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Sample records for plate osteosynthesis solve

  1. Plate failure following plate osteosynthesis in periprosthetic femoral fractures.

    PubMed

    Boesmueller, Sandra; Baumbach, Sebastian F; Hofbauer, Marcus; Wozasek, Gerald E

    2015-10-01

    Increasing numbers of total knee and hip arthroplasties result in a growing number of periprosthetic femoral fractures (PPFF). PPFF with a stable stem component are treated commonly with plate osteosynthesis. Therefore plate failure is seen as a major complication. The aim of this retrospective study was to investigate the patients' outcome after plate failure. The database of a Level 1 trauma center was searched for all patients treated for a PPFF with plate osteosynthesis. Patients with plate failure were investigated specifically. Standard demographic data, details on initial arthroplasty, trauma, and treatment were recorded for all patients. All fractures were classified and their outcome reviewed. Seven (8.8%) out of 80 patients treated with plate osteosynthesis following PPFF met our inclusion criterion being plate failure. All these patients were female, with an average age at primary surgery of 74 ± 13 years and a mean follow-up of 885 days (range, 264-2549). Four patients suffered a PPFF after total hip arthroplasty (THA) (2 Vancouver Type B1 and 2 Type C) and three after total knee arthroplasty (TKA) (Lewis-Rorabeck Type II). Following plate failure, four patients healed uneventfully and three patients experienced complications such as pseudarthrosis, screw loosening, and further plate failure. In patients with poor bone quality, bone graft, bone cement, and bone biologics have to be considered in revision surgery. Furthermore, long-stem revision and tumor prosthesis are an additional solution.

  2. Minimally invasive plate osteosynthesis: tibia and fibula.

    PubMed

    Beale, Brian S; McCally, Ryan

    2012-09-01

    Fractures of the tibia and fibula are common in dogs and cats and occur most commonly as a result of substantial trauma. Tibial fractures are often amenable to repair using the minimally invasive plate osteosynthesis (MIPO) technique because of the minimal soft tissue covering of the tibia and relative ease of indirect reduction and application of the implant system on the tibia. Treatment of tibial fractures by MIPO has been found to reduce surgical time, reduce the time for fracture healing, and decrease patient morbidity, while at the same time reducing complications compared with traditional open reduction and internal fixation.

  3. Currents of plate osteosynthesis in osteoporotic bone.

    PubMed

    Lampropoulou-Adamidou, Kalliopi; Karampinas, Panagiotis K; Chronopoulos, Efstathios; Vlamis, John; Korres, Demetrios S

    2014-05-01

    Osteoporotic fractures are becoming more prevalent with ageing of populations worldwide. Inadequate fixation or prolonged immobilization after non-surgical care leads to serious life-threatening events, poor functional results and lifelong disability. Thus, a stable internal fixation and rapid initiation of rehabilitation are required for faster return of function. Conventional internal fixation attempts to achieve the exact anatomy, often with extended soft-tissue stripping and compression of the periosteum, causing disturbance of the metaphyseal and comminuted fracture's bone blood supply. This technique relies on frictional forces between bone and plate. Osteoporotic bone might not be able to generate enough torque with the screw to securely fix the plate to bone. Thus, this surgical management have resulted in increased incidence of poor results in elderly, osteoporotic patients. The newly developed locked internal fixators, locking compression plates and less invasive stabilization system, consist of plate and screw systems where the screws are locked in the plate, minimizing the compressive forces exerted between plate and bone. Thus, the plate does not need to compress the bone nor requires precise anatomical contouring of a plate disturbing the periosteal blood supply. These fixators allowed the development of the minimal invasive percutaneous osteosynthesis. Nowadays, locking plates are the fixation method of choice for osteoporotic, diaphyseal or metaphyseal, severely comminuted fractures.

  4. [The use of blade plate and dynamic screw plate osteosynthesis].

    PubMed

    Oestern, H J; Gänsslen, A

    2010-02-01

    Osteosynthesis in fracture treatment and in some reconstructive procedures with blade plates or dynamic screw systems was the standard procedure for several decades. In this review, the current options and concepts using blade plate osteosynthesis, stabilization of proximal and distal femur fractures and reconstructive procedures with the dynamic hip screw or the dynamic condylar blade are discussed. On the basis of a literature review, the present indications, results and region-specific complications are reported and discussed.Blade plates are used mainly in the context of reconstructive procedures, as well as in the treatment of pseudoarthroses. The Pauwel procedure in femoral neck non-unions is one of the best known indications. In contrast, the dynamic hip screw is the gold standard for stabilization of femoral neck and most pertrochanteric fractures, whereas the dynamic condylar screw is still an alternative to internal fixators for proximal and distal femoral fracture fixations.

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

    PubMed Central

    Sonderegger, Juerg; Grob, Karl R.; Kuster, Markus S.

    2010-01-01

    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. PMID:21808699

  6. Comparison of minimally invasive plate osteosynthesis and conventional plate osteosynthesis for humeral shaft fracture

    PubMed Central

    Yu, Bin-feng; Liu, Liang-le; Yang, Guo-jing; Zhang, Lei; Lin, Xi-peng

    2016-01-01

    Abstract Background: The objective of this meta-analysis was to compare the efficacy and safety of minimally invasive plate osteosynthesis (MIPO) and conventional plate osteosynthesis (CPO) for humeral shaft fracture. Methods: Potential academic articles were identified from the Cochrane Library, Medline (1966–2016.3), PubMed (1966–2016.3), Embase (1980–2016.3), and ScienceDirect (1966–2016.3). Gray studies were identified from the references of the included literature. Randomized controlled trials (RCTs) and non-RCT involving MIPO and CPO for humeral shaft fracture were included. Two independent reviewers performed independent data abstraction. I2 statistic was used to assess heterogeneity. Fixed or random effects model was used for meta-analysis. Results: Two RCTs and 3 non-RCTs met the inclusion criteria. There was a lower incidence of iatrogenic radial nerve palsy in patients with MIPO (P = 0.006). There was no statistically significant difference in in the risk of developing nonunion, delay union, malformation, screw loosening, infection, operation time, UCLA, and MEPS function score between the 2 groups. Conclusion: MIPO decreased incidence of iatrogenic radial nerve palsy and is an efficacy and safety technique for humeral shaft fracture. Due to the limited quality and data of the evidence currently available, more high-quality RCTs are required. PMID:27684839

  7. Fixation properties of a biodegradable "free-form" osteosynthesis plate.

    PubMed

    Väänänen, Petteri; Nurmi, Janne T; Nuutinen, Juha-Pekka; Jakonen, Sanna; Happonen, Harri; Jank, Siegfried

    2008-10-01

    The Inion FreedomPlate, a "free-form" osteosynthesis plate, is a biodegradable plate with just pilot holes for drilling. The construction of the plate allows the surgeon a placement of screws in optimal position. The screw heads can either be countersunk into the plate or cut off. Furthermore, the plate can be cut and contoured to match the bone. The aim of this study was to determine the mechanical properties of the Inion FreedomPlate compared to a conventional biodegradable plate. Acrylic pipes were fixed together with plates and screws. Tensile and cantilever bending tests were performed to measure the fixation properties. In the tensile test, the samples were loaded with a constant speed of 5 mm/min until failure of fixation. The yield load, maximum failure load, and initial stiffness were recorded, and the failure mode was visually determined. In the cantilever bending test, the samples were loaded with a constant speed of 50 mm/min (with a moment arm of 45 mm) until failure of fixation. The yield bending moment and initial stiffness were recorded, and the failure mode was determined. The results of the study show that the new free-form plate provides at least as strong fixation as the tested conventional biodegradable plate. No clinically relevant difference was found between free-form plates fixed with into-the-plate countersunk screws and those fixed with screws without heads.

  8. Biomechanical study of different plate configurations for distal humerus osteosynthesis.

    PubMed

    Bogataj, M; Kosel, F; Norris, R; Krkovic, M; Brojan, M

    2015-05-01

    Fractures of the distal humerus are most commonly fixed by open reduction and internal fixation, using plates and screws, either in a locking or in a non-locking construct. Three different plating systems are commonly used in practice. The most important differences between them are in plate orientation, which affects both the rigidity of the osteosynthesis and invasiveness of the surgical procedure. Unfortunately, there is no common agreement between surgeons about which plate configuration brings the best clinical outcome. In this study, we investigate the theoretical rigidity of plate osteosyntheses considering two types of AO/ASIF configurations (90° angle between plates), Mayo clinic (Acumed) configuration (180° between plates) and dorsal fixation of both plates. We also compared the results for cases with and without contact between the bone fragments. In the case of no bone contact, the Mayo clinic plate configuration is found to be the most rigid, followed by both AO/ASIF plate configurations, and the least rigid system is the Korosec plate configuration. On the other hand, no significant differences between all types of fixation configurations are found in cases with contact in-between the bone fragments. Our findings show that this contact is very important and can compensate for the lack of load carrying capacity of the implants. This could therefore incite other implant fixation solutions, leading to less invasive surgical procedures and consequently improved clinical outcome.

  9. [Midcarpal partial arthrodesis with locking plate osteosynthesis].

    PubMed

    Hernekamp, J-F; Kneser, U; Kremer, T; Bickert, B

    2017-08-08

    Preservation of residual mobility and pain reduction in the wrist in advanced carpal collapse (scapholunate advanced collapse, SLAC or scaphoid nonunion advanced collapse, SNAC). Advanced osteoarthritis of the radiocarpal and intercarpal articulations, SLAC/SNAC stages 2-3. Arthrotic alterations to the proximal joint surface of the lunate bone or the corresponding joint surface of the radius (lunate fossa). Dorsal longitudinal incision and exposure of the wrist capsule using a radial pedunculated capsular flap. Resection of the scaphoid bone. Chondrolysis of the corresponding joint surface between the capitate bone and the lunate bone as well as between the hamate bone and the triquetral bone. Harvesting and insertion of radial cancellous bone. Repositioning of the lunate bone. Introduction of the plate and filling of the screwholes. Closure of the wrist capsule. Neutral placement of a lower arm plaster cast. Postoperative physiotherapy from out of the supporting cast to an extent of 20-0-20° extension-flexion. For protection the support cast should remain in place for 8 weeks. Complete consolidation of the bone in the X‑ray control in all 11 patients 12 weeks postoperatively. No implant-based complications. In one case a postoperative carpal tunnel syndrome had to be surgically treated. The postoperative extent of mobility showed overall satisfactory results with extension-flexion of 53° ± 18° (47% of the healthy side) and radial-ulnar abduction 30 ± 5° (58% of the healthy side). The postoperative values on the visual analog pain scale (VAS) were 0.7 ± 1.2 at rest and 4.3 ± 2.8 under load bearing. The gripping power was 19 ± 14 kg (56% of the non-operated side) and the disabilities of the arm, shoulder, hand (DASH) value was 33 ± 24.

  10. Minimally invasive plating osteosynthesis for mid-distal third humeral shaft fractures.

    PubMed

    Lian, Kejian; Wang, Lei; Lin, Dasheng; Chen, Zhiwen

    2013-08-01

    Mid-distal third humeral shaft fractures can be effectively treated with minimally invasive plating osteosynthesis and intramedullary nailing (IMN). However, these 2 treatments have not been adequately compared. Forty-seven patients (47 fractures) with mid-distal third humeral shaft fractures were randomly allocated to undergo either minimally invasive plating osteosynthesis (n=24) or IMN (n=23). The 2 groups were similar in terms of fracture patterns, fracture location, age, and associated injuries. Intraoperative measurements included blood loss and operative time. Clinical outcome measurements included fracture healing, radial nerve recovery, and elbow and shoulder discomfort. Radiographic measurements included fracture alignment, time to healing, delayed union, and nonunion. Functional outcome was satisfactory in both groups. Mean American Shoulder and Elbow Surgeons score and Mayo score were both better for the minimally invasive plating osteosynthesis group than for the IMN group (98.2 vs 97.6, respectively, and 93.5 vs 94.1, respectively; P<.001). Operative time was shorter and less intraoperative blood loss occurred in the minimally invasive plating osteosynthesis group than in the IMN group. Average time to union was similar in both groups. Primary union was achieved in 23 of 24 patients in the minimally invasive plating osteosynthesis group and in 22 of 23 in the IMN group. Minimally invasive plating osteosynthesis may have outcomes comparable with IMN for the management of mid-distal third humeral shaft fractures. Minimally invasive plating osteosynthesis is more suitable for complex fractures, especially for radial protection and motion recovery of adjacent joints, compared with IMN for simple fractures.

  11. ["Elastic osteosynthesis" with autocompression plates of carbon fiber reinforced thermoplastic material].

    PubMed

    Stange, J; Mittelmeier, H

    1989-06-01

    The problem of atrophic bone that occurs in osteosynthesis employing rigid plates is first depicted. Attempts at fabricating "simirigid" plates, which, however, have so far failed to gain any practical importance are then discussed. The reason for this seems to be that made of duroplastics cannot be molded during the operation and the thermoplastics do not have sufficient strength. The production of semirigid plates made of thermoplastic Polyethersulfon (PES), reinforced with 20% short carbon fibres, results in plates which are made moldable by heating in a small oven, white retaining sufficient static strength, although only limited fatigue strength. Biomechanical examinations revealed that with appropriate dimensioning of the plates, "elastic osteosynthesis" results in less loss of mechanical function of the stabilized bones, so that less atrophy of the bone may be expected. During more pronounced exercise loading, a reversible "springiness" of the fracture results, which might stimulate callus formation and improved stability.

  12. Redesign of Indonesian-made osteosynthesis plates to enhance their mechanical behavior.

    PubMed

    Dewo, P; van der Houwen, E B; Suyitno; Marius, R; Magetsari, R; Verkerke, G J

    2015-02-01

    Mechanical properties determined by fatigue strength, ductility, and toughness are important measures for osteosynthesis plates in order to tolerate some load-bearing situations caused by muscle contractions and weight-bearing effects. Previous study indicated that Indonesian-made plates showed lower mechanical strength compared to the European AO standard plate. High stress under load-bearing situations often starts from surface of the plate; we therefore refined the grain size of the surface by using shot peening and surface mechanical attrition treatment (SMAT). Single cycle bending tests showed that shot-peened and SMAT-treated plates had significantly higher load limit and bending stress compared to the original plates (p<0.05). Weibull analysis confirmed the improvement of proportional load limit of SMAT-treated plates. Fatigue limit also increased upon shot-peening and SMAT treatment (improvement ratio 18% and 27%, respectively). Significant improvement ratio of fatigue tests can be observed in SMAT-treated plates compared to the untreated and shot-peened plates. Fatigue performance demonstrated equivalent results between SMAT-treated and standard plate. These designated that mechanical properties of Indonesian-made plates can be improved upon SMAT treatment leading to significant enhancement of mechanical strength thus is comparable to the standard plate. Our findings highlight the benefits of SMAT treatment to improve mechanical strength of Indonesian-made osteosynthesis plates.

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

    PubMed Central

    2012-01-01

    Background and purpose 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 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. Patients and methods From 2002 through 2011, 58 consecutive patients (60 fractures) with low-energy PFF around or below a stable femoral stem, i.e. Vancouver type B1 and C fractures, underwent osteosynthesis with a locking plate. All patients had a total hip replacement (THR). They were followed up clinically and radiographically, with 6 weeks between visits, until fracture union or until death. Fracture union was evaluated 6 months postoperatively. Results At a median follow-up time of 23 (0–121) months after PFF, 8 patients (8 fractures) had been reoperated due either to infection (n = 4), failure of fixation (n = 3), or loosening of the femoral stem (n = 1). All the patients who had been followed up for at least 6 months—and who did not undergo reoperation or die—went on to fracture union (n = 43). Interpretation Locking-plate osteosynthesis of periprosthetic Vancouver type B1 and C fractures gives good results regarding fracture union. It appears that spanning of the prosthesis to avoid stress-rising areas is important for successful treatment. Infection is the major cause of failure. PMID:23140109

  14. Influence of the osteosynthesis plate on ultrasound propagation in the bone

    PubMed Central

    Bezuti, Márcio Takey; Mandarano-Filho, Luiz Garcia; Barbieri, Giuliano; Mazzer, Nilton; Barbieri, Cláudio Henrique

    2014-01-01

    Objective: To analyze the influence of steel plates for osteosynthesis on the velocity of ultrasound propagation (VU) through the bone. Methods: The transverse coronal and sagittal velocity of ultrasound propagation underwater were measured on the intact bone and then on assemblies of the same bone with two types of osteosynthesis plates (DCP and semi tubular), fixed onto the dorsal side of the bones. The first arriving signal (FAS) was the ultrasound parameter used, taking the coronal and sagittal diameters as the distances to calculate velocity. Intergroup statistical comparisons were made at significance level of 1% (p<0.01). Results: Velocity was higher on the intact bones than on the bone-plate assemblies and higher for the semitubular than for the compression plates, although differences were not statistically significant for most comparisons (p=0.0132 to 0.9884), indicating that the steel plates do not interfere significantly with ultrasound wave propagation through the bone-plate assemblies. Conclusion: The velocity reduction effect was attributed to the greater reflection coefficient of the steel as compared to that of bone and water. Ultrasonometry can, thus, be used in the evaluation of healing of fractures fixed with steel plates. Experimental Study. PMID:25328436

  15. Distal radius fractures: Minimally invasive plate osteosynthesis with dorsal bicolumnar locking plates fixation

    PubMed Central

    Chen, Alvin Chao-Yu; Chou, Ying-Chao; Cheng, Chun-Ying

    2017-01-01

    Background: Controversy still exists regarding the current treatment modalities for unstable distal radius fractures. There are yet few articles investigating the efficacy of bicolumnar dorsal plating technique, which is designed to minimize tissue dissection while providing sufficiently secure fixation. A clinical study was performed to evaluate the feasibility of the minimally invasive plate osteosynthesis (MIPO) technique using a modified dorsal approach for the treatment of distal radius fractures. Materials and Methods: Thirty patients with unilateral distal radius fracture who underwent bicolumnar plate fixation with a minimally invasive dorsal approach between September 2008 and December 2010 were included in this retrospective study. Twenty four patients (8 men and 16 women) with a mean age of 53 years (range 18-85 years) were available for followup of at least 1 year or more were included in final study. Herein, we report the functional radiological outcomes of the study. There were three cases of AO Type A fracture, five cases of AO Type B fracture, and 16 cases of AO Type C fracture. Results: The union was achieved in all the patients. The functional results at one-year followup, assessed using the modified Gartland and Werley scoring system, were excellent in 14 patients, good in seven patients, and fair in three patients. The average correction of deformity was 4.1 mm for radial height, 7.6° for radial inclination, and 20.7° for volar tilt. Conclusions: MIPO with a dorsal approach is a feasible option for the management of displaced distal radius fractures and can result in favorable surgical outcomes. PMID:28216757

  16. Tardy palsy of descending branch of posterior interosseous nerve: sequela to plate osteosynthesis of forearm bones.

    PubMed

    Lal, Hitesh; Bansal, Pankaj; Khare, Rahul; Mittal, Deepak

    2010-02-01

    We report a case of tardy paralysis of the descending branch of the posterior interosseous nerve as a consequence of plate osteosynthesis for fracture of both bone forearms. The patient had been operated on 23 years earlier and palsy occurred after a gap of 19 years. The most probable antecedent cause of the palsy was the use of a high-profile implant. The patient was treated by removal of the plate and tendon transfer. Copyright 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  17. Treatment of Intercondylar Humeral Fractures With 3D-Printed Osteosynthesis Plates.

    PubMed

    Shuang, Feng; Hu, Wei; Shao, Yinchu; Li, Hao; Zou, Hongxing

    2016-01-01

    The aim of the study was to evaluate the efficacy custom 3D-printed osteosynthesis plates in the treatment of intercondylar humeral fractures.Thirteen patients with distal intercondylar humeral fractures were randomized to undergo surgery using either conventional plates (n = 7) or 3D-printed plates (n = 6) at our institution from March to October 2014. Both groups were compared in terms of operative time and elbow function at 6 month follow-up.All patients were followed-up for a mean of 10.6 months (range: 6-13 months). The 3D-printing group had a significantly shorter mean operative time (70.6 ± 12.1 min) than the conventional plates group (92.3 ± 17.4 min). At the last follow-up period, there was no significant difference between groups in the rate of patients with good or excellent elbow function, although the 3D-printing group saw a slightly higher rate of good or excellent evaluations (83.1%) compared to the conventional group (71.4%).Custom 3D printed osteosynthesis plates are safe and effective for the treatment of intercondylar humeral fractures and significantly reduce operative time.

  18. Treatment of Intercondylar Humeral Fractures With 3D-Printed Osteosynthesis Plates

    PubMed Central

    Shuang, Feng; Hu, Wei; Shao, Yinchu; Li, Hao; Zou, Hongxing

    2016-01-01

    Abstract The aim of the study was to evaluate the efficacy custom 3D-printed osteosynthesis plates in the treatment of intercondylar humeral fractures. Thirteen patients with distal intercondylar humeral fractures were randomized to undergo surgery using either conventional plates (n = 7) or 3D-printed plates (n = 6) at our institution from March to October 2014. Both groups were compared in terms of operative time and elbow function at 6 month follow-up. All patients were followed-up for a mean of 10.6 months (range: 6–13 months). The 3D-printing group had a significantly shorter mean operative time (70.6 ± 12.1 min) than the conventional plates group (92.3 ± 17.4 min). At the last follow-up period, there was no significant difference between groups in the rate of patients with good or excellent elbow function, although the 3D-printing group saw a slightly higher rate of good or excellent evaluations (83.1%) compared to the conventional group (71.4%). Custom 3D printed osteosynthesis plates are safe and effective for the treatment of intercondylar humeral fractures and significantly reduce operative time. PMID:26817880

  19. Guidelines for surgical approaches for minimally invasive plate osteosynthesis in cats.

    PubMed

    Schmierer, Philipp A; Pozzi, Antonio

    2017-07-20

    Minimally invasive plate osteosynthesis (MIPO) is one of the most recent fixation techniques that embody the concept of biological osteosynthesis. Several studies evaluating MIPO in dogs have been published in the recent years. However, there are few clinical reports of MIPO in cats and no description of the surgical approaches. The purpose of our study was to describe the safe corridors for plate insertion in cats using the MIPO technique. The surgical approaches for the humerus, radius-ulna, femur and tibia were developed after reviewing the described techniques and surgical approaches for MIPO in dogs, while considering any relevant anatomical difference between dogs and cats. Following the MIPO approaches, the limbs were anatomically dissected and the relationship between proximal and distal positions of the implants and neurovascular structures was noted. The surgical approaches developed for the humerus and radius-ulna differed from what had been reported previously, because relevant anatomical differences were found between dogs and cats. Anatomical landmarks for safe plate application were described for all the major long bones in cats. No damage to vital structures following plate insertion was detected in the dissection. In this cadaveric study, we evaluated the safety of the surgical approaches for MIPO in cats. By respecting the anatomical landmarks described in this report, damage to the neurovascular structures can be avoided performing the MIPO technique in cats.

  20. Central acetabular fracture with dislocation treated by minimally invasive plate osteosynthesis.

    PubMed

    2015-06-01

    Central acetabular fractures with dislocation are usually the result of high-energy trauma, resulting in joint incongruity, and are frequently associated with other injuries. Open reduction and internal fixation has been the standard treatment for acetabular fractures, but it is associated with extensive surgical trauma, and complications such as haematoma formation, iatrogenic nerve injury, and heterotopic ossification. We present the case of a 63-year-old female who sustained a central acetabular fracture of the hip with dislocation as a result of an automobile collision. Closed reduction of the dislocation was performed, and the fracture was managed by minimally invasive plate osteosynthesis using a specially prepared plate. At 01 year postoperatively, radiographs showed the fracture to have been well-healed with good congruity of the joint. However, heterotopic ossification of the joint was noted. The technique allowed reduction of the fracture with minimal surgical trauma.

  1. Numerical simulations of human tibia osteosynthesis using modular plates based on Nitinol staples.

    PubMed

    Tarniţă, Daniela; Tarniţă, D N; Popa, D; Grecu, D; Tarniţă, Roxana; Niculescu, D; Cismaru, F

    2010-01-01

    The shape memory alloys exhibit a number of remarkable properties, which open new possibilities in engineering and more specifically in biomedical engineering. The most important alloy used in biomedical applications is NiTi. This alloy combines the characteristics of the shape memory effect and superelasticity with excellent corrosion resistance, wear characteristics, mechanical properties and a good biocompatibility. These properties make it an ideal biological engineering material, especially in orthopedic surgery and orthodontics. In this work, modular plates for the osteosynthesis of the long bones fractures are presented. The proposed modular plates are realized from identical modules, completely interchangeable, made of titanium or stainless steel having as connecting elements U-shaped staples made of Nitinol. Using computed tomography (CT) images to provide three-dimensional geometric details and SolidWorks software package, the three dimensional virtual models of the tibia bone and of the modular plates are obtained. The finite element models of the tibia bone and of the modular plate are generated. For numerical simulation, VisualNastran software is used. Finally, displacements diagram, von Misses strain diagram, for the modular plate and for the fractured tibia and modular plate ensemble are obtained.

  2. Bone plates for osteosynthesis - a systematic review of test methods and parameters for biomechanical testing.

    PubMed

    Schorler, Hendrik; Capanni, Felix; Gaashan, Muneer; Wendlandt, Robert; Jürgens, Christian; Schulz, Arndt-Peter

    2017-05-24

    Bone plates for osteosynthesis are subject to biomechanical testing for safety and regulatory purposes. International standards applicable for those devices are designed for bone plates used in the surgical fixation of the skeletal system but not necessarily for all device variants available. We intend to summarize the test methods and parameters presented in the literature to evaluate bone plates in a clinical environment, especially for modern anatomically shaped implants. We conducted a systematic review on published biomechanical studies for lower and upper extremities (clavicle, humerus, ulna, radius, metacarpal, femur, tibia, fibula, metatarsal). The search process led to the identification of 159 relevant articles containing 330 individual tests, which were analyzed concerning various test criteria including test methods and parameters per bone segment for static and dynamic loading tests, as well as number of cycles, chosen bone model and outcome variables. The biomechanical literature for bone plates is diverse, inconsistent and heterogeneous. Test methods are not commonly applied per bone plate location and test parameters are not uniformly specified and displayed. They vary in particular for bending and torsion tests as well as for the number of loading cycles for dynamic testing. Outcome variables are not commonly applied nor defined. Consequently this paper is the first in a planned chronological series of three to identify the need (this publication), to develop a systematic procedural approach (2. publication) and to apply the process exemplary on a bone plate sample (3. publication).

  3. [Proximal humeral fractures with angle-stable plate osteosynthesis--is everything better now?].

    PubMed

    Frangen, T M; Dudda, M; Martin, D; Arens, S; Greif, S; Muhr, G; Kälicke, T

    2007-02-01

    Proximal humeral fractures are common in the elderly as distribution peaks in the 6th and 7th decade. Optimal operative strategy regarding complex proximal humeral fractures is still being discussed controversely. Aim of the study was to evaluate implant associated problems of angle-stable implants in comparison to other established osteosynthetic methods. 198 patients with proximal humeral fractures were treated operatively from 2000 to 2004 in our department with a primary angle-stable plate osteosynthesis. 166 patients (98 females and 68 males) were followed up. Retrospectively we characterized the fractures type by using the NEER-classification and assessed the functional results with the CONSTANT-score (CS). Overall the average score was 73,4+/-20 points (range 22-94 points) compared to the non-affected side (90,8+/-8 points (46-100 points)). Patients with anatomical reduction of the fracture showed significant better results in the CS (p<0,05). Compared with other osteosynthetic methods, the use of angle-stable plate osteosynthesis showed no better functional results in the end. In 10,8% a humeral head necrosis occurred. 36 patients (21,6%) revealed a secondary loss of reduction with dislocation of the locking screws, regardless the angle-stable fixation. In 14 cases operative revision was necessary. Using angle-stable implants in the operative treatment of complex proximal humeral fractures good results can be achieved in most cases. Nevertheless, in comparison to alternative operative solutions, the results do not show significant better functional outcome. Important for good functional outcome was an exact anatomical reduction as a material independent variable rather than the decision to use more expensive angle-stable implants. Those, who can fulfil such surgical demands, achieve similar results for the patient, even without using angle-stable implants.

  4. Interindividual anatomical variations affect the plate-to-bone fit during osteosynthesis of distal radius fractures.

    PubMed

    Yoneda, Hidemasa; Iwatsuki, Katsuyuki; Hara, Tatsuya; Kurimoto, Shigeru; Yamamoto, Michiro; Hirata, Hitoshi

    2016-06-01

    We hypothesized that interindividual variations in the teardrop, which represents the volar projection of the lunate facet of the distal radius, cause unsatisfactory fitting of the volar locking plate to the bone. This can cause flexor tendon ruptures. Herein, we conducted a cross-sectional study and measured the ratio of teardrop height and the teardrop inclination angle as parameters of teardrop configuration for 200 standardized lateral radiographs (average age of the patients, 51 years). We also quantified the influence of the teardrop morphology by analyzing the fit of three locking plates to three radii with differing teardrop inclination angles using a three-dimensional computer-aided design system. The average ratios of the teardrop height and teardrop inclination angle were 0.42° (0.30-0.56°) and 28.8° (9.9-44.9°), respectively. The teardrop inclination angle was moderately correlated with age in men but not in women. In the plate-to-bone fit analyses, the fit of all the plates was significantly different between bones, with the configuration of the radius with the lowest teardrop inclination angle being the closest approximation to that of each plate. We demonstrated the interindividual variation in the shape of the teardrop and its influence on the fit of the volar plate, highlighting the importance of careful plate selection for achieving osteosynthesis of bones with a high teardrop inclination angle. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:953-960, 2016. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review

    PubMed Central

    Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-01-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950’s, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation. PMID:26889439

  6. Comparison of the effect on bone healing process of different implants used in minimally invasive plate osteosynthesis: limited contact dynamic compression plate versus locking compression plate

    PubMed Central

    Xue, Zichao; Xu, Haitao; Ding, Haoliang; Qin, Hui; An, Zhiquan

    2016-01-01

    Minimally invasive plate osteosynthesis (MIPO) has been widely accepted because of its satisfactory clinical outcomes. However, the implant construct that works best for MIPO remains controversial. Different plate designs result in different influence mechanisms to blood flow. In this study, we created ulnar fractures in 42 beagle dogs and fixed the fractures using MIPO. The dogs were randomly divided into two groups and were fixed with a limited contact dynamic compression plate (LC-DCP) or a locking compression plate (LCP). Our study showed that with MIPO, there was no significant difference between the LCP and the LC-DCP in terms of fracture fixation, bone formation, or mineralization. Combined with the previous literature, we inferred that the healing process is affected by the quality of fracture reduction more than plate selection. PMID:27885262

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

    PubMed

    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.

  8. Minimally invasive plate osteosynthesis in the treatment of proximal humeral fracture

    PubMed Central

    Leung, F.; Chan, C. F.; Chow, S. P.

    2006-01-01

    The management of fractures of the proximal shaft of the humerus has been evolving since the development of new techniques and new implants in recent years. It seems that this kind of fracture has an increasing incidence in the older, osteoporotic population. In the last 2 years, we have operated on 17 patients, with an average age of 65, who had proximal humeral shaft fractures treated by minimally invasive percutaneous osteosynthesis (MIPO) technique using the metaphyseal locking compression plate. Our study evaluated the surgical technique used and the outcome for these patients with regards to their range of movement and shoulder function. Our results showed that all the patients could achieve at least 140º of shoulder abduction in the first 6 months after the operation, except for three patients who had shoulder impingement. These patients had an average Constant score of 76.8. All fractures had bony union at 6 months, except one, which was probably due to poor reduction in the initial operation. Another complication that we encountered was radial nerve neuropraxia. The ways to prevent these complications are discussed. In conclusion, MIPO fixation using the metaphyseal locking compression plate is a good option for the management of proximal humeral shaft fractures. It provides early functional recovery, but we had to pay special attention to some of the surgical details in order to minimise complications. PMID:17033765

  9. [Outcomes of minimally invasive plate osteosynthesis (MIPO) with volar locking plates in distal radius fractures: A review].

    PubMed

    Liverneaux, P; Ichihara, S; Facca, S; Hidalgo Diaz, J J

    2016-12-01

    Minimally invasive plate osteosynthesis (MIPO) has been used in recent years to treat fractures of the distal radius with volar locking plates. Its advantages are the preservation of the pronator quadratus and good esthetics. The MIPO technique was described originally with two incisions: one distal transverse or longitudinal incision and one proximal longitudinal incision. The trend is now to use a single longitudinal incision less than 20mm long. Functional and radiological outcomes are comparable to those of conventional techniques. The MIPO technique is indicated for extra-articular and intra-articular fractures. Arthroscopy may be used concurrently in the latter case. When the distal radius fracture is associated with a proximal shaft fracture, a double incision is needed to introduce a longer plate. The relative contraindications of the MIPO technique are comminuted intra-articular fractures in osteoporotic elderly patients. If reduction is problematic, a larger incision can easily be made. Copyright © 2016 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  10. Comparing the In Vitro Stiffness of Straight-DCP, Wave-DCP, and LCP Bone Plates for Femoral Osteosynthesis

    PubMed Central

    Mariolani, José Ricardo Lenzi; Belangero, William Dias

    2013-01-01

    The objective of this study was to compare the Locking Compression Plate (LCP) with the more cost-effective straight-dynamic compression plate (DCP) and wave-DCPs by testing in vitro the effects of plate stiffness on different types of diaphyseal femur fractures (A, B, and C, according to AO classification). The bending structural stiffness of each plate was obtained from four-point bending tests according to ASTM F382-99(2008). The plate systems were tested by applying compression/bending in different osteosynthesis simulation models using wooden rods to simulate the fractured bone fragments. Kruskal-Wallis test showed no significant difference in the bending structural stiffness between the three plate models. Rank-transformed two-way ANOVA showed significant influence of plate type, fracture type, and interaction plate versus fracture on the stiffness of the montages. The straight-DCP produced the most stable model for types B and C fractures, which makes its use advantageous for complex nonosteoporotic fractures that require minimizing focal mobility, whereas no difference was found for type A fracture. Our results indicated that DCPs, in straight or wave form, can provide adequate biomechanical properties for fixing diaphyseal femoral fractures in cases where more modern osteosynthesis systems are cost restrictive. PMID:24959354

  11. Long Volar Plating for Metadiaphyseal Fractures of Distal Radius: Study Comparing Minimally Invasive Plate Osteosynthesis versus Conventional Approach.

    PubMed

    Pire, Emilie; Hidalgo Diaz, Juan José; Salazar Botero, Santiago; Facca, Sybille; Liverneaux, Philippe A

    2017-08-01

    Background  Minimally invasive plate osteosynthesis (MIPO) has been used in wrist surgery for several years. The purpose of this retrospective study was to compare clinical and radiologic outcomes of MIPO technique with those of a conventional approach in the treatment of metadiaphyseal distal radius fracture by long volar plating. Materials and Methods  Our series consisted of 32 fractures in 31 patients, mean age 63.9 years, including 16 men and 15 women. MIPO technique was used in 15 wrists (group 1) and conventional approach (> 60 mm of skin incision) in 17 wrists (group 2). In group 1, a long volar plate was inserted under pronator quadratus through a 15- to 30-mm distal incision then fixed to the epiphysis of the distal radius. Then, through a 15- to 30-mm proximal incision, the plate was fixed to the diaphysis of the radius, thus reducing the fracture. Results  In group 1, mean distal incision size was 23.5 and 16.9 mm for proximal one. Mean total scar size (sum of both distal and proximal incisions) was 40.0 mm in group 1 and 84.1 mm in group 2. Mean tourniquet time was 58.4 minutes in group 1 and 68.9 minutes in group 2. At latest follow-up, no significant difference was noted in both the groups concerning pain, quick-DASH score, grip strength, ROM, and radiologic data. One extensor pollicis longus rupture treated by tendon transfer was done in group 1. Conclusion  The MIPO technique for metadiaphyseal fractures of the distal radius by long volar plating has cosmetic and economic advantages compared with the conventional approach. Conversion to conventional approach is possible at any time in case of technical difficulties. Level of Evidence  III.

  12. Treatment of distal intraarticular tibial fractures: A biomechanical evaluation of intramedullary nailing vs. angle-stable plate osteosynthesis.

    PubMed

    Kuhn, Sebastian; Greenfield, Julia; Arand, Charlotte; Jarmolaew, Andrey; Appelmann, Philipp; Mehler, Dorothea; Rommens, Pol M

    2015-10-01

    In factures of the distal tibia with simple articular extension, the optimal surgical treatment remains debatable. In clinical practice, minimally invasive plate osteosynthesis and intramedullary nailing are both routinely performed. Comparative biomechanical studies of different types of osteosynthesis of intraarticular distal tibial fractures are missing due to the lack of an established model. The goal of this study was first to establish a biomechanical model and second to investigate, which are the biomechanical advantages of angle-stable plate osteosynthesis and intramedullary nailing of distal intraarticular tibial fractures. Seven 4(th) generation biomechanical composite tibiae featuring an AO 43-C2 type fracture were implanted with either osteosynthesis technique. After primary lag screw fixation, 4-hole Medial Distal Tibial Plate (MDTP) with triple proximal and quadruple distal screws or intramedullary nailing with double proximal and triple 4.0mm distal interlocking were implanted. The stiffness of the implant-bone constructs and interfragmentary movement were measured under non-destructive axial compression (350 and 600 N) and torsion (1.5 and 3Nm). Destructive axial compression testing was conducted with a maximal load of up to 1,200 N. No overall superior biomechanical results can be proclaimed for either implant type. Intramedullary nailing displays statistically superior results for axial loading in comparison to the MDTP. Torsional loading resulted in non-statistically significant differences for the two-implant types with higher stability in the MDTP group. From a biomechanical view, the load sharing intramedullary nail might be more forgiving and allow for earlier weight bearing in patients with limited compliance.

