average operation time and blood loss were (61.5± 11.6) min and ( 165.2±91.2) ml, respectively. 1 case with accidents of blood vessel and 1 case with pneumonia were found without neurovascular injuries. All fractures were radiographically healed in an average of 3-5 months. No necrosis of humeral head appeared and 30 (83.3%) cases were excellent or good according to Neer scoring system. Two part fracture and early operation ( within 3 days after operation) might improve the postoperative function of shoulder joint, but the patient's age, gender and ASA score were not statistically with Neer score.Conclusions PHILOS plate fixation is a suitable procedure for displaced proximal humeral fractures via stable fixation and early rehabilitation, especially for elderly patients combined with osteoporosis.%目的 探讨肱骨近端锁定型钉(PHILOS)板治疗老年人移位的肱骨近端骨折的疗效。方法 回顾性分析2004年2月至2007年3月用PHILOS板治疗的36例肱骨近端骨折患者,Neer分型二部分骨折14例,三部分骨折17例,四部分骨折5例。统计手术时间、输血量和手术并发症,评价肩关节功能。 结果 患者平均年龄72.2岁,平均随访14.5个月。术中平均输血165.2 ml,术后X线显示骨折复位满意,无神经、血管损

  3. Locking proximal humerus plate/proximal humeral internal locking system versus other internal fixations for the treatment of proximal humeral fractures in adults: a Meta analysis%肱骨近端锁定钢板或肱骨近端内锁定系统与其他内固定治疗肱骨近端骨折的Meta分析

    Institute of Scientific and Technical Information of China (English)

    胡稷杰; 金丹; 魏宽海; 任高宏; 余斌; 王钢

    2012-01-01

    目的 对采用肱骨近端锁定钢板(LPHP)或肱骨近端内锁定系统(PHILOS)与其他内固定治疗肱骨近端骨折(PHFs)的疗效进行Meta分析,为临床治疗提供参考依据. 方法 通过计算机检索MEDLINE(1966年至2011年12月)、EMbase(1966年至2011年12月)、Cochrane图书馆(2011年第4期)和中国生物医学文献数据库(2001至2011年)等,搜集有关LPHP/PHILOS和其他内固定治疗PHFs的各种对照研究,对纳入的文献选择Neer评分、Constant-Murley功能评分、肩关节疼痛和功能障碍指数(SPADI)量表和美国肩肘外科医师(ASES)评分、异位骨化发生率、感染率、肱骨头缺血坏死率、骨折延迟愈合率、螺钉松动率、钢板断裂率、肩峰下撞击征发生率、肱骨头半脱位发生率、肩关节活动受限发生率、肩关节疼痛发生率、二次手术率作为Meta分析的评价指标,采用RevMan 5.0进行分析. 结果 共纳入18项研究1133例患者.LPHP/PHILOS与其他内固定治疗PHFs相比,螺钉松动率更低,差异均有统计学意义[OR=0.23,95% CI(O.07,0.74),P=O.01].LPHP/PHILOS与其他内固定治疗PHFs的Neer评分优良率、异位骨化发生率、感染率、肱骨头缺血坏死率、骨折延迟愈合率、钢板断裂率、肩峰撞击征发生率、肱骨头半脱位发生率、肩关节活动受限发生率比较,差异均无统计学意义(P>0.05). 结论 LPHP/PHILOS与其他内固定在特定条件下各有利弊,不能盲目扩大LPHP/PHILOS的临床适应证,治疗方案要结合患者的病情甚至经济情况综合考虑.%Objective To evaluate and compare locking proximal humerus plate/proximal humeral internal locking system (LPHP/PHILOS) versus other internal fixations in the treatment of proximal humeral fractures (PHFs) in adults.Methods According to Cochrane Reviews,Cochrane library (Issue 4,2011),Ovid MEDLINE (from January 1966 to December 2011),EMbase (from January 1966 to December 2011),Chinese National Knowledge

  4. CONTROL SYSTEM FOR TILTABLE PLATE WITH TWO DEGREES OF FREEDOM FOR RESEARCH OF DYNAMIC MANIPULATION PROBLEMS

    Directory of Open Access Journals (Sweden)

    D. Dobriborsci

    2017-01-01

    Full Text Available The paper presents results of work on control system design for tiltable plate with two degrees of freedom. Designed robotic system includes technical vision system that provides an opportunity to get the position of the control object placed on the square plate. Two servomotors provide each tilting axis operation. Single-board computer transmits angle values and other design elements to the servomotors by USB interface from the workstation. The problem of the object stabilization in the given coordinates on the plate is solved.