  13. Resorbable plate osteosynthesis of sagittal split osteotomies with major bone movement.

    PubMed

    Landes, Constantin A; Kriener, Susanne

    2003-05-01

    . Microscopy showed a chronic foreign body reaction. Two patients (11 percent) developed a sterile fistula 3 and 4 months after surgery, draining implant debris. Here, the biopsies showed a granulocytic infiltrate that subsided clinically after excisional biopsy. The assignment of MacroSorb plates followed by PolyMax plates was done in an otherwise unchanged treatment protocol. Comparison of the number of patients in each group with stable osteosyntheses and regular healing showed no significant differences by Fisher's exact test (p = 0.1516); therefore, the authors focused on the combined results for both treatments. The current osteosynthesis systems showed sufficient stability for mandibular fixation after sagittal split osteotomy and repositioning more than 10 mm distant when two plates were applied to each side; however, 27 percent of patients had complications, including relapses. Disadvantages were the cost, breakability, diameter, and need to place the screws vertically to the plate, necessitating a bent instrument or transbuccal incisions.

  14. Minimally invasive plate osteosynthesis for humeral shaft fractures: are results reproducible?

    PubMed

    Concha, Juan M; Sandoval, Alejandro; Streubel, Philipp N

    2010-12-01

    Minimally invasive plate osteosynthesis (MIPO) has been advocated as a safe approach to humeral shaft fracture management. We evaluated the reproducibility of this technique in a regional hospital. Thirty-five patients underwent MIPO of humerus shaft fractures. Fifteen patients had an open fracture, six a preoperative radial nerve palsy, and nine a concomitant thoracic, musculoskeletal or vascular injury. At an average 12-month follow-up, 91% of fractures healed after a mean of 12 weeks (range, 8-16). Two infections occurred. Final alignment averaged 4° of varus (range, 5° of valgus to 20° of varus). Active elbow ROM averaged 114° (range, 60-135°) and was less than 100° in nine elbows. Five of six preoperative radial nerve injuries recovered spontaneously. Healing and infection rates in this study are consistent with those reported in the literature. Lower elbow ROM and higher fracture angulation at healing were nevertheless found. MIPO is technically demanding and requires adequate intraoperative imaging and surgical experience in order to obtain adequate fracture alignment. Brachialis muscle scarring and inadequate postoperative rehabilitation may be involved in limited elbow range of motion.

  15. Minimally invasive plate osteosynthesis for humeral shaft fractures: are results reproducible?

    PubMed Central

    Concha, Juan M.; Sandoval, Alejandro

    2009-01-01

    Minimally invasive plate osteosynthesis (MIPO) has been advocated as a safe approach to humeral shaft fracture management. We evaluated the reproducibility of this technique in a regional hospital. Thirty-five patients underwent MIPO of humerus shaft fractures. Fifteen patients had an open fracture, six a preoperative radial nerve palsy, and nine a concomitant thoracic, musculoskeletal or vascular injury. At an average 12-month follow-up, 91% of fractures healed after a mean of 12 weeks (range, 8–16). Two infections occurred. Final alignment averaged 4° of varus (range, 5° of valgus to 20° of varus). Active elbow ROM averaged 114° (range, 60–135°) and was less than 100° in nine elbows. Five of six preoperative radial nerve injuries recovered spontaneously. Healing and infection rates in this study are consistent with those reported in the literature. Lower elbow ROM and higher fracture angulation at healing were nevertheless found. MIPO is technically demanding and requires adequate intraoperative imaging and surgical experience in order to obtain adequate fracture alignment. Brachialis muscle scarring and inadequate postoperative rehabilitation may be involved in limited elbow range of motion. PMID:19844708

  16. Treatment of Humeral Shaft Fractures: Minimally Invasive Plate Osteosynthesis Versus Open Reduction and Internal Fixation

    PubMed Central

    Esmailiejah, Ali Akbar; Abbasian, Mohammad Reza; Safdari, Farshad; Ashoori, Keyqobad

    2015-01-01

    Background: The optimal technique for operative fixation of humeral shaft fractures remains controversial and warrants research. Objectives: The purpose of the current study was to compare the functional and clinical outcomes of conventional open reduction and internal fixation (ORIF) with minimally invasive plate osteosynthesis (MIPO) in patients with fractures in two-third distal humeral shaft. Patients and Methods: In the current prospective case-control study, 65 patients with humeral shaft fractures were treated using ORIF (33 patients) or MIPO (32 patients). Time of surgery, time of union, incidence of varus deformity and complications were compared between the two groups. Also, the university of California-Los Angeles (UCLA) shoulder rating scale and Mayo Elbow performance score (MEPS) were used to compare the functional outcomes between the two groups. Results: The median of union time was shorter in the MIPO group (4 months versus 5 months). The time of surgery and functional outcomes based on the UCLA and MEPS scores were the same. The incidence of varus deformity was more than 5° and was higher and the incidence of nonunion, infection and iatrogenic radial nerve injury were lower in the MIPO group; however, the differences were not significant. Conclusions: Due to the shorter union time, to some extent less complication rate and comparable functional and clinical results, the authors recommend to use the MIPO technique in treating the mid-distal humeral shaft fracture. PMID:26543844

  17. Minimally Invasive Plating Osteosynthesis in the Treatment of Humeral Shaft Fractures: A Meta-Analysis.

    PubMed

    Zhang, Quan; Sun, Ning; Huang, Qiang; Zhu, Shiwen; Wu, Xinbao

    2017-04-01

    Whether minimally invasive plating osteosynthesis (MIPO) or other operative interventions is superior in the treatment of humeral shaft fractures remains controversial. Therefore, we conducted a meta-analysis to quantitatively compare the clinical outcomes of MIPO and other operative interventions in the treatment of humeral shaft fractures. Pubmed, Embase, and Web of Science were systematically searched to identify all available studies comparing clinical outcomes between patients receiving MIPO and other operative interventions. The weight mean difference (WMD) was pooled to compare the operative time, union time, University of California, Los Angeles (UCLA) score, and Mayo elbow performance index (MEPI).The risk ratio (RR) was pooled to compare the union rate, and incidence of complications. Pooled estimates were calculated by using a fixed-effects model or a randomized-effects model, according to the heterogeneity among studies. Nine studies were included in this meta-analysis. Our results suggest that both MIPO and other operative interventions can achieve similar union time, UCLA score, MEPI, and union rate. However, MIPO is associated with better outcomes including shorter operation time, and lower incidence of radial nerve injury. Evidence from this meta-analysis demonstrated that, MIPO is effective but safer than other operative interventions in the treatment of humeral shaft fracture. However, due to the potential limitations in this meta-analysis, randomized controlled trials with larger sample sizes using appropriate blinding methods are needed to confirm these findings.

  18. Technical Errors May Affect Accuracy of Torque Limiter in Locking Plate Osteosynthesis.

    PubMed

    Savin, David D; Lee, Simon; Bohnenkamp, Frank C; Pastor, Andrew; Garapati, Rajeev; Goldberg, Benjamin A

    2016-01-01

    In locking plate osteosynthesis, proper surgical technique is crucial in reducing potential pitfalls, and use of a torque limiter makes it possible to control insertion torque. We conducted a study of the ways in which different techniques can alter the accuracy of torque limiters. We tested 22 torque limiters (1.5 Nm) for accuracy using hand and power tools under different rotational scenarios: hand power at low and high velocity and drill power at low and high velocity. We recorded the maximum torque reached after each torque-limiting event. Use of torque limiters under hand power at low velocity and high velocity resulted in significantly (P < .0001) different mean (SD) measurements: 1.49 (0.15) Nm and 3.73 (0.79) Nm. Use under drill power at controlled low velocity and at high velocity also resulted in significantly (P < .0001) different mean (SD) measurements: 1.47 (0.14) Nm and 5.37 (0.90) Nm. Maximum single measurement obtained was 9.0 Nm using drill power at high velocity. Locking screw insertion with improper technique may result in higher than expected torque and subsequent complications. For torque limiters, the most reliable technique involves hand power at slow velocity or drill power with careful control of insertion speed until 1 torque-limiting event occurs.

  19. Plate on plate osteosynthesis for the treatment of nonhealed periplate fractures.

    PubMed

    Arealis, Georgios; Nikolaou, Vassilios S; Lacon, Andrew; Ashwood, Neil; Hamlet, Mark

    2014-01-01

    Purpose. The purpose of this paper is to present our technique for the treatment of periplate fractures. Methods. From 2009 to 2012 we treated three patients. In all cases the existing plate was left and the new one placed over the existing. Locking screws were placed through both plates. The other screws in the new plate were used as best suited the fracture. Results. In all cases less than 6 months had passed between fractures. None of the original fractures had healed. Mean followup was 2 years. All fractures proceeded to union within 7 months. No complications were recorded. All the patients returned to their normal activities and were satisfied with the results of their treatment. Conclusion. Our plate on plate technique is effective for the treatment of periplate fractures. A solid fusion can be achieved at the new fracture site without disturbing the previous fixation.

  20. Plate on Plate Osteosynthesis for the Treatment of Nonhealed Periplate Fractures

    PubMed Central

    Nikolaou, Vassilios S.; Lacon, Andrew; Ashwood, Neil; Hamlet, Mark

    2014-01-01

    Purpose. The purpose of this paper is to present our technique for the treatment of periplate fractures. Methods. From 2009 to 2012 we treated three patients. In all cases the existing plate was left and the new one placed over the existing. Locking screws were placed through both plates. The other screws in the new plate were used as best suited the fracture. Results. In all cases less than 6 months had passed between fractures. None of the original fractures had healed. Mean followup was 2 years. All fractures proceeded to union within 7 months. No complications were recorded. All the patients returned to their normal activities and were satisfied with the results of their treatment. Conclusion. Our plate on plate technique is effective for the treatment of periplate fractures. A solid fusion can be achieved at the new fracture site without disturbing the previous fixation. PMID:24967127

  1. Establishment of a Segmental Femoral Critical-size Defect Model in Mice Stabilized by Plate Osteosynthesis

    PubMed Central

    Manassero, Mathieu; Decambron, Adeline; Huu Thong, Bui Truong; Viateau, Véronique; Bensidhoum, Morad; Petite, Hervé

    2016-01-01

    The use of tissue-engineered bone constructs is an appealing strategy to overcome drawbacks of autografts for the treatment of massive bone defects. As a model organism, the mouse has already been widely used in bone-related research. Large diaphyseal bone defect models in mice, however, are sparse and often use bone fixation which fills the bone marrow cavity and does not provide optimal mechanical stability. The objectives of the current study were to develop a critical-size, segmental, femoral defect in nude mice. A 3.5-mm mid-diaphyseal femoral ostectomy (approximately 25% of the femur length) was performed using a dedicated jig, and was stabilized with an anterior located locking plate and 4 locking screws. The bone defect was subsequently either left empty or filled with a bone substitute (syngenic bone graft or coralline scaffold). Bone healing was monitored noninvasively using radiography and in vivo micro-computed-tomography and was subsequently assessed by ex vivo micro-computed-tomography and undecalcified histology after animal sacrifice, 10 weeks postoperatively. The recovery of all mice was excellent, a full-weight-bearing was observed within one day following the surgical procedure. Furthermore, stable bone fixation and consistent fixation of the implanted materials were achieved in all animals tested throughout the study. When the bone defects were left empty, non-union was consistently obtained. In contrast, when the bone defects were filled with syngenic bone grafts, bone union was always observed. When the bone defects were filled with coralline scaffolds, newly-formed bone was observed in the interface between bone resection edges and the scaffold, as well as within a short distance within the scaffold. The present model describes a reproducible critical-size femoral defect stabilized by plate osteosynthesis with low morbidity in mice. The new load-bearing segmental bone defect model could be useful for studying the underlying mechanisms in bone

  2. Total Hip Arthroplasty Using a Short-Stemmed Femoral Component in the Presence of a Long Dynamic Condylar Screw Osteosynthesis Plate

    PubMed Central

    Buttaro, Martin; Piuzzi, Nicolas; Comba, Fernando; Zanotti, Gerardo; Piccaluga, Francisco

    2014-01-01

    We present a potential indication of a short-stemmed femoral component in a patient with multiple comorbidities presenting with hip posttraumatic osteoarthritis and a long dynamic condylar screw osteosynthesis plate. Removal of the plate and implantation of a long stem would have been related to a much longer operative time and potential local or systemic complications. PMID:25349758

  3. Is cannulated-screw fixation an alternative to plate osteosynthesis in open book fractures? A biomechanical analysis.

    PubMed

    Lázaro Gonzálvez, Ángel; Martínez Reina, Javier; Cano Luis, Pedro; Jiménez Baquero, Juan; Sueiro Fernández, José; Giráldez Sánchez, Miguel Ángel

    2016-09-01

    The current biomechanical work compares the symphyseal and sacroiliac stability obtained with two systems of bone osteosynthesis. The two methods of fixation compared were the 6-hole suprapubic non-locked plate and pubic fixation with two cannulated screws, a novel technique that can be applied percutaneously in the clinical practice. The aim of this study was to examine the validity of the use of two-cannulated-screws osteosynthesis in order to minimize the secondary effects of open fixation, especially in patients in whom an open reduction is contraindicated. A biomechanical study was designed in 9 fresh, human pelvis specimens, simulating an AO B1.1 type injury, using both fixation systems sequentially in each specimen. In both parts of the test, the specimens were subjected to an axial load of 300N. Displacements and rotations between the different pelvic elements were studied by means of a discrete set of points. The absence of differences between the two systems has been set as the null hypothesis. There were significant differences in favor of the cross-cannulated screws in most of the displacements measured at the pubic symphysis and sacroiliac joint. Fixation of the AO B1.1 type fractures with cross cannulated screws restores the biomechanical behavior of the pubic symphysis, obtaining better stability than fixation with the 6-hole non-locked plate. To date, no comparative, biomechanical studies have been conducted with these two systems of osteosynthesis. This study demonstrates that cross-cannulated screws fixation of the pubic symphysis in AO B1.1 pelvic fractures should be considered as an alternative to the conventional plating system. © 2016 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2017-06-01

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

  5. Evaluation of locked plate in the osteosynthesis of fractures in osteoporotic bones.

    PubMed

    Oboirien, Muhammad; Agbo, Stephen Patrick; Ajiboye, Lukman Olalekan

    2017-01-01

    The use of conventional dynamic compression plates (DCPs) in osteoporotic bones is associated with higher chances of implant failure. The advent and use of locking combi-plates have ensured a stable construct during osteosynthesis of fractures in osteoporotic bones. The study aims to assess the outcome of use of locking combi-plates in the management of fractures in osteoporotic bones in our environment. Cases of patients with nonunion and localized osteoporosis from January 2014 to December 2014 that were managed with locked combi-plates were reviewed. Outcome was assessed by time to healing, stability of implant construct after 6 and 12 months. There were 10 patients with mean age of 47.4 ± 12.63 years. There were 9 males and 1 female, and road traffic crashes were the mechanism of injury in 90% (n = 9) and gunshot injuries in 10% (n = 1). Atrophic nonunion was the most common indication for osteosynthesis with 80%, followed by fibrous nonunion with 10.0%. The humerus was the most common long bone involved with 50%. Locked broad DCP was used in 62.5%, and the duration between initial injury and surgery was 6 and 48 months, with an average of 17.5 months. The outcome was such that 90% healed after 12 months on follow-up while one case had the implant backing out and delay union at 6 months. The use of locked plate in the management of nonunion in the presence of osteoporosis ensures stable fixation construct and healing. Contexte: L'utilisation de plaques de compression dynamiques conventionnelles dans les os ostéoporotiques est associée à des chances plus élevées de défaillance de l'implant. L'avènement et l'utilisation de combi-plaques de verrouillage ont assuré une construction stable lors de l'ostéosyntheis de fractures dans les os ostéoporotiques. Objectifs: L'étude vise à évaluer le résultat de l'utilisation de combi-plaques de verrouillage dans la gestion des fractures dans les os ostéoporotiques dans notre environnement. Méthodologie: Les

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

    PubMed Central

    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

  7. External Fixator for Maintaining Reduction Before Volar Plating: A Simple Treatment Method for Association of Osteosynthesis Type C3 Distal Radius Fracture.

    PubMed

    Tsai, Chun-Hao; Hsu, Chin-Jung; Wang, Ta-I; Fong, Yi-Chin; Hsu, Horng-Chaung; Lin, Tsung-Li

    2016-03-01

    Volar plating for Association of Osteosynthesis type C3 distal radius fractures involves more time and more radiation exposure because it is extremely difficult to simultaneously maintain the reduction and restore the congruity of the articular surface. The authors present a technique of maintaining the acceptable reduction by using an external fixator followed by open volar plating for restoring articular congruity. A consecutive series of 96 Association of Osteosynthesis type C3 distal radius fractures treated with the technique were retrospectively reviewed between January 2004 and December 2012. The technique makes surgery simpler and more effective, and reduces radiation exposure.

  8. Minimally Invasive Osteosynthesis with a Bridge Plate Versus a Functional Brace for Humeral Shaft Fractures: A Randomized Controlled Trial.

    PubMed

    Matsunaga, Fabio Teruo; Tamaoki, Marcel Jun Sugawara; Matsumoto, Marcelo Hide; Netto, Nicola Archetti; Faloppa, Flavio; Belloti, Joao Carlos

    2017-04-05

    Nonoperative treatment has historically been considered the standard for fractures of the shaft of the humerus. Minimally invasive bridge-plate osteosynthesis for isolated humeral shaft fractures has been proven to be a safe technique, with good and reproducible results. This study was designed to compare clinical and radiographic outcomes between patients who had been treated with bridge plate osteosynthesis and those who had been managed nonoperatively with a functional brace. A prospective randomized trial was designed and included 110 patients allocated to 1 of 2 groups: surgery with a bridge plate or nonoperative treatment with a functional brace. The primary outcome was the Disabilities of the Arm, Shoulder and Hand (DASH) score at 6 months. The score on the Short Form-36 (SF-36) life-quality questionnaire, complications of treatment, Constant-Murley score for the shoulder, pain level, and radiographic results were assessed as secondary outcomes. Participants were assessed at 2 weeks; 1, 2, and 6 months; and 1 year after the interventions. The mean DASH score of the bridge plate group was statistically superior to that of the functional brace group (mean scores, 10.9 and 16.9, respectively; p = 0.046) only at 6 months. The bridge plate group also had a significantly more favorable nonunion rate (0% versus 15%) and less mean residual angular displacement seen on the anteroposterior radiograph (2.0° versus 10.5°) (both p < 0.05). No difference between the groups was detected with regard to the SF-36 score, pain level, Constant-Murley score, or angular displacement seen on the lateral radiograph. This trial demonstrates that, compared with functional bracing, surgical treatment with a bridge plate has a statistically significant advantage, of uncertain clinical benefit, with respect to self-reported outcome (DASH score) at 6 months, nonunion rate, and residual deformity in the coronal plane as seen on radiographs. Therapeutic Level I. See Instructions for

  9. Callus Formation and Mineralization after Fracture with Different Fixation Techniques: Minimally Invasive Plate Osteosynthesis versus Open Reduction Internal Fixation

    PubMed Central

    Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

    Minimally invasive plate osteosynthesis(MIPO) has been considered as an alternative for fracture treatment. Previous study has demonstrated that MIPO technique has the advantage of less soft tissue injury compared with open reduction internal fixation (ORIF). However, the comparison of callus formation and mineralization between two plate osteosynthesis methods remains unknown. In this experiment, ulna fracture model was established in 42 beagle dogs. The fractures underwent reduction and internal fixation with MIPO or ORIF. Sequential fluorescent labeling and radiographs were applied to determine new callus formation and mineralization in two groups after operation. At 4, 8 and 12 weeks postoperatively, the animals were selected to be sacrificed and the ulna specimens were analyzed by Micro-CT. The sections were also treated with Masson staining for histological evaluation. More callus formation was observed in MIPO group in early stage of fracture healing. The fracture union rate has no significant difference between two groups. The results indicate that excessive soft tissue stripping may impact early callus formation. As MIPO technique can effectively reduce soft tissue injury with little incision, it is considered to be a promising alternative for fracture fixation. PMID:26444295

  10. Minimally invasive percutaneous plate osteosynthesis for ankle fractures: a prospective observational cohort study.

    PubMed

    Pires, Robinson Esteves Santos; Mauffrey, Cyril; de Andrade, Marco Antônio Percope; Figueiredo, Leonardo Brandão; Giordano, Vincenzo; Belloti, João Carlos; dos Reis, Fernando Baldy

    2014-10-01

    The gold standard for the surgical management of ankle fractures is through open reduction and internal fixation. The rate of wound problems has been reported to be as high as 18%, especially in patients with poor vascular supply or in diabetics. Minimally invasive percutaneous plate osteosynthesis (MIPPO) has been described as a potential solution for these patients. This is a prospective observational cohort study. From October 2009 to February 2010, and following ethical approval of our research, adult patients admitted at our level I trauma center with a closed lateral malleolar displaced unstable fracture (Lauge-Hansen supination-external rotation) with or without a medial-sided injury and patients with an undisplaced fracture associated with medial clear space opening on external rotation stress radiographs were recruited and managed using MIPPO technique. All patients were followed up for a minimum of 12 months post-surgery (12-20 with a mean of 16.5 months). Trauma mechanism, comorbidities, classifications, trauma-surgery interval, image intensifier duration, surgery duration, complications, and function American Orthopaedic Foot and Ankle Society (AOFAS) were analyzed. Thirty-two patients were recruited of which 20 fulfilled the inclusion criteria (16 females, 4 males) and were available for follow-up. Ten fractures (50%) were classified as 44-B1, 7 fractures (35%) as 44-B2, and 3 fractures (15%) as 44-B3 according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association classification (100% were supination-external rotation injuries). At 8 weeks post-surgery, all fractures had healed. The duration of surgery ranged between 15 and 73 min (average 32.8) from skin incision to closure. There were 2 complications (1 malunion and 1 skin necrosis requiring implant removal). At 12-month follow-up, AOFAS average was 88.3 (72-100 standard deviation of 6.8 points). MIPPO technique proved to be a viable option for lateral malleolar fracture

  11. Retrograde Tibial Nailing: a minimally invasive and biomechanically superior alternative to angle-stable plate osteosynthesis in distal tibia fractures

    PubMed Central

    2014-01-01

    Background Currently, antegrade intramedullary nailing and minimally invasive plate osteosynthesis (MIPO) represent the main surgical alternatives in distal tibial fractures. However, neither choice is optimal for all bony and soft tissue injuries. The Retrograde Tibial Nail (RTN) is a small-caliber prototype implant, which is introduced through a 2-cm-long incision at the tip of the medial malleolus with stab incisions sufficient for interlocking. During this project, we investigated the feasibility of retrograde tibial nailing in a cadaver model and conducted biomechanical testing. Methods Anatomical implantations of the RTN were carried out in AO/OTA 43 A1-3 fracture types in three cadaveric lower limbs. Biomechanical testing was conducted in an AO/OTA 43 A3 fracture model for extra-axial compression, torsion, and destructive extra-axial compression. Sixteen composite tibiae were used to compare the RTN against an angle-stable plate osteosynthesis (Medial Distal Tibial Plate, Synthes®). Statistical analysis was performed by Student's t test. Results Retrograde intramedullary nailing is feasible in simple fracture types by closed manual reduction and percutaneous reduction forceps, while in highly comminuted fractures, the use of a large distractor can aid the reduction. Biomechanical testing shows a statistically superior stability (p < 0.001) of the RTN during non-destructive axial loading and torsion. Destructive extra-axial compression testing resulted in failure of all plate constructs, while all RTN specimens survived the maximal load of 1,200 N. Conclusions The prototype retrograde tibial nail meets the requirements of maximum soft tissue protection by a minimally invasive surgical approach with the ability of secure fracture fixation by multiple locking options. Retrograde tibial nailing with the RTN is a promising concept in the treatment of distal tibia fractures. PMID:24886667

  12. Is minimally invasive application by intramedullary osteosynthesis in comparison with volar plating real benefit in the treatment of distal radius fractures?

    PubMed Central

    Vlček, Martin; Jaganjac, Edib; Pech, Jan; Jonáš, David; Kebrle, Radek

    2014-01-01

    Purpose of the study: Can minimally invasive intramedullary osteosynthesis of distal radius fractures provide better therapeutic results than multidirectional locking plates. Retrospective study of 68 patients operated for distal radius fractures, 18 were treated with intramedullary X-screw (XSCR) fixation and 50 with the multidirectional angle-stable plate system (APTUS). The evaluation at 1-year follow-up included functional status of the wrist and hand, and radiographic findings. In the XSCR group, the functional outcomes of the treated extremity did not achieve values comparable with those of the uninjured side in any of the parameters measured. The radiographic findings did not meet the requirements of successful healing due to failure to restore an anatomical volar tilt in 22.2% cases. In the APTUS group, comparable values of the injured and the uninjured side were achieved in radial deviation, ulnar deviation, pronation, supination and grip strength. The radiographic criteria of successful healing were met by all fractures treated by locking plate osteosynthesis. Implant migration associated with secondary displacement of bone fragments was recorded in 33.3 % of the XSCR patients and only in 4.0 % of the APTUS patients. The overall evaluation show that intramedullary osteosynthesis does not produce better treatment outcomes compared with plate osteosynthesis in indicated types of fractures. PMID:24856379

  13. Periprosthetic Vancouver type B1 and C fractures treated by locking-plate osteosynthesis: fracture union and reoperations in 60 consecutive fractures.

    PubMed

    Froberg, Lonnie; Troelsen, Anders; Brix, Michael

    2012-12-01

    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 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. From 2002 through 2011, 58 consecutive patients (60 fractures) with low-energy PFF around or below a stable femoral stem, i.e. Vancouver type B1 and C fractures, underwent osteosynthesis with a locking plate. All patients had a total hip replacement (THR). They were followed up clinically and radiographically, with 6 weeks between visits, until fracture union or until death. Fracture union was evaluated 6 months postoperatively. At a median follow-up time of 23 (0-121) months after PFF, 8 patients (8 fractures) had been reoperated due either to infection (n = 4), failure of fixation (n = 3), or loosening of the femoral stem (n = 1). All the patients who had been followed up for at least 6 months-and who did not undergo reoperation or die-went on to fracture union (n = 43). Locking-plate osteosynthesis of periprosthetic Vancouver type B1 and C fractures gives good results regarding fracture union. It appears that spanning of the prosthesis to avoid stress-rising areas is important for successful treatment. Infection is the major cause of failure.

  14. Novel management of distal tibial and fibular fractures with Acumed fibular nail and minimally invasive plating osteosynthesis technique

    PubMed Central

    Wang, Tie-Jun; Ju, Wei-Na; Qi, Bao-Chang

    2017-01-01

    Abstract Rationale: Anatomical characteristics, such as subcutaneous position and minimal muscle cover, contribute to the complexity of fractures of the distal third of the tibia and fibula. Severe damage to soft tissue and instability ensure high risk of delayed bone union and wound complications such as nonunion, infection, and necrosis. Patient concerns: This case report discusses management in a 54-year-old woman who sustained fractures of the distal third of the left tibia and fibula, with damage to overlying soft tissue (swelling and blisters). Plating is accepted as the first choice for this type of fracture as it ensures accurate reduction and rigid fixation, but it increases the risk of complications. Diagnosis: Closed fracture of the distal third of the left tibia and fibula (AO: 43-A3). Interventions: After the swelling was alleviated, the patient underwent closed reduction and fixation with an Acumed fibular nail and minimally invasive plating osteosynthesis (MIPO), ensuring a smaller incision and minimal soft-tissue dissection. Outcomes: At the 1-year follow-up, the patient had recovered well and had regained satisfactory function in the treated limb. The Kofoed score of the left ankle was 95. Lessons: Based on the experience from this case, the operation can be undertaken safely when the swelling has been alleviated. The minimal invasive technique represents the best approach. Considering the merits and good outcome in this case, we recommend the Acumed fibular nail and MIPO technique for treatment of distal tibial and fibular fractures. PMID:28328865

  15. Fixator-assisted Technique Enables Less Invasive Plate Osteosynthesis in Medial Opening-wedge High Tibial Osteotomy: A Novel Technique.

    PubMed

    Lee, Dong Hoon; Ryu, Keun Jung; Kim, Jae Hwa; Kim, Hae Hwa; Soung, Sahyun; Shin, Soowan

    2015-10-01

    Opening-wedge high tibial osteotomy is a well-established procedure in the management of medial osteoarthritis of the knee and correction of proximal tibia vara. Recently, surgical approaches using less invasive plate osteosynthesis have been used with the goal of minimizing complications from more extensive soft tissue exposures. However, to our knowledge, less invasive fixator-assisted plate osteosynthesis has not been tested in the setting of opening-wedge high tibial osteotomy. The purposes of this study were (1) to assess the complications associated with use of a fixator-assisted less invasive plate osteosynthesis technique to stabilize an opening-wedge high tibial osteotomy in the treatment of proximal tibial vara; and (2) to evaluate the ability of this technique to achieve correction of the proximal tibial deformity and achieve osseous union. From June 2011 to June 2013, a total of 157 limbs in 83 patients who underwent fixator-assisted high tibial osteotomy for (1) idiopathic genu vara; or (2) osteoarthritis of the knee with proximal tibia vara were initially enrolled. Of these, eight limbs (5%) were excluded on the way; thus, 149 limbs in 77 patients were evaluated. During the period in question, no other techniques were used for proximal tibial osteotomy. The surgical procedures included less preparation of soft tissue, proximal tibial osteotomy, application of a temporary external fixator, correction of alignment, and final fixation with the help of an external fixator. Complications were assessed by chart review and the alignment in both coronal and sagittal planes was compared pre- and postoperatively. Radiographic review to confirm osseous union and alignment was performed by two of the authors not involved in clinical care of the patient. Delayed union was described as union occurring later than 4 months. Thirty limbs out of 149 tibiae (20%) showed complications, all of which were resolved without leaving any sequela. Twenty-seven limbs out of 149

  16. Elastically suspending the screw holes of a locked osteosynthesis plate can dampen impact loads.

    PubMed

    Capanni, Felix; Hansen, Kirk; Fitzpatrick, Daniel C; Madey, Steven M; Bottlang, Michael

    2015-06-01

    Impact damping by elastic fixation is a principal engineering strategy to increase the durability of load-bearing structures exposed to prolonged dynamic loading. This biomechanical study evaluated axial impact damping provided by a novel dynamic locking plate. In this design, locking screw holes are elastically suspended within a silicone envelope inside the locking plate. Axial impact damping was assessed for 3 distinct fixation constructs applied to bridge a 10-mm fracture gap of a femoral diaphysis surrogate: a standard locking plate, a dynamic locking plate, and an Ilizarov ring fixator. First, the 3 fixation constructs were characterized by determining their axial stiffness. Subsequently, constructs were subjected to a range of axial impact loads to quantify damping of force transmission. Compared with standard locked plating constructs, dynamic plating constructs were 58% less stiff (P < .01) and Ilizarov constructs were 88% less stiff (P < .01). Impact damping correlated inversely with construct stiffness. Compared with standard plating, dynamic plating constructs and Ilizarov constructs dampened the transmission of impact loads by up to 48% (P < .01) and 74% (P < .01), respectively. In conclusion, lower construct stiffness correlated with superior damping of axial impact loads. Dynamic locking plates provide significantly greater impact damping compared with standard locking plates.

  17. Case-Match Controlled Comparison of Minimally Invasive Plate Osteosynthesis and Intramedullary Nailing for the Stabilization of Humeral Shaft Fractures.

    PubMed

    Davies, Gareth; Yeo, Gerald; Meta, Mahendrakumar; Miller, David; Hohmann, Erik; Tetsworth, Kevin

    2016-11-01

    To compare the risk of major complications after either minimally invasive plate osteosynthesis (MIPO) or intramedullary nailing (IMN) of humeral shaft fractures. Retrospective, case-match controlled study. A major metropolitan tertiary referral trauma center in Australia. Thirty patients with fractures of the humeral shaft. Either MIPO or IMN were performed on 15 patients each with traumatic humeral shaft fractures. The cumulative risk of 3 major complications associated with these procedures: nonunion, infection, and iatrogenic radial nerve injury. An overall major complication rate of 53% was observed in the patients treated with IMN; one complication (7%) was identified in those managed with humeral MIPO, a nonunion. Complications after IMN included 4 patients (27%) with nonunion, 3 patients (20%) with iatrogenic radial nerve injuries, and 1 patient (7%) with a wound infection. Statistical analysis revealed a significant between-group difference (P = 0.01) in the cumulative rate of major complications. When each of these complications was considered independently, no statistically significant difference was demonstrated. This study suggests that humeral MIPO results in a significantly lower pooled major complication rate than that of IMN, and it should therefore be considered an attractive alternative to IMN in those patients requiring surgical stabilization of a traumatic humeral shaft fracture. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

  18. Treatment of Palatal Fractures by Osteosynthesis with 2.0-mm Locking Plates as External Fixator

    PubMed Central

    Cienfuegos, Ricardo; Sierra, Eduardo; Ortiz, Benjamin; Fernández, Gerardo

    2010-01-01

    Treatment options for palatal fractures range from orthodontic braces, acrylic bars, and arch bars for maxillomandibular fixation to internal fixation, with plates and screws placed under the palate mucosa and periosteum, together with pyriform aperture or alveolar plating plus buttress reconstruction. Forty-five patients, ages 4 to 56, were treated using medium- or high-profile locking plates placed over the palatal mucosa as an external fixator for palatal fractures, together with treatment for other associated facial fractures. In open fractures, plates were placed after approximating the edges of the mucosal wounds. Plates and screws for palate fixation were removed at 12 weeks, when computed tomography scans provided evidence of fracture healing. All palatal fractures healed by 12 weeks, with no cases of mucosal necrosis, bone exposure, fistulae, or infections. This approach achieves adequate stability, reduces the risk of bone and mucosal necrosis, and promotes healing of mucosal wounds in case of open fractures. PMID:22132261

  19. Clinical, Morphological, and Molecular Evaluations of Bone Regeneration With an Additive Manufactured Osteosynthesis Plate.

    PubMed

    Thor, Andreas; Palmquist, Anders; Hirsch, Jan-Michaél; Rännar, Lars-Erik; Dérand, Per; Omar, Omar

    2016-10-01

    There is limited information on the biological status of bone regenerated with microvascular fibula flap combined with biomaterials. This paper describes the clinical, histological, ultrastructural, and molecular picture of bone regenerated with patient-customized plate, used for mandibular reconstruction in combination with microvascular osteomyocutaneous fibula flap. The plate was virtually planned and additively manufactured using electron beam melting. This plate was retrieved from the patient after 33 months. Microcomputed tomography, backscattered-scanning electron microscopy, histology, and quantitative-polymerase chain reaction were employed to evaluate the regenerated bone and the flap bone associated with the retrieved plate. At retrieval, the posterior two-thirds of the plate were in close adaptation with the underlying flap, whereas soft tissue was observed between the native mandible and the anterior one-third. The histological and structural analyses showed new bone regeneration, ingrowth, and osseointegration of the posterior two-thirds. The histological observations were supported by the gene expression analysis showing higher expression of bone formation and remodeling genes under the posterior two-thirds compared with the anterior one-third of the plate. The observation of osteocytes in the flap indicated its viability. The present data endorse the suitability of the customized, additively manufactured plate for the vascularized fibula mandibular reconstruction. Furthermore, the combination of the analytical techniques provides possibilities to deduce the structural and molecular characteristics of bone regenerated using this procedure.

  20. [Biomechanical investigation of fixed-angle plate osteosynthesis of the proximal humerus].

    PubMed

    Röderer, G; AbouElsoud, M; Gebhard, F; Claes, L; Aschoff, A J; Kinzl, L

    2010-02-01

    Proximal humeral fractures are common in the elderly population and are often associated with osteoporosis. Fixation of unstable proximal humeral fractures is problematic due to loss of fixation in osteoporotic bone. Fixed-angle devices are intended to provide superior mechanical stability due to the principle of an internal fixator. The NCB(R)-PH (non-contact-bridging proximal humerus) plate is a new fixed-angle device that locks the screws to the plate by secondary insertion of a locking cap. The aim of this study was to investigate if and to what extent NCB-PH plates applied in the locked mode provide higher mechanical stability in a proximal humerus fracture model. For this investigation 16 (8 pairs) fresh frozen cadaveric humeri were used. An AO/ASIF 11-B 1 fracture of the proximal humerus was created in each bone and fixed with the NCB-PH plate. In a paired setting one bone was fixed with the plate in the locked mode and the other with the plate in the non-locked mode. The bones were then subjected to 100 cycles of axial loading and interfragmentary motion was measured. Bones surviving this test were subjected to load-to-failure testing and the force at which failure occurred was recorded. Bones fixed with the plate in the locked mode showed a statistically significant lower (51%) interfragmentary rotation compared to bones fixed with the plate in the non-locked mode. There was also a tendency for the bones fixed with the plate in the locked mode to fail first under higher forces (16%) during load-to-failure testing. The NCB-PH plate provides superior interfragmentary stability when used in the locked mode in a human cadaveric proximal humerus fracture model. Therefore, we recommend that all screws should be inserted in the locked mode. The results suggest that the NCB-PH plate in the locked mode provides higher primary postoperative stability thus permitting early functional treatment of the patient.

  1. [Treatment of mid-distal humeral shaft fractures associated with radial nerve palsy using minimally invasive plating osteosynthesis technique].

    PubMed

    An, Zhiquan; Zeng, Bingfang; He, Xiaojian; Huang, Peiyan

    2008-05-01

    To explore the possibility of treating mid-distal humeral shaft fractures associated with radial nerve palsies with minimal invasive plating osteosynthesis (MIPO) techniques. From April 2003 to October 2006, 10 patients with mid-distal humeral shaft fractures associated with radial nerve palsies were treated. All patients were male, aged 19-58 years. According to AO/ASIF classification, there were 4 cases of B1 type, 2 cases of B3 type, 1 case of A2 type, 1 case of B2 type, 1 case of C3 type and 1 case of A3 type. A straight 4.5 mm dynamic compression plate was placed on the anterior aspect of humerus through two small incisions located on the anterior side of proximal and distal part of the arm. The radial nerve exploration was performed through a lateral small incision made on the fracture site. The fractures were then reduced by manual manipulation and the plate was fixated to the main fragments with 3 screws in each end of the plate. The postoperative complications, the bone healing time, and the recovery time of the radial nerve functions were recorded. The functions of the affected shoulder and elbow were assessed with UCLA and Mayo elbow performance score system respectively. All incision healed by first intention. Ten patients were followed up 9-36 months with an average of 15.7 months. The X-ray films showed that the union of fractures was achieved 12-16 weeks (13.6 weeks on average). The function of the radial nerves recovered completely 12-36 weeks (17.8 weeks on average) in 9 patients. The abductions of the affected shoulder were 150-170 degrees (165 degrees on average). The ROM of the elbows were 130-140 degrees (135.5 degrees on average). According to the UCLA shoulder scoring system, 9 patients achieved the excellent result and 1 patient achieved the good result. All the patients had the excellent results according to Mayo elbow performance score system. The mid-distal humeral shaft fractures associated with radial nerve palsies can be treated with

  2. Implant Material, Type of Fixation at the Shaft, and Position of Plate Modify Biomechanics of Distal Femur Plate Osteosynthesis.

    PubMed

    Kandemir, Utku; Augat, Peter; Konowalczyk, Stefanie; Wipf, Felix; von Oldenburg, Geert; Schmidt, Ulf

    2017-08-01

    To investigate whether (1) the type of fixation at the shaft (hybrid vs. locking), (2) the position of the plate (offset vs. contact) and (3) the implant material has a significant effect on (a) construct stiffness and (b) fatigue life in a distal femur extraarticular comminuted fracture model using the same design of distal femur periarticular locking plate. An extraarticular severely comminuted distal femoral fracture pattern (OTA/AO 33-A3) was simulated using artificial bone substitutes. Ten-hole distal lateral femur locking plates were used for fixation per the recommended surgical technique. At the distal metaphyseal fragment, all possible locking screws were placed. For the proximal diaphyseal fragment, different types of screws were used to create 4 different fixation constructs: (1) stainless steel hybrid (SSH), (2) stainless steel locked (SSL), (3) titanium locked (TiL), and (4) stainless steel locked with 5-mm offset at the diaphysis (SSLO). Six specimens of each construct configuration were tested. First, each specimen was nondestructively loaded axially to determine the stiffness. Then, each specimen was cyclically loaded with increasing load levels until failure. Construct Stiffness: The fixation construct with a stainless steel plate and hybrid fixation (SSH) had the highest stiffness followed by the construct with a stainless steel plate and locking screws (SSL) and were not statistically different from each other. Offset placement (SSLO) and using a titanium implant (TiL) significantly reduced construct stiffness. Fatigue Failure: The stainless steel with hybrid fixation group (SSH) withstood the most number of cycles to failure and higher loads, followed by the stainless steel plate and locking screw group (SSL), stainless steel plate with locking screws and offset group (SSLO), and the titanium plate and locking screws group (TiL) consecutively. Offset placement (SSLO) as well as using a titanium implant (TiL) reduced cycles to failure. Using the

  3. Locking-plate osteosynthesis versus intramedullary nailing for fixation of olecranon fractures: a biomechanical study.

    PubMed

    Nowak, Tobias E; Burkhart, Klaus J; Andres, Torsten; Dietz, Sven O; Klitscher, Daniela; Mueller, Lars P; Rommens, Pol M

    2013-05-01

    Intramedullary nailing and locked plating for fixation of olecranon fractures has recently gained popularity. However, these two new technologies have not been compared for their biomechanical efficacy. The aim of this study was to evaluate the biomechanical stability of two newly designed fracture fixation devices for treating olecranon fractures during dynamic continuous loading: the ION intramedullary locking nail and the LCP precontoured locking compression plate. Simulated oblique olecranon fractures were created in eight pairs of fresh-frozen cadaver ulnae and stabilised using either the LCP or ION. Specimens were then subjected to continuous dynamic loading (from 25 to 200 N), with a continuous angle alteration between 0° and 90° of flexion, to perform a matched-pairs comparison. Significant differences in the distance between markers surrounding the fracture gap was determined using the Wilcoxon test after four and 300 loading cycles. The ION resulted in significantly less displacement in the fracture gap at 0° extension (P = 0.036), 45° flexion (P = 0.035) and 90° flexion (P = 0.017) after 300 cycles of continuous loading. The measured displacements were small and were probably not of clinical significance. No mechanical failure or hardware migration was seen with either fixation technique. This study shows significantly less micromotion for the ION than for the LCP in treating oblique olecranon fractures after 300 cycles of dynamic loading. Both implant types could be appropriate surgical techniques for fixation of selected olecranon fractures and osteotomies.

  4. Minimally invasive plate osteosynthesis with a locking compression plate is superior to open reduction and internal fixation in the management of the proximal humerus fractures.

    PubMed

    Lin, Tao; Xiao, Baojun; Ma, Xiucai; Fu, Dehao; Yang, Shuhua

    2014-06-16

    The use of minimally invasive plate osteosynthesis (MIPO) via anterolateral deltoid splitting has good outcomes in the management of proximal humerus fractures. While using this approach has several advantages, including minimal soft tissue disruption, preservation of natural biology and minimal blood loss, there is an increased risk for axillary nerve damage. This study compared the advantages and clinical and radiological outcomes of MIPO or open reduction and internal fixation (ORIF) in patients with proximal humerus fractures. A matched-pair analysis was performed, and patient groups were matched according to age (±3 years), sex and fracture type. Forty-three pairs of patients (average age: MIPO, 63 and ORIF, 61) with a minimum follow-up of 12 months were enrolled in the study group. The patients were investigated radiographically and clinically using the Constant score. The MIPO technique required less surgery time and caused less blood loss compared to ORIF (p < 0.01). In addition, MIPO required a smaller incision, resulted in less scarring, and was cosmetically more appealing and acceptable to female patients than ORIF. Following MIPO, patients had better functional results at 3 and 6 months, with better outcomes, less pain, higher satisfaction in activities of daily living, and a higher range of motion when compared to ORIF (p < 0.05). Fracture configuration, according to the AO/ASIF(Association for the Study of Internal Fixation) fracture classification, did not significantly influence the functional results. The complication rate was comparable between both groups. The use of MIPO with a locking compression plate in the management of proximal humerus fractures is a safe and superior option compared to ORIF.

  5. Minimally invasive plate osteosynthesis with a locking compression plate is superior to open reduction and internal fixation in the management of the proximal humerus fractures

    PubMed Central

    2014-01-01

    Background The use of minimally invasive plate osteosynthesis (MIPO) via anterolateral deltoid splitting has good outcomes in the management of proximal humerus fractures. While using this approach has several advantages, including minimal soft tissue disruption, preservation of natural biology and minimal blood loss, there is an increased risk for axillary nerve damage. This study compared the advantages and clinical and radiological outcomes of MIPO or open reduction and internal fixation (ORIF) in patients with proximal humerus fractures. Methods A matched-pair analysis was performed, and patient groups were matched according to age (±3 years), sex and fracture type. Forty-three pairs of patients (average age: MIPO, 63 and ORIF, 61) with a minimum follow-up of 12 months were enrolled in the study group. The patients were investigated radiographically and clinically using the Constant score. Results The MIPO technique required less surgery time and caused less blood loss compared to ORIF (p < 0.01). In addition, MIPO required a smaller incision, resulted in less scarring, and was cosmetically more appealing and acceptable to female patients than ORIF. Following MIPO, patients had better functional results at 3 and 6 months, with better outcomes, less pain, higher satisfaction in activities of daily living, and a higher range of motion when compared to ORIF (p < 0.05). Fracture configuration, according to the AO/ASIF(Association for the Study of Internal Fixation) fracture classification, did not significantly influence the functional results. The complication rate was comparable between both groups. Conclusion The use of MIPO with a locking compression plate in the management of proximal humerus fractures is a safe and superior option compared to ORIF. PMID:24934152

  6. Osteosynthesis using plates and screws after removing a limited area of the periosteum in order to reduce misclassified during radiological assessment metacarpal shaft fractures.

    PubMed

    Neagu, T P; Popescu, S A; Cobilinschi, C; Tincu, R; Tiglis, M; Lascar, I

    2016-01-01

    Hand fractures are one of the most common causes for presenting to the emergency room. Metacarpal fractures count about 18 to 44% of all hand fractures, and are most often standalone closed injuries, without misplacement, not needing operative treatment. We present a case in which osteosynthesis with plates and screws was used to reduce two metacarpal fractures in order to allow an early motion recovery, despite the fact that a small portion of the periosteum needed to be removed. The type of fractures were misclassified according to the radiological findings, therefore the correct diagnosis was established during surgery. The results according to the radiological aspects and to the DASH score were excellent with 95% function recovery at twelve months. In this case, the use of osteosynthesis with plates and screws led to a good fracture healing without any major complications. However, there are a series of complications related to this method that should be taken into consideration. Being misled by the radiological aspects of the fractures, the most certain way to classify a metacarpal shaft fracture is through exploratory surgery, even if in most of the cases the three radiological views are enough to establish the diagnosis. Abbreviations: DASH score = Disability of Arm, Shoulder and Hand score, TAM = Total Active Motion, MCP = metacarpal phalangeal joint, PIP = proximal inter phalangeal joint.

  7. Osteosynthesis using plates and screws after removing a limited area of the periosteum in order to reduce misclassified during radiological assessment metacarpal shaft fractures

    PubMed Central

    Neagu, TP; Popescu, SA; Cobilinschi, C; Tincu, R; Tiglis, M; Lascar, I

    2016-01-01

    Hand fractures are one of the most common causes for presenting to the emergency room. Metacarpal fractures count about 18 to 44% of all hand fractures, and are most often standalone closed injuries, without misplacement, not needing operative treatment. We present a case in which osteosynthesis with plates and screws was used to reduce two metacarpal fractures in order to allow an early motion recovery, despite the fact that a small portion of the periosteum needed to be removed. The type of fractures were misclassified according to the radiological findings, therefore the correct diagnosis was established during surgery. The results according to the radiological aspects and to the DASH score were excellent with 95% function recovery at twelve months. In this case, the use of osteosynthesis with plates and screws led to a good fracture healing without any major complications. However, there are a series of complications related to this method that should be taken into consideration. Being misled by the radiological aspects of the fractures, the most certain way to classify a metacarpal shaft fracture is through exploratory surgery, even if in most of the cases the three radiological views are enough to establish the diagnosis. Abbreviations: DASH score = Disability of Arm, Shoulder and Hand score, TAM = Total Active Motion, MCP = metacarpal phalangeal joint, PIP = proximal inter phalangeal joint PMID:27974942

  8. One-third tubular-hook-plate osteosynthesis for olecranon osteotomies in distal humerus type-C fractures: a preliminary report of results and complications.

    PubMed

    Schmidt-Horlohé, K; Wilde, P; Bonk, A; Becker, L; Hoffmann, R

    2012-03-01

    Distal humerus fractures are rare and challenging to treat. Anatomic reduction of the articular surface and stable osteosynthesis are mandatory for satisfactory results. The transolecranon approach allows superior visualisation of the joint. However, controversy exists regarding how best to fix the osteotomy. The purpose of the present study was to investigate the eligibility of a one-third tubular hook plate for osteosynthesis of olecranon osteotomies in distal humerus type-C fractures. A consecutive series of 34 patients who were treated through an olecranon osteotomy and underwent fixation using a one-third tubular hook plate were identified. Thirty-one patients (17 females, 14 males) with a median age of 50 years (14-87, standard deviation (SD) 18.3) were available for a comprehensive assessment after a mean of 12.3 months (6-20, SD 3.7). Using the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, six (19.4%) fractures were categorised as type C2 and 25 (80.6%) were categorised as C3. Physical and radiological examinations were performed. The Mayo Elbow Performance Score (MEPS) and the Disabilities of the Arm, Shoulder and Hand score (DASH) were evaluated. Mean extension-flexion ROM was found to be 102° (50-145°, SD 25). Pronation and supination were only slightly compromised. The mean MEPS was 87.2 points (50-100, SD 12.4). Fourteen patients (45.2%) were rated as excellent, and 15 (48.4%) were rated as good. One patient was rated fair, and one patient was rated as poor, respectively. Mean DASH score was 24.4 points (0-65, SD 20.3). Complications regarding the osteotomy occurred in seven patients (22.5%). Revision surgery was necessary in five cases (16%). At follow-up, all osteotomies went on to union. Mild joint degeneration (Broberg I) was found in 10 patients (32.2%). Implant removal was carried out in 15 patients (48.4%). Based on this study, the osteosynthesis of olecranon osteotomies using a one-third tubular hook plate can be regarded

  9. Assessment of fracture healing after minimally invasive plate osteosynthesis or open reduction and internal fixation of coexisting radius and ulna fractures in dogs via ultrasonography and radiography.

    PubMed

    Pozzi, Antonio; Risselada, Marije; Winter, Matthew D

    2012-09-15

    To evaluate fracture healing after minimally invasive plate osteosynthesis (MIPO) or open reduction and internal fixation (ORIF) of coexisting radius and ulna fractures in dogs via ultrasonography and radiography. Prospective cohort study. 16 dogs with radius-ulna fractures that underwent MIPO (n = 9; 2 dogs were subsequently not included in the analyses because of incomplete follow-up information) or ORIF (7). Dogs in the 2 treatment groups were matched by age, body weight, and configuration of the fractures. Fracture healing was evaluated with ultrasonography, power Doppler ultrasonography, and radiography every 3 to 4 weeks until healing was complete; a semiquantitative score based on the number of Doppler signals was used to characterize neovascularization, and subjective B-mode ultrasonographic and radiographic scores were assigned to classify healing. Fractures in dogs that underwent MIPO healed in significantly less time than did fractures in dogs that underwent ORIF (mean ± SD; 30 ± 10.5 days and 64 ± 10.1 days, respectively). Radiography revealed that fractures in dogs that underwent MIPO healed with significantly more callus formation than did fractures in dogs that underwent ORIF. Although Doppler ultrasonography revealed abundant vascularization in fractures that were healing following MIPO, no significant difference in neovascularization scores was found between groups. For dogs with radius-ulna fractures, data indicated that bridging osteosynthesis combined with a minimally invasive approach contributed to rapid healing after MIPO. The MIPO technique may offer some clinical advantage over ORIF, given that complete radius-ulna fracture healing was achieved in a shorter time with MIPO.

  10. Treatment of the humeral shaft fractures - minimally invasive osteosynthesis with bridge plate versus conservative treatment with functional brace: study protocol for a randomised controlled trial

    PubMed Central

    2013-01-01

    Background Humeral shaft fractures account for 1 to 3% of all fractures in adults and for 20% of all humeral fractures. Non-operative treatment is still the standard treatment of isolated humeral shaft fractures, although this method can present unsatisfactory results. Surgical treatment is reserved for specific conditions. Modern concepts of internal fixation of long bone shaft fractures advocate relative stabilisation techniques with no harm to fracture zone. Recently described, minimally invasive bridge plate osteosynthesis has been shown to be a secure technique with good results for treating humeral shaft fractures. There is no good quality evidence advocating which method is more effective. This randomised controlled trial will be performed to investigate the effectiveness of surgical treatment of humeral shaft fractures with bridge plating in comparison with conservative treatment with functional brace. Methods/Design This randomised clinical trial aims to include 110 patients with humeral shaft fractures who will be allocated after randomisation to one of the two groups: bridge plate or functional brace. Surgical treatment will be performed according to technique described by Livani and Belangero using a narrow DCP plate. Non-operative management will consist of a functional brace for 6 weeks or until fracture consolidation. All patients will be included in the same rehabilitation program and will be followed up for 1 year after intervention. The primary outcome will be the DASH score after 6 months of intervention. As secondary outcomes, we will assess SF-36 questionnaire, treatment complications, Constant score, pain (Visual Analogue Scale) and radiographs. Discussion According to current evidence shown in a recent systematic review, this study is one of the first randomised controlled trials designed to compare two methods to treat humeral shaft fractures (functional brace and bridge plate surgery). Trial registration Current Controlled Trials: ISRCTN

  11. Enhancing screw stability in osteosynthesis with hydroxyapatite granules.

    PubMed

    Hasegawa, K; Yamamura, S; Dohmae, Y

    1998-01-01

    We employed hydroxyapatite (HA) granules to enhance screw fixation in revision surgery of failed osteosynthesis with a compression hip screw system in an 83-year-old woman. After reduction of the fracture, the fracture site with a large bone defect was filled with HA granules, and osteosynthesis was accomplished with a double cannulated lag screw and plate system. We feel that this HA granule augmentation method may also be suitable for osteosynthesis in other osteoporotic fractures.

  12. [Subtotal Segment Resection, Augmenting Angle-Stable Plate Osteosynthesis and Allogenic Bone Graft as Treatment Option for Juxtacortical Osteosarcoma in the Knee Region].

    PubMed

    Zajonz, D; Pfraenger, J R; Dubitzki, S; Panzert, S; Seider, D; Lingscheidt, T; Hammer, N; Prietzel, T

    2015-06-01

    Juxtacortical osteosarcomas are a group of rare primary bone tumours. They differ from medullary osteosarcomas in their anatomic location (outside of the corticalis), low metastasis rate and better prognosis. The only evidence-based treatment of juxtacortical osteosarcomas is the wide surgical resection. In this technical report we will introduce a new surgical technique, including the subtotal resection of the tumour-bearing bone segment, defect reconstruction by means of an augmenting fixed-angle plate osteosynthesis and homologous cancellous bone graft. If necessary, a subsequent plastic coverage of the soft tissue defect was performed. The technique will be presented by means of three illustrated cases of young patients with juxtacortical osteosarcomas in the proximity of the knee joint. Following diagnostic confirmation by means of an incision biopsy and tumour staging, the three patients underwent this new surgical technique. In the postoperative follow-up and re-staging, two to seven years after surgery, all patients were under complete remission, had functionally restored knee joints (Karnofsky score 90 % or higher) and showed good aesthetic results. The surgical technique described may therefore be an adequate alternative to the complete resection of the tumour-bearing bone segment with prosthetic reconstruction and should be considered on the basis of the illustrated functional results in individual cases. Georg Thieme Verlag KG Stuttgart · New York.

  13. Comparison of Minimally Invasive Percutaneous Plate Osteosynthesis and Open Reduction Internal Fixation on Proximal Humeral Fracture in Elder Patients: A Systematic Review and Meta-Analysis

    PubMed Central

    2017-01-01

    Objective The study aims to compare minimally invasive percutaneous plate osteosynthesis (MIPO) and open reduction internal fixation (ORIF) in the treatment of proximal humeral fracture in elder patients. Method PubMed, Medline, EMbase, Ovid, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wangfang, and VIP Database for Chinese Technical Periodicals were searched to identify all relevant studies from inception to October 2016. Data were analyzed with Cochrane Collaboration's Review Manage 5.2. Results A total of 630 patients from 8 publications were included in the systematic review and meta-analysis. The pooled results showed that MIPO was superior to ORIF in the treatment of proximal humeral fracture in elder patients. It was reflected in reducing blood loss, operation time, postoperative pain, or fracture healing time of the surgery and in improving recovery of muscle strength. Concerning complications, no significant difference was seen between MIPO and ORIF. Conclusion The MIPO was more suitable than ORIF for treating proximal humeral fracture in elder patients. PMID:28698871

  14. Open reduction and palmar plate-osteosynthesis in combination with a nanocrystalline hydroxyapatite spacer in the treatment of comminuted fractures of the distal radius.

    PubMed

    Huber, F-X; Hillmeier, J; Herzog, L; McArthur, N; Kock, H-J; Meeder, P J

    2006-06-01

    In a prospective study, we used the nanocrystalline hydroxyapatite paste Ostim (Osartis, Obernburg, Germany) in combination with a palmar plate to treat comminuted radius fractures with a metaphyseal and articular component in order to examine the clinical use of Ostim as a bone substitute. Twenty-one patients with 22 radius fractures of AO types C2 and C3 were included in the study. The measurements, taken 10.2+/-1.3 months after the initial treatment, revealed a dorsopalmar tilt of 8.8+/-3.7 degrees , a radioulnar inclination of 18.8+/-2.8 degrees and an ulnar variance of 0.8+/-1.8mm. According to the Gartland and Werley evaluation, eight of the treated fractures attained an excellent, 11 a good and the remaining three a fair result. The study demonstrates that Ostim, in combination with angularly stable osteosynthesis, can be used as an acceptable bone substitute for the treatment of type C2 and C3 radial fractures.

  15. Complication rates and reduction potential of palmar versus dorsal locking plate osteosynthesis for the treatment of distal radius fractures.

    PubMed

    Wichlas, F; Haas, N P; Disch, A; Machó, D; Tsitsilonis, S

    2014-12-01

    The aim of this study was to evaluate the complication rates of volar versus dorsal locking plates and postoperative reduction potential after distal radius fractures. For this study 285 distal radius fractures (280 patients/59.4 % female) treated with locked plating were retrospectively evaluated. The mean age of the patients was 54.6 years (SD 17.4) and the mean follow-up was 33.2 months (SD 17.2). The palmar approach was used in 225 cases and the dorsal approach in 60 cases (95 % type C fractures). Adequate reduction was achieved with both approaches, regardless of fracture severity. In the dorsal group, the complications and implant removal rates were significantly higher and the operative time was also longer. Based on these facts, we advocate the palmar locking plate for the vast majority of fractures. In cases of complex multifragmentary articular fractures where no compromise in reduction is acceptable, and with the biomechanical equality of palmar and dorsal plating remaining unproven, dorsal plating may still be considered. Therapeutic level IV.

  16. Resorbable poly(D,L)lactide plates and screws for osteosynthesis of condylar neck fractures in sheep.

    PubMed

    Rasse, Michael; Moser, Doris; Zahl, Christian; Gerlach, Klaus Louis; Eckelt, Uwe; Loukota, Richard

    2007-01-01

    We made osteotomies in the condylar neck in 12 adult sheep to simulate fractures, and joined the two ends with 2 poly(D,L)lactide (PDLLA) plates and 8 PDLLA screws 2mm in diameter. The animals were killed after 2, 6, and 12 months and bony healing was assessed macroscopically and histologically. The plates and screws remained intact and there was no displacement of the bony ends. The degrading plates, which were still visible in the specimens after 6 months, had been replaced by bone. At 12 months the PDLLA had been resorbed with no foreign body reaction and no resorption of underlying bone. The articular discs showed no signs of degeneration.

  17. A Novel Shape Memory Plate Osteosynthesis for Noninvasive Modulation of Fixation Stiffness in a Rabbit Tibia Osteotomy Model

    PubMed Central

    Müller, Christian W.; Pfeifer, Ronny; Meier, Karen; Decker, Sebastian; Reifenrath, Janin; Gösling, Thomas; Wesling, Volker; Krettek, Christian; Krämer, Manuel

    2015-01-01

    Nickel-titanium shape memory alloy (NiTi-SMA) implants might allow modulating fracture healing, changing their stiffness through alteration of both elastic modulus and cross-sectional shape by employing the shape memory effect (SME). Hypotheses: a novel NiTi-SMA plate stabilizes tibia osteotomies in rabbits. After noninvasive electromagnetic induction heating the alloy exhibits the SME and the plate changes towards higher stiffness (inverse dynamization) resulting in increased fixation stiffness and equal or better bony healing. In 14 rabbits, 1.0 mm tibia osteotomies were fixed with our experimental plate. Animals were randomised for control or induction heating at three weeks postoperatively. Repetitive X-ray imaging and in vivo measurements of bending stiffness were performed. After sacrifice at 8 weeks, macroscopic evaluation, µCT, and post mortem bending tests of the tibiae were carried out. One death and one early implant dislocation occurred. Following electromagnetic induction heating, radiographic and macroscopic changes of the implant proved successful SME activation. All osteotomies healed. In the treatment group, bending stiffness increased over time. Differences between groups were not significant. In conclusion, we demonstrated successful healing of rabbit tibia osteotomies using our novel NiTi-SMA plate. We demonstrated shape-changing SME in-vivo through transcutaneous electromagnetic induction heating. Thus, future orthopaedic implants could be modified without additional surgery. PMID:26167493

  18. Design considerations for a novel shape-memory-plate osteosynthesis allowing for non-invasive alteration of bending stiffness.

    PubMed

    Krämer, Manuel; Müller, Christian W; Hermann, Maike; Decker, Sebastian; Springer, André; Overmeyer, Ludger; Hurschler, Christof; Pfeifer, Ronny

    2017-08-23

    Biomechanical stimuli play a major role in fracture healing. Changing the fixation stiffness through the course of healing might accelerate bone healing and prevent healing complications. Shape memory alloy (SMA) based implants were developed to allow for non-invasive stiffness alteration during the fracture healing process. To gain a deeper understanding of the implant functionality based on the alloy characteristics and geometric design, the mechanical properties of different shape memory alloys where mechanically characterized. SMA bone plates were manufactured and the structural bending stiffness of the implants was determined at different temperatures and configurations. The temperature required for complete recovery of shape after deformation increased continuously with increasing pseudo-plastic deformation in SMA probes. Full recovery was observed at temperatures ranging from 38°C to 52°C after pseudo-plastic deformations ranging from 0.2% to 1.0% outer fibre strain, respectively. The small fragment inverse-dynamisation implants revealed bending stiffnesses ranging from 0.09Nm(2) to 0.34Nm(2) in the initial state and from 0.16Nm(2) to 0.46Nm(2) after shape alteration. Dependent on the design, a relative gain of the implant stiffness ranging from 18.8% to 115.0% could be observed. The large inverse-dynamisation implants revealed bending stiffnesses from 3.7Nm(2) to 7.1Nm(2) before and 4.1Nm(2) to 12.6Nm(2) after triggering the shape memory effect. Dependent on the design a gain in stiffness from 11.8% to 117.2% was observed. Warming the SMA implant to 40°C for a short period of time, leads to a moderate increase in implant stiffness of up to 64.5%, while triggering the implant with 50°C leads to a maximum increase in stiffness of up to 127.3%. The Nitinol shape memory bone plates have a huge potential for improving the treatment of long shaft fractures by allowing for the increase, decrease or incremental change of implant stiffness in fracture

  19. Periprosthetic fracture around a stable femoral stem treated with locking plate osteosynthesis: distal femoral locking plate alone versus with cerclage cable.

    PubMed

    Shin, Young-Soo; Han, Seung-Beom

    2017-07-01

    To promote rapid bone healing, an adequate stable fixation implant with a percutaneous reduction instrument should be used for Vancouver type B1 or C fractures. The objective of this study was to describe radiographic and clinical outcomes of patients with periprosthetic fracture (PPF) around a stable femoral stem, treated with a distal femoral locking plate alone or with a cerclage cable. A total of 21 patients with PPF amenable to either a reverse distal femoral locking plate (LCP DF(®)) alone or with a cerclage cable, with a mean age of 75.7 years, were included. In these patients, ten fractures were treated with a reverse LCP DF(®) alone and were classified as group I, and 11 additionally received a cerclage cable and were classified as group II. Group II had a significantly longer operation time (P = 0.019) than group I and included one patient with nonunion at the final 24-month follow-up visit after the initial fracture reduction. However, this difference in nonunion rate for the two groups is more likely to inappropriate indications than surgical techniques. When comparing the stability of the fractures in both groups, there was no statistically significant difference, which might be attributed to the stable fixed-angle implant.

  20. Immediate multiple osteosynthesis in polytrauma.

    PubMed

    Costa, P; Giancecchi, F; Tartaglia, I; Fontanesi, G

    1991-06-01

    Thirty polytraumatized patients underwent immediate osteosynthesis of two or more long bone fractures for a total of 82 operations (plus an additional 14 for pelvis, hand, and foot fractures). Since 1983, according to the modern and rational concepts of "all at one time treatment", open fractures as well as associated closed lesions are stabilized immediately if the patient's general condition permits. This type of procedure requires adequate facilities as well as availability of and collaboration between teams of specialists, but it is inarguably advantageous for the patient (relief of pain, drastic reduction in the rate of embolism, improvement of respiratory and circulatory function, only one anesthesia), the surgeons (operation technically easier and shorter), and the ancillary medical personnel (easier nursing, rapid functional rehabilitation). The methods of osteosynthesis should be carefully selected in order to guarantee stability, rapid application, and low aggressiveness. The use of plates and screws is limited, while external fixation is employed frequently. Interlocked intramedullary nailing is adopted with increasing frequency. Review of cases treated by this method shows considerable improvement in terms of healing, functional recovery, and resumption of social and occupational activity.

  1. On solving the irregularly-shaped plate buckling problem

    NASA Technical Reports Server (NTRS)

    Smith, James P.

    1993-01-01

    This paper develops methods for finding critical buckling loads of isotropic plates. In particular, this paper is motivated by the lack of tabular data for non-rectangular plates such as general trapezoids. High order displacement functions are used, and boundary conditions are imposed by utilizing the Lagrange multiplier method, which allows for a variety of constraint conditions. The element is derived with the use of minimum potential energy and subparametric mappings. An example is given, and several test cases are presented to show the validity of the approach in the one element case.

  2. On solving the irregularly-shaped plate buckling problem

    NASA Technical Reports Server (NTRS)

    Smith, James P.

    1993-01-01

    This paper develops methods for finding critical buckling loads of isotropic plates. In particular, this paper is motivated by the lack of tabular data for non-rectangular plates such as general trapezoids. High order displacement functions are used, and boundary conditions are imposed by utilizing the Lagrange multiplier method, which allows for a variety of constraint conditions. The element is derived with the use of minimum potential energy and subparametric mappings. An example is given, and several test cases are presented to show the validity of the approach in the one element case.

  3. New technique for sternal osteosynthesis.

    PubMed

    Roux, D; Fournial, G; Glock, Y; Nottin, R

    1995-10-01

    In our department, we have developed a new method for sternal osteosynthesis. This technique uses steel threads and a sternal retractor. The removable valves are removed and placed with a two-pulley device, which allows good osteosynthesis without assistance or effort.

  4. [Steel or titanium for osteosynthesis : A mechanobiological perspective].

    PubMed

    Heyland, M; Duda, G N; Märdian, S; Schütz, M; Windolf, M

    2017-02-01

    An implant used for stabilizing a fracture creates a mechanical construct, which directly determines the biology of bone healing. The stabilization of fractures places high mechanical demands on implants and therefore steel and titanium are currently almost exclusively used as the materials of choice. The possible range of attainable mechanobiological stimulation for mechanotherapy as a function of plate stiffness depending on the selection of the plate material and the physical and mechanical properties of the material options are discussed. An overview of the material properties of steel and titanium is given. For dynamically fixed long bone fractures as examples, various finite element models of plate osteosynthesis (steel/titanium) are created and the plate working length (PWL, screw configuration close to fracture) is varied. The interfragmentary movement (IFM) as a measure of mechanobiological stimulation is evaluated. Stimulation in the form of IFM varies across the fracture and also as a function of the osteosynthesis material and the configuration. The influence of the material appears to be notably smaller than the influence of PWL but both lose their influence largely over a bridged fracture situation (contact). With a flexible titanium plate and large PSS, a greater mechanobiological stimulation is produced. An essential prerequisite for the secondary fracture healing is an appropriate mechanobiological environment, which can be controlled by the osteosynthesis material and the configuration and is also affected by the type of fracture and load.

  5. Solving the vibroacoustic equations of plates by minimization of error on a sample of observation points.

    PubMed

    Collery, Olivier; Guyader, Jean-Louis

    2010-03-01

    In the context of better understanding and predicting sound transmission through heterogeneous fluid-loaded aircraft structures, this paper presents a method of solving the vibroacoustic problem of plates. The present work considers fluid-structure coupling and is applied to simply supported rectangular plates excited mechanically. The proposed method is based on the minimization of the error of verification of the plate vibroacoustic equation of motion on a sample of points. From sampling comes an aliasing effect; this phenomenon is described and solved using a wavelet-based filter. The proposed approach is validated in presenting very accurate results of sound radiation immersed in heavy and light fluids. The fluid-structure interaction appears to be very well described avoiding time-consuming classical calculations of the modal radiation impedances. The focus is also put on different samplings to observe the aliasing effect. As perspectives sound radiation from a non-homogeneous plate is solved and compared with reference results proving all the power of this method.

  6. Plate osteosynthesis of the humerus shaft fracture an its association with radial nerve injury--a retrospective study in Melaka General Hospital.

    PubMed

    Lim, K E; Yap, C K; Ong, S C; Aminuddin

    2001-06-01

    Over a seven-year period, 170 cases of humerus fractures were plated in Hospital Melaka. Of these, 131 cases were successfully traced for this study. Besides looking at fracture epidemiology, its relationship with radial nerve injury was examined. The incidence of post-traumatic wrist drop in closed and compound fractures were 14.9% and 35.3% respectively. In relation to the site of fracture, lower third fracture had the highest incidence of wrist drop (29%). The recovery from post-traumatic wrist drop was 83%. The average duration taken for recovery was 11.8 weeks. The incidence of post-operative wrist drop was high at 17.6% but all recovered during follow-up.

  7. Are allogenic or xenogenic screws and plates a reasonable alternative to alloplastic material for osteosynthesis--a histomorphological analysis in a dynamic system.

    PubMed

    Jacobsen, C; Obwegeser, J A

    2010-12-01

    Despite invention of titanium and resorbable screws and plates, still, one of the main challenges in bone fixation is the search for an ideal osteosynthetic material. Biomechanical properties, biocompatibility, and also cost effectiveness and clinical practicability are factors for the selection of a particular material. A promising alternative seems to be screws and plates made of bone. Recently, xenogenic bone pins and screws have been invented for use in joint surgery. In this study, screws made of allogenic sheep and xenogenic human bone were analyzed in a vital and dynamic sheep-model and compared to conventional titanium screws over a standard period of bone healing of 56 days with a constant applied extrusion force. Biomechanical analysis and histomorphological evaluation were performed. After 56 days of insertion xenogenic screws made of human bone showed significantly larger distance of extrusion of on average 173.8 μm compared to allogenic screws made of sheep bone of on average 27.8 and 29.95 μm of the titanium control group. Severe resorption processes with connective tissue interposition were found in the histomorphological analysis of the xenogenic screws in contrast to new bone formation and centripetal vascularization of the allogenic bone screw, as well as in processes of incorporation of the titanium control group. The study showed allogenic cortical bone screws as a substantial alternative to titanium screws with good biomechanical properties. In contrast to other reports a different result was shown for the xenogenic bone screws. They showed insufficient holding strength with confirmative histomorphological signs of degradation and insufficient osseointegration. Before common clinical use of xenogenic osteosynthetic material, further evaluation should be performed.

  8. Re-use of explanted osteosynthesis devices: a reliable and inexpensive reprocessing protocol.

    PubMed

    Danesi, Valentina; Cristofolini, Luca; Stea, Susanna; Traina, Francesco; Beraudi, Alina; Tersi, Luca; Harman, Melinda; Viceconti, Marco

    2011-10-01

    Orthopaedic surgical treatments emphasizing immobilization using open reduction and internal fixation with osteosynthesis devices are widely accepted for their efficacy in treating complex fractures and reducing permanent musculoskeletal deformity. However, such treatments are profoundly underutilized in low- and middle-income countries (LMIC), partially due to inadequate availability of the costly osteosynthesis devices. Orthopaedic surgeons in some LMIC regularly re-use osteosynthesis devices in an effort to meet treatment demands, even though such devices typically are regulated for single-use only. The purpose of this study is to report a reprocessing protocol applied to explanted osteosynthesis devices obtained at a leading trauma care hospital. Explanted osteosynthesis devices were identified through a Register of Explanted Orthopaedic Prostheses. Guidelines to handle ethical issues were approved by the local Ethical Committee and informed patient consent was obtained at the time of explant surgery. Primary acceptance criteria were established and applied to osteosynthesis devices explanted between 2005 and 2008. A rigorous protocol for conducting decontamination and visual inspection based on specific screening criteria was implemented using simple equipment that is readily available in LMIC. A total of 2050 osteosynthesis devices, including a large variety of plates, screws and staples, were reprocessed using the decontamination and inspection protocols. The acceptance rate was 66%. Estimated labour time and implementation time of the protocol to reprocess a typical osteosynthesis unit (1 plate and 5 screws) was 25 min, with an estimated fixed cost (in Italy) of €10 per unit for implementing the protocol, plus an additional €5 for final sterilization at the end-user hospital site. This study was motivated by the treatment demands encountered by orthopaedic surgeons providing medical treatment in several different LMIC and their need for access to basic

  9. Quasi-simultaneous interaction method for solving 2D boundary layer flows over plates and airfoils

    NASA Astrophysics Data System (ADS)

    Bijleveld, H. A.; Veldman, A. E. P.