  5. Overview of locking systems

    Energy Technology Data Exchange (ETDEWEB)

    Gee, K.T.; Scott, S.H.; Wilde, M.G. [Sandia National Labs., Albuquerque, NM (United States); Highland, S.E. [Albuquerque Safe Co., Albuquerque, NM (United States)

    1993-12-01

    The purpose of this document is to present technical information that should be useful for understanding and applying locking systems for physical protection and control. There are major sections on hardware for locks, vaults, safes, and security containers. Other topics include management of lock systems and safety considerations. This document also contains notes on standards and specifications and a glossary.

  6. outcome of plate osteosynthesis in the management of proximal ...

    African Journals Online (AJOL)

    Rush pins with blade plates, locking plates and IM nails. (8-10). IM fixation ... Three patients who had pathological fractures from tumour and infection were excluded from the study. Results: ... being implant failure, nonunion, osteonecrosis of.

  7. Mantle Convection, Plate Tectonics, and the Asthenosphere: A Bootstrap Model of the Earth's Internal Dynamics

    Science.gov (United States)

    Lenardic, A.; Hoink, T.

    2008-12-01

    Several studies have highlighted the role of a low viscosity asthenosphere in promoting plate-like behavior in mantle convection models. It has also been argued that the asthenosphere is fed by mantle plumes (Phipps- Morgan et al. 1993; Deffeyes 1972) and that the existence of the specific plume types required for this depends on plate subduction (Lenardic and Kaula 1995; Jellinek et al. 2002). Independent of plumes, plate subduction can generate a non-adiabatic temperature gradient which, together with temperature dependent mantle viscosity, leads to a low viscosity near surface region. The above suggests a conceptual model in which the asthenosphere can not be defined solely in terms of material properties but must also be defined in terms of an active process, plate tectonics, which both maintains it and is maintained by it. The bootstrap aspect of the model is its circular causality between plates and the asthenosphere, neither being more fundamental than the other and the existence of each depending on the other. Several of the feedbacks key to the conceptual model will be quantified. The implications for modeling mantle convection in a plate-tectonic mode will also be discussed: 1) A key is to get numerical simulations into the bootstrap mode of operation and this is dependent on assumed initial conditions; 2) The model implies potentially strong hysteresis effects (e.g., transition between convection states, associated with variable yield stress, will occur at different values depending on whether the yield stress is systematically lowered or raised between successive models).

  8. Biomechanical investigation of an alternative concept to angular stable plating using conventional fixation hardware

    Directory of Open Access Journals (Sweden)

    Radtke Roman

    2010-05-01

    Full Text Available Abstract Background Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence" utilizing conventional (non-locked implants in comparison to conventional LC-DCP (limited contact dynamic compression plate and LCP (locking compression plate stabilization, in a human cadaveric diaphyseal gap model. Methods In eight pairs of human cadaveric femora, one femur per pair was randomly assigned to receive a Fence construct with either elevated or non-elevated plate, while the contralateral femur received either an LCP or LC-DCP instrumentation. Fracture gap motion and fatigue performance under cyclic loading was evaluated successively in axial compression and in torsion. Results were statistically compared in a pairwise setting. Results The elevated Fence constructs allowed significantly higher gap motion compared to the LCP instrumentations (axial compression: p ≤ 0.011, torsion p ≤ 0.015 but revealed similar performance under cyclic loading (p = 0.43. The Fence instrumentation with established bone-plate contact revealed larger fracture gap motion under axial compression compared to the conventional LC-DCP osteosynthesis (p ≤ 0.017. However, all contact Fence specimens survived the cyclic test, whereas all LC-DCP constructs failed early during torsion testing (p Conclusions Even though accentuated fracture gap motion became obvious, the "Fence" technique is considered an alternative to cost-intensive locking-head devices. The concept can be of interest in cases were angle-stable implants are unavailable and can lead to new strategies in implant design.

  9. Vortex dynamics and wall shear stress behaviour associated with an elliptic jet impinging upon a flat plate

    Science.gov (United States)

    Long, J.; New, T. H.

    2016-07-01

    Vortical structures and dynamics of a Re h = 2100 elliptic jet impinging upon a flat plate were studied at H/ d h = 1, 2 and 4 jet-to-plate separation distances. Flow investigations were conducted along both its major and minor planes using laser-induced fluorescence and digital particle image velocimetry techniques. Results show that the impingement process along the major plane largely consists of primary jet ring-vortex and wall-separated secondary vortex formations, where they subsequently separate from the flat plate at smaller H/ d h = 1 and 2 separation distances. Key vortex formation locations occur closer to the impingement point as the separation distance increases. Interestingly, braid vortices and rib structures begin to take part in the impingement process at H/ d h = 4 and wave instabilities dominate the flow field. In contrast, significantly more coherent primary and secondary vortices with physically larger vortex core sizes and higher vortex strengths are observed along the minor plane, with no signs of braid vortices and rib structures. Lastly, influences of these different flow dynamics on the major and minor plane instantaneous and mean skin friction coefficient levels are investigated to shed light on the effects of separation distance on the wall shear stress distributions.