    2012-11-01

    This paper studies unsteady 2D boundary layer flows over dented plates and a NACA 0012 airfoil. An inviscid flow is assumed to exist outside the boundary layer and is solved iteratively with the boundary layer flow together with the interaction method until a matching solution is achieved. Hereto a quasi-simultaneous interaction method is applied, in which the integral boundary layer equations are solved together with an interaction-law equation. The interaction-law equation is an approximation of the external flow and based on thin-airfoil theory. It is an algebraic relation between the velocity and displacement thickness. The interaction-law equation ensures that the eigenvalues of the system of equations do not have a sign change and that no singularities occur. Three numerical schemes are used to solve the boundary layer flow with the interaction method. These are: a standard scheme, a splitting method and a characteristics solver. All schemes use a finite difference discretization. The three schemes yield comparable results for the simulations carried out. The standard scheme is deviating most from the splitting and characteristics solvers. The results show that the eigenvalues remain positive, even in separation. As expected, the addition of the interaction-law equation prevents a sign change of the eigenvalues. The quasi-simultaneous interaction scheme is applicable to the three numerical schemes tested.

  10. Nonunion After Clavicle Osteosynthesis: High Incidence of Propionibacterium acnes.

    PubMed

    Gausden, Elizabeth B; Villa, Jordan; Warner, Stephen J; Redko, Mariya; Pearle, Andrew; Miller, Andy; Henry, Michael; Lorich, Dean G; Helfet, David L; Wellman, David S

    2017-04-01

    The objective of this study was to review the etiology of clavicle nonunions after osteosynthesis and investigate the outcomes of a treatment with a single-stage revision. Retrospective case series. Orthopaedic specialty hospital. Twenty cases of nonunion after osteosynthesis of the clavicle were identified. The average age was 44 years (±13 years). In 9 cases, there was catastrophic implant failure that prompted the revision surgery. In the 18 cases in which cultures were taken, 15 of the 18 (83%) were treated as infections with a course of antibiotics. In 14 cases, the cultures were positive for Propionibacterium acnes. Fifteen patients were treated with a prolonged course of antibiotics. Eighteen patients had follow-up, and the average time to radiographic union was 22 weeks. There were no cases of nonunion after revision surgery. There is a high rate of positive cultures in cases of nonunion after osteosynthesis of the clavicle. This suggests the etiology of midshaft clavicle nonunions may result from a combination of suboptimal mechanical fixation and latent infection. Our treatment protocol of superior and anterior plating, interfragmentary fixation, bone grafting, and appropriate antimicrobial treatment of latent infections has resulted in 100% union rate. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

  11. [Osteosynthesis and cup revision in periprosthetic acetabulum fractures using a Kocher-Langenbeck approach].

    PubMed

    Schwabe, P; Märdian, S; Perka, C; Schaser, K-D

    2016-04-01

    Reconstruction/stable fixation of the acetabular columns to create an adequate periacetabular requirement for the implantation of a revision cup. Displaced/nondisplaced fractures with involvement of the posterior column. Resulting instability of the cup in an adequate bone stock situation. Periprosthetic acetabulum fractures with inadequate bone stock. Extended periacetabular defects with loss of anchorage options. Isolated periprosthetic fractures of the anterior column. Septic loosening. Dorsal approach. Dislocation of hip. Mechanical testing of inlaying acetabular cup. With unstable cup situation explantation of the cup, fracture fixation of acetabulum with dorsal double plate osteosynthesis along the posterior column. Cup revision. Hip joint reposition. Early mobilization; partial weight bearing for 12 weeks. Thrombosis prophylaxis. Clinical and radiological follow-ups. Periprosthetic acetabular fracture in 17 patients with 9 fractures after primary total hip replacement (THR), 8 after revision THR. Fractures: 12 due to trauma, 5 spontaneously; 7 anterior column fractures, 5 transverse fractures, 4 posterior column fractures, 1 two column fracture after hemiendoprosthesis. 5 type 1 fractures and 12 type 2 fractures. Operatively treated cases (10/17) received 3 reinforcement ring, 2 pedestal cup, 1 standard revision cup, cup-1 cage construct, 1 ventral plate osteosynthesis, 1 dorsal plate osteosynthesis, and 1 dorsal plate osteosynthesis plus cup revision (10-month Harris Hip Score 78 points). Radiological follow-up for 10 patients: consolidation of fractures without dislocation and a fixed acetabular cup. No revision surgeries during follow-up; 2 hip dislocations, 1 transient sciatic nerve palsy.

  12. Mechanical aspects of a multidirectional, angular stable osteosynthesis system and comparison with four conventional systems.

    PubMed

    Gbara, Ali; Heiland, Max; Schmelzle, Rainer; Blake, Felix

    2008-04-01

    Following open reduction, internal fixation of fractures of the mandible is predominantly achieved using plates and screws. Today, a multitude of osteosynthesis systems are available on the market. One therapy modality, primarily developed for orthopaedic surgery, is using angular stable osteosynthesis plate systems. The dominating principle of these is the bond between screw and plate following insertion. This principle of an "internal fixateur" results in a more stable fixation of the fragments associated with less compression of the bone surfaces. A new multidirectional osteosynthesis system (TiFix=Smartlock, Hamburg - Germany) was modified to fit the maxillofacial region and compared with four other well established osteosynthesis systems developed by Mondial, Medicon, Synthes, Leibinger-Stryker, one of these (Unilock by Synthes) being also angular stable. The resistance to deformation in varying directions was investigated following fixation in four different materials. The TiFix system proved more resistant to deformation even when mounted with fewer screws than the non-angular stable systems. This system results in greater stability even when fewer screws are used. For the clinician this means smaller access incisions, less soft tissue trauma, better aesthetic results, decreased duration of operation and a reduction of costs.

  13. Resorbable continuous-fibre reinforced polymers for osteosynthesis.

    PubMed

    Dauner, M; Planck, H; Caramaro, L; Missirlis, Y; Panagiotopoulos, E

    1998-03-01

    Four institutes from three countries in the European Union have collaborated under the BRITE-EURAM framework programme for the development of processing technologies for resorbable osteosynthesis devices. The devices should be continuous-fibre reinforced, and the technology should offer the possibility of orienting the fibres in the main trajectories. Poly-L-lactide and poly-L-DL-lactides have been synthesized for reinforcement fibres and matrix material, respectively. Melt-spun P-L-LA fibres of a strength of 800 MPa have been embedded in an amorphous P-L-DL-LA 70 : 30 matrix by compression moulding. Ethyleneoxide sterilized samples have been tested in vitro and in vivo. A satisfying bending modulus has been reached (6 GPa). Yet with 50% strength retention after ten weeks, fast degradation occurred that could be related to residual monomers. By this fast degradation 70% resorption after one year could be observed in the non-functional animal studies in rabbits. There was only a mild inflammatory reaction, which confirmed the good biocompatibility of the materials even during the resorption period. Further effort has to concentrate on the reduction of initial monomer content. The great advantage of the processing method to orient fibres in the device will be utilized in prototype samples, e.g. an osteosynthesis plate with fixation holes. Copyright 1998 Chapman & Hall

  14. Osteosynthesis system for vertebra arthrodesis

    DOEpatents

    Ameil, Marc; Huppert, Jean; Jermann, Jean-Louis; Marnay, Thierry

    2000-01-01

    An osteosynthesis system for vertebral arthrodesis, having at least one vertebral compression or distraction bar capable of extending over a portion at least of the rachis; at least one vertebral anchoring member having an end head with a spherical surface, an intermediate shank and a vertebral anchoring portion; and, associated with each anchoring member, a common support for receiving, coupling and immobilizing the vertebral anchoring member and the bar, the common support including a first concave housing for receiving the bar, a second concave housing, for receiving the spherical head, and a screwthreaded member, for immobilization of the bar and the anchoring member on the support, the immobilization member having at least one nut which is screwed onto a screwthreaded portion of the support. The first housing is disposed to the exterior of the screwthreaded portion of the support and is open laterally and upwardly, in opposite relationship to the rachis, so that the bar is immobilized by a peripheral portion of the nut.

  15. A comparative animal experimental study of differently dimensioned osteosynthesis screws used in the mid-face.

    PubMed

    Bähr, W; Lessing, R

    1993-12-01

    The soft tissue covering most of the midfacial skeleton is relatively thin. On account of this plates and screws of the 2 mm systems used in the osteosynthesis of this region can bulge and/or be palpable through the thin integument. This shortcoming has prompted the need to develop smaller systems. The present study was designed to investigate whether these more delicate systems are capable of withstanding the midfacial forces that come to bear during functional mastication. For the study a Le Fort I osteotomy was carried out in 10 sheep. The mobile maxilla was fixed with osteosynthesis plates and screws. This paper reports on 40 plates and 170 screws of two AO titanium systems. It compares the strength of 1.5 mm and 2.0 mm AO screws. The anchorage of the screws was assessed by evaluating the nature of contact between the screw and interfacial bone. The loaded screws showed no discernible differences in postoperative bone remodelling that could be correlated to the osteosynthesis systems. Although the experimental situation may not be directly comparable to the trauma or osteotomy case, this study lends credibility to the assumption that the 1.5 mm screw system could be used instead of the 2.0 mm system, even in mid-face areas associated with high masticatory loads.

  16. Uncemented revision stem for biological osteosynthesis in periprosthetic femoral fractures.

    PubMed

    Eingartner, C; Volkmann, R; Pütz, M; Weller, S

    1997-01-01

    Fractures around a femoral prosthesis have been treated with plating and additional cement, but this leads to further reduction of bone stock in the proximal femur. Since February 1992, we have dealt with this problem in 12 patients by revision using a long uncemented stem and distal interlocking combined with homologous bone grafting. Bony ingrowth and remodelling led to restoration of the proximal femur. After bone healing, removal of the distal interlocking screws converts the distal load transfer to the proximal anchoring of the revision stem so that osteointegration can occur in the trochanteric region. The clinical results were good in all the patients after a mean follow up of 23.5 months. This is a method which provides biological osteosynthesis and is especially indicated in younger patients.

  17. Midshaft Clavicular Fractures - Osteosynthesis with Minimally Invasive Technique

    PubMed Central

    Al-Sadek, Tabet A.; Niklev, Desislav; Al-Sadek, Ahmed

    2016-01-01

    BACKGROUND: Fractures of the clavicle are one of the most common fractures in modern orthopaedics and traumatology practice. Knowing the mechanism of trauma, and it’s pathophysiological elements, it’s clear distinction and it’s individual features are essential to the development of more new and effective methods for their treatment, and the minimising of postoperative complications. AIM: The aim of this paper was to present the results of our patients treated with minimally invasive plate osteosynthesis (MIPO). MATERIAL AND METHODS: Between January 2011 and March 2013, 12 patients were treated with MIPO technique. The mean age was 47.5 years (range, 16-79 years). Outcomes and complications of clinical treatment were reviewed. RESULTS: All fractures healed within a mean period of 4.9 months (range, 2-10 months). Regarding complications, there was no occurrence of implant failure or deep infection. There were no nonunions, but one 79-year-old man had a delayed union. Almost of all the cases didn’t need bending of the plate. Seven plates were removed by their hopes. And there weren’t any cases that required new incisions. CONCLUSIONS: A pre-contoured plate anatomically configured to fit the clavicle was easier to apply. MIPO technique for midshaft clavicle fractures may be a good option. PMID:28028406

  18. Solving TEAM problem 8 (slot in a plate) on a PC with ELEKTRA

    SciTech Connect

    Turner, L.R.

    1996-05-01

    This note presents the solution of TEAM Problem 8, a problem in nondestructive testing with eddy currents. A differential probe consisting of two thin coils 15 mm apart produces a signal. The computation used a fairly coarse three-dimensional mesh: fewer than 8000 elements, fewer than 20,000 equations. Subtracting the signal from a differential probe over a plate with no flaw from the signal over a plate with a flaw eliminated the effects of mesh coarseness. Even though this process requires taking the difference of two already small differences, the solution for the effect of the flaw agrees well with the three sets of experimental results as the results agree with each other. With the use of this process, the results do not show the effects of the edge of the plate that complicate the experimental results. On a 90-MHz Pentium PC, each position of the probe required a 10-minute solution for the case with the flaw and another 10-minute solution without the flaw.

  19. [Risk factors for failure of osteosynthesis. After periprosthetic fractures of the knee joint].

    PubMed

    Hanschen, M; Biberthaler, P

    2014-06-01

    The increasing number of implantations of total knee endoprostheses shows a correlation with an increase in revision operations and periprosthetic fractures. This article presents strategies for prevention of complications after open reduction internal fixation (ORIF) of periprosthetic fractures in addition to the classification of periprosthetic fractures of the knee joint. Osteosynthetic treatment is only applicable in some of the cases. Although special periprosthetic, angle locking plates are available for osteosynthesis, treatment of periprosthetic fractures of the knee joint remains a challenge with a high complication rate. If the prosthesis becomes loosened, the prosthesis should be replaced and ORIF should not be performed. The risk factors for failure of osteosynthesis include the prosthesis model and the associated reduction of residual bone and the mostly osteoporotic bone structures.

  20. [Compatibility and allergies of osteosynthesis materials].

    PubMed

    Thomsen, M; Thomas, P

    2017-02-01

    Metal implants for osteosynthesis are nowadays standard in orthopedic and trauma surgery. Steel implants, especially cerclages, bands and wires, can show more corrosion due to friction and lead to encapsulation in connective tissue with fluid borders even without loosening. Corrosion and fluid borders are potentially more susceptible to incompatibility and infections. Titanium implants have the advantage of better allergic compatibility. Problems may occur in material removal, especially with titanium implants because material fractures occur more frequently. Particularly with fixed angle constructions, the blocking of titanium-titanium bonding and/or screws in bone can occur by adhesion and ingrowth. Apart from single case reports there is no evidence that modern steel implants cause more allergic reactions than titanium; therefore, in the treatment by osteosynthesis the stability, risk of loosening, manifestation of allergies and the possibility of material removal must always be considered.

  1. Minimally invasive osteosynthesis technique for articular fractures.

    PubMed

    Beale, Brian S; Cole, Grayson

    2012-09-01

    Articular fractures require accurate reduction and rigid stabilization to decrease the chance of osteoarthritis and joint dysfunction. Articular fractures have been traditionally repaired by arthrotomy and internal fixation. Recently, minimally invasive techniques have been introduced to treat articular fractures, reducing patient morbidity and improving the accuracy of reduction. A variety of techniques, including distraction, radiographic imaging, and arthroscopy, are used with the minimally invasive osteosynthesis technique of articular fractures to achieve a successful repair and outcome.

  2. EXPERIENCE WITH miniplate osteosynthesis in THE MANAGEMENT OF mandibular fractures IN NORTHWEST NIGERIA.

    PubMed

    Akhiwu, B I; Efunkoya, A A; Omeje, K U; Amole, I O; Osunde, D O; Isa, L

    2015-01-01

    Fractures of the mandible are the commonest facial fractures and various treatment modalities exist like wire osteosynthesis and the use of miniplates and screw with most of the industrially developed world leaning towards the use of miniplates in the treatment of these fractures. The use has however been limited in developing countries (including Nigeria) mostly due to the cost of the plates and screws. To identify the versatility of miniplates in the treatment of mandibular fractures at a tertiary care centre in a developing country. All Subjects aged 16 years and above in whom mandibular fractures were diagnosed were recruited over a two year period. Patients were treated under general anesthesia using either the miniplates and screws or wire osteosynthesis while some patients had both miniplates and maxillo-maxillary fixation. A total of 94 patients were recruited for the study of which 89.4% were males while the age group 16 to 25 years constituted the majority. Though 29.8% of the study population was involved in business, only 9.6 % were professional motorcyclists. Motorcycle-related road traffic crashes constituted the commonest aetiologic agent with 41.5%, while combination fractures were the commonest fracture types seen in 54.3% of the study participants. Of the 94 patients, 77.7% had treatment of mandibular fractures by open reduction and immobilization with mini plates, while 7.4% had mini plates with Maxillo-maxillary fixation and 14.9% had wire osteosynthesis only. The site of fracture was significantly associated with the treatment modality (p= 0.02). This study showed that the choice of fixation appliances in mandibular fractures was influenced by the number of fractures and the multiplicity of fracture sites. Miniplates offered functionally stable fixation with minimum complications.

  3. Minimally invasive plate osteosynthesis fracture reduction techniques in small animals.

    PubMed

    Peirone, Bruno; Rovesti, Gian Luca; Baroncelli, Alessandro Boero; Piras, Lisa

    2012-09-01

    Indirect fracture reduction is used to align diaphyseal fractures in small animals when using minimally-invasive fracture repair. Indirect reduction achieves functional fracture reduction without opening the fracture site. The limb is restored to length and spatial alignment is achieved to ensure proper angular and rotational alignment. Fracture reduction can be accomplished using a variety of techniques and devices, including hanging the limb, manual traction, distraction table, external fixators, and a fracture distractor. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. [Osteosynthesis of mandible by means of solcoseryl dental adhesive paste].

    PubMed

    Zalyan, G; Zalyan, G

    2006-12-01

    The author presents the method of mandibular fractures treatment--osteosynthesis by means of solcoseryl dental adhesive paste. The use of solcoseryl dental adhesive paste accelerates the incarnation of wound and prevents the surgical complications.

  5. Osteosynthesis with Rush's double nail by the "Eiffel Tower" method in pseudarthrosis impacted in good position and retarded union.

    PubMed

    Zinghi, G F; Lanfranchi, R

    1980-04-01

    The "Eiffel Tower" method of nailing has not attracted the interest in Italy that it deserves, both because its utilisaton in fractures is difficult when closed reduction of the fragments is difficult, and because the attention of surgeons has been progressively directed towards osteosynthesis by open reduction. Our experience over many years, however, has convinced us that, in the diaphysis, only the intramedullary nail can provide the quick recovery that is not always forthcoming in the case of plating. We need only think of comminuted fractures, where the possible necrosis of one or more fragments demands a certain amount of prudence in allowing direct weight bearing. Therefore, in adopting the double Rush system, we extended its application to the intramedullary osteosynthesis of metaphyseal fractures. It was a short step from this to the surgical treatment of pseudarthrosis impacted in good position or retarded union, the results of which were encouraging, as demonstrated by the eighty-one cases reported in this paper.

  6. A Novel Biodegradable Polycaprolactone Fixator for Osteosynthesis Surgery of Rib Fracture: In Vitro and in Vivo Study

    PubMed Central

    Yu, Yi-Hsun; Fan, Chin-Lung; Hsu, Yung-Heng; Chou, Ying-Chao; Ueng, Steve W. N.; Liu, Shih-Jung

    2015-01-01

    Osteosynthesis surgery for rib fractures is controversial and challenging. This study developed a noval poly(ε-caprolactone) (PCL)-based biodegradable “cable-tie” fixator for osteosynthesis surgery for rib fractures. A biodegradable fixator specifically for fractured ribs was designed and fabricated by a micro-injection molding machine in our laboratory. The fixator has three belts that could be passed through matching holes individually. The locking mechanism allows the belt movement to move in only one direction. To examine the in vitro biomechanical performance, ribs 3–7 from four fresh New Zealand rabbits were employed. The load to failure and stress-strain curve was compared in the three-point bending test among native ribs, titanium plate-fixed ribs, and PCL fixator-fixed ribs. In the in vivo animal study, the sixth ribs of New Zealand rabbits were osteotomized and osteosynthesis surgery was performed using the PCL fixator. Outcomes were assessed by monthly X-ray examinations, a final micro-computed tomography (CT) scan, and histological analysis. The experimental results suggested that the ribs fixed with the PCL fixator were significantly less stiff than those fixed with titanium plates (p < 0.05). All ribs fixed with the PCL fixators exhibited union. The bridging callus was confirmed by gross, radiographic micro-three-dimensional (3D) CT, and histological examinations. In addition, there was no significant inflammatory response of the osteotomized ribs or the PCL-rib interface during application. The novel PCL fixator developed in this work achieves satisfactory results in osteosynthesis surgery for rib fractures, and may provide potential applications in other orthopedic surgeries. PMID:28793672

  7. Surface properties of Indonesian-made narrow dynamic compression plates.

    PubMed

    Dewo, P; Sharma, P K; van der Tas, H F; van der Houwen, E B; Timmer, M; Magetsari, R; Busscher, H J; van Horn, J R; Verkerke, G J

    2008-07-01

    The enormous need of orthopaedic (surgical) implants such as osteosynthesis plates is difficult to be fulfilled in developing countries commonly rely on imported ones. One of the alternatives is utilization of local resources, but only after they have been proven safe to use, to overcome this problem. Surface properties are some of the determining factors of safety for those implants. We have succeeded in developing prototype of osteosynthesis plate and the results indicate that Indonesian-made plates need improvement with regards to the surface quality of physical characterization.

  8. Skeletal stability and morbidity with self-reinforced P (L/DL) LA resorbable osteosynthesis in bimaxillary orthognathic surgery.

    PubMed

    Moure, Christophe; Qassemyar, Quentin; Dunaud, Olivier; Neiva, Cecilie; Testelin, Sylvie; Devauchelle, Bernard

    2012-01-01

    We present a retrospective study of 30 consecutive cases of bimaxillary orthognathic surgery with biodegradable self-reinforced poly-L/DL-lactide plates and tacks, for the same indication of Angle class III malocclusion. We reported the skeletal stability and morbidity at 1 year after surgery. All patients underwent bimaxillary procedure. We used self-reinforced poly-L/DL lactic acid copolymer. Stabilization of Lefort I osteotomy was achieved by four plates L-shaped. Sagittal split osteotomies were fixed by two straight-plates. Lateral cephalograms were taken before (T0), soon after (T1) and more than 1 year after surgery (T2). Eight standard landmarks and four angular measurements were taken into account. All differences of the landmarks and angles were measured at T1 and T2. The regular clinical follow-up was scheduled for a minimum period of 1 year. The mean advanced maxillary was 3.33 mm and the mean mandibular setback was 6.13 mm. The mean mandibular relapse was 2.2 mm (non-significant). Horizontal maxilla mean variation was 0.8 mm at 1 year at A-point. Vertical maxilla stability depends on maxillary movements: impaction stability is better as an isolated advancement or associated with pull-down movement. We found six inflammatory reactions and two of them need the removal of the plates. Bimaxillary orthognathic procedure with bioresorbable osteosynthesis is a reliable and reproducible method. Angle class III malocclusions could be entirely and successfully managed with bioresorbable osteosynthesis. The stability and suites at 1 year are comparable to titanium osteosynthesis. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  9. [Osteosynthesis treatment of periorbital fractures with the mandibular mesh system].

    PubMed

    Kurzeja, A

    1984-10-01

    We report about 11 patients with periorbital fracture. Blow-out fracture and patients with fracture of the anterior wall of the frontal sinus. Treatment was operative osteosynthesis. We used for that the Mandibular Mesh System of 3M Company, Germany. We usually observed the patients for one year and got a firm unification of the fragments, as well a good cosmetic success from the beginning. We had not seen any complications caused by the osteosynthesis material. The author consider the most important advantages of this system to be the considerably smaller measurements, the possibility to form the osteosynthetical sheets out of a lattice, the higher solidity of Titanium and the good formability.

  10. Finite element analysis of stress distribution on the mandible and condylar fracture osteosynthesis during various clenching tasks.

    PubMed

    Hijazi, Loai; Hejazi, Wael; Darwich, Mhd Ayham; Darwich, Khaldoun

    2016-12-01

    The purpose of the study was to evaluate the effect of clenching tasks on the stress and strain of condylar osteosynthesis screws and plates, as well as on the stress, strain distribution and displacement on the whole mandible and bone surrounding screws. Three-dimensional finite element models of the mandible, two straight four-hole plates and eight screws were established. Six static clenching tasks were simulated in this study: incisal clench (INC), intercuspal position (ICP), right unilateral molar clench (RMOL), left unilateral molar clench (LMOL), right group function (RGF) and left group function (LGF). Based on the simulation of the six clenching tasks, none of the inserted screws and plates were broken or bended. For the whole mandibular bone, the maximum von Mises stress and von Mises strain observed were yielded by the ICP. For the bone surrounding the inserted screws, the maximum von Mises stress and von Mises strain were yielded by the LMOL (49.2 MPa and 3795.1 μ). Clenching tasks had significant effects on the stress distribution on the condylar osteosynthesis and the bone surrounding screws. Contralateral occlusion task (LMOL) had the maximal results of von Mises stress and strain and healing problems could be occur, this result confirms the importance of soft diet after surgery.

  11. Osteosynthesis of the proximal femur anchorage of a cervical nail.

    PubMed

    el Banna, S; Burny, F; Bourgois, R; Donkerwolcke, M; Moulart, F

    1994-01-01

    One of the factors determining the stability of osteosynthesis is the mechanical strength of the bone fragments required for the anchorage of the implant. The aim is to study the driving of a Thornton nail in the proximal epiphysis of a human femur as a way to measure the strength of the trabecular bone and to predict the stability of the implanted system.

  12. [Minimal invasive osteosynthesis with cannulated screws in metacarpal fractures].

    PubMed

    Romo-Rodríguez, R; Arroyo-Berezowsky, C

    2017-01-01

    Metacarpal fractures comprise 18 to 44% of hand fractures. Fractures from the second to the fifth metacarpals are 88% of the metacarpal fractures and fractures of the fifth metacarpals are the most common. Fractures of the neck of the fifth metacarpal are about 20% of all the hand fractures. Most of these fractures can be treated conservatively with good functional results. However, for those neck and shaft unstable fractures that need surgical treatment, there is no gold standard for osteosynthesis. Recently, there have been reports of minimally invasive osteosynthesis using headless retrograde intramedullary cannulated screws with good functional results. We report our short term experience treating nine fifth metacarpal neck fractures, one fourth metacarpal neck fracture and a transverse fifth metacarpal shaft fracture that did not fulfill criteria for conservative treatment. We treated them with minimally invasive osteosynthesis using retrograde intramedullary headless cannulated screws. All patients showed radiographic healing and had full range of motion of the metacarpophalangeal joint at one month follow up except for one patient who suffered a dorsal mutilating hand injury along with a fifth metacarpal neck fracture. One patient had osteoporotic bone and we could not control height loss with screws, so we had to use k-wires. Minimally invasive osteosynthesis with cannulated headless retrograde screws is a good option to treat neck and transverse diaphyseal fractures of the metacarpals. It confers a stable construct that allows early range of motion and return to activities.

  13. [Minimally invasive intraoperative CT-guided correction of calcaneal osteosynthesis].

    PubMed

    Mayr, E; Häuser, H; Rüter, A; Bohndorf, K

    1999-03-01

    This article describes the CT-guided osteosynthesis of calcaneus fractures. This procedure is minimal invasive and offers the opportunity to reduce and to stabilize such fractures very exactly under intraoperative CT-controll only by stab-incisions. A running study will define the ranking of this method.

  14. [DHS osteosynthesis for proximal femoral fractures: infectious complications].

    PubMed

    Hrubina, M; Skoták, M; Běhounek St, J

    2013-01-01

    Evaluation of infectious complications in patients with proximal femoral fractures treated by osteosynthesis using dynamic hip screws (DHS). The group included 501 patients with 532 DHS procedures performed in the years 1996-2010. In 31 patients osteosynthesis was carried out bilaterally. Osteosynthesis was indicated for femoral neck fracture in 18 hips and for pertrochanteric fracture in 514 hips. Prophylactic antibiotic therapy was administered within 48 hours of surgery. The occurrence of infectious complications (surface and deep wound infection), presence of infectious agents, risk factors, and the course of treatment and its outcome were investigated. Of 532 fractures treated by DHS osteosynthesis, seven were infected (1.3%) as follows: one fracture of the femoral neck with methicillin-resistant Staphylococcus aureus, and, of six pertrochanteric fractures, four with Staphylococcus aureus, one with Escherichia coli and one with Staphylococcus epidermidis. Surface wound infection was diagnosed in one case (0.2%) and deep infection in six cases (1.1%). Five revision DHS procedures were carried out in five patients. One or more risk factors were found in each patient with infected DHS. The treatment of infection included wound dressing and abscess drainage without reoperation in two cases, implant removal in three, and implant removal with femoral head resection and spacer insertion in two cases. Second-stage total hip arthroplasty (THA) was performed in one case. Of the seven infected fractures, five (71%) healed successfully. DISCUSSION DHS osteosynthesis is a reliable method for treating proximal femoral fractures. The 1.3% infection rate in our group is comparable with other relevant studies. This complication is serious and requires prolonged treatment but is not as devastating as an infected THA. For the treatment of infected DHS osteosynthesis, standard methods from screw removal to second-stage THA were employed. Infectious complications following

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

    PubMed

    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.

  16. Finite element analysis of osteosynthesis screw fixation in the bone stock: an appropriate method for automatic screw modelling.

    PubMed

    Wieding, Jan; Souffrant, Robert; Fritsche, Andreas; Mittelmeier, Wolfram; Bader, Rainer

    2012-01-01

    The use of finite element analysis (FEA) has grown to a more and more important method in the field of biomedical engineering and biomechanics. Although increased computational performance allows new ways to generate more complex biomechanical models, in the area of orthopaedic surgery, solid modelling of screws and drill holes represent a limitation of their use for individual cases and an increase of computational costs. To cope with these requirements, different methods for numerical screw modelling have therefore been investigated to improve its application diversity. Exemplarily, fixation was performed for stabilization of a large segmental femoral bone defect by an osteosynthesis plate. Three different numerical modelling techniques for implant fixation were used in this study, i.e. without screw modelling, screws as solid elements as well as screws as structural elements. The latter one offers the possibility to implement automatically generated screws with variable geometry on arbitrary FE models. Structural screws were parametrically generated by a Python script for the automatic generation in the FE-software Abaqus/CAE on both a tetrahedral and a hexahedral meshed femur. Accuracy of the FE models was confirmed by experimental testing using a composite femur with a segmental defect and an identical osteosynthesis plate for primary stabilisation with titanium screws. Both deflection of the femoral head and the gap alteration were measured with an optical measuring system with an accuracy of approximately 3 µm. For both screw modelling techniques a sufficient correlation of approximately 95% between numerical and experimental analysis was found. Furthermore, using structural elements for screw modelling the computational time could be reduced by 85% using hexahedral elements instead of tetrahedral elements for femur meshing. The automatically generated screw modelling offers a realistic simulation of the osteosynthesis fixation with screws in the adjacent

  17. Finite Element Analysis of Osteosynthesis Screw Fixation in the Bone Stock: An Appropriate Method for Automatic Screw Modelling

    PubMed Central

    Wieding, Jan; Souffrant, Robert; Fritsche, Andreas; Mittelmeier, Wolfram; Bader, Rainer

    2012-01-01

    The use of finite element analysis (FEA) has grown to a more and more important method in the field of biomedical engineering and biomechanics. Although increased computational performance allows new ways to generate more complex biomechanical models, in the area of orthopaedic surgery, solid modelling of screws and drill holes represent a limitation of their use for individual cases and an increase of computational costs. To cope with these requirements, different methods for numerical screw modelling have therefore been investigated to improve its application diversity. Exemplarily, fixation was performed for stabilization of a large segmental femoral bone defect by an osteosynthesis plate. Three different numerical modelling techniques for implant fixation were used in this study, i.e. without screw modelling, screws as solid elements as well as screws as structural elements. The latter one offers the possibility to implement automatically generated screws with variable geometry on arbitrary FE models. Structural screws were parametrically generated by a Python script for the automatic generation in the FE-software Abaqus/CAE on both a tetrahedral and a hexahedral meshed femur. Accuracy of the FE models was confirmed by experimental testing using a composite femur with a segmental defect and an identical osteosynthesis plate for primary stabilisation with titanium screws. Both deflection of the femoral head and the gap alteration were measured with an optical measuring system with an accuracy of approximately 3 µm. For both screw modelling techniques a sufficient correlation of approximately 95% between numerical and experimental analysis was found. Furthermore, using structural elements for screw modelling the computational time could be reduced by 85% using hexahedral elements instead of tetrahedral elements for femur meshing. The automatically generated screw modelling offers a realistic simulation of the osteosynthesis fixation with screws in the adjacent

  18. Advantages of modified osteosynthesis in treatment of osteoporotic long bones fractures--experimental model.

    PubMed

    Sisljagić, Vladimir; Jovanović, Savo; Mrcela, Tomislav; Radić, Radivoje; Belovari, Tatjana

    2009-12-01

    In surgery of fractured long bones, a patient suffering from osteoporosis represents constant challenge to a surgeon and applied material and instruments that need to destroy as little as possible of an already damaged bone. One potential way of increasing the contact surface between the implants and osteoporotic bone is injection of bone cement (methyl-metacrilat, Palakos) into a prepared screw bed. This method of osteosynthesis was therefore subjected to experimental research to prove that application of modified osteosynthesis using bone cement in treatment of fractures in osteoporotic patients has advantage over the standard method of osteosynthesis because this modified method enables significantly greater firmness and stability of the osteosynthesis, which is the essential precondition of a successful fracture healing. The research was carried out on six macerated cadaveric preparations of a shin bone from the osteological collection from Institute for Anatomy, School of Medicine, University "J. J. Strossmayer". All samples of long bones were artificially broken in the middle part of the diaphysis and then standard osteosynthesis and modified osteosynthesis with screws filled with bone cement were performed on the samples. Results show that under identical static action of the moment of torsion in the modified osteosynthesis torsion angle deviation is lower than in the standard osteosynthesis. In modified osteosynthesis with bone cement the first results for angle of torsion deviation greater than 0.2 degrees were noticed after 120 minutes, while in the standard method of osteosynthesis they were noticed already in the first minute.

  19. Case Study: Osteosynthesis, Tenodesis Effect, and Side-to-Side Tendon Repair in Hand Transplantation.

    PubMed

    Drijkoningen, Tessa; Peters, Rinne M; Eberlin, Kyle R; Mudgal, Chaitanya S; Cetrulo, Curtis L

    2015-09-01

    Osteosynthesis and tendon repair are essential in upper extremity transplantation to optimally restore function. Transplant surgeons should be aware of all technical issues involved in osteosynthesis, tendon balancing, and tension setting as well as repair in an effort to optimize the function of the transplanted hand. Preoperative planning is vital to achieve good functional results. We present a case of successful osteosynthesis and side-to-side tendon repair, which led to a desirable functional outcome in hand transplantation.

  20. [Soft tissue protective and minimally invasive osteosynthesis for metacarpal fractures II-V].

    PubMed

    Dumont, C; Burchhardt, H; Tezval, M

    2012-09-01

    motion was limited in 6 patients after 8 weeks (range 6-12 weeks) with a deficit in flexion of finger to distal palmar crease of 1.0 cm (range 0.5-1.5 cm), 2 patients showed a deficit in finger extension of 10° in the metacarpophalangeal joint. One patient showed restricted finger extension of 15° in the proximal phalangeal joint after tendon rupture and tendon reconstruction. Complications were observed, such as circumscribed redness in two patients at the entry point of k-wires which was managed by early removal of the implant. Perforation of the k-wire occurred in one patient with subcapital and diaphyseal fracture and was managed by plate osteosynthesis. One diaphyseal transverse refracture healed after plate osteosynthesis, three circumscribed cases of paresthesia occurred, one at the entry point of the K-wires and two at the level of fracture.

  1. Improved Diagnosis of Infection Associated with Osteosynthesis by Use of Sonication of Fracture Fixation Implants

    PubMed Central

    Yano, Maysa Harumi; Klautau, Giselle Burlamaqui; da Silva, Cely Barreto; Nigro, Stanley; Avanzi, Osmar; Mercadante, Marcelo Tomanink

    2014-01-01

    Previous studies have shown that sonication fluid cultures from removed orthopedic devices improved the microbiological diagnosis of orthopedic implant-associated infections; however, few of these investigations have applied sonication to the removed fracture fixation devices to evaluate its utility for the diagnosis of osteosynthesis-associated infection (OAI). We compared sonication fluid to conventional tissue cultures from 180 subjects with different sizes of plates and screws (n = 156), spinal implants (n = 26), and intramedullary nails (n = 3), of whom 125 and 55 subjects had OAI and noninfected osteosynthesis (NIO), respectively. The sensitivity for detecting OAI was 90.4% for sonication fluid culture and 56.8% for periprosthetic tissue cultures (P < 0.05), and the specificities were 90.9% and 96.4%, respectively. Sonication fluid culture detected more pathogens than peri-implant tissue culture (113 versus 71; P < 0.001), while polymicrobial infections were diagnosed by sonication fluid cultures and tissue cultures in 20.8% and 8% (P < 0.001), respectively. Microbiological diagnosis was achieved exclusively by sonication fluid cultures for 47 (90.4%) subjects, and among them, 18 (38.3%) had previously received antibiotics, whereas in five (9.6%) infected subjects, tissue culture was positive and the sonication fluid culture was negative. Among 39 (31.2%) OAI cases receiving antibiotics, the identification of the organisms occurred in 38.5% and 82.1% of the tissue and sonication fluid cultures, respectively (P < 0.049). We demonstrated that sonication fluid culture from removed osteosyntheses has the potential for improving the microbiological diagnosis of OAI. PMID:25232155

  2. Aseptic nonunion of the tibia treated by intramedullary osteosynthesis.

    PubMed

    Gualdrini, G; Rollo, G; Montanari, A; Zinghi, G F

    1996-01-01

    The authors report 52 cases of aseptic nonunion of the tibia treated by intramedullary osteosynthesis. The means of synthesis used were the Küntscher nail, the Eiffel Tower Rush nail, and the Grosse-Kempf nail. Which means of synthesis was used depended on the site and the features of the nonunion. Healing occurred in all of the cases after an average of 5 months. Mean follow-up was 4.5 years.

  3. [Osteosynthesis in facial bones: silicon nitride ceramic as material].

    PubMed

    Neumann, A; Unkel, C; Werry, C; Herborn, C U; Maier, H R; Ragoss, C; Jahnke, K

    2006-12-01

    The favorable properties of silicon nitride (Si3N4) ceramic, such as high stability and biocompatibility suggest its biomedical use as an implant material. The aim of this study was to test its suitability for osteosynthesis. A Si3N4 prototype minifixation system was manufactured and implanted for osteosynthesis of artificial frontal bone defects in three minipigs. After 3 months, histological sections, CT and MRI scans were obtained. Finite element modeling (FEM) was used to simulate stresses and strains on Si3N4 miniplates and screws to calculate survival probabilities. Si3N4 miniplates and screws showed satisfactory intraoperative workability. There was no implant loss, displacement or fracture. Bone healing was complete in all animals and formation of new bone was observed in direct contact to the implants. Si3N4 ceramic showed a good biocompatibility outcome both in vitro and in vivo. This ceramic may serve as biomaterial for osteosynthesis, e.g. of the midface including reconstruction of the floor of the orbit and the skull base. Advantages compared to titanium are no risk of implantation to bone with mucosal attachment, no need for explantation, no interference with radiological imaging.

  4. [METHOD OF OSTEOSYNTHESIS OF SUPRACONDULAR FRACTURES OF THE HUMERUS].

    PubMed

    Neverov, V A; Chernyaev, S N; Shinkarenko, D V

    2015-01-01

    A treatment of fractures of distal metadiaphysis of the humeral bone remains an actual problem of modern traumatology at present time. This is associated with immediate proximity of the radial nerve and risk of iatrogenic injury in external fixation, presence of short distal fragment, comminuted nature of fracture, complexity of treatment method selection, need of extensible approach. Biomechanical features of different fixators were analyzed in consideration of presence of short distal fragment, traumatic of. external fixation and risk of iatrogenic injury of the nerve. The authors suggested the method of osteosynthesis of the humerus by using blocking osteosynthesis with preliminary extension of intra-medullary canal of distal fragment for obtaining stable osteosynthesis (priority No 2014105323 from 14.02.2014). The proposed method allowed avoiding the iatrogenic neuropathy of the radial nerve, providing the stability of fixation higher, than in case of external fixation. It excludes the need of external immobilization and combines the period of bony union with the period of rehabilitation and socially integrates the patient in minimal terms.

  5. Stability of osteosynthesis with bicortical screws placed in a triangular shape in mandibular sagittal split 5 mm advancement osteotomy: biomechanical tests.

    PubMed

    Hadi, Geha; Karine, Bruyere-Garnier; Yves, Caire; Pierre, Lapelerie

    2010-12-01

    Sagittal split ramus osteotomy (SSRO) is common in orthognathic surgery, and osteosynthesis with bicortical titanium screws placed in a triangular shape is used for stabilisation. We biomechanically tested the stability of this configuration in 5 mm advancement SSRO with condylar replacement in the initial position using six fresh frozen human mandibles raised subperiosteally for surgical simulation. Osteotomy was done after marking the initial positions of the condyles and the symphysis on graph paper. The condyle was set in its initial position and the symphysis advanced exactly 5mm; this position was maintained during osteosynthesis using 2.7 mm bicortical screws placed in a triangular shape. The mandible was then placed horizontally on the testing machine and a continuous static force was applied perpendicularly at a displacement speed of 5 mm/min. A stainless steel plate was used to transmit the forces independently of the teeth. A mean force of 129.6 Newtons (N) was applied at the elastic/plastic limit on an effort/displacement curve, which is well beyond the maximal mean (SD) chewing forces of 21 N (14) measured after bilateral sagittal split ramus osteotomy (BSSRO). A linear equation relating force to displacement was worked out from this experiment. Osteosynthesis using three bicortical screws mounted triangularly after advancement SSRO of 5 mm is experimentally stable, and our results could be used experimentally to compare two osteosyntheses using the equation. Copyright © 2009 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. Augmented osteosynthesis of OTA 44-B fractures in older patients: a technique allowing early weightbearing.

    PubMed

    Assal, Mathieu; Christofilopoulos, Panayiotis; Lübbeke, Anne; Stern, Richard

    2011-12-01

    To determine the effectiveness of an augmented technique of osteosynthesis in allowing early weightbearing in older patients with OTA 44-B (Danis-Weber B) fractures. Case series. University Level I trauma center. Thirty-six patients, nonconsecutive, with OTA 44-B fractures. Augmented internal fixation using an intramedullary wire, lateral plate, and screw augmentation with polymethylmethacrylate. Healed fracture with no loss of reduction. American Orthopaedic Foot and Ankle Society score; percentage of patients who returned to prefracture function. All patients began weightbearing as tolerated in a removable brace at a mean of 13.5 days postoperatively. Thirty patients were available for follow-up at a minimum of 12 months (range, 12-14 months). All fractures healed with no loss of reduction. The mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score was 84.9 (range, 74-100), and 90% of patients returned to prefracture function. There were two infections, one in a 74-year-old diabetic woman and the other in a 92-year-old woman with pre-existing arterial insufficiency and a small ulcer over the tip of the second toe. Augmented internal fixation consisting of intramedullary wire, lateral plate, and screw augmentation with polymethylmethacrylate may allow for very early weightbearing without risk of secondary loss of reduction or disruption of the ankle mortise in older patients with OTA 44-B (Danis-Weber B) malleolar fractures.

  7. Percutaneous osteosynthesis of Galeazzi fracture-dislocation.

    PubMed

    Gadegone, Wasudeo M; Salphale, Yogesh; Magarkar, Ds

    2010-10-01

    A Galeazzi fracture is defined as a fracture of the radius associated with dislocation of the distal radio-ulnar joint (DRUJ). The conventional surgical technique of nailing does not give enough stability and open reduction, internal fixation with the plate is associated with numerous complications. The stacked nailing for the management of these injuries provides adequate stability, maintains the relationship of the DRUJ and promotes uneventful union by closed technique. The purpose of this study is to evaluate the results of simple, user-friendly, low cost elastic stacked nailing for the management of Galeazzi fracture dislocation. We treated 22 young adults with fresh Galeazzi fracture-dislocation of the forearm, from January 2004 to January 2008, by percutaneous fixation of fracture by stacked elastic nailing at our institute. There were 19 males and three females and the age group ranged from 20-56 years (average 35 years). Surgery was performed within 48 to 72 hours under the guidance of image intensifier. Medullary cavity was filled with two elastic titanium nails having unequal lengths and diameter. One nail acts as a reduction nail and the other acts as a stabilizing nail. The results were evaluated using Mikic criteria based on union, alignment, relationship of the DRUJ, and movements at the inferior radio ulnar joint, elbow and wrist. In six cases, following radiological union, nails in the radius were extracted between six to nine months after operation because of discomfort complained by the patient at site of insertion. After one year follow-up, 18 patients had excellent, four had fair results. Closed reduction and internal fixation of Galeazzi fracture by two elastic rods re-establishes the normal relationship of the fractured fragments and the DRUJ without repair of the ligaments. The stability is achieved by the flexibility and elasticity of the nails, crowding of the medullary canal and anchorage they gain in the radial diaphysis. Elastic nailing

  8. Percutaneous osteosynthesis of Galeazzi fracture-dislocation

    PubMed Central

    Gadegone, Wasudeo M; Salphale, Yogesh; Magarkar, DS

    2010-01-01

    Background: A Galeazzi fracture is defined as a fracture of the radius associated with dislocation of the distal radio-ulnar joint (DRUJ). The conventional surgical technique of nailing does not give enough stability and open reduction, internal fixation with the plate is associated with numerous complications. The stacked nailing for the management of these injuries provides adequate stability, maintains the relationship of the DRUJ and promotes uneventful union by closed technique. The purpose of this study is to evaluate the results of simple, user-friendly, low cost elastic stacked nailing for the management of Galeazzi fracture dislocation. Materials and Methods: We treated 22 young adults with fresh Galeazzi fracture-dislocation of the forearm, from January 2004 to January 2008, by percutaneous fixation of fracture by stacked elastic nailing at our institute. There were 19 males and three females and the age group ranged from 20-56 years (average 35 years). Surgery was performed within 48 to 72 hours under the guidance of image intensifier. Medullary cavity was filled with two elastic titanium nails having unequal lengths and diameter. One nail acts as a reduction nail and the other acts as a stabilizing nail. The results were evaluated using Mikic criteria based on union, alignment, relationship of the DRUJ, and movements at the inferior radio ulnar joint, elbow and wrist. Results: In six cases, following radiological union, nails in the radius were extracted between six to nine months after operation because of discomfort complained by the patient at site of insertion. After one year follow-up, 18 patients had excellent, four had fair results. Conclusion: Closed reduction and internal fixation of Galeazzi fracture by two elastic rods re-establishes the normal relationship of the fractured fragments and the DRUJ without repair of the ligaments. The stability is achieved by the flexibility and elasticity of the nails, crowding of the medullary canal and

  9. Supraintercondylar fractures of the humerus--treatment by the Vigliani osteosynthesis.

    PubMed

    Fama, G

    1987-03-01

    Nineteen cases of supraintercondylar fractures of the humerus treated by the Vigliani osteosynthesis technique are described. This consists of wide transolecranon exposure of the fracture, stabilisation of the epiphyseal fragments with a transcondylar screw, and of the metaphyseo-epiphyseal junction with two condylo-diaphyseal "Eiffel Tower" Kirschner wires. The ulnar nerve is transposed anteriorly and the operation is carried out early in order to prevent neural disturbances and intra and/or periarticular ossification. The results confirm the validity of this method, which respects the delicate structure of this part of the humerus. Postoperative plaster is necessary as an indispensable complement to "minimum" osteosynthesis but this is quite free from risk. The importance of careful and gradual mobilisation of the elbow is also confirmed. Finally, this method combines the advantages of stable osteosynthesis in compression (screw and nut) at the epiphyseal site, with those of elastic osteosynthesis (Kirschner wires) at the metaphyseo-epiphyseal junction.

  10. [Segmental posterior spinal osteosynthesis using the Luque-Dove technic].

    PubMed

    Kerboul, B; Courtois, B

    1989-03-01

    The Hartshill frame is method for segmental osteosynthesis of the spine. It is attached at each vertebral level by sub-laminal metal wires. This frame therefore ensures immediate stability and avoids the need for a post-operative corset. It enables correction of frontal deformities (scoliosis) whilst retaining sagittal physiological curves (lumbar lordosis--dorsal kyphosis). It ensures the fixation of posterior spinal instability (destruction of posterior ligaments and bone tissue, spondylolisthesis, etc.). The Hartshill frame can thus be seen to be a posterior brace. It has been used in 92 patients, (53 lumbar disorders, 10 cases of scoliosis, 4 of kyphosis, 19 tumors, 6 fractures). Results are generally entirely satisfactory in the mid term apart from fractures (recurrence of initial displacement). Specific complications are of a neurological nature (cases of cutaneous hyperesthesia, one severe motor deficit) long-term problems with device and material are uncommon; rupture of sub-laminar wire 8 cases; secondary incurving of frame 1 case.

  11. [Historical review of the treatment of fractures. Contribution of the Belgian surgery to the origin and development of osteosynthesis].

    PubMed

    Andrianne, Y; Hinsenkamp, M

    2011-01-01

    The word osteosynthesis was proposed by A. Lambotte in 1904. His definition, given in 1908, is still valid today: "Osteo-synthesis is the artificial contention of the bone fragments of fractures, by special devices acting directly on bones, exposed or not, with the aim to strongly fix them in their original position". The authors review the methods of contention before the invention of osteosynthesis and later the developments of bone fixation techniques. They insist in particular on the durable innovations of various pioneers including A. Lambotte, R. Danis, R. Hoffmann and G. Küntscher. The School of Brussels has been implicated in the developments and conceptualisation of osteo-synthesis.

  12. Single cycle to failure in bending of three standard and five locking plates and plate constructs.

    PubMed

    Blake, C A; Boudrieau, R J; Torrance, B S; Tacvorian, E K; Cabassu, J B; Gaudette, G R; Kowaleski, M P

    2011-01-01

    To evaluate the biomechanical properties of standard and locking plates in bending. We hypothesised that titanium (Ti) constructs would have the greatest deformation and that String of Pearl (SOP) constructs would have the greatest strength and stiffness, and would behave differently compared to plates alone. Dynamic compression plates (DCP), stainless steel (SS) limited contact (LC)-DCP®, Ti LC-DCP, locking compression plates (LCP), 10 mm and 11 mm advanced locking plate system (ALPS 10 / 11), SOP and Fixin plates were evaluated individually and as constructs applied to a validated bone model simulating a bridging osteosynthesis. Bending stiffness and strength were compared using one-way ANOVA with post hoc Tukey, and unpaired t-test (p <0.05). The SOP plates had significantly greater stiffness than all other plates; Ti LC-DCP, ALPS 10 and Fixin plates had significantly lower stiffness than all other plates. The SOP constructs had the highest mean bending stiffness, and strength that was significantly different from only the Ti LC-DCP, ALPS 10 and Fixin constructs. The ALPS 10 constructs had the lowest mean bending stiffness, and strength that was significantly different from only ALPS 11 and SOP constructs. Comparison of bending structural stiffness of plates versus constructs showed a significant difference in all plate pairs except for the DCP and ALPS 10. Due to differing plate construct properties inherent to these diverse implant systems, identical approaches to fracture management and plate application cannot be applied.

  13. [Dynamic Hip Screw Osteosynthesis for Proximal Femoral Fractures in Patients with Coxarthrosis].

    PubMed

    Hrubina, M; Skoták, M; Letocha, J

    2015-01-01

    Evaluation of a group of patients with coxarthrosis who sustained fractures of the proximal femur and were treated by dynamic hip screw (DHS) osteosynthesis. The group comprised 23 DHS osteosyntheses in 22 patients treated between the years 1997 and 2012. The indication to osteosynthesis in all 23 cases was a stable pertrochanteric fracture of the femur; all patients had grade III or grade IV coxarthrosis (assessed on the Kellgren & Lawrence scale) and their physical health was classified as ASA 3 or 4. Preventive antibiotic therapy was administered within 48 hours of surgery. The evaluated factors included operative time, blood loss, specific complications such as infection, osteosynthetic material fractiure or osteosynthesis failure, requirement of revision surgery, post-operative mobility and patient survival. The follow-up was 2 years. The operative time was 35 min to 85 min (average, 49 min); blood losses ranged from 50 ml to 450 ml (average, 189 ml). Of the 23 hips, infectious complication was found in one (4.3%) and osteosynthetic material fractiure also in one (4.3%). There was no necessity of revision surgery due to osteosynthesis failure, nor any conversion to total hip arthroplasty. Postoperative mobility (with use of walking aids or forearm crutches) was achieved in 17 (77.3%) patients. The average survival of the patients was 6.3 months, the range from 7 days to 3 years. DHS osteosynthesis is a reliable method for the treatment of proximal femoral fractures due to osteoporosis. These fractures in patients with coxarthosis are primarily indicated to total hip arthroplasty. However, this is questionable in polymorbid elderly patients in whom hip replacement carries high risk. In such patients DHS osteosynthesis is preferred as a less risky procedure. DHS osteosynthesis is indicated for stable pertrochanteric fractures of the femur in a limited number of patients with advanced coxarthrosis in whom total hip replacement would be associated with an undue

  14. Enhancing fixation strength in periprosthetic femur fractures by orthogonal plating-A biomechanical study.

    PubMed

    Lenz, Mark; Stoffel, Karl; Gueorguiev, Boyko; Klos, Kajetan; Kielstein, Heike; Hofmann, Gunther O

    2016-04-01

    Orthogonal plate osteosynthesis enhances fixation stability in periprosthetic femur fractures. Another option are locking attachment plates (LAP) allowing bicortical locking screw placement lateral to the prosthesis stem. Stability of lateral plate osteosynthesis with two LAP (2LAP) was compared to anterolateral orthogonal plate osteosynthesis (OP) with one LAP in a periprosthetic femur fracture model. In six pairs of fresh frozen human femora with cemented Charnley hip prosthesis, a transverse osteotomy was set distal to the tip of the prosthesis simulating a Vancouver type B1 fracture. Each pair was instrumented using a plate tensioner with either one lateral plate and two LAP, or two orthogonal anterolateral plates and one LAP. Stiffness was determined in a four-point-bending test prior to cyclic testing (2Hz) with physiologic profile and progressively increasing load up to catastrophic construct failure. Paired t-test and Wilcoxon-signed-rank test were used for statistical evaluation at a level of significance p = 0.05. The OP construct exhibited a significantly higher number of cycles and load to failure (39,627 cycles ± 4,056; 4,463 N ± 906) compared to the 2LAP construct (32,927 cycles ± 3,487; 3,793 N ± 849), p < 0.01. Mediolateral bending and torsional stiffness of the OP (1610 N/mm ± 249; 16.9 Nm/mm ± 6.3) were significantly higher compared to 2 LAP (1077 N/mm ± 189; 12.1 Nm/mm ± 3.9), p = 0.03 for both comparisons. Orthogonal plate osteosynthesis is a valuable option in periprosthetic fracture surgery, offering increased stability compared to a single lateral plate fixed with two LAP.

  15. Anatomical variations of the proximal radius and their effects on osteosynthesis.

    PubMed

    Giannicola, Giuseppe; Manauzzi, Erica; Sacchetti, Federico M; Greco, Alessandro; Bullitta, Gianluca; Vestri, Annarita; Cinotti, Gianluca

    2012-05-01

    In fractures of the radial head and neck requiring open reduction and internal fixation, osteosynthesis may be safely applied in a limited zone. We conducted a morphometric study of the proximal radius at the level of the safe zone to identify different morphologic types of this anatomical region. We analyzed 44 dried cadaveric radii. We measured the whole length of the radius, the length of the neck and head, and the minimum and maximum diameter of the radial head. The morphologic aspect of the neck-head curvature of the safe zone was evaluated qualitatively and quantitatively. The proximal radius at the level of the safe zone exhibited different radii of bending. In particular, we identified a morphologic type A, which showed a flat profile (25% of cases), morphologic types B and C, which showed a low concave curvature (64%), and a marked concave curvature (11%), respectively, of the safe zone. The profile of the proximal radius in the safe zone shows substantial morphologic variations that should be taken into account when operating on fractures of the proximal radius, to avoid malunions, pain, and stiffness of the elbow joint. A preoperative radiograph of the contralateral uninjured radius may be helpful in selecting the most appropriate internal fixation device to reconstruct the proximal radius after comminuted fractures. Knowledge of the proper bending radius of the safe zone allows the surgeon to select the most appropriate plate, and to achieve good fracture reduction and anatomical restoration of the proximal radius. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  16. [Arthroscopic percutaneous osteosynthesis of low-energy tibial plateau fractures].

    PubMed

    Zhou, Ziguang

    2009-11-01

    To explore the treatment of low-energy tibial plateau fractures with arthroscopic percutaneous osteosynthesis. From May 2004 to April 2008, 27 cases of tibial plateau fractures were treated with arthroscopic management. There were 19 males and 8 females, aged 18-61 years old (mean 41.5 years old). Fracture was caused by traffic accident in 18 cases, by falling from height in 6 cases, by bruise in 2 cases, and by other in 1 case. There were 8 cases of type I, 12 cases of type II, 2 cases of type III and 5 cases of type IV according to Schatzker classification. The time from injury to operation was 3-15 days (mean 5.2 days). After symptomatic managements were performed arthroscopically in 11 cases of meniscus tear, 4 cases of medial collateral ligament rupture of knee joint, 3 cases of anterior cruciate ligament rupture of knee joint and 2 cases of cartilage fracture resulting in joint bodies, fracture was reduced and fixed with 2 or 4 cannulated screws (7 mm in diameter). Autograft of ilium was given 6 cases of bone defect. Early functional exercise was done. The operation time was 55-150 minutes (mean 93 minutes); the hospitalization days were 7-22 days (mean 16 days). All incision healed primarily. Edema of the affected leg occurred in all patients and subsided after 3 days of symptomatic management. In one patient who did not cooperate in functional exercise, adhesion occurred and normal function was recovered after by manual dissolution under conditions of anesthesia after 3 months of operation. All patients were followed up 6-36 months (mean 16.6 months). The range of motion of knee joint was 105-140 degrees (mean 121 degrees). According to Lysholm scale of knee joint, the score was 72-100 points (mean 93.6 points) 6 months after operation. The X-ray film showed no signs of osteoarthritis. Arthroscopic percutaneous osteosynthesis yields satisfactory results and can be accepted as an alternative and effective method for the treatment of low-energy tibial plateau

  17. Numerical and experimental analyses of drills used in osteosynthesis.

    PubMed

    Basiaga, Marcin; Paszenda, Zbigniew; Szewczenko, Janusz; Kaczmarek, Marcin

    2011-01-01

    This paper presents the results of numerical analysis and experimental studies of the process of bone drilling using drills applied in osteosynthesis procedures. In the studies, two surgical drills with a diameter d = 4.5 mm and varying in drill point geometry 2κ were used. Thermal analysis based on FEM allowed determining the distribution of temperatures generated in the bone as a function of rotational speed of the drill. The results indicate that both drill point geometry and rotational speed of the drill have influence on temperatures generated in bone tissue. Additionally, the range was determined for possible values of rotational speed, which does not initiate the process of thermal necrosis of bone. The experimental studies of the process of drilling in a femur model showed the impact of drill point geometry on the values describing the cutting process. It was concluded that the highest values of torques and axial forces during cutting occur in the tools with angle 2κ₂ = 120°.

  18. Drill Free Screws: a new form of osteosynthesis screw.

    PubMed

    Heidemann, W; Gerlach, K L; Gröbel, K H; Köllner, H G

    1998-06-01

    Although the application of self-tapping and non self-tapping screws is virtually universal in cranio-maxillofacial surgery, the inevitable, time consuming procedure of drilling a pilot hole has some potential disadvantages, such as damage to nerves, tooth roots or tooth germs, thermal necrosis of the bone and drill bit breakage. Drill Free Screws (DFS) are a recently developed type of osteosynthesis screws, having a tip like a cork screw and specially formed cutting flutes which enable insertion of the screws without drilling. DFS 1.5 and 2 mm were inserted into discs of wood, polyvinylchloride (PVC) and porcine mandibular bone of varying thicknesses between 2 and 4 mm. The values of insertion torque and maximum torque were recorded using an electric torque tester. Thereafter, the screws were inserted with a fixed torque and uniaxial pull out tests were performed. In comparison with this, the same procedure was performed using 1.5 and 2 mm self-tapping titanium screws. Ten trials for each screw-material-combination were conducted to determine insertion torque, maximum torque and pull out analysis. The results showed that the holding power of DFS lay between 70 and 104% of the holding power of self-tapping titanium screws; only in PVC was the difference more than 15%.

  19. Problem Solving

    ERIC Educational Resources Information Center

    Kinsella, John J.

    1970-01-01

    Discussed are the nature of a mathematical problem, problem solving in the traditional and modern mathematics programs, problem solving and psychology, research related to problem solving, and teaching problem solving in algebra and geometry. (CT)

  20. [Osteosynthesis in the Surgical Treatment of Prognathism: State of The Art].

    PubMed

    Durão, Nuno; Amarante, José

    2017-03-31

    Prognathism is a common skeletal facial abnormality, associated with class III malocclusion, often with repercussions in quality of life. In addition to orthodontic treatment, sagittal split ramus osteotomy is the most common technique for its correction, and segment osteosynthesis is an important element of the post-surgical outcome. A search for relevant literature was conducted in the PubMed/MEDLINE database and in other relevant sources. The stability of different fixation methods, their repercussions on inferior alveolar nerve lesions, and the type of material are among the most researched subjects. Recent research about the type of osteosynthesis applied in the sagittal split ramus osteotomy for mandibular setback is discussed. Miniplates appear to be the better option for fixation of sagittal split osteotomy for mandibular setback. Bioabsorbable osteosynthesis may be an acceptable alternative to titanium.

  1. Are there too many screw holes in plates for fracture fixation?

    PubMed

    Lv, Hongzhi; Chang, Wenli; Yuwen, Peizhi; Yang, Na; Yan, Xiaoli; Zhang, Yingze

    2017-04-21

    Implant breakage after the fixation of traumatic fractures is rare; however, when it occurs, it is debilitating for the patients and a challenge for surgeons. The purpose of this study was to analyze and identify the independent risk factors for implant breakage of traumatic fractures treated with plate osteosynthesis. We reviewed the medical records of patients with a fracture to any part of their four extremities, clavicle, hand or foot, who underwent surgical plate osteosynthesis from January 2005 to January 2015, and who sustained a subsequent implant breakage. Kaplan-Meier univariate and multivariate Cox regressions were performed to identify independent associations of potential risk factors for implant breakage in this cohort. We identified 168 patients who underwent plate osteosynthesis surgery and had subsequent internal fixator breakage. The mean patient age was 40.63 ± 16.71 years (range, 3 to 78 years), with 72.0% (121) males and 28.0% (47) females. The average time between surgery and implant breakage was 12.85 ± 12.42 months (range, 1 to 60 months). In the final regression model, we show that inserting screws close to the fracture line is an independent predictive risk factor for implant breakage (HR, 2.165, 95%CI, 1.227 to 3.822; P = 0.008). We found that inserting screws close to the fracture line is related to an increased risk of internal fixator breakage in patients treated with plate osteosynthesis after fracture. Plates with additional holes likely lead to an increased risk of implant breakage, presumably because surgeons cannot resist inserting extra screws into the holes adjacent to the fracture line, which reduces the stiffness of the plate. We have addressed this problem by designing a plate without holes adjacent to the fracture line.

  2. [Hip fractures in the elderly : Osteosynthesis versus joint replacement].

    PubMed

    Knobe, M; Siebert, C H

    2014-04-01

    Osteoporotic fractures of the femoral neck and trochanteric region pose an ever-expanding existential problem both for the individual and for society. Despite numerous innovations and advances regarding implant design, mortality and the systemic and mechanical complication rates remain high. Depiction of treatment options for femoral neck fractures and trochanteric femur fractures in the elderly comparing joint replacement and osteosynthesis. A search of the Medline, Embase and Cochrane databases was carried out focusing on hip fracture treatment. Randomized or quasi-randomized controlled trials, meta-analyses and reviews comparing joint replacement or fixation implants in the elderly were included. Displaced fractures of the femoral neck often require total joint arthroplasty whereas trochanteric fractures are amenable to internal fixation. Cemented total hip replacement as opposed to cementless techniques is recommended in the elderly and yields good functional results in active patients. Hemiarthroplasty is the treatment of choice in infirm patients with multiple comorbidities and cognitive impairment. Trochanteric fractures (AO/OTA types A1 and A2) can be successfully treated with intramedullary or extramedullary fixation. Adequate reduction and stable fixation are prerequisites for uneventful healing. A meticulous operative technique can prevent iatrogenic complications. In summary, there are many parameters affecting the outcome in the treatment of fragility and hip fractures. Technical features as well as surgeon characteristics play an important role and the ultimate solution has yet to be developed. Even though fracture morphology may indicate a specific treatment option, patient characteristics play an important role in decision-making. The development of centers of fragility fracture care in Germany could help to lower the complication rate and increase quality of life in hip fracture patients in the future.

  3. NASA Solve

    NASA Image and Video Library

    NASA Solve lists opportunities available to the general public to contribute to solving tough problems related to NASA’s mission through challenges, prize competitions, and crowdsourcing activities...

  4. Development and Clinical Evaluation of MatrixMANDIBLE Subcondylar Plates System (Synthes).

    PubMed

    Cortelazzi, Roberto; Altacera, Mario; Turco, Monica; Antonicelli, Viviana; De Benedittis, Michele

    2015-06-01

    In this article, authors report the different steps of development and clinical validation of MatrixMANDIBLE Subcondylar Plates (Synthes, Soletta, Switzerland), a specialized osteosynthesis system developed by Synthes during the past 4 years. Between 2009 and 2013, a total of 62 patients were treated for subcondylar and condylar neck fractures via a preauricular or retromandibular/transparotid approach. The MatrixMANDIBLE Subcondylar Plates System consists of a Trapezoidal Plate, a three-dimensional (3D) 4-hole 1.0-mm plate for smaller fracture areas, the Lambda Plate, a 7-hole 1.0-mm linear plate which mimics the two miniplates technique, and the Strut Plate, a 3D 1.0-mm plate with great versatility of employment. All devices satisfy the principles of a functionally stable osteosynthesis as stated by Champy et al. None of the plates broke and no macroscopic condylar displacement was noted on radiological follow-up. Clinical and functional parameters assessed at 6 months postoperative (mandibular range of motion, pain, dental occlusion) were almost restored. MatrixMANDIBLE Subcondylar Plates System (Synthes) has proved to provide sufficient mechanical stiffness and anatomically accurate fracture reduction to avoid major postoperative drawbacks of subcondylar and condylar neck fractures.

  5. The Clinical Feasibility of Newly Developed Thin Flat-Type Bioresorbable Osteosynthesis Devices for the Internal Fixation of Zygomatic Fractures: Is There a Difference in Healing Between Bioresorbable Materials and Titanium Osteosynthesis?

    PubMed

    Sukegawa, Shintaro; Kanno, Takahiro; Nagano, Daiki; Shibata, Akane; Sukegawa-Takahashi, Yuka; Furuki, Yoshihiko

    2016-10-14

    In recent years, bioresorbable plates have undergone remarkable development. However, there has been no attendant improvement in their strength, because strength requires thickness, and complications such as palpability are related to the thickness of bioresorbable plate systems. In this clinical study, we compared the surgical management of zygomatic fractures using newly developed thinner bioresorbable materials or conventional titanium miniplates. Twelve patients with zygomatic fractures were randomly divided equally into 2 groups (6 with new bioresorbable osteosynthesis materials and 6 with standard titanium miniplates). Using computed tomography, we evaluated the thickness of the soft tissue and plate at the zygomaticofrontal sutures in each patient with the help of detailed radiographic computed tomography data at 6 months postoperatively. We compared the amount of soft-tissue volume increase between the uninjured healthy and injured operated sides in each patient. Both groups eventually achieved satisfactory healing, with a favorable restoration of form and function and without any complications, including palpability. The amount of soft-tissue volume increase at the operated side relative to the uninjured healthy side using new thin bioresorbable plates was 131.1% (range: 101.5-165.8). On the other hand, that of titanium miniplates was 126.4% (range: 102.2-167.6). There was no statistically significant difference (P > 0.05). This newly developed thinner flat-type bioresorbable plate system could be considered clinically useful in the treatment of zygomatic fractures even in easily palpated areas, such as the infraorbital rim or zygomaticofrontal sutures, without any healing differences in skeleton as compared with conventional titanium miniplates.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work

  6. Complications of Minimally Invasive Percutaneous Plating for Distal Tibial Fractures

    PubMed Central

    Muzaffar, Nasir; Bhat, Rafiq; Yasin, Mohammad

    2016-01-01

    Background The management of distal tibia fractures continues to remain a source of controversy and debate. Objectives The aim of this study was to evaluate the various complications of minimally invasive percutaneous plate osteosynthesis (MIPPO) using a locking plate for closed fractures of distal tibia in a retrospective study. Patients and Methods Twenty-five patients with distal tibial fractures, treated by minimally invasive percutaneous plate osteosynthesis, were evaluated in a retrospective study. We studied the rate, probable etiological factors and preventive and corrective measures of various complications associated with minimally invasive plating of distal tibia. Results Mean age of the patients was 41.16 years (range 22 - 65). There were 13 male and 12 female patients. All fractures united at an average duration of 16.8 weeks. There were two cases of superficial and two cases of deep infection, and deep infections required removal of hardware for cure. There were four cases of ankle stiffness, most of them occurring in intra-articular fractures, three cases of palpable implant, three cases of malunion, one case of loss of reduction and one patient required reoperation. The average AO foot and ankle score was 83.6. Conclusions We found MIPPO using locking plate to be a safe and effective method for the treatment of distal tibial fractures in properly selected patients yet can result in a variety of complications if proper precautions before, during and after surgery are not taken care of. PMID:28182170

  7. [Osteosynthesis of subcondylar fractures using compression screws with the Eckelt technic. Experiences and difficulties with the technic over 5 years].

    PubMed

    Maladière, E; Chikhani, L; Meningaud, J P; Favre, E; Bertrand, J C; Guilbert, F

    1999-05-01

    With creation of new fixation material, the surgical treatment of displaced subcondylar fractures is most frequently used in adults. The Eckelt compression osteosynthesis is described as an easy procedure in the current literature, but, in our experience, several problems require our attention. We report the treatment of 57 patients with displaced subcondylar fractures where compression osteosynthesis was indicated. The difficulty of this technique is presented on the basis of a 5-years experience.

  8. Radiotherapy and Smoking History Are Significant Independent Predictors for Osteosynthesis-Associated Late Complications in Vascular Free Fibula Reconstruction of Mandible.

    PubMed

    Chen, YiMing; Wu, JiaLing; Gokavarapu, Sandhya; Shen, Qingcheng; Ji, Tong

    2017-09-01

    The vascular fibula flap is an ideal choice for function and appearance reconstruction of mandible. Despite the high success rate, "late complications" such as Ti plate exposure and local infection related to osteosynthesis are not uncommon. A retrospective cohort of patients who received vascular fibula reconstruction for mandible from January 2011 to December 2013 from the Department of Oral and Maxillofacial Oncology in a tertiary hospital were charted: clinical, pathological, and therapeutic factors were analyzed for late complications in univariate and multivariate analyses. One hundred forty-two patients were finally analyzed with median follow-up time of 47 months; 19 of them had "late complications," which occurred at a median of 8 months. Preoperative or postoperative radiotherapy (P = 0.02), type of Ti plate (P = 0.019), and the disease characteristics (P = 0.02) were significant factors on univariate. Cox regression suggested postoperative radiation (P = 0.009) and smoking history (P = 0.037) were independent significant factors for late complications. Secondary reconstruction (P = 0.069) and preoperative radiotherapy (P = 0.086) were borderline significant. Postoperative radiation and smoking history are associated with late complications. Mini Ti plate should be less used. Patients with risk factors need to be observed for at least 6 to 16 months before further management.

  9. A Sandwich Method Using Kapandji Intrafocal Pinning to Facilitate Palmar Plating of Displaced Distal Radius Fractures.

    PubMed

    Huang, Hui-Kuang; Huang, Yi-Chao; Wang, Jung-Pan; Chang, Ming-Chau

    2017-09-01

    The use of palmar plating in the treatment of dorsally displaced distal radius fracture is very common, and can result in a good functional outcome. We present an easy "sandwich method" to reduce the fracture and to facilitate osteosynthesis. Firstly, the dorsal Kapandji intrafocal wire was applied to achieve the reduction of the dorsally displaced fracture and provide a volar-directed force. Then the intra-articular fractures were reduced or the metaphyseal defect is stuffed with bone graft if necessary. Finally, the anatomical plate is used to buttress and push back the distal fragment to complete the osteosynthesis. The postoperative radiographic parameters, comparing with the contralateral noninjured side, could achieve similar radial height, radial inclination, volar tilt, and ulnar variance without significant difference.

  10. Effect of hafnium and titanium coated implants on several blood biochemical markers after osteosynthesis in rabbits.

    PubMed

    Yousef, Ashraf; Akhtyamov, Ildar; Shakirova, Faina; Zubairova, Lyaili; Gatina, Elmira; Aliev, Capital Ie Cyrilliclchin

    2014-01-01

    An experimental study comparing the dynamics of several biochemical markers before and after osteosynthesis, utilizing implants coated with titanium and hafnium nitrides and non-coated implants on rabbits' bones. The Study has been conducted on 30 rabbits of both sexes, at the age of 6-7 months, weighing 2526.5±74.4 gm. Animals underwent open osteotomy of the tibia in the middle third of the diaphysis followed by the intramedullary nailing. The level of alkaline phosphatase, calcium, phosphorus, total protein, glucose, ALT and AST were monitored for 60 days. the use of implants coated with titanium and hafnium nitrides, which have high strength, thermal and chemical stability, was not accompanied by the development of additional negative reactive changes compared to non-coated implants. Nanotechnology used in manufacturing bioinert coatings for implants for osteosynthesis, has made the post-operative period less complicated as reflected by less expressed changing in the markers of bone metabolism and hepatotoxicity.

  11. [Drill wire osteosynthesis in subcapital humerus fractures: percutaneous or open procedure?].