  10. Modeling the dynamic operation of a small fin plate heat exchanger - parametric analysis

    Science.gov (United States)

    Motyliński, Konrad; Kupecki, Jakub

    2015-09-01

    Given its high efficiency, low emissions and multiple fuelling options, the solid oxide fuel cells (SOFC) offer a promising alternative for stationary power generators, especially while engaged in micro-combined heat and power (μ-CHP) units. Despite the fact that the fuel cells are a key component in such power systems, other auxiliaries of the system can play a critical role and therefore require a significant attention. Since SOFC uses a ceramic material as an electrolyte, the high operating temperature (typically of the order of 700-900 °C) is required to achieve sufficient performance. For that reason both the fuel and the oxidant have to be preheated before entering the SOFC stack. Hot gases exiting the fuel cell stack transport substantial amount of energy which has to be partly recovered for preheating streams entering the stack and for heating purposes. Effective thermal integration of the μ-CHP can be achieved only when proper technical measures are used. The ability of efficiently preheating the streams of oxidant and fuel relies on heat exchangers which are present in all possible configurations of power system with solid oxide fuel cells. In this work a compact, fin plate heat exchanger operating in the high temperature regime was under consideration. Dynamic model was proposed for investigation of its performance under the transitional states of the fuel cell system. Heat exchanger was simulated using commercial modeling software. The model includes key geometrical and functional parameters. The working conditions of the power unit with SOFC vary due to the several factors, such as load changes, heating and cooling procedures of the stack and others. These issues affect parameters of the incoming streams to the heat exchanger. The mathematical model of the heat exchanger is based on a set of equations which are simultaneously solved in the iterative process. It enables to define conditions in the outlets of both the hot and the cold sides

  11. Modeling the dynamic operation of a small fin plate heat exchanger – parametric analysis

    Directory of Open Access Journals (Sweden)

    Motyliński Konrad

    2015-09-01

    Full Text Available Given its high efficiency, low emissions and multiple fuelling options, the solid oxide fuel cells (SOFC offer a promising alternative for stationary power generators, especially while engaged in micro-combined heat and power (μ-CHP units. Despite the fact that the fuel cells are a key component in such power systems, other auxiliaries of the system can play a critical role and therefore require a significant attention. Since SOFC uses a ceramic material as an electrolyte, the high operating temperature (typically of the order of 700–900 °C is required to achieve sufficient performance. For that reason both the fuel and the oxidant have to be preheated before entering the SOFC stack. Hot gases exiting the fuel cell stack transport substantial amount of energy which has to be partly recovered for preheating streams entering the stack and for heating purposes. Effective thermal integration of the μ-CHP can be achieved only when proper technical measures are used. The ability of efficiently preheating the streams of oxidant and fuel relies on heat exchangers which are present in all possible configurations of power system with solid oxide fuel cells. In this work a compact, fin plate heat exchanger operating in the high temperature regime was under consideration. Dynamic model was proposed for investigation of its performance under the transitional states of the fuel cell system. Heat exchanger was simulated using commercial modeling software. The model includes key geometrical and functional parameters. The working conditions of the power unit with SOFC vary due to the several factors, such as load changes, heating and cooling procedures of the stack and others. These issues affect parameters of the incoming streams to the heat exchanger. The mathematical model of the heat exchanger is based on a set of equations which are simultaneously solved in the iterative process. It enables to define conditions in the outlets of both the hot and the

  12. Computer fluid dynamics (CFD) study of a plate heat exchanger working with nanofluids

    Science.gov (United States)

    Stan, Liviu-Constantin; Cǎlimǎnescu, Ioan

    2016-12-01

    The industry fosters many types of heat exchangers such double pipe or plate heat exchangers (HX), but lately the plate HX are gaining the high ground in many applications. Such a plate HX is made out of serial plate modules packed together allowing the warm and cold fluids to pass through and exchange the heat. The paper is demonstrating the functioning of a medium sized plate HX functioning with 10% Al2O3 and water nanofluids flowing in both cold and warm sides of the HX. The influence of the nanofluid properties will be investigated as impact upon the outlet temperature of the fluid leaving the HX. Using the RSM methodology. The main conclusion of this study is that there is a balance between the nanofluids increased conductivity and their increased viscosity. The nanofluids are working well for those applications where the flow is not impeded by narrow fluid passages where the bigger influence of the viscosity is actually worsening the heat transfer conditions instead of increasing it, since the influence of viscosity in that kind of applications is three time bigger. A nanofluid conductivity threshold was also detected over which the nanofluids say with 15$ or 20% alumina content is useless for the overall heat transfer conditions.