    PubMed

    Imhoff, M; Sadr, I; Lehner, J H; Hasse, F M; Gahr, R H

    1992-04-01

    Between 1978 and mid-1990, 135 patients suffering from dislocated, non-luxated fracture of the humerus at the anatomical neck (fractura colli anatomici) were treated by means of open or closed percutaneous drill wire osteosynthesis. Follow-up examination after an average of 9 months did not show any significant differences between the two surgical approaches in 117 patients, independent of the shape of the fracture. However, in about 30% of the cases it was impossible to employ the percutaneous approach due to the presence of an obstacle to reduction, so that open reduction and fixation was the only choice. A great majority of the functional results must be considered as good, fractures of the tubercles having the most unfavourable prognosis independent of the surgical technique. It is, therefore, recommended to first try closed reduction with percutaneous drill wire osteosynthesis. If there are any obstacles to reduction, open reduction should be restored to during the surgery session.

  12. An accuracy study of computer-planned implant placement in the augmented maxilla using osteosynthesis screws.

    PubMed

    Verhamme, L M; Meijer, G J; Soehardi, A; Bergé, S J; Xi, T; Maal, T J J

    2017-04-01

    Previous research on the accuracy of flapless implant placement of virtually planned implants in the augmented maxilla revealed unfavourable discrepancies between implant planning and placement. By using the osteosynthesis screws placed during the augmentation procedure, the surgical template could be optimally stabilized. The purpose of this study was to validate this method by evaluating its clinically relevant accuracy. Twelve consecutive fully edentulous patients with extreme resorption of the maxilla were treated with a bone augmentation procedure. Virtual implant planning was performed and a surgical template was manufactured. Subsequently, six implants were installed using the surgical template, which was only supported by the osteosynthesis screws. Implant deviations between planning and placement were calculated. A total of 72 implants were installed. Mean deviations found in the mesiodistal direction were 0.817mm at the implant tip and 0.528mm at the implant shoulder. The angular deviation was 2.924°. In the buccolingual direction, a deviation of 1.038mm was registered at the implant tip and 0.633mm at the implant shoulder. The angular deviation was 3.440°. This study showed that implant placement in the augmented maxilla using a surgical template supported by osteosynthesis screws is accurate.

  13. FIXATION OF SUPRACONDYLAR FEMORAL FRACTURES: A BIOMECHANICAL ANALYSIS COMPARING 95° BLADE PLATES AND DYNAMIC CONDYLAR SCREWS (DCS)

    PubMed Central

    Percope Andrade, Marco Antônio; Rodrigues, André Soares; Mendonça, Celso Junio; Santos Portela, Luiz Gustavo

    2015-01-01

    Objective: To determine, by means of comparative biomechanical tests, whether greater compressive load resistance and flexion is presented by 95° angled blade plates or by dynamic condylar screws (DCS), and to correlate the failure type presented during the tests with each type of plate. Methods: Sixty-five porcine femurs were subjected to 1 cm medial wedge osteotomy, in the metaphysis, to simulate an unstable supracondylar femoral fracture. Osteosynthesis was performed on these pieces: 35 were fixed using 95° lateral blade plates and 30 with DCS plates. Another variable studied was the failure type presented in each group, in an attempt to correlate this with the type of plate. Results: There were no statistically significant differences in biomechanical resistance between the two types of plates, or between the failure type and the plate type used for the osteosynthesis. Conclusion: The two types of plate behaved in a similar fashion. However, the angled blade plate proved to be superior to the DCS in the flexion test. No statistical difference in failure type or type of plate used was observed. PMID:27022525

  14. [Biomechanical comparative study of three types of osteosynthesis in the treatment of supra and intercondylar fractures of the humerus in adults].

    PubMed

    Fornasiéri, C; Staub, C; Tourné, Y; Rumelhart, C; Saragaglia, D

    1997-01-01

    Supra and intercondylar fractures are the most common fractures of the distal end of the humerus in adult. An osteosynthesis consisting of a plate is the treatment of choice. But location and type of plate always remain open for debate. The authors present the results of an in vitro biomechanical study, which compared the stiffness of three types of osteosynthesis commonly used in these fractures. The devices were on one hand the premolded lateral plate of Lecestre and Dupont (Howmedica) used alone or in conjunction with a medial 1/3 tubular plate of the AO group, and on the other hand a posterior plate, of which we are developing a new model, the Lambda plate (Protek) "Y"-shaped, monoblock, flat and molded on the humerus during operation. The study compared these different methods of fixation on fresh human humeri. In a first part, the posterior plate was compared to the single lateral one; in a second part, the posterior plate was compared to the coupled lateral and medial plates. The three plates were made of identical material. Both studies used eight pairs of bones with supra and intercondylar fractures realized by sawing. Each bone of a pair was fixed with one of the two types of device. Each humerus underwent different loading forces; sagittal bending (anterior and posterior) and torsion. The displacements were recorded using a calibrated measuring device coupled to two displacement sensors. The stiffness was calculated on force/displacement curves. In anterior bending, the Lambda posterior fixation was significantly stiffer than the single lateral one (p < 0.05) (239 +/- 109 versus 129 +/- 65 N/mm), and was not significantly different of the bilateral fixation (229 +/- 93 versus 224 +/- 108 N/mm). In posterior bending, the mean stiffness of the Lambda fixation was not significantly different to that of the lateral fixation (91 +/- 27 versus 91 +/- 52 N/mm), and less than that of the bilateral one (130 +/- 39 versus 170 +/- 70 N/mm), but not significantly

  15. Development of titanium fixation screw for hydroxyapatite osteosynthesis (APACERAM).

    PubMed

    Tanaka, Yoshihide

    2008-11-01

    Cranioplasty using custom-made HAP ceramic implants is a common procedure for skull defects. However, miniplate fixation using commercially available screws to stabilize the HAP flap is associated with several problems due to characteristic brittleness. The authors have thus developed a suitable screw for this procedure. Hydroxyapatite blocks (porosity, 40%; thickness, 5 mm) were prepared. Holes were created using a phi 1.4-mm drill. Five types of screw were evaluated for HAP condition after insertion, fixation strength on pull-out test, and fasten plate strength based on maximum torque. Based on this evaluation, the most effective screws were cylindrical style in shape, 4.8 mm in effective length, phi 1.6 mm in effective diameter, and 0.2 mm in edge height. A novel screw with high fixation potential for the miniplate technique was developed in this study.

  16. Solving Quartics

    ERIC Educational Resources Information Center

    Kulkarni, R. G.

    2007-01-01

    A technique is presented, which is different from the well-known Ferrari's method, to solve a general quartic equation. Formulae for the four roots of quartic are derived. A numerical example verifies the formulae obtained.

  17. History of internal fixation with plates (part 2): new developments after World War II; compressing plates and locked plates.

    PubMed

    Hernigou, Philippe; Pariat, Jacques

    2017-07-01

    The first techniques of operative fracture with plates were developed in the 19th century. In fact, at the beginning these methods consisted of an open reduction of the fracture usually followed by a very unstable fixation. As a consequence, the fracture had to be opened with a real risk of (sometimes lethal) infection, and due to unstable fixation, protection with a cast was often necessary. During the period between World Wars I and II, plates for fracture fixation developed with great variety. It became increasingly recognised that, because a fracture of a long bone normally heals with minimal resorption at the bone ends, this may result in slight shortening and collapse, so a very rigid plate might prevent such collapse. However, as a consequence, delayed healing was observed unless the patient was lucky enough to have the plate break. One way of dealing with this was to use a slotted plate in which the screws could move axially, but the really important advance was recognition of the role of compression. After the first description of compression by Danis with a "coapteur", Bagby and Müller with the AO improved the technique of compression. The classic dynamic compression plates from the 1970s were the key to a very rigid fixation, leading to primary bone healing. Nevertheless, the use of strong plates resulted in delayed union and the osteoporosis, cancellous bone, comminution, and/or pathological bone resulted in some failures due to insufficient stability. Finally, new devices represented by locking plates increased the stability, contributing to the principles of a more biological osteosynthesis while giving enough stability to allow immediate full weight bearing in some patients.

  18. [Follow-up examinations after removal of titanium plates coated with anodic titanium oxide ceramic].

    PubMed

    Velich, Norbert; Németh, Zsolt; Barabás, József; Szabó, György

    2002-04-01

    Transformation of the titanium metal surface with titanium oxides produced in various ways belongs among the most up-to-date procedures. The authors as pioneers in this field (e.g. Nobel Biocare TiUnite surface), have been utilizing for more than 15 years dental root implants and fixing elements (for mandibular osteosynthesis) coated with titanium oxide ceramics, produced by anodic oxidation and thermal treatment. The aim of this work was to assess the extent to which a titanium oxide ceramic coating influences the fate of plates applied for osteosynthesis within the human body. During a 5-year period (1995-1999), 108 of 1396 titanium oxide ceramic plates had to be removed for various reasons: loosening of the plate [47], osteomyelitis [25], a palpable swelling and tenderness [21] at the request of the patient for psychological reasons (13) or breaking of the plate [2]. When these 108 plates were removed, it was not possible to detect metallosis in even a single case; nor was there any tissue damage that could be attributed to the surface of the plates, whereas the literature data indicate that such damage is relatively frequent in the environment of traditional titanium fixing elements. The present investigation confirms the favourable properties of the titanium oxide ceramic surface.

  19. A nickel-titanium shape memory alloy plate for contactless inverse dynamization after internal fixation in a sheep tibia fracture model: A pilot study.

    PubMed

    Decker, Sebastian; Krämer, Manuel; Marten, Anna-Katharina; Pfeifer, Ronny; Wesling, Volker; Neunaber, Claudia; Hurschler, Christof; Krettek, Christian; Müller, Christian W

    2015-01-01

    Inverse dynamization has recently been proposed for the treatment of tibia non-unions. Nickel-titanium (NiTi) shape memory alloys (SMAs) may provide an opportunity for contactless non-invasive alteration of the stiffness of an implant after surgery. The aim of this pilot study was to analyze the feasibility of the one way shape memory effect in a large animal as well as the feasibility of our ovine large animal fracture model. A tibia osteotomy was performed in three sheep, followed by NiTi plate osteosynthesis in two cases and standard locking compression plate (LCP) osteosynthesis in one sheep. Contactless induction heating was performed after 3 weeks in order to alter the stiffness of the NiTi plates. Euthanasia was followed by biomechanical analysis after 8 weeks. Successful change of configuration through contactless induction heating was shown in both SMA plates by image intensifier control. Although large differences in bending and torsional stiffness were observed between the operated and contralateral tibia, the sheep ambulated almost normally at six weeks post-operative. We were able to trigger the one way shape memory effect which non-invasively altered the stiffness of the plate osteosynthesis.

  20. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  1. [Efficacy of motor control at patients with cerebral hemiparesis in rehabilitation conditions with application of transosseous distraction cranio-osteosynthesis].

    PubMed

    Shein, A P; Skripnikov, A A; Krivoruchko, G A

    2014-01-01

    To study influence of transosseous distraction cranio-osteosynthesis on functional state of neuromotor system at patients with hemispheric stroke consequences, severe craniocerebral trauma analyzed dynamics of electroneuromyography index--cerebrospinal index, obtained by testing of extremities muscles at 28 persons in residual disease period. Data analysis obtained in control period testify to positive cerebrospinal index dynamics is maximum evident in long-term post-operative period and on leads from upper paretic limb. Thus, electrophysiologically identified increase of motor control efficacy of paretic limbs muscles at patients with cerebral alteration consequences in treatment by transosseous distraction cranio-osteosynthesis.

  2. The evolution of the Ilizarov technique: part 2: the principles of distraction osteosynthesis.

    PubMed

    Goldstein, Rachel Y; Jordan, Charles J; McLaurin, Toni M; Grant, Alfred

    2013-01-01

    The history of limb-lengthening surgery can be traced back to the 19th Century. Since that time, the orthopaedic community has made tremendous progress in performing successful lengthening procedures. Among the important contributors to the field is Dr. Gavril Ilizarov. Because of advancements over the past century, limb lengthening has become a viable method of treating severe bony deformities and defects. This article, the second of a two-part series, reviews the principles of distraction osteosynthesis, including a thorough discussion of indications, instrumentation, and surgical technique.

  3. [Basic studies of ultrasonic surgery. IV. Osteosynthesis in bone welding using ultrasound].

    PubMed

    Müller, T; Wolf, E; Winckler, U; Wehner, W

    1982-07-01

    A conglomerate of homologous bone-chips and n-butyl-cyanoacrylate fixes the fragments in the ultrasonic osteosynthesis. The sound pressure leads to the forced penetration of the monomer into preformed gaps of the bone surface (Volkmann and Haversian canals) up to maximum 300 microns during the polymerisation forced by ultrasound. A toothing effect between the conglomerate and the cortex takes place in this way, this one leads to a higher mechanical resistance and to specialities in the regenerative process. The term welding is founded scientifically by the mechanism of the connecting formation. On the other hand the application of the ultrasound is sensible in order to force the polymerisation.

  4. Charcot neuroarthropathy: realignment of diabetic foot by means of osteosynthesis using intramedullary screws - case report.

    PubMed

    Dos Santos, Alexandre Leme Godoy; Albino, Rômulo Ballarin; Ortiz, Rafael Trevisan; Sakaki, Marcos Hideyo; de Andrade Corsato, Marcos; Fernandes, Tulio Diniz

    2014-01-01

    Diabetes mellitus is a serious disease that affects a large portion of the population. Charcot neuroarthropathy is one of its major complications and can lead to osteoarticular deformities, functional incapacity, ulcers and ankle and foot infections. Realignment of the foot by means of arthrodesis presents a high rate of implant failure due to weight-bearing on an insensitive foot. The aim of this report was to describe successful use of intramedullary osteosynthesis with compression screws to stabilize the deformed foot, in a diabetic patient with neuroarthropathy.

  5. Impact of deep sternal wound infection management with vacuum-assisted closure therapy followed by sternal osteosynthesis: a 15-year review of 23,499 sternotomies.

    PubMed

    Baillot, Richard; Cloutier, Daniel; Montalin, Livia; Côté, Louise; Lellouche, François; Houde, Chanel; Gaudreau, Geneviève; Voisine, Pierre

    2010-04-01

    This study was undertaken to examine the outcome of patients with deep sternal wound infection (DSWI) now treated with vacuum-assisted closure (VAC) therapy as a bridge to sternal osteosynthesis with horizontal titanium plate fixation. From 1992 to 2007, a consecutive cohort of 23,499 patients underwent open-heart surgery (OHS) in our institution. The period under study was divided in two according to the use of therapeutic modalities: conventional (1992-2001, N=118 DSWI): debridement/drainage with primary closure and irrigation (N=37), debridement/drainage, open packing followed by pectoralis myocutaneous flaps (PMFs) (N=81); contemporary (2002-2007, N=149 DSWI): conventional treatment (N=24) and VAC therapy (N=125/83.8%). VAC was followed by sternal osteosynthesis with horizontal titanium plates in 92 patients (61.7%). DSWI was diagnosed in 267 out of 23 499 (1.1%) patients of our entire series according to Center for Disease Control - Atlanta (CDC) criteria, 118 out of 13 180 (0.9%) in the first and 149 out of 10 319 (1.4%) in the second period (p=0.001). Hospital mortality (N=267/23,499) has been 10.25% for the entire cohort under study without any difference between groups (1992-2001: 11.4%; 2002-2007: 9.1%, p=0.67). More recently, VAC therapy (N=125) was associated with a lower mortality (4.8% vs 14.1%, p=0.01). Stepwise multivariable logistic regression analysis for both periods revealed that prolonged intubation in the intensive care unit (ICU), use of bilateral internal thoracic artery grafting (BIMA), diabetes, re-operation for bleeding and body mass index (BMI) >30 kgm(-2) are the most powerful predictors of DSWI. In the more recently treated patients using VAC therapy, combined procedures (valve and graft) also emerged as a significant predictor. For the entire study, Staphylococcus epidermidis (49.6%) has been the most frequently identified pathogen, followed by Staphylococcus aureus (38.8%). Methicillin-resistant S.aureus (MRSA) was observed in 4

  6. Chemical and structural analyses of titanium plates retrieved from patients.

    PubMed

    Pinto, C M S A; Asprino, L; de Moraes, M

    2015-08-01

    The aim of this study was to evaluate the microscopic structure and chemical composition of titanium bone plates and screws retrieved from patients with a clinical indication and to relate the results to the clinical conditions associated with the removal of these devices. Osteosynthesis plates and screws retrieved from 30 patients between January 2010 and September 2013 were studied by metallographic, gas, and energy dispersive X-ray (EDX) analyses and the medical records of these patients were reviewed. Forty-eight plates and 238 screws were retrieved. The time elapsed between plate and screw insertion and removal ranged between 11 days and 10 years. Metallographic analysis revealed that all the plates were manufactured from commercially pure titanium (CP-Ti). The screw samples analyzed consisted of Ti-6Al-4V alloy, except four samples, which consisted of CP-Ti. Titanium plates studied by EDX analysis presented greater than 99.7% titanium by mass. On gas analysis of Ti-6Al-4V screws, three samples were outside the standard values. One CP-Ti screw sample and one plate sample also presented an oxygen analysis value above the standard. The results indicated that the physical properties and chemical compositions of the plates and screws did not correspond with the need to remove these devices or the time of retention.

  7. Feynman's wobbling plate

    NASA Astrophysics Data System (ADS)

    Tuleja, Slavomir; Gazovic, Boris; Tomori, Alexander; Hanc, Jozef

    2007-03-01

    In the book Surely You Are Joking, Mr. Feynman! Richard Feynman tells a story of a Cornell cafeteria plate being tossed into the air. As the plate spun, it wobbled. Feynman noticed a relation between the two motions. He solved the motion of the plate by using the Lagrangian approach. This solution didn't satisfy him. He wanted to understand the motion of the plate by analyzing the motion of its individual particles and the forces acting on them. He was successful, but he didn't tell us how he did it. We provide an elementary explanation for the two-to-one ratio of wobble to spin frequencies, based on an analysis of the motion of the particles and the forces acting on them. We also demonstrate the power of numerical simulation and computer animation to provide insight into a physical phenomenon and guidance on how to do the analysis.

  8. In vitro biomechanical comparison of limited contat dynamic compression plate and locking compression plate.

    PubMed

    Aguila, A Z; Manos, J M; Orlansky, A S; Todhunter, R J; Trotter, E J; Van der Meulen, M C H

    2005-01-01

    The locking compression plate (LCP) supports biological osteosynthesis by functioning as an internal fixator, rather than as a full or limited contact bone plate which must be adequately contoured and affixed directly to the bone for stable internal fixation of the fracture. In order to help justify the use of the LCP in our veterinary patients, in vitro biomechanical testing was performed comparing the LCP to the conventional limited contact dynamic compression plate (LC-DCP) in canine femurs. We hypothesized that the LCP construct would be at least as stiff under bending and torsional loads as the LC-DCP. The LCP and LC-DCP were applied over a 20-mm osteotomy gap to contralateroal bones within each pair of 14 femora. Non-destructive four-point bending and torsion, and cyclical testing in torsion were performed. The constructs were then loaded to failure in torsion. In medial-lateral and lateral-medial structural bending, significant differences were not found between the LCP and LC-DCP, however, at the gap, the LCP construct was stiffer than the LC-DCP in lateral-medial bending. Significant differences in behaviour over time were not noted between the plate designs during cyclical testing. When loading the constructs to failure in internal rotation, the LC-DCP failed at a significantly lower twist angle (P = .0024) than the LCP. Based on the similar performance with loading, the locking compression plate is a good alternative implant for unstable diaphyseal femoral fracture repair in dogs.

  9. Effect of hafnium and titanium coated implants on several blood biochemical markers after osteosynthesis in rabbits

    PubMed Central

    Yousef, Ashraf; Akhtyamov, Ildar; Shakirova, Faina; Zubairova, Lyaili; Gatina, Elmira; Aliev, Еlchin

    2014-01-01

    Purpose: An experimental study comparing the dynamics of several biochemical markers before and after osteosynthesis, utilizing implants coated with titanium and hafnium nitrides and non-coated implants on rabbits’ bones. Materials and methods: The Study has been conducted on 30 rabbits of both sexes, at the age of 6-7 months, weighing 2526.5±74.4 gm. Animals underwent open osteotomy of the tibia in the middle third of the diaphysis followed by the intramedullary nailing. The level of alkaline phosphatase, calcium, phosphorus, total protein, glucose, ALT and AST were monitored for 60 days. Results: the use of implants coated with titanium and hafnium nitrides, which have high strength, thermal and chemical stability, was not accompanied by the development of additional negative reactive changes compared to non-coated implants. Conclusion: Nanotechnology used in manufacturing bioinert coatings for implants for osteosynthesis, has made the post-operative period less complicated as reflected by less expressed changing in the markers of bone metabolism and hepatotoxicity. PMID:25419385

  10. A new method for osteosynthesis using dielectric (non-conductive) fixation devices.

    PubMed

    Dobrev, R P; Vladimirov, B J

    1984-01-01

    Investigation in the field of electrophysiology shows that bioelectric phenomena of different origin are present in bone, the most important being the bioelectric potential connected with bone viability and metabolism. The negative biopotential is high at the fracture site where metabolism is also increased. During healing the negative values decrease and when it is complete the configuration of biopotentials along the length of the bone regains the pattern characteristic of intact bone. Negative biopotentials are needed to achieve callus formation and they disappear when healing has occurred. A metal device is used for osteosynthesis to obtain stable fixation of the fragments, but the electroconductive metal produces a 'short-circuit' of biopotentials along its length, so depriving the bone of necessary negative biopotential. Consequently the intensity of the metabolic processes is also reduced, leading to a relative delay in callus formation. Although a plaster cast may fail to provide adequate stability the natural electrophysiological conditions are preserved, and the period of callus formation is shortened. The negative biopotentials required for fracture union may be preserved by using non-conductive (dielectric) implants to achieve stable osteosynthesis.

  11. [Morphological peculiarities of consolidation of experimental mandible fractures by osteosynthesis using Kollapan and retabolil].

    PubMed

    Beriashvili, G K; Menabde, G T; Chikhladze, R T

    2006-07-01

    The Purpose of the research was to study in the experiment morphological particularities of mandible fracture consolidation by osteosynthesis using Kollapan and Retabolil. The experiments were carried out on sexually matured rabbits. In the first series of the experiments (the control group), mandibula bones fracture was prototyped lower, whereas bone fragments were fixed by miniplate. In the second series of the experiments (the study group) bone fragments were bolted by the above mentioned way but diastase between bone fragments was filled by Kollapan granules, containing klaforan, and animals were intramuscularly anabolic material (the retabolil 0.4 mg/kg). On the 3-d and 15-th days, as well as, after 1 and 2 months after operation observing all corresponding rules, animals were killed and patologico-anatomic study of jaw bone was carried out. The analysis of the results showed that in experimental animals both in the control and the study groups reparative regeneration of bone tissues runs with the formation of periosteum and intermedium regenerator, at the same time consolidation of the bone defect in the main group occurs earlier than in the control group. The Results of the studies point out that Retabolil under osteosynthesis is an osteoinductive material and Kollapan, having osteoinductive, osteoconductive, and osteoprotective characteristics, promotes speeding of the process of jaw bones fracture consolidation.

  12. Removal of titanium plates coated with anodic titanium oxide ceramic: retrospective study.

    PubMed

    Velich, Norbert; Németh, Zsolt; Suba, Csongor; Szabó, György

    2002-09-01

    Transformation of the surface of metallic titanium with titanium oxides prepared in various ways is a modern procedure. For more than 15 years, the authors have been utilizing fixing elements coated with titanium oxide ceramics, prepared by anodic oxidation and thermal treatment, for purposes of jawbone osteosynthesis. The aim of the authors' work was to assess the extent to which the titanium oxide ceramic coating influences the fate of the plates used for osteosynthesis within the human organism, in regard to the possible need for their removal. During a 5-year period, 108 of 1,396 plates coated with anodic titanium oxide had to be removed for various reasons: plate exposure (47), osteomyelitis (25), palpable swelling and tenderness (21), patient request for psychological reasons (13), or fracture of the plate (2). In none of these 108 cases was metallosis observed, which otherwise is reported relatively frequently in the vicinity of traditional titanium fixing elements, nor was any tissue damage connected with the surface of the plates. The results indicate the favorable properties of the titanium oxide ceramic surface.

  13. Fixation of zygomatic and mandibular fractures with biodegradable plates

    PubMed Central

    Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

    2013-01-01

    Context: In this prospective study, 13 randomly selected patients underwent treatment for zygomatic–complex fractures (2 site fractures) and mandibular fractures using 1.5 / 2 / 2.5-mm INION CPS biodegradable plates and screws. Aims: To assess the fixation of zygomatic-complex and mandibular fractures with biodegradable copolymer osteosynthesis system. Materials and Methods: In randomly selected 13 patients, zygomatic-complex and mandibular fractures were plated using resorbable plates and screws using Champy's principle. All the cases were evaluated clinically and radiologically for the type of fracture, need for the intermaxillary fixation (IMF) and its duration, duration of surgery, fixation at operation, state of reduction at operation, state of bone union after operation, anatomic reduction, paresthesia, occlusal discrepancies, soft tissue infection, immediate and late inflammatory reactions related to biodegradation process, and any need for the removal of the plates. Statistical Analysis Used: Descriptives, Frequencies, and Chi-square test were used. Results: In our study, the age group range was 5 to 55 years. Road traffic accidents accounted for the majority of patients six, (46.2%). Postoperative occlusal discrepancies were found in seven patients as mild to moderate, which resolved with IMF for 1-8 weeks. There were minimal complications seen and only as soft tissue infection. Conclusions: Use of biodegradable osteosynthesis system is a reliable alternative method for the fixation of zygomatic-complex and mandibular fractures. The biodegradable system still needs to be refined in material quality and handling to match the stability achieved with metal system. Biodegradable plates and screws is an ideal system for pediatric fractures with favorable outcome. PMID:23662255

  14. Moving Divertor Plates in a Tokamak

    SciTech Connect

    S.J. Zweben, H. Zhang

    2009-02-12

    Moving divertor plates could help solve some of the problems of the tokamak divertor through mechanical ingenuity rather than plasma physics. These plates would be passively heated on each pass through the tokamak and cooled and reprocessed outside the tokamak. There are many design options using varying plate shapes, orientations, motions, coatings, and compositions.

  15. [Hemodynamics in soft tissues after upper third of the leg lengthening by Ilizarov osteosynthesis technique].

    PubMed

    Kononovich, N A; Petrovskaia, N V

    2013-02-01

    An experimental study has been performed. The leg was lengthened in 12 adult mongrel dogs by transosseous distraction osteosynthesis in the zone of upper third of the leg bone shaft by 14-18% of the segment length using the rate of 1.0 mm for 4 times. The formation of mechanically strong shaft part occurred after 35 days after device fixation. Under created conditions the unidirectional cyclic changes of blood circulation and morphofunctional state occurred in soft tissue segment, that were more marked in the extensor muscle group. Implementation of preventive-and-treatment measures directed to improvement of vascular elastotonic properties allowed to decrease the degree of disordering hemodynamics of the lengthened limb. This will have a positive effect on the final clinical outcome.

  16. External fixators and minimally invasive osteosynthesis in small animal veterinary medicine.

    PubMed

    Palmer, Ross H

    2012-09-01

    Modern external skeletal fixation (ESF) is a very versatile system that is well suited to the ideals of minimally invasive osteosynthesis (MIO). It offers variable-angle, locked fixation that can be applied with minimal to no disruption of the fracture zone. Technological advances in ESF have fostered the ability to use more simple frame applications than in previous generations. Even when rigid bilateral or multiplanar frames are required, timely staged-disassembly is easy to perform and allows for a gradual shift of loading from the frame to the healing bony column. Hybrid ESF is ideally suited for the MIO treatment of many juxta-articular fractures and osteotomies. Adherence to the principles of ESF and postoperative care is essential to overcome the various disadvantages that are inherent to ESF.

  17. [Arthroscopically assisted osteosynthesis of dorsally tilted intraarticular distal radius fractures--technique and results].

    PubMed

    Lutz, M; Wieland, T; Deml, C; Erhart, S; Rudisch, A; Klestil, T

    2014-10-01

    The present paper describes the indication and application of an arthroscopically assisted osteosynthesis for distal radius fractures. Visualisation of articular incongruency is emphasised with special regard to articular fracture fragment reduction. In addition to that, classification of soft tissue injuries and treatment options are discussed. The final clinical and radiological results of 17 patients are presented: DASH and PRWE averaged 4.9 and 6.0 respectively. Active range of motion measured 123° for flexion/extension, 51° for radial and ulnar deviation and 163° for pronosupination, which is 87%, 98% and 97%, respectively, compared with the opposite wrist. Radial inclination at final follow-up was 23°, palmar tilt measured 6° and ulnar variance averaged -1.2 mm. The scapholunate gap at follow-up was 1.6 mm, and the scapholunate angle measured 57°.

  18. Repair of defects and osteosynthesis of long bones in children with osteoclastoma

    NASA Astrophysics Data System (ADS)

    Ryzhikov, D. V.; Gubina, E. V.; Podorozhnaya, V. T.; Senchenko, E. V.; Sadovoy, M. A.

    2016-08-01

    The paper is aimed at reporting a retrospective analysis covering the period from 2007 to 2015. The study involved 22 patients with benign osteoclastoma (OC), 14 male and 8 female children aged 9 to 19. All patients had monostotic lesions with the following location of pathological foci: humerus—11 patients, femoral bone—7, shin bone— 1, fibular bone—1, and ulnar bone—1. All 22 patients underwent surgery. Surgical treatment included resection of tumor focus within intact tissues (in cases of eccentric foci, bony bridge was preserved in the area of minimum damage, which was treated by electrocoagulation together with the cavity) together with bone grafting and intramedullary reinforcement of the affected bone (which provides stable osteosynthesis, early mobilization, and prevention of functional deficits in most patients). Consolidation was achieved in 100% of the operated patients.

  19. Prognostic value of dynamic MRI positive enhancement integral color mapping in osteosynthesis of undisplaced femoral neck fractures.

    PubMed

    Morimoto, Masatoshi; Takahashi, Yoshinori; Kubo, Takahiro; Sugiura, Kosuke; Tamaki, Yasuaki; Toki, Shunichi; Suganuma, Katsuyoshi; Inoue, Kazumasa; Adachi, Keisuke; Chikawa, Takashi; Sairyo, Koichi; Nagamachi, Akihiro

    2017-07-01

    The common treatment for an undisplaced femoral neck fracture is osteosynthesis. Two major complications of osteosynthesis are non-union and late collapse of the femoral head. We speculated that femoral head perfusion is one of the most important factors that affect the outcome of osteosynthesis after femoral neck fracture. We have preoperatively estimated femoral head perfusion by dynamic MRI positive enhancement integral color mapping (PEICM). The purpose of this study was to evaluate the outcomes of undisplaced femoral neck fractures based on PEICM. Sixty-eight patients participated in this prospective study. All patients underwent PEICM in a 1.5-Tesla MRI machine using coronal fast spoiled gradient echo imaging sequences with gadopentetate dimeglumine as the contrast agent. Femoral head perfusion was displayed via color mapping using PEICM. Three types were distinguished. For type A, the color was identical to unaffected side indicated normal perfusion. For type B, the color was darker than unaffected side indicated decreased perfusion. For type C, the color was black indicated complete absence of perfusion. All patients underwent osteosynthesis with three cannulated screws. The rates of non-union and late collapse for each type were calculated. Sixteen patients were classified as Type A, 43 as Type B, and 6 as Type C. The non-union rates were 0% for Type A, 6.7% for Type B, and 50.0% for Type C. The late collapse rates were 0% for Type A, 4.4% for Type B, and 0% for Type C. PEICM precisely detected femoral head perfusion. Primary prosthetic replacement should be considered for older patients with Type C to minimize the chances of revision surgery, even in undisplaced femoral neck fractures. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  20. [Humerus varus: correction by proximal valgus osteotomy with precontourned plate fixation in children].

    PubMed

    Tallón-López, J; Domínguez-Amador, J J; Andrés-García, J A

    2014-01-01

    Varus deformity of the proximal humerus in children is a little known pathology due to its low incidence of presentation. Progress has been made in recent years in understanding the possible etiology and pathophysiological causes. Radiological criteria for diagnosis and functional impairment that occurs have also been defined. However, there are few reports in the literature about the surgical treatment of this deformity in children. In this paper we present a case of surgical treatment of this deformity by corrective osteotomy fixed with precontoured external maleolar plate osteosynthesis.

  1. Peen plating

    NASA Technical Reports Server (NTRS)

    Babecki, A. J. (Inventor); Haehner, C. L.

    1973-01-01

    A process for metal plating which comprises spraying a mixture of metallic powder and small peening particles at high velocity against a surface is described. The velocity must be sufficient to impact and bond metallic powder onto the surface. In the case of metal surfaces, the process has as one of its advantages providing mechanical working (hardening) of the surface simultaneously with the metal plating.

  2. Recurrent sternal infection following treatment with negative pressure wound therapy and titanium transverse plate fixation.

    PubMed

    Gaudreau, Geneviève; Costache, Victor; Houde, Chanel; Cloutier, Daniel; Montalin, Livia; Voisine, Pierre; Baillot, Richard

    2010-04-01

    To provide a definition for recurrent sternal infection (RSI), analyse the risk factors and describe the management of this complication following treatment of deep sternal wound infection (DSWI) with horizontal titanium sternal osteosynthesis and coverage with pectoralis major myocutaneous flaps. Between 2002 and 2007, 10665 patients were submitted to open-heart surgery (OHS) in our institution, of whom 149 (1.4%) developed a DSWI. Negative pressure wound therapy (NPWT) followed by sternal osteosynthesis with musculocutaneous coverage was used in 92 (61.7%) patients. A retrospective review was done using a prospectively maintained database to identify risk factors for recurrent infection in this group of patients. Of the 92 patients who underwent sternal osteosynthesis, nine (9.8%) developed recurrent sternal infection requiring hardware removal. Univariate analysis showed that preoperative methicillin-resistant Staphylococcus aureus (MRSA) status (33.3% vs 6.1%; p=0.03) and prolonged intubation time in ICU (44.4% vs 14.6%; p<0.05) were significant risk factors. Two-thirds of these patients were also found to be infected with the same germ as the one responsible for their initial DSWI. No death was reported and sternal integrity was preserved in all patients despite plate removal. To lower the rate of RSI in patients treated with transverse sternal ostheosynthesis along with myocutaneous coverage for DSWI, surgeons must consider the MRSA preoperative status as a significant predictor of RSI and/or persistent infection. Chest-wall integrity in patients with RSI can be maintained after hardware removal, even after only a few weeks following initial plating. Copyright (c) 2009 European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. Professor G. A. Ilizarov's contribution to the method of transosseous osteosynthesis.

    PubMed

    Shevtsov, V I

    1997-01-01

    The author of the article, Professor Vladimir I. Shevtsov, General Director of The Russian Center who worked together with Academician G. A. Ilizarov for almost a quarter of the century describes the main stages in the development of the Ilizarov method and apparatus in historical context, and concentrates on the main trends of traumatology and orthopaedics worked out by G. A. Ilizarov. G. A. Ilizarov's involvement in the experimental and theoretical substantiation of transosseous osteosynthesis is emphasized as well as the various studies that have resulted in the discovery of the stimulating influence of tension stress on the genesis and growth of tissues which have come to be known as the "Ilizarov Effect." Thus the article provides a review of the prominent contribution of G. A. Ilizarov to pioneering new ways of treating patients with fractures including severe open injuries of limbs, pseudarthroses and defects, limb length deficiency and deformities as well as the many other orthopaedic conditions to which a G. A. Ilizarov's method has been applied.

  4. Influence of Laser Irradiation Low Intensity on Reparative Osteogenesis and Angiogenesis Under Transosseous Osteosynthesis

    PubMed Central

    Iryanov, Yuri Mikhailovich

    2016-01-01

    Introduction: The use of non-medicinal facilities of correcting processes for various pathological conditions is one of the most urgent problems of modern medicine. The purpose of the work is to study the efficiency of low-intensive of infrared laser irradiation in promoting reparative osteogenesis and angiogenesis during fracture treatment under transosseous osteosynthesis with a qualitative and quantitative morphological analysis. Methods: A tibial fracture was modeled experimentally in rats from control and experimental groups, then repositioning and fixation of fragments performed. The fracture zone of the experimental group animals was exposed to pulsed infrared laser irradiation of low intensity. The animals from control group underwent irradiation simulation. The operated bones were investigated using x-ray, light and electron microscopy, x-ray electron probe microanalysis. Results: The sessions of laser irradiation decreased inflammatory process severity, activated fibrillogenesis and angiogenesis, accelerated the compactization of newly formed bone tissue, and enhanced its maturity degree while primary healing occurred in the fracture. Conclusion: Laser therapy of fracture zone ensures the formation of regenerated bone and fragment union within earlier periods. PMID:28144431

  5. [Titanium or steel as osteosynthesis material : Systematic literature search for clinical evidence].

    PubMed

    Joeris, Alexander; Goldhahn, Sabine; Rometsch, Elke; Höntzsch, Dankward

    2017-02-01

    The selection of the appropriate implant material, stainless steel or titanium, is still the decision of the surgeon and/or the affiliated institution. Additionally, remarkable international differences can be found between the different markets, which cannot really be explained. A systematic literature search was performed to verify whether there is clinical evidence for the preference of one material over the other. The systematic literature search was performed utilizing the internet databases PubMed, Cochrane and Web of Science. Comparative studies were included that reported on adult patients with osteosynthesis of extremities after trauma using either stainless steel or titanium implants. Information was extracted about infection rates, incidence of clinically relevant allergies, problems with implant removal and other complications. A total of 18 publications were identified to be eligible and 2 referenced articles were added. In summary, there is insufficient clinical evidence that the use of titanium or steel implants has a positive or negative effect on fracture healing, shows different rates of allergies, different rates of infections or mechanical failure. No supporting evidence could be identified for the difficulties with removal of titanium implants reported by surgeons. This systematic literature search did not provide any clinical evidence for material-related differences between titanium or stainless steel implants for fracture fixation. Based on the current clinical evidence both titanium and steel implants can be considered to be of equal value. The reported difficulties with implant removal are not reflected in the published literature.

  6. [Expression and dynamics of peptidergic nerve fibers in granulation tissue after distance osteosynthesis].

    PubMed

    Wolf, K; Höcherl, E; Farkas, T; Pfister, C

    2001-10-01

    The transmitters and/or modulators calcitonin gene-related peptide (CGRP), substance P (SP), neuropeptide Y (NPY) and vasointestinal polypeptide (VIP) are supposed to be involved in bone growth, fracture healing and internal remodeling. Immunohistochemical proof of neuropeptide positive fibers in normal bone let us assume that these substances effect the early phase of fracture healing. Exact time of appearance of neuropeptide positive fibers, localisation in the bone, chemospecifity and mode of genesis are unknown so fare. Research was done on a model of distance osteosynthesis of the rabbit tibia. Primary and secondary antibodies were used for indirect immunohistochemical technique. We put more strength on the concrete stereological calculation of length of the nerve fibers than on a conventional statistical evaluation. After histological preparation of tissue specimens from the interfragmental gap and the bone marrow beside the gap the neuropeptides CGRP, SP and NPY were immunohistochemically expressed. Sprouting of CGRP- and SP-positive nerve fibers has its origin in the bone marrow. A vascularisation in the early state of osteoneogenesis after fracture seems impossible without the nerval peptidergic influence and transmission.

  7. Changes in blood-flow in the bones after osteotomy and osteosynthesis.

    PubMed

    Kunze, K G; Hofstetter, H; Posalaky, I; Winkler, B

    1981-01-01

    The blood-flow can be measured with the method of "tracer microspheres". In 15 adult shepherd-dog bastards the blood-flow in the bones of the posterior extremity was determined. The blood-flow in callous bone is 6 times higher than in cortical bone. The values for blood-flow are decreasing from the proximal to the distal end, in cortical as well as in callous bone. In 10 of the 15 dogs the blood-flow was determined after manipulation of the bone. If the medullary cavity of the tibia was evacuated the blood-flow of the corticalis in the bone shaft diminished; it was reduced 3 times more than after removal of the periost. If an osteotomy was performed in the middle of the shaft, the blood-flow was more reduced distally than proximally. In the corticalis of the shaft the blood-flow of the proximal fragment drops only when an osteosynthesis is performed. In extended oblique fractures the upper ends of the fragments--proximally as well as distally--are endangered by a reduction of the blood-flow.

  8. New miniplate for osteosynthesis of mandibular angle fractures designed to improve formation of new bone.

    PubMed

    Pituru, Teodora Silagieva; Bucur, Alexandru; Gudas, Claudiu; Pituru, Silviu-Mirel; Marius Dinca, Octavian

    2016-04-01

    The purpose of this article is to present the study of a new miniplate designed to keep the maximum strains developed in the cortical bone near the fracture line during accidental biting to values below the threshold causing bone resorption. Designed to offer maximum fracture stability with minimal implanted volume and patient intrusion, the design uses a novel approach to account for the effects of the distance from the fracture line to the nearest screws. Its geometry minimizes the peak forces that can develop during most cases of mandible biomechanical loadings. A three-dimensional (3D) osteosynthesis finite element model for a human mandible confirmed the operational effectiveness of the miniplate. It also provided numerical estimates for the strains and screw forces in the cortical surface during incisor bites with clinically relevant forces of 200 N. Two prototypes, 0.6 mm and 0.8 mm in thickness, were repeatedly tested on fractured sheep mandibles, fixed in a purpose-built jig, to loads up to 150% of the maximum forces developed by human patients. The tests indicated good fracture stability, and the proof tests carried for each of the two prototypes terminated at more than 350 N due to failure of the loading cable and respectively, secondary mandible fractures occurring away from the miniplate.

  9. Rotational stability in screw-fixed scaphoid fractures compared to plate-fixed scaphoid fractures.

    PubMed

    Jurkowitsch, Josef; Dall'Ara, E; Quadlbauer, S; Pezzei, Ch; Jung, I; Pahr, D; Leixnering, M

    2016-11-01

    The literature describes the treatment of scaphoid fractures comparing the volar and dorsal approaches, the advantages and disadvantages of percutaneous screw fixation, as well as the treatment of scaphoid nonunions using different types of cancellous or corticocancellous bone grafts. Yet, to date no studies are available comparing the outcome of rotational stability in screw-fixed scaphoid fractures to angular stable systems. The purpose of this study is to provide reliable data about rotational stability in stabilised scaphoid fractures and to gain information about the rigidity and the stability of the different types of fixation. Three groups of different stabilisation methods on standardised scaphoid B2 fractures were tested for rotational stability. Stabilisation was achieved using one or two cannulated compression screws (CCS) or angular stable plating. We performed ten repetitive cycles up to 10°, 20° and 30° rotation, measuring the maximum torque and the average dissipated work at angle level. Our study showed that rotational stability using a two CCS fixation is significantly (p < 0.05) higher than single CCS fixation. Using the angular stable plate system was also superior to the single CCS (p < 0.05). There was, however, no significant difference between two CCS fixation and angular stable plate fixation. Even though indications of using screws or plate systems might be different and plate osteosynthesis may be preferable in treatment of dislocated or comminuted fractures as well as for nonunions, our study showed a better rotational stability by choosing more than just one screw for osteosynthesis. Angular stable plating of scaphoid fractures also provides more rotational stability than single CCS fixation. The authors therefore hypothesise higher union rates in scaphoid fractures using more stable fixation systems.

  10. Biomechanical comparison of straight DCP and helical plates for fixation of transverse and oblique bone fractures.

    PubMed

    Aksakal, Bunyamin; Gurger, Murat; Say, Yakup; Yilmaz, Erhan

    2014-01-01

    Biomechanical comparison of straight DCP and helical plates for fixation of transversal and oblique tibial bone fractures were analyzed and compared to each other by axial compression, bending and torsion tests. An in vitro osteosynthesis of transverse (TF) and oblique bone fracture (OF) fixations have been analysed on fresh sheep tibias by using the DCP and helical compression plates (HP). Statistically significant differences were found for both DCP and helical plate fixations under axial compression, bending and torsional loads. The strength of fixation systems was in favor of DC plating with exception of the TF-HP fixation group under compression loads and torsional moments. The transvers fracture (TF) stability was found to be higher than that found in oblique fracture (OF) fixed by helical plates (HP). However, under torsional testing, compared to conventional plating, the helical plate fixations provided a higher torsional resistance and strength. The maximum stiffness at axial compression loading and maximum torsional strength was achieved in torsional testing for the TF-HP fixations. From in vitro biomechanical analysis, fracture type and plate fixation system groups showed different responses under different loadings. Consequently, current biomechanical analyses may encourage the usage of helical HP fixations in near future during clinical practice for transverse bone fractures.

  11. Evaluation of the clinical performance of ultrahigh molecular weight polyethylene fiber cable using a dog osteosynthesis model.

    PubMed

    Oe, Kenichi; Jingushi, Seiya; Iida, Hirokazu; Tomita, Naohide

    2013-01-01

    The purpose of this study was to assess the removability and biological reactivity of an ultrahigh molecular weight polyethylene (UHMWPE) fiber cable as a new biomaterial for osteosynthesis. We used a pull-out test and an implantation test to analyze the performance of the UHMWPE fiber cable using a dog model, and compared its characteristics with those of a wire cable and a soft wire. In the pull-out test, the UHMWPE fiber cable was as easy to remove as the soft wire, and both the UHMWPE fiber cable and the soft wire were significantly easier to remove than the wire cable. The fixation capability and the biological reactivity of the UHMWPE fiber cable were examined in an osteosynthesis model of the dog greater trochanter, and were compared with those of the soft wire. The bone union rate, assessed radiographically, was very similar when using the UHMWPE fiber cable and the soft wire. However, in the soft wire group, both the surface of the greater trochanter under the fixation material and the penetration area around the fixation material showed an increased tendency toward a biological reaction, including inflammation and granulation tissue formation, as compared to the UHMWPE fiber cable group. The UHMWPE fiber cable was as easily removed from the bone tissue as the soft wire, and was easier to remove than the wire cable. Additionally, the UHMWPE fiber cable caused reduced biological reactivity with the surrounding tissue, as compared with the soft wire. In conclusion, the UHMWPE fiber cable appeared to be a suitable fixation material for osteosynthesis.

  12. Usefulness of osteosynthesis device made of hydroxyapatite-poly-L-lactide composites in port-access cardiac surgery.

    PubMed

    Ito, Tsutomu; Kudo, Mikihiko; Yozu, Ryohei

    2008-12-01

    Port-access minimally invasive cardiac surgery has been developed with the aim of reducing surgical invasion. We conduct port-access cardiac surgery, generally through an intercostal space. To ensure sufficient visual field, either the upper or lower rib may be divided. In the process of restoration of divided ribs, we have developed a bone fixation technique using a new osteosynthesis device by way of prevention of pseudoarthrosis. Forty-five consecutive patients underwent right-sided anterior intercostal thoracotomy under the port-access method between July 2006 and July 2007. We used a totally resorbable osteosynthesis device (Super Fixsorb; Takiron Co., Ltd., Osaka, Japan) consisting of a mix of poly-L-lactide (PLLA) and particulate resorbable uncalcined hydroxyapatite (u-HA). Fixation of the rib-costal cartilage was sufficiently achieved in this manner. No clinical symptoms suggestive of inflammation or infection were identified in the areas corresponding to the site of bone junction, and no patients have suffered pseudoarthrosis perioperatively and up to one year after surgery. Computed tomographic (CT) scanning clearly visualized these devices, and their attachment to the rib surfaces was confirmed in the patient who underwent CT scanning after the longest tested interval of 133 days after surgery. In this study, the possibility was suggested that the advantages of u-HA/PLLA composite, such as early osteoconductive property and bioactive property, might beneficially affect bone fusion. We conclude that this osteosynthesis device can be applied in various fields, including cardiovascular surgery, and that its use will contribute to improvement of patients' postoperative quality of life.

  13. Problem of Electromagnetoviscoelasticity for Multiply Connected Plates

    NASA Astrophysics Data System (ADS)

    Kaloerov, S. A.; Samodurov, A. A.

    2015-11-01

    A method for solving the problem of electromagnetoviscoelasticity for multiply connected plates is proposed. The small-parameter method is used to reduce this problem to a recursive sequence of problems of electromagnetoelasticity, which are solved by using complex potentials. A procedure is developed to determine, using complex potentials, approximations of the basic characteristics (stresses, electromagnetic-field strength, electromagnetic-flux density) of the electromagnetoelastic state at any time after application of a load. A plate with an elliptic hole is considered as an example. The variation in the electromagnetoelastic state of the multiply connected plate with time is studied

  14. Stability of Three-Layered Annular Plate with Composite Facings

    NASA Astrophysics Data System (ADS)

    Pawlus, D.

    2017-02-01

    Paper presents the behaviour of three-layered annular plates subjected to loads acting in plate plane. Plates are composed of laminated fibre-reinforced composite facings and foam core. The static and dynamic parameters of plate critical state were evaluated. The sensitivity of composite structure of plate to the acting of quickly increasing in time loads is shown. The problem has been solved numerically using the finite element method. Results have been compared with ones obtained for plate models with isotropic layers. These plate models have also been calculated solving formulated task analytically and numerically by means of the finite difference method. Solutions to the problem concern the axisymmetrical and asymmetrical plate buckling modes. Numerous presented tables and figures create the image of the stability behaviour of examined composite plates.

  15. Stability of Three-Layered Annular Plate with Composite Facings

    NASA Astrophysics Data System (ADS)

    Pawlus, D.

    2016-10-01

    Paper presents the behaviour of three-layered annular plates subjected to loads acting in plate plane. Plates are composed of laminated fibre-reinforced composite facings and foam core. The static and dynamic parameters of plate critical state were evaluated. The sensitivity of composite structure of plate to the acting of quickly increasing in time loads is shown. The problem has been solved numerically using the finite element method. Results have been compared with ones obtained for plate models with isotropic layers. These plate models have also been calculated solving formulated task analytically and numerically by means of the finite difference method. Solutions to the problem concern the axisymmetrical and asymmetrical plate buckling modes. Numerous presented tables and figures create the image of the stability behaviour of examined composite plates.

  16. [Morphological characteristics of reparative osteogenesis under the conditions of transosseous osteosynthesis and intramedullary introduction of hydroxyapatite-coated wires].

    PubMed

    Ir'ianov, Iu M; Popkov, A V; Antonov, N I

    2014-01-01

    In the experiments performed on 16 dogs, an open comminuted tibial fracture was modeled, then wires with hydroxyapatite coating were inserted intramedullary, and osteosynthesis was performed using the Ilizarov fixator. Bone regenerates were studied 14-360 days after the surgery using the methods of light microscopy, scanning electron microscopy, and X-ray electron probe microanalysis. It was found that a zone of active reparative osteo- and angiogenesis was formed around the wires, as well as a bone sheath with the properties of osteogenesis conductor and inductor. Fracture consolidation occured early according to the primary type without cartilaginous and connective tissue formation in bone adhesion.

  17. The Optimum Plate to Plate Spacing for Maximum Heat Transfer Rate from a Flat Plate Type Heat Exchanger

    NASA Astrophysics Data System (ADS)

    Ambarita, Himsar; Kishinami, Koki; Daimaruya, Mashashi; Tokura, Ikuo; Kawai, Hideki; Suzuki, Jun; Kobiyama, Mashayosi; Ginting, Armansyah

    The present paper is a study on the optimum plate to plate spacing for maximum heat transfer rate from a flat plate type heat exchanger. The heat exchanger consists of a number of parallel flat plates. The working fluids are flowed at the same operational conditions, either fixed pressure head or fixed fan power input. Parallel and counter flow directions of the working fluids were considered. While the volume of the heat exchanger is kept constant, plate number was varied. Hence, the spacing between plates as well as heat transfer rate will vary and there exists a maximum heat transfer rate. The objective of this paper is to seek the optimum plate to plate spacing for maximum heat transfer rate. In order to solve the problem, analytical and numerical solutions have been carried out. In the analytical solution, the correlations of the optimum plate to plate spacing as a function of the non-dimensional parameters were developed. Furthermore, the numerical simulation is carried out to evaluate the correlations. The results show that the optimum plate to plate spacing for a counter flow heat exchanger is smaller than parallel flow ones. On the other hand, the maximum heat transfer rate for a counter flow heat exchanger is bigger than parallel flow ones.

  18. Fixed-angle plates in patella fractures - a pilot cadaver study

    PubMed Central

    2011-01-01

    Objective Modified anterior tension wiring with K-wires and cannulated lag screws with anterior tension wiring are currently the fixation of choice for patellar fractures. Failure of fixation, migration of the wires, postoperative pain and resulting revision surgery, however, are not uncommon. After preliminary biomechanical testing of a new fixed-angle plate system especially designed for fixation of patella fractures the aim of this study was to evaluate the surgical and anatomical feasibility of implanting such a plate-device at the human patella. Methods In six fresh unfixed female cadavers without history of previous fractures around the knee (average age 88.8 years) a bilateral fixed-angle plate fixation of the patella was carried out after previous placement of a transverse central osteotomy. Operative time, intra-operative problems, degree of retropatellar arthritis (following Outerbridge), quality of reduction and existence of any intraarticular screw placement have been raised. In addition, lateral and anteroposterior radiographs of all specimens were made. Results Due to the high average age of 88.8 years no patella showed an unimpaired retropatellar articular surface and all were severely osteoporotic, which made a secure fixation of the reduction forceps during surgery difficult. The operation time averaged 49 minutes (range: 36-65). Although in postoperative X-rays the fracture gap between the fragments was still visible, the analysis of the retropatellar surface showed no residual articular step or dehiscence > 0.5 mm. Also in a total of 24 inserted screws not one intraarticular malposition was found. No intraoperative complications were noticed. Conclusions Osteosynthesis of a medial third patella fracture with a bilateral fixed-angle plate-device is surgically and anatomically feasible without difficulties. Further studies have to depict whether the bilateral fixed-angle plate-osteosynthesis of the patella displays advantages over the established

  19. Percutaneous Cannulated Compression Screw Osteosynthesis in Phalanx Fractures: The Surgical Technique, the Indications, and the Results

    PubMed Central

    Kisch, Tobias; Wenzel, Eike; Mailänder, Peter; Stang, Felix

    2017-01-01

    Objective: Fractures of metacarpals and phalanges are very common fractures, and there are a lot of treatment modalities. The purpose of the study was to describe the technique of percutaneous fixation of phalangeal fractures using a cannulated compression screw fixation system and its results. Methods: We conducted a prospective clinical study on 43 patients with different types of phalangeal fractures undergoing a percutaneous cannulated compression screw osteosynthesis. Parameters such as average operation time and clinical outcome were evaluated postoperatively. Results: Forty-three patients were treated using a percutaneous cannulated compression screw fixation system for phalanx fractures of the proximal (n = 26), middle phalanx (n = 16), or distal phalanx (n = 1). All fractures healed after 6 to 8 weeks except in 1 patient with secondary loss of reduction occurring 2.5 weeks after surgery. No infections were observed. The mean total active motion values were 247.56° ±16.16° and 244.35° ± 11.61° for the intra-articular fracture and 251.25° ± 19.86° for the shaft fractures; the mean Disabilities of the Arm, Shoulder, and Hand (DASH) score 3 months after the surgery was 1.67 ± 2.74. Conclusions: The advantages of this technique are the avoidance of an open procedure requiring extensive soft-tissue dissection with the risks of tendon adhesions and the achievement of interfragmentary compression. Because of the interfragmentary compression, it is superior to simple K-wires. With regard to indications, our primary focus was on unicondylar proximal interphalangeal joint fractures, shaft fractures, and simple oblique 2-fragment fractures. PMID:28293333

  20. [Absorbable osteosynthesis: experimental and clinical approach in surgery of the hand].

    PubMed

    Merle, M; Voche, P H

    1994-01-01

    Given the advances in the field of high molecular-weight polylactides, it is now possible to obtain biomaterials of great strength with a resorption rate that ranges from a few months to several years. Experimental evaluation of the biomaterials was done in rabbits with implantation of intramedullary rods after fracture of the knee. The results of histological studies and assessment, using MR imaging, indicated good compatibility of the intramedullary rods. Applications for human clinical practice centered on metacarpophalangeal arthrodesis of the thumb performed for rheumatoid polyarthritis and intractable sprains of the metacarpophalangeal. Operations were performed on 52 patients with a rate of consolidation of 96%. No synovitis-like reactions were observed concurrent with massive release of the biomaterial. As a first step, this type of osteosynthesis could be applied to the upper extremity where stresses are relatively minimal. Eventually, screws of reduced diameter could be developed for the treatment of articular and unstable fractures of the metacarpophalangeals. There are already 3.5 mm-screws that can be used for malleolar fixation at the level of the lower extremity. Because of the wide variety of biomaterials that are currently available, it is important to be familiar with their composition, so that patients will be spared certain complications linked to resorption, especially inflammatory reactions. The biomaterials presented here belong to a class of biomaterials that have demonstrated good compatibility. At the present time, the cost of biodegradable materials remains high but it is important to emphasize the social and economic consequences of their use, since there is no need for a secondary procedure to remove them.

  1. Plate electronics

    NASA Astrophysics Data System (ADS)

    Carlowicz, Michael

    Using a Cray T3D supercomputer and a simple assumption about the physical character of Earth's mantle, a pair of researchers from the University of California at Berkeley have built a computer model that may help explain why the planet's tectonic plates look the way they do.In creating a three-dimensional numerical simulation of convection in the Earth's interior, UC researchers Hans-Peter Bunge and Mark Richards simplified their model to account for just one major physical effect: that the viscosity of the mantle increases with depth. Reviewing some recent—but not yet widely accepted—seismic data, Bunge and Richards assumed for the sake of the model that the viscosity of the mantle increases by a factor of 30 from the lithosphere to the core-mantle boundary. Relying on that assumption, the pair ran the model for nearly three weeks on a supercomputer at Los Alamos National Laboratory and found that the simulation produced an effect similar to what we see on the surface of Earth. The model produced a surface paralleling the actual width of plates and the geometry of the plate boundaries.

  2. Management of pediatric mandibular fractures using bioresorbable plating system – Efficacy, stability, and clinical outcomes: Our experiences and literature review

    PubMed Central

    Singh, Mahinder; Singh, R.K.; Passi, Deepak; Aggarwal, Mohit; Kaur, Guneet

    2015-01-01

    Aims The purpose of this study was to determine the efficacy and stability of the biodegradable fixation system for treatment of mandible fractures in pediatric patients by measuring the bite force. Methods Sixty pediatric patients with mandibular fractures (36 males, 24 females) were included in this study. The 2.5-mm resorbable plates were adapted along Champy's line of ideal osteosynthesis and secured with four 2.5 mm diameter monocortical resorbable screws, 8 mm in length. All patients were followed for 10 months. Clinical parameters, such as soft tissue infection, nonunion, malunion, implant exposure, malocclusion, nerve injury, and bite force for stability, were prospectively assessed. Results Adequate fixation and primary bone healing was achieved in 100% of the cases. Six minor complications (10%) were observed: 2 soft tissue infections (3%), 1 plate dehiscence (2%), 1 malocclusion (2%), and 2 paresthesia (3%). Conclusion 2.5-mm resorbable plating system along Champy's line of ideal osteosynthesis is a good treatment modality for mandible fractures in pediatric patients. PMID:27195206

  3. Modal interaction in postbuckled plates. Theory

    NASA Technical Reports Server (NTRS)

    Thurston, Gaylen A.

    1989-01-01

    Plates can have more than one buckled solution for a fixed set of boundary conditions. The theory for the identification and the computation of multiple solutions in buckled plates is examined. The theory predicts modal interaction (which is also called change in buckle pattern or secondary buckling) in experiments on certain plates with multiple theoretical solutions. A set of coordinate functions is defined for Galerkin's method so that the von Karman plate equations are reduced to a coupled set of cubic equations in generalized coordinates that are uncoupled in the linear terms. An iterative procedure for solving modal interaction problems is suggested based on this cubic form.

  4. Influence of screw insertion order on compression generated by bone plates in a fracture model.

    PubMed

    Jermyn, K; Roe, S C

    2011-01-01

    Present recommendations regarding order of screw insertion for compression plate osteosynthesis in veterinary training are variable. We hypothesized that placement of a neutrally positioned screw would reduce the magnitude of compression that could be generated by a subsequently placed compression screw. Canine tibial diaphyseal segments were fixed to a plate attached to a bone surrogate and load cell, and the compression generated by screw tightening was measured. Three different screw insertion order patterns were evaluated using both dynamic compression plate (DCP) and limited contact dynamic compression plate (LC-DCP) implants. In group CN, the first screw was placed in compression mode and the second in neutral mode; in group NC, the first screw was placed in neutral mode and the second in compression mode; in group LNC, the first screw was placed partially tightened in neutral mode and the second in compression mode followed by complete tightening of the neutral screw. Screw insertion order significantly influenced the amount of compression generated with both groups CN and LNC demonstrating significantly greater compression generation when compared with group NC (p <0.0001). Compression generated by group CN constructs was also significantly greater than group LNC (p = 0.0013). Evaluation of group CN data to assess the influence of plate and drill guide combinations on compressive force generated did not demonstrate a statistically significant difference. To maximize compression using a load screw in a bone plate, following securement of the opposite bone fragment to the plate, it should be placed before a neutral screw is placed.

  5. Sustained relief of pain from osteosynthesis surgery of rib fracture by using biodegradable lidocaine-eluting nanofibrous membranes.

    PubMed

    Yu, Yi-Hsun; Hsu, Yung-Heng; Chou, Ying-Chao; Fan, Chin-Lung; Ueng, Steve W N; Kau, Yi-Chuan; Liu, Shih-Jung

    2016-10-01

    Various effective methods are available for perioperative pain control in osteosynthesis surgery, but they are seldom applied intraoperatively. The aim of this study was to evaluate a biodegradable poly([d,l]-lactide-co-glycolide) (PLGA)/lidocaine nanofibrous membrane for perioperative pain control in rib fracture surgery. Scanning electron microscopy showed high porosity of the membrane, and an ex vivo high-performance liquid chromatography study revealed an excellent release profile for both burst and controlled release of lidocaine within 30days. Additionally, the PLGA/lidocaine nanofibrous membrane was applied in an experimental rabbit rib osteotomy model. Implantation of the membrane around the osteotomized rib during osteosynthesis surgery resulted in a significant increase in weight gain, food and water consumption, and daily activity compared to the study group without the membrane. In addition, all osteotomized ribs were united. Thus, application of the PLGA/lidocaine nanofibrous membrane may be effective for sustained relief of pain in oeteosynthesis surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Use of the titanium vertical ribs osteosynthesis system for reconstruction of large posterolateral chest wall defect in lung cancer.

    PubMed

    Berthet, Jean-Philippe; D'Annoville, Thomas; Canaud, Ludovic; Marty-Ané, Charles-Henri

    2011-08-01

    We report a case of reconstruction of a large full-thickness posterolateral defect of the chest wall after resection of a stage III non-small cell lung carcinoma (NSCLC) using the combination of a vertical expandable prosthetic titanium device and a polytetrafluoroethylene (PTFE) mesh. A 40-year-old female presented with a NSCLC classified as type IIIA and required both neoadjuvant radiotherapy and chemotherapy. An en bloc resection including the left upper lobe, posterolateral segments of five ribs (K3-K7) and vertebral bodies (T3-T6) was performed through a posterior J-shaped approach. A vertical rib osteosynthesis system was used to ensure thoracic wall stability and mechanical organ protection, prevent ventilatory impairment, avoid incarceration of the tip of the scapula, and maintain an acceptable cosmetic aspect. The device was locked onto the middle arch of the second and eighth ribs. We hung the PTFE mesh from the titanium bars with multiple non-absorbable sutures under maximal tension. Final pathological classification was T4N0M0 with an R0 final resection status. After an uneventful course, the patient was discharged on postoperative day 10. This first experience indicates that vertical rib osteosynthesis combined with a PTFE mesh can be used safely and easily in a one-stage procedure for major posterior chest wall defects.

  7. Bone Repair on Fractures Treated with Osteosynthesis, ir Laser, Bone Graft and Guided Bone Regeneration: Histomorfometric Study

    NASA Astrophysics Data System (ADS)

    dos Santos Aciole, Jouber Mateus; dos Santos Aciole, Gilberth Tadeu; Soares, Luiz Guilherme Pinheiro; Barbosa, Artur Felipe Santos; Santos, Jean Nunes; Pinheiro, Antonio Luiz Barbosa

    2011-08-01

    The aim of this study was to evaluate, through the analysis of histomorfometric, the repair of complete tibial fracture in rabbits fixed with osteosynthesis, treated or not with infrared laser light (λ780 nm, 50 mW, CW) associated or not to the use of hydroxyapatite and guided bone regeneration (GBR). Surgical fractures were created, under general anesthesia (Ketamina 0,4 ml/Kg IP and Xilazina 0,2 ml/Kg IP), on the dorsum of 15 Oryctolagus rabbits that were divided into 5 groups and maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet and had water ad libidum. On groups II, III, IV and V the fracture was fixed with wire osteosynthesis. Animals of groups III and V were grafted with hydroxyapatite and GBR technique used. Animals of groups IV and V were irradiated at every other day during two weeks (16 J/cm2, 4×4 J/cm2). Observation time was that of 30 days. After animal death (overdose of general anesthetics) the specimes were routinely processed to wax and underwent histological analysis by light microscopy. The histomorfometric analysis showed an increased bone neoformation, increased collagen deposition, less reabsorption and inflammation when laser was associated to the HATCP. It is concluded that IR laser light was able to accelerate fracture healing and the association with HATCP and GBR resulted on increased deposition of CHA.

  8. Clinical application of locked plating system in children. An orthopaedic view

    PubMed Central

    Zafra-Jimenez, Jose Alberto; Rodriguez Martin, Juan

    2010-01-01

    In recent years, the locked plating system has gained favour in the treatment of certain fractures in adults; however, there is not much information regarding its use in children. We think there could be some advantages and applications such as: an alternative to external fixation, the bridge plating technique, unicortical screws, removal of hardware, metadiaphyseal fractures, periarticular fractures, poor quality bone, and allograft fixation. However, there are some disadvantages to keep in mind and the final decision for using it should be based on the osteosynthesis method principle the surgeon would like to apply. In this review article we discuss the up-to-date possible clinical applications and issues of this system. PMID:20162415

  9. Reality-augmented virtual fluoroscopy for computer-assisted diaphyseal long bone fracture osteosynthesis: a novel technique and feasibility study results.

    PubMed

    Zheng, G; Dong, X; Gruetzner, P A

    2008-01-01

    In this paper, a novel technique to create a reality-augmented virtual fluoroscopy for computer-assisted diaphyseal long bone fracture osteosynthesis and feasibility study results are presented. With this novel technique, repositioning of bone fragments during closed fracture reduction and osteosynthesis can lead to image updates in the virtual imaging planes of all acquired images without any radiation. The technique is achieved with a two-stage method. After acquiring a few (normally two) calibrated fluoroscopic images and before fracture reduction, the first stage, data preparation, interactively identifies and segments the bone fragments from the background in each image. After that, the second stage, image updates, repositions the fragment projection on to each virtual imaging plane in real time during fracture reduction and osteosynthesis using an OpenGL-based texture warping. Combined with a photorealistic virtual implant model rendering technique, the present technique allows the control of a closed indirect fracture osteosynthesis in the real world through direct insight into the virtual world. The first clinical study results show the reduction in the X-ray radiation to the patient as well as to the surgical team, and the improved operative precision, guaranteeing more safety for the patient. Furthermore, based on the experiences gained from this clinical study, two technical enhancements are proposed. One focuses on eliminating the user interactions with automated identifications and segmentations of bone fragments. The other focuses on providing non-photorealistic implant visualization. Further experiments are performed to validate the effectiveness of the proposed enhancements.

  10. Impact on multilayered composite plates

    NASA Technical Reports Server (NTRS)

    Kim, B. S.; Moon, F. C.

    1977-01-01

    Stress wave propagation in a multilayer composite plate due to impact was examined by means of the anisotropic elasticity theory. The plate was modelled as a number of identical anisotropic layers and the approximate plate theory of Mindlin was then applied to each layer to obtain a set of difference-differential equations of motion. Dispersion relations for harmonic waves and correction factors were found. The governing equations were reduced to difference equations via integral transforms. With given impact boundary conditions these equations were solved for an arbitrary number of layers in the plate and the transient propagation of waves was calculated by means of a Fast Fourier Transform algorithm. The multilayered plate problem was extended to examine the effect of damping layers present between two elastic layers. A reduction of the interlaminar normal stress was significant when the thickness of damping layer was increased but the effect was mostly due to the softness of the damping layer. Finally, the problem of a composite plate with a crack on the interlaminar boundary was formulated.

  11. [Osteosynthesis under arthroscopic control of separated tibial plateau fractures. 26 case reports].

    PubMed

    Cassard, X; Beaufils, P; Blin, J L; Hardy, P

    1999-06-01

    open surgical technique for the types of fracture that we have treated (type III and IV). A minimal, percutaneous osteosynthesis which was the only possibility under arthroscopic control, did not modify the anatomical results.

  12. Biodegradable calcium polyphosphate/polyvinyl-urethane carbonate composites for osteosynthesis applications

    NASA Astrophysics Data System (ADS)

    Ramsay, Scott Desmond

    The formation of biodegradable implants for use in osteosynthesis has been a major goal of biomaterials research for the past two to three decades. Self-reinforced polylactide systems represent the most significant success of this research to date, however with elastic constants of, at most, 12--15 GPa, they fail to provide the necessary initial stiffness required of devices designed for stabilizing fractures of major load-bearing bones. One objective of this study has been the development of a biodegradable composite suitable for fabrication of implants for the repair of fractures of major load-bearing bones. Specifically, this research has focussed on the use of calcium polyphosphate (CPP), an uiorganic polymer in combination with polyvinyl-urethane carbonate (PVUC) organic polymers. Composite samples were formed as interpenetrating phase composites (IPC), particle-reinforced composites (PRC), and fibre-reinforced composites (FRC). Additionally, the IPCs were produced as both monolithic and laminated specimens. PRC samples exhibit too low asmade elastic constant for fracture fixation applications, while the IPC and FRC samples exhibit desired as-made strength and bending stiffness but lose these properties too rapidly when exposed to aqueous-based in vitro aging, simulating in vivo conditions. An investigation to determine the mechanism of the rapid in vitro degradation was undertaken using a model IPC system to study the effect of the interfacial strength on the mechanical properties of the composite. In addition, these studies provided further support for a hypothesis to explain the observed high mechanical properties of the as-made CPP-PVUC interpenetrating phase composites. It was found that strong interfacial strength is very significant in obtaining appropriate mechanical properties in the IPC system. Results support the conclusion that a rapid loss of the CPP-PVUC interface through exposure to an aqueous environment, as well as stresses imposed on the CPP

  13. Analysis of hydraulic instability of ANS involute fuel plates

    SciTech Connect

    Sartory, W.K.

    1991-11-01

    Curved shell equations for the involute Advanced Neutron Source (ANS) fuel plates are coupled to two-dimensional hydraulic channel flow equations that include fluid friction. A complete set of fluid and plate boundary conditions is applied at the entrance and exit and along the sides of the plate and the channel. The coupled system is linearized and solved to assess the hydraulic instability of the plates.

  14. Vortex Dynamics around Pitching Plates

    DTIC Science & Technology

    2014-04-29

    lengths of travel. Computations have reasonable agreement with experiments, despite large differences in Reynolds number. Computations show that the tip...ratio effects (tip effects) for pitching wings which has not been examined in detail with computations . By performing parameter studies with varied... Computational setup Three-dimensional incompressible flow over the flat-plate wing is numerically solved with the immersed boundary projection method25, which

  15. Finite element analysis of shear deformable laminated composite plates

    SciTech Connect

    Kam, T.Y.; Chang, R.R. )

    1993-03-01

    A shear deformable finite element is developed for the analysis of thick laminated composite plates. The finite element formulation is based on Mindlin's plate theory in which shear correction factors are derived from the exact expressions for orthotropic materials. The element is used to solve a variety of problems on deflection, stress distribution, natural frequency and buckling of laminated composite plates. The effects of material properties, plate aspect ratio, length-to-thickness ratio, number of layers and lamination angle on the mechanical behaviors of laminated composite plates are investigated. Optimal lamination arrangements of layers for laminated composite plates of particular applications are determined.

  16. New concepts for bone fracture treatment and the Locking Compression Plate.

    PubMed

    Wagner, Michael; Frenk, Andre; Frigg, Röbi

    2004-01-01

    The operative treatment of bone fractures using plates and screws is a standard successful technique. Internal fixation with plates and screws leads to additional trauma and disturbance of the bone blood supply, which increases the risk of delayed union and infection. However, problems also are encountered in the fixation of osteoporotic bone. The locked internal fixator technique is an approach to optimize internal fixation. It aims at flexible elastic fixation to imitate spontaneous healing, including induction of callus formation. The technology supports what is currently called "minimally invasive plate osteosynthesis" (MIPO), which provides priority to biology over mechanics. An implant system called "Locking Compression Plate (LCP)" was developed, based on many years of experience with compression plating and good clinical results obtained with internal fixators, such as the Less Invasive Stabilization Systems (LISS). It combines the two treatment methods (ie, the compression plating and locked internal fixation methods) into one system. This chapter describes the basic principles of locked internal fixators and some clinical results with the LISS and LCP systems to illustrate the potential of these new systems.

  17. The RIVET: a novel technique involving absorbable fixation for hydroxyapatite osteosynthesis.

    PubMed

    Shido, Hirokazu; Sakamoto, Yoshiaki; Miwa, Tomoru; Ohira, Takayuki; Yoshida, Kazunari; Kishi, Kazuo

    2013-05-01

    Cranioplasty using custom-made hydroxyapatite (HAP) ceramic implants is a common procedure for the repair of skull defects. The advantages of using HAP are that it is nonmetallic, unlike titanium; biocompatible; and osteoconductive. Furthermore, it can be molded to any complex shape that may be needed. A disadvantage is that titanium screws and plates are in development for its fixation. We developed a technique for implant fixation using bioabsorbable screws and plates, and named this technique RIVET: resorbable immobilization for vacuolar en bloc technique.Before each operation, the implant was customized for the patient in question on the basis of models prepared using computed tomography data. The bioabsorbable plates were attached to the implant by drilling, tapping, and screwing, as shown in the video (http://links.lww.com/SCS/A43). The interior portion of the screw was then melted to flatten it against the internal surface of the implant, forming a rivet to join the plate and HAP implant.We used this technique for cranial reconstruction in 2 patients, with satisfying and functional results. We did not encounter any complications.In conclusion, the technique described here allows surgeons to fix implants and plates together more rigidly, giving a better result than possible with previous methods.