  13. Continuum dynamics of the formation, migration and dissociation of self-locked dislocation structures on parallel slip planes

    Science.gov (United States)

    Zhu, Yichao; Niu, Xiaohua; Xiang, Yang

    2016-11-01

    In continuum models of dislocations, proper formulations of short-range elastic interactions of dislocations are crucial for capturing various types of dislocation patterns formed in crystalline materials. In this article, the continuum dynamics of straight dislocations distributed on two parallel slip planes is modelled through upscaling the underlying discrete dislocation dynamics. Two continuum velocity field quantities are introduced to facilitate the discrete-to-continuum transition. The first one is the local migration velocity of dislocation ensembles which is found fully independent of the short-range dislocation correlations. The second one is the decoupling velocity of dislocation pairs controlled by a threshold stress value, which is proposed to be the effective flow stress for single slip systems. Compared to the almost ubiquitously adopted Taylor relationship, the derived flow stress formula exhibits two features that are more consistent with the underlying discrete dislocation dynamics: (i) the flow stress increases with the in-plane component of the dislocation density only up to a certain value, hence the derived formula admits a minimum inter-dislocation distance within slip planes; (ii) the flow stress smoothly transits to zero when all dislocations become geometrically necessary dislocations. A regime under which inhomogeneities in dislocation density grow is identified, and is further validated through comparison with discrete dislocation dynamical simulation results. Based on the findings in this article and in our previous works, a general strategy for incorporating short-range dislocation correlations into continuum models of dislocations is proposed.

  14. Operando lithium plating quantification and early detection of a commercial LiFePO4 cell cycled under dynamic driving schedule

    Science.gov (United States)

    Anseán, D.; Dubarry, M.; Devie, A.; Liaw, B. Y.; García, V. M.; Viera, J. C.; González, M.

    2017-07-01

    Lithium plating is considered one of the most detrimental phenomenon in lithium ion batteries (LIBs), as it increases cell degradation and might lead to safety issues. Plating induced LIB failure presents a major concern for emerging applications in transportation and electrical energy storage. Hence, the necessity to operando monitor, detect and analyze lithium plating becomes critical for safe and reliable usage of LIB systems. Here, we report in situ lithium plating analyses for a commercial graphite||LiFePO4 cell cycled under dynamic stress test (DST) driving schedule. We designed a framework based on incremental capacity (IC) analysis and mechanistic model simulations to quantify degradation modes, relate their effects to lithium plating occurrence and assess cell degradation. The results show that lithium plating was induced by large loss of active material on the negative electrode that eventually led the electrode to over-lithiate. Moreover, when lithium plating emerged, we quantified that the loss of lithium inventory pace was increased by a factor of four. This study illustrates the benefits of the proposed framework to improve lithium plating analysis. It also discloses the symptoms of lithium plating formation, which prove valuable for novel, online strategies on early lithium plating detection.

  15. 锁定钛板及半肩关节置换治疗肱骨近端骨折的疗效分析%Locking plates and semi-shoulder arthroplasty for complex proximal humeral fractures

    Institute of Scientific and Technical Information of China (English)

    吕扬; 李少柟; 周方; 田耘; 姬洪全; 张志山

    2011-01-01

    目的 探讨锁定钛板及半肩关节置换术治疗肱骨近端骨折的疗效与适应证。方法 2005年1月至2008年12月共收治51例肱骨近端骨折患者,其中39例获得随方,男12例,女27例;平均年龄65.1岁(17 ~ 80岁)。骨折按Neer分型:二部分骨折23例,三部分骨折10例,四部分骨折6例。受伤至手术时间平均为5.5d(1~9d)。手术方式选择:二部分骨折及年龄<60岁的患者使用锁定钛板内固定治疗,四部分骨折及年龄> 60岁的患者使用半肩关节置换术。本组使用肱骨近端内固定系统(PHILOS)钛板切开复位内固定32例(PHILOS钛板组),其中二部分骨折23例,三部分骨折9例;采用肱骨头置换术治疗7例(关节置换组),其中三部分骨折1例,四部分骨折6例。结果 PHILOS钛板组患者手术时间平均为84 min(60 ~ 140 min),失血量平均为155 mL( 100 ~400 mL);关节置换组患者手术时间平均为125 min( 100 ~ 170 min),失血量平均为220 mL(150~450) mL。39例患者术后获平均23个月(16~46个月)随访,无一例出现并发症。PHILOS钛板组28例术后3个月复查X线片示骨折愈合,另4例术后6个月骨折愈合,肩臂手功能丧失量