  18. Finite Element Analysis of Elasto-plastic Plate Bending Problems using Transition Rectangular Plate Elements

    NASA Astrophysics Data System (ADS)

    Kanber, Bahattin; Bozkurt, O. Yavuz

    2006-08-01

    In this work, the finite element analysis of the elasto-plastic plate bending problems is carried out using transition rectangular plate elements. The shape functions of the transition plate elements are derived based on a practical rule. The transition plate elements are all quadrilateral and can be used to obtain efficient finite element models using minimum number of elements. The mesh convergence rates of the models including the transition elements are compared with the regular element models. To verify the developed elements, simple tests are demonstrated and various elasto-plastic problems are solved. Their results are compared with ANSYS results.

  19. [Structural reorganization of the dermis of dog tibia during its elongation by the method of transosseous distraction osteosynthesis].

    PubMed

    Gorbach, Ye N

    2014-01-01

    Using the methods of light, scanning and transmission electron microscopy, immunohistochemistry and morphometry the status of the various components of the dermis was studied in the experiment performed on 16 adult mongrel dogs that had their shank extended by 17% of its original length using the method of transosseous distraction osteosynthesis with a daily rate of 1 mm for 4 steps. During the period of distraction, a reduction in the thickness of the dermis, change of the architectonics of its fibrous component, active collageno- and elastogenesis, cell proliferation, and the expressiveness of heteromorphism of fibroblast and macrophage cell populations were detected. In postdistraction period, all the indices were gradually approaching the norm. The data obtained may serve as criteria for the estimation of the stages of the reparative process developing under the created conditions and should be considered in the development of new technologies aimed at optimizing reparative-regenerative processes during tibial lengthening.

  20. Nonlinear modeling of truss-plate joints

    Treesearch

    Leslie H. Groom; Anton Polensek

    1992-01-01

    A theoretical model is developed for predicting mechanisms of load transfer between a wood member and a metal die-punched truss plate. The model, which treats a truss-plate tooth as a beam on an inelastic foundation of wood and applies Runae-Kutta numerical analysis to solve the governing differentia1 equations, predicts the load-disp1acement trace and ultimate load of...

  1. Problem Solving. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2004-01-01

    No longer solely the domain of Mathematics, problem solving permeates every area of today's curricula. Ideally students are applying heuristics strategies in varied contexts and novel situations in every subject taught. The ability to solve problems is a basic life skill and is essential to understanding technical subjects. Problem-solving is a…

  2. Reverse shoulder arthroplasty for proximal humeral fractures: outcomes comparing primary reverse arthroplasty for fracture versus reverse arthroplasty after failed osteosynthesis.

    PubMed

    Shannon, Steven F; Wagner, Eric R; Houdek, Matthew T; Cross, William W; Sánchez-Sotelo, Joaquin

    2016-10-01

    Surgical treatment of proximal humeral fractures in the elderly pose challenges in decision making. Reverse total shoulder arthroplasty (RTSA) has been established as a reliable option for salvage of failed hemiarthroplasty, although few studies have analyzed RTSA after failed open reduction with internal fixation (ORIF). This study evaluated the outcomes of patients with failed osteosynthesis who undergo salvage RTSA compared with patients undergoing primary RTSA for proximal humeral fractures. We retrospectively reviewed 18 patients who underwent primary RTSA for acute proximal humeral fractures and 26 patients who underwent arthroplasty after failed ORIF at our institution between 2003 and 2013. Minimum follow-up was 2 years, with a mean follow-up 3 years (range, 2.0-6.0 years). There are no statistically significant differences in clinical outcomes between the two cohorts in the American Shoulder and Elbow Surgeons scores and in the most recent forward flexion or external rotation. The salvage RTSA cohort experienced a higher complication rate (8%), including dislocation and aseptic loosening. The primary RTSA cohort had a 5% complication rate, with 1 late prosthetic joint infection requiring reoperation. Although RTSA after failed ORIF has a higher rate of complications compared with acute RTSA, the revision and reoperation rate as well as clinical outcomes and shoulder function remained comparable. When a surgeon approaches these complex fractures in patients with poor underlying bone stock, this study supports acute arthroplasty or ORIF with the knowledge that salvage RTSA still has the potential to achieve good outcomes if osteosynthesis fails. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  3. Clinical accuracy of waferless maxillary positioning using customized surgical guides and patient specific osteosynthesis in bimaxillary orthognathic surgery.

    PubMed

    Heufelder, Marcus; Wilde, Frank; Pietzka, Sebastian; Mascha, Frank; Winter, Karsten; Schramm, Alexander; Rana, Majeed

    2017-09-01

    Computer-assisted planning and surgery for the treatment of orthognathic deformities have been extensively documented over the last decade. Computerized and customized wafers have lacked to improve the accuracy of maxillary positioning, resulting in a drawback of computer-assisted orthognathic surgery. The aim of this study was to determine the accuracy of a new technique of waferless maxillary positioning using customized surgical guides and patient specific osteosynthesis implants in bimaxillary orthognathic surgery. 22 consecutive patients were evaluated prospectively by fusing preoperative planning and postoperative outcome using CT scan evaluation. The median deviation of the maxilla position between the preoperative plan and the surgical result was 0.39 mm. The accuracy of left-right-positioning was median 0.30 mm at a range of 0-0.95 mm. Up-down-positioning showed a median accuracy of 0.33 mm at a range of 0-1.22 mm. Higher values were determined for the anterior-posterior-positioning of the maxilla with median 0.7 mm at a range of 0-2.0 mm. The results demonstrate the high predictability of maxillary positioning by CAD/CAM fabricated customized surgical guides and patient specific osteosynthesis. Use of this new digital approach may achieve surgeon independent accuracy of maxillary positioning, facilitating resident training even in the treatment of complex malformations. The high costs, however, may restrict routine use of this technique. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  4. Plate fixation of periprosthetic femur fractures: What happens to the cement mantle?

    PubMed

    Konstantinidis, Lukas; Schmidt, Benjamin; Bernstein, Anke; Hirschmüller, Anja; Schröter, Steffen; Südkamp, Norbert Paul; Helwig, Peter

    2017-02-01

    Osteosynthesis of periprosthetic femur fractures by screw fixation around the implanted prosthetic stem is currently regarded as the biomechanically superior option compared with cerclage. The aim of this biomechanical study was damage analysis of the cement mantle after revision screw insertion. A prosthetic stem (Bicontact) was implanted in 20 cadaveric femora in cemented technique. A locking compression plate (Synthes) was then applied to the lateral femur at the level of the prosthetic stem. The method of plate fixation to the femur was assigned randomly to three groups: bicortical non-locking screws, monocortical locking screws, and bicortical locking screws. This was followed by applying a fluctuating axial load (2100 N, 0.5 Hz) for 20,000 cycles. After testing, macroscopic and microscopic evaluations of the cement mantle were conducted. Cracks formed in the cement mantle in 14% of the 80 screw holes. The type of screw (bicortical or monocortical; locking or non-locking) had no significant effect on the number of cracks (p = 0.52). The relationship between manifestation of crack damage and cement mantle thickness was not significant (p = 0.36), whereas the relationship between crack formation and screw position was significant (p = 0.019). Those screws whose circumference was only partially within the cement mantle yielded a significantly lower number of cracks compared with screws positioned completely within the cement mantle or even touching the prosthetic stem. In order to reduce the incidence of crack formation in the cement mantle during plate osteosynthesis of periprosthetic femur fractures, the screws should not be either placed within the cement mantle or make direct contact with the stem.

  5. Corrugated cover plate for flat plate collector

    DOEpatents

    Hollands, K. G. Terry; Sibbitt, Bruce

    1978-01-01

    A flat plate radiant energy collector is providing having a transparent cover. The cover has a V-corrugated shape which reduces the amount of energy reflected by the cover away from the flat plate absorber of the collector.

  6. Absolute Plate Velocities from Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Kreemer, Corné; Zheng, Lin; Gordon, Richard

    2015-04-01

    The orientation of seismic anisotropy inferred beneath plate interiors may provide a means to estimate the motions of the plate relative to the sub-asthenospheric mantle. Here we analyze two global sets of shear-wave splitting data, that of Kreemer [2009] and an updated and expanded data set, to estimate plate motions and to better understand the dispersion of the data, correlations in the errors, and their relation to plate speed. We also explore the effect of using geologically current plate velocities (i.e., the MORVEL set of angular velocities [DeMets et al. 2010]) compared with geodetically current plate velocities (i.e., the GSRM v1.2 angular velocities [Kreemer et al. 2014]). We demonstrate that the errors in plate motion azimuths inferred from shear-wave splitting beneath any one tectonic plate are correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. The SKS-MORVEL absolute plate angular velocities (based on the Kreemer [2009] data set) are determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25±0.11° Ma-1 (95% confidence limits) right-handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ=19.2° ) differs insignificantly from that for continental lithosphere (σ=21.6° ). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ=7.4° ) than for continental

  7. Biomechanical Loading Evaluation of Unsintered Hydroxyapatite/poly-l-lactide Plate System in Bilateral Sagittal Split Ramus Osteotomy

    PubMed Central

    Sukegawa, Shintaro; Kanno, Takahiro; Manabe, Yoshiki; Matsumoto, Kenichi; Sukegawa-Takahashi, Yuka; Masui, Masanori; Furuki, Yoshihiko

    2017-01-01

    OSTEOTRANS MX® (Takiron Co., Ltd., Osaka, Japan) is a bioactive resorbable maxillofacial osteosynthetic material composed of an unsintered hydroxyapatite/poly-l-lactide composite, and its effective osteoconductive capacity has been previously documented. However, the mechanical strength of this plate system is unclear. Thus, the aim of this in vitro study was to assess its tensile and shear strength and evaluate the biomechanical intensity of different osteosynthesis plate designs after sagittal split ramus osteotomy by simulating masticatory forces in a clinical setting. For tensile and shear strength analyses, three mechanical strength measurement samples were prepared by fixing unsintered hydroxyapatite/poly-l-lactide composed plates to polycarbonate skeletal models. Regarding biomechanical loading evaluation, 12 mandibular replicas were used and divided into four groups for sagittal split ramus osteotomy fixation. Each sample was secured in a jig and subjected to vertical load on the first molar teeth. Regarding shear strength, the novel-shaped unsintered hydroxyapatite/poly-l-lactide plate had significantly high intensity. Upon biomechanical loading evaluation, this plate system also displayed significantly high stability in addition to bioactivity, with no observed plate fracture. Thus, we have clearly demonstrated the efficacy of this plate system using an in vitro model of bilateral sagittal split ramus osteotomy of the mandible. PMID:28773126

  8. Biomechanical Loading Evaluation of Unsintered Hydroxyapatite/poly-l-lactide Plate System in Bilateral Sagittal Split Ramus Osteotomy.

    PubMed

    Sukegawa, Shintaro; Kanno, Takahiro; Manabe, Yoshiki; Matsumoto, Kenichi; Sukegawa-Takahashi, Yuka; Masui, Masanori; Furuki, Yoshihiko

    2017-07-07

    OSTEOTRANS MX(®) (Takiron Co., Ltd., Osaka, Japan) is a bioactive resorbable maxillofacial osteosynthetic material composed of an unsintered hydroxyapatite/poly-l-lactide composite, and its effective osteoconductive capacity has been previously documented. However, the mechanical strength of this plate system is unclear. Thus, the aim of this in vitro study was to assess its tensile and shear strength and evaluate the biomechanical intensity of different osteosynthesis plate designs after sagittal split ramus osteotomy by simulating masticatory forces in a clinical setting. For tensile and shear strength analyses, three mechanical strength measurement samples were prepared by fixing unsintered hydroxyapatite/poly-l-lactide composed plates to polycarbonate skeletal models. Regarding biomechanical loading evaluation, 12 mandibular replicas were used and divided into four groups for sagittal split ramus osteotomy fixation. Each sample was secured in a jig and subjected to vertical load on the first molar teeth. Regarding shear strength, the novel-shaped unsintered hydroxyapatite/poly-l-lactide plate had significantly high intensity. Upon biomechanical loading evaluation, this plate system also displayed significantly high stability in addition to bioactivity, with no observed plate fracture. Thus, we have clearly demonstrated the efficacy of this plate system using an in vitro model of bilateral sagittal split ramus osteotomy of the mandible.

  9. "Death by a thread"--peritonitis due to visceral perforation by a guide wire, during proximal femur osteosynthesis with DHS: a fatal case and legal implications.

    PubMed

    Durão, Carlos; Barros, André; Guerreiro, Rui; Pedrosa, Frederico

    2015-04-01

    Iatrogenic intestinal perforations in orthopaedic surgery are very rare. Reports of iatrogenic lesions caused by a guide wire during femur fracture osteosynthesis are even scarcer. There are no similar reports in recent literature. As opposed to what is normally described the lesion documented in this case report was not identified on time resulting in death by peritonitis. The forensic autopsy allowed the identification of an intestinal perforation with faecal leakage to peritoneal space in association with a vesical perforation enabling the reproduction of the guide wire path. In view of the increasing number of osteosynthesis it is essential for the surgeon to be aware of possible complications due to guide wire perforations. Cases like this go unnoticed if the forensic pathologist is not familiarized with the surgical technique which may explain the rarity of such descriptions in literature.

  10. Comparison of double locking plate constructs with single non-locking plate constructs in single cycle to failure in bending and torsion.

    PubMed

    Hutcheson, K D; Butler, J R; Elder, S E

    2015-01-01

    To evaluate the biomechanical properties of single 3.5 mm broad dynamic compression plate (DCP) and double 3.5 mm String-of-Pearls (SOP) plate constructs in single-cycle bending and torsion. We hypothesized that the double SOP construct would outperform the broad DCP in both bending and torsional testing. Broad DCP plates and double 3.5 mm SOP plates were secured to a previously validated bone model in an effort to simulate bridging osteosynthesis. Constructs were tested in both four-point bending and torsional testing. The double SOP constructs had significantly greater bending stiffness, bending strength, bending structural stiffness, and torsional stiffness when compared to the broad DCP constructs. The single broad DCP constructs had significantly higher yield torque and yield angles during torsional testing. Although the in vitro mechanical performance of the double SOP construct was significantly greater than the single broad DCP constructs under bending loads, the actual differences were small. Various patient, fracture, and implant factors must be considered when choosing an appropriate implant for fracture fixation.

  11. Tibial Lengthening Using a Fixator-Assisted Lengthening Plate: A New Technique

    PubMed Central

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

    2016-01-01

    Background There are many techniques that are used for limb lengthening. Lengthening a limb over a plate is an alternative choice used in children or when using an intramedullary nail is difficult. Objectives In this study, we presented a new technique for tibial lengthening using a monolateral external fixator over a lengthening plate. Materials and Methods For tibial lengthening, a monolateral external fixator was attached to the composite bone model medially. After a corticotomy was performed, the lengthening plate was placed laterally. Three locking screws were inserted proximally, and two cortical screws were inserted into a lengthening hole that was 1 cm below the osteotomy site. We avoided contact between the screws of the lengthening plate and the pins of the external fixator. During bone lengthening with the monolateral external fixator, the screws at the lengthening hole were able to slide distally with the distal segment of the tibia to allow for tibial elongation. Two locking screws were fixed at the distal locking holes of the plate when the bone elongation was complete. The external fixator was then removed. Results The fixator-assisted lengthening plate allowed bone lengthening without malalignment. There were no mechanical problems associated with the external fixator during the lengthening process. Plate osteosynthesis was stable after the fixator was removed. There was no contact between the screws of plate and the Schanz pins of the external fixator under C-arm fluoroscopy. Conclusions The fixator-assisted lengthening plate technique helps to maintain the stability and alignment at both sides of an osteotomy during tibial elongation. It allows the early removal of the external fixator immediately after lengthening is completed. This technique can be applied in children with open physes and in patients with a narrow medullary canal who are unsuitable for limb lengthening over an intramedullary nail. PMID:28184364

  12. Degradation behaviour of LAE442-based plate-screw-systems in an in vitro bone model.

    PubMed

    Wolters, Leonie; Besdo, Silke; Angrisani, Nina; Wriggers, Peter; Hering, Britta; Seitz, Jan-Marten; Reifenrath, Janin

    2015-04-01

    The use of absorbable implant materials for fixation after bone fracture helps to avoid a second surgery for implant removal and the risks and costs involved. Magnesium (Mg) is well known as a potential metallic material for degradable implants. The aim of the present in vitro study was to evaluate if degradable LAE442-based magnesium plate-screw-systems are suitable candidates for osteosynthesis implants in load-bearing bones. The corrosion behaviour was tested concerning the influence of different surface treatments, coatings and screw torques. Steel plates and screws of the same size served as control. Plates without special treatment screwed on up to a specified torque of 15cNm or 7cNm, NaOH treated plates (15cNm), magnesium fluoride coated plates (15cNm) and steel plates as control (15cNm) were examined in pH-buffered, temperature-controlled SBF solution for two weeks. The experimental results indicate that the LAE442 plates and screws coated with magnesium fluoride revealed a lower hydrogen evolution in SBF solution as well as a lower weight loss and volume decrease in μ-computed tomography (μCT). The nanoindentation and SEM/EDX measurements at several plate areas showed no significant differences. Summarized, the different screw torques did not affect the corrosion behaviour differently. Also the NaOH treatment seemed to have no essential influence on the degradation kinetics. The plates coated with magnesium fluoride showed a decreased corrosion rate. Hence, it is recommended to consider this coating for the next in vivo study. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Large Deflections of Elastic Rectangular Plates

    NASA Astrophysics Data System (ADS)

    Razdolsky, A. G.

    2015-11-01

    It is known that elastic large deflections of thin plates are governed by von Karman nonlinear equations. The analytical solution of these equations in the general case is unfeasible. Samuel Levy, in 1942, showed that large deflections of the rectangular plate can be expressed as a double series of sine-shaped harmonics (deflection harmonics). However, this method gave no way of creating the computer algorithm of solving the problem. The stress function expression taken in the Levy's method must be revised to find the approach that takes into account of all possible products of deflection coefficients. The algorithm of solving the problem for the rectangular plate with an arbitrary aspect ratio under the action of the lateral distributed load is reported in this paper. The approximation of the plate deflection is taken in the form of double series proposed by Samuel Levy. However, the expression for the stress function is presented in the form that incorporates products of deflection coefficients in the explicit form in distinction to the Levy's expression. The number of harmonics in the deflection expression may be arbitrary. The algorithm provides composing the system of governing cubic equations, which includes the deflection coefficients in the explicit form. Solving the equation system is based on using the principle of minimum potential energy. A method of the gradient descent is applied to find the equilibrium state of the plate as the minimum point of the potential energy. A computer program is developed on the basis of the present algorithm. Numerical examples carried out for the plate model with 16 deflection harmonics illustrate the potentialities of the program. The results of solving the examples are presented in the graphical form for the plates with a different aspect ratio and may be used under designing thin-walled elements of airplane and ship structures.

  14. Poisson-Boltzmann theory for two parallel uniformly charged plates

    SciTech Connect

    Xing Xiangjun

    2011-04-15

    We solve the nonlinear Poisson-Boltzmann equation for two parallel and like-charged plates both inside a symmetric electrolyte, and inside a 2:1 asymmetric electrolyte, in terms of Weierstrass elliptic functions. From these solutions we derive the functional relation between the surface charge density, the plate separation, and the pressure between plates. For the one plate problem, we obtain exact expressions for the electrostatic potential and for the renormalized surface charge density, both in symmetric and in asymmetric electrolytes. For the two plate problems, we obtain new exact asymptotic results in various regimes.

  15. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  16. Strategies for Problem Solving.

    ERIC Educational Resources Information Center

    Karmos, Joseph S.; Karmos, Ann H.

    Problem-solving skills are becoming increasingly important in the workplace, and more schools are including them in the curriculum. Knowledge of problem solving will be critical to a work force that is dealing with advanced technology, yet many students have yet to master these skills. Based on this premise, this guide attempts to show how…

  17. Teaching through Problem Solving

    ERIC Educational Resources Information Center

    Fi, Cos D.; Degner, Katherine M.

    2012-01-01

    Teaching through Problem Solving (TtPS) is an effective way to teach mathematics "for" understanding. It also provides students with a way to learn mathematics "with" understanding. In this article, the authors present a definition of what it means to teach through problem solving. They also describe a professional development vignette that…

  18. Techniques of Problem Solving.

    ERIC Educational Resources Information Center

    Krantz, Steven G.

    The purpose of this book is to teach the basic principles of problem solving in both mathematical and non-mathematical problems. The major components of the book consist of learning to translate verbal discussion into analytical data, learning problem solving methods for attacking collections of analytical questions or data, and building a…

  19. Group Problem Solving.

    ERIC Educational Resources Information Center

    King, James C.

    1988-01-01

    This pamphlet discusses group problem solving in schools. Its point of departure is that teachers go at problems from a number of different directions and that principals need to capitalize on those differences and bring a whole range of skills and perceptions to the problem-solving process. Rather than trying to get everyone to think alike,…

  20. Techniques of Problem Solving.

    ERIC Educational Resources Information Center

    Krantz, Steven G.

    The purpose of this book is to teach the basic principles of problem solving in both mathematical and non-mathematical problems. The major components of the book consist of learning to translate verbal discussion into analytical data, learning problem solving methods for attacking collections of analytical questions or data, and building a…

  1. Problem Solving and Intelligence.

    ERIC Educational Resources Information Center

    Resnick, Lauren B.; Glaser, Robert

    This paper argues that a major aspect of intelligence is the ability to solve problems and that careful analysis of problem-solving behavior is a means of specifying many of the psychological processes that make up intelligence. The focus is on the mechanisms involved when, in the absence of complete instruction, a person must "invent" a new…

  2. Chemical Reaction Problem Solving.

    ERIC Educational Resources Information Center

    Veal, William

    1999-01-01

    Discusses the role of chemical-equation problem solving in helping students predict reaction products. Methods for helping students learn this process must be taught to students and future teachers by using pedagogical skills within the content of chemistry. Emphasizes that solving chemical reactions should involve creative cognition where…

  3. [Treatment of mid-distal humeral shaft fractures associated with radial nerve palsysis by minimally invasive screwed nails osteosynthesis technique].

    PubMed

    Zang, Wei; Liu, Yun-feng; Wu, Quan-min

    2009-07-01

    To investigate the surgical treatment of mid-distal humeral shaft fractures associated with radial nerve palsysis with minimal invasive screwed nails osteosynthesis technique. Thirty-six patients treated mid-distal humeral shaft fractures associated with radial nerve palsysis from January 2004 to January 2008. There were 28 males and 8 females whose age ranged from 20- to 58-years-old with an average of 36.5-years-old. Injury reasons: mechanical injury 18 cases, traffic injury 8 cases, accidents injury 10 cases, all cases were closed fracture. According to AO/ASIF classification, type A1 5 cases, type A2 7 cases, type B1 8 cases, type B2 7 cases, type B3 5 cases, type C3 4 cases. The small lateral incision was performed located to the fracture. After exploration of the radial nerve, the fractures were reduced. By acromion small lateral incision, the deltoid was separated. In the posterior macronodular slotted antegrade reamed bored with medullary cavity drill and selected a suitable screwed nail screwed into the medullary cavity distal. Along the slot, the locking pieces were inserted to complete the fixation. The postoperative complication, fracture healing time, radial nerve function recovery time, the motion of shoulder and elbow were recorded. The incision of all cases healed with stage I . The patients were followed up for 9-36 weeks with an average of 18.5 weeks. The X-ray examination showed fractures healing in 12-16 weeks (average of 15.6 weeks). Radial nerve function recovered fully at 12-36 weeks after operation (average of 17.8 weeks). Shoulder abduction is 150 degrees-170 degrees with an average of 160 degrees; elbow motion of activities was 130 degrees-140 degrees with an average of 135 degrees. The ASES method was used to assess the shoulder joint function, 20 cases gained the excellent result, 12 good and 4 poor. And according to HSS method, 36 cases of elbow joint function gained the excellent result. The surgical treatment of mid-distal humeral

  4. Interlocking Nailing Versus Interlocking Plating in Intra-articular Calcaneal Fractures: A Biomechanical Study.

    PubMed

    Reinhardt, Sophia; Martin, Heiner; Ulmar, Benjamin; Döbele, Stefan; Zwipp, Hans; Rammelt, Stefan; Richter, Martinus; Pompach, Martin; Mittlmeier, Thomas

    2016-08-01

    Open reduction and internal fixation with a plate is deemed to represent the gold standard of surgical treatment for displaced intra-articular calcaneal fractures. Standard plate fixation is usually placed through an extended lateral approach with high risk for wound complications. Minimally invasive techniques might avoid wound complications but provide limited construct stability. Therefore, 2 different types of locking nails were developed to allow for minimally invasive technique with sufficient stability. The aim of this study was to quantify primary stability of minimally invasive calcaneal interlocking nail systems in comparison to a variable-angle interlocking plate. After quantitative CT analysis, a standardized Sanders type IIB fracture model was created in 21 fresh-frozen cadavers. For osteosynthesis, 2 different interlocking nail systems (C-Nail; Medin, Nov. Město n. Moravě, Czech Republic; Calcanail; FH Orthopedics SAS; Heimsbrunn, France) as well as a polyaxial interlocking plate (Rimbus; Intercus GmbH; Rudolstadt, Germany) were used. Biomechanical testing consisted of a dynamic load sequence (preload 20 N, 1000 N up to 2500 N, stepwise increase of 100 N every 100 cycles, 0.5 mm/s) and a load to failure sequence (max. load 5000 N, 0.5 mm/s). Interfragmentary movement was detected via a 3-D optical measurement system. Boehler angle was measured after osteosynthesis and after failure occurred. No significant difference regarding load to failure, stiffness, Boehler angle, or interfragmentary motion was found between the different fixation systems. A significant difference was found with the dynamic failure testing sequence where 87.5% of the Calcanail implants failed in contrast to 14% of the C-Nail group (P < .01) and 66% of the Rimbus plate. The highest load to failure was observed for the C-Nail. Boehler angle showed physiologic range with all implants before and after the biomechanical tests. Both minimally invasive interlocking nail systems

  5. Osteotomy and osteosynthesis in complex segmental genioplasty with double surgical guide

    PubMed Central

    Assis, Adriano; Olate, Sergio; Asprino, Luciana; de Moraes, Márcio

    2014-01-01

    Chin osteotomy is used in esthetic and functional procedure; genioplasty shows different surgical options as lineal osteotomy, curved osteotomy, segmental osteotomy and others for different conditions of the face. This communication shows the use of two surgical guides used in a patient with extremely facial asymmetry; the surgical plan was realized in a stereolithographic biomodel. The first surgical guide was used for osteotomy and the second surgical guide was used for putting the plate, previously bent, and for segmented osteotomy in the planned position on the biomodel; this technique showed adequate adaptation and security in this extremely asymmetric case. The potential use of this surgical guide was discussed. PMID:24995074

  6. Comparison of Outcomes of Intertrochanteric Fracture Fixation Using Percutaneous Compression Plate Between Stable and Unstable Fractures in the Elderly.

    PubMed

    Carvajal-Pedrosa, Cristina; Gómez-Sánchez, Rafael C; Hernández-Cortés, Pedro

    2016-06-01

    To evaluate the outcomes of treatment with a percutaneous compression plate (PCCP) in stable and unstable intertrochanteric hip fractures. Clinical prospective nonrandomized cohort study. San Cecilio University Hospital, Granada (Spain). A tertiary-care hospital. Patients older than 65 years undergoing surgery for an intertrochanteric hip fracture (n = 657) were divided according to the OTA/AO classification, into stable (31-A1) (group A, n = 363) and unstable fractures (31-A2) (group B, n = 294). Osteosynthesis with a PCCP (Orthofix Inc). Blood loss, wound complications, postoperative pain, operative and fluoroscopy time, functional outcomes, device-related complications, consolidation time, and mortality. Patients with unstable fractures were significantly worse with respect to postoperative pain, immediately (P = 0.020), at 6 weeks (P = 0.0001), and at 3 months (P = 0.009), and with respect to independent walking ability at 6 weeks. No other significant differences were observed. The outcomes of osteosynthesis with PCCP seem to be equally satisfactory in stable and unstable intertrochanteric fractures, with stable fractures having less pain and a greater ability to walk earlier. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  7. Solving Equations Today.

    ERIC Educational Resources Information Center

    Shumway, Richard J.

    1989-01-01

    Illustrated is the problem of solving equations and some different strategies students might employ when using available technology. Gives illustrations for: exact solutions, approximate solutions, and approximate solutions which are graphically generated. (RT)

  8. Problem Solving and Learning

    NASA Astrophysics Data System (ADS)

    Singh, Chandralekha

    2009-07-01

    One finding of cognitive research is that people do not automatically acquire usable knowledge by spending lots of time on task. Because students' knowledge hierarchy is more fragmented, "knowledge chunks" are smaller than those of experts. The limited capacity of short term memory makes the cognitive load high during problem solving tasks, leaving few cognitive resources available for meta-cognition. The abstract nature of the laws of physics and the chain of reasoning required to draw meaningful inferences makes these issues critical. In order to help students, it is crucial to consider the difficulty of a problem from the perspective of students. We are developing and evaluating interactive problem-solving tutorials to help students in the introductory physics courses learn effective problem-solving strategies while solidifying physics concepts. The self-paced tutorials can provide guidance and support for a variety of problem solving techniques, and opportunity for knowledge and skill acquisition.

  9. Solving tooth sensitivity.

    PubMed

    Miller, Michael B

    2010-01-01

    Solving tooth sensitivity requires both you and the patients to be resilient and to understand that if one approach doesn't work, you can try another one that is non-invasive or, at worst, minimally invasive. Much like the clinician who posted the original question, I strongly believe that it is our responsibility to convince patients that jumping to a radical solution could be totally unnecessary--and expensive-- and still might not solve the problem.

  10. [Ultrasound monitoring of consolidation processes in fractures of long tubular bones in osteosynthesis using bioactive implants].

    PubMed

    Zavadovskaia, V D; Popov, V P; Akbasheva, O E; Grigor'ev, E G; Druzhinina, T V

    2014-01-01

    To show the capabilities of ultrasound monitoring to assess consolidation processes in fractures of long tubular bones in the use of bioactive material-containing implants. Eighty-two (45.1%) patients whose bone fragments had been fixed with bioactive material-coated plates and 100 (54.9%) patients with bioinert material-coated ones were examined. Consolidation changes were estimated by ultrasound and X-ray studies 2, 4, 6, and 12 months after surgery. Bone metabolic changes were determined by US osteometry 2 months following surgery. Ultrasound data were compared with the biochemical markers: C-terminal telopeptide (CrossLaps) and osteocalcin. Ultrasound monitoring of the rates of consolidation and the time course of changes in bone strength versus the biochemical markers established the positive effect of bioactiveplates on the process of consolidation in fractures of tubular bones and made it possible to consider local osteopenic syndrome to be a prognostically favorable sign of timely callus formation.

  11. Bending and buckling behavior analysis of foamed metal circular plate.

    PubMed

    Fan, Jian Ling; Ma, Lian Sheng; Zhang, Lu; De Su, Hou

    2016-07-04

    This paper establishes a density gradient model along the thickness direction of a circular plate made of foamed material. Based on the first shear deformation plate theory, the result is deduced that the foamed metal circular plate with graded density along thickness direction yields axisymmetric bending problem under the action of uniformly distributed load, and the analytical solution is obtained by solving the governing equation directly. The analyses on two constraint conditions of edge radial clamping and simply supported show that the density gradient index and external load may affect the axisymmetric bending behavior of the plate. Then, based on the classical plate theory, the paper analyzes the behavior of axisymmetric buckling under radial pressure applied on the circular plate. Shooting method is used to obtain the critical load, and the effects of gradient nature of material properties and boundary conditions on the critical load of the plate are analyzed.

  12. Absolute plate velocities from seismic anisotropy: Importance of correlated errors

    NASA Astrophysics Data System (ADS)

    Zheng, Lin; Gordon, Richard G.; Kreemer, Corné

    2014-09-01

    The errors in plate motion azimuths inferred from shear wave splitting beneath any one tectonic plate are shown to be correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. Our preferred set of angular velocities, SKS-MORVEL, is determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25 ± 0.11° Ma-1 (95% confidence limits) right handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ = 19.2°) differs insignificantly from that for continental lithosphere (σ = 21.6°). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ = 7.4°) than for continental lithosphere (σ = 14.7°). Two of the slowest-moving plates, Antarctica (vRMS = 4 mm a-1, σ = 29°) and Eurasia (vRMS = 3 mm a-1, σ = 33°), have two of the largest within-plate dispersions, which may indicate that a plate must move faster than ≈ 5 mm a-1 to result in seismic anisotropy useful for estimating plate motion. The tendency of observed azimuths on the Arabia plate to be counterclockwise of plate motion may provide information about the direction and amplitude of superposed asthenospheric flow or about anisotropy in the lithospheric mantle.

  13. Williamson Polishing & Plating Site

    EPA Pesticide Factsheets

    Williamson Polishing & Plating Co. Inc. was a plating shop located in the Martindale-Brightwood neighborhood of Indianapolis. The facility conducted job shop polishing and electroplating services. The vacant site contains a 14,651-square-foot building.

  14. Growth Plate Fractures

    MedlinePlus

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  15. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  16. [Thoracic inestability fixed with bioabsorbable screws and plates].

    PubMed

    Nolasco-de la Rosa, A L; Mosiñoz-Montes, R; Matehuala-García, J; Cuautle-Ramírez, A A; Román-Guzmán, E; Reyes-Miranda, A L; Quero-Sandoval, F

    2016-01-01

    Flail chest is managed with mechanical ventilation or inhaloteraphy and analgesia. Little has been published on the use of bioabsorbable material and its evolution in flail chest fixation. This is a descriptive study of patients with unstable chest undergoing fixation with bioabsorbable plates and screws in a period from February 2009 to December 2011. We report 18 cases, aged 33-74 years (mean 53), three with bilateral involvement; rib fixation was performed between 1-21 days of the accident (mean 1.5). They started walking the next day in 14 cases; postoperative stay was four days (range 3-14). The heart rate of patients prior to surgery was 90 per minute (range 82-100) and lowered to 84 after fixation (range 82-92), preoperative respiratory rate was 26 per minute (range 22-28) and below 22 per minute (range 20 to 26) in postoperative period. The use of bioabsorbable material for osteosynthesis of costal fractures did not show side effects in our period of study.

  17. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  18. Study on plate silencer with general boundary conditions

    NASA Astrophysics Data System (ADS)

    Liu, Gongmin; Zhao, Xiaochen; Zhang, Wenping; Li, Shuaijun

    2014-09-01

    A plate silencer consists of an expansion chamber with two side-branch rigid cavities covered by plates. Previous studies showed that, in a duct, the introduction of simply supported or clamped plates into an air conveying system could achieve broadband quieting from low to medium frequencies. In this study, analytical formulation is extended to the plate silencer with general boundary conditions. A set of static beam functions, which are a combination of sine series and third-order polynomial, is employed as the trial functions of the plate vibration velocity. Greens function and Kirchhoff-Helmholtz integral are used to solve the sound radiation in the duct and the cavity, and then the vibration velocity of the plate is obtained. Having obtained the vibration velocity, the pressure perturbations induced by the plate oscillation and the transmission loss are found. Optimization is carried out in order to obtain the widest stopband. The transmission loss calculated by the analytical method agrees closely with the result of the finite element method simulation. Further studies with regard to the plate under several different classical boundary conditions based on the validated model show that a clamped-free plate silencer has the worst stopband. Attempts to release the boundary restriction of the plate are also made to study its effect on sound reflection. Results show that a softer end for a clamped-clamped plate silencer helps increase the optimal bandwidth, while the same treatment for simply supported plate silencer will result in performance degradation.

  19. Plating Tank Control Software

    SciTech Connect

    Krafcik, John

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  20. Obliquity along plate boundaries

    NASA Astrophysics Data System (ADS)

    Philippon, Mélody; Corti, Giacomo

    2016-12-01

    Most of the plate boundaries are activated obliquely with respect to the direction of far field stresses, as roughly only 8% of the plate boundaries total length shows a very low obliquity (ranging from 0 to 10°, sub-orthogonal to the plate displacement). The obliquity along plate boundaries is controlled by (i) lateral rheological variations within the lithosphere and (ii) consistency with the global plate circuit. Indeed, plate tectonics and magmatism drive rheological changes within the lithosphere and consequently influence strain localization. Geodynamical evolution controls large-scale mantle convection and plate formation, consumption, and re-organization, thus triggering plate kinematics variations, and the adjustment and re-orientation of far field stresses. These geological processes may thus result in plate boundaries that are not perpendicular but oblique to the direction of far field stresses. This paper reviews the global patterns of obliquity along plate boundaries. Using GPlate, we provide a statistical analysis of present-day obliquity along plate boundaries. Within this framework, by comparing natural examples and geological models, we discuss deformation patterns and kinematics recorded along oblique plate boundaries.

  1. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  2. Proximal Femoral Morphology and the Relevance to Design of Anatomically Precontoured Plates: A Study of the Chinese Population

    PubMed Central

    Lin, Kang-Ping; Lee, Pei-Yuan

    2014-01-01

    Adequately shaped femoral plate is critical for the fixation of fracture in the pertrochanteric regions. Lateral aspect of greater trochanter is an important region where the proximal femoral plate anchored. However, little is known regarding the morphology of greater trochanter. The objective of this study was to measure main dimensions of greater trochanter and other regions in the proximal end of the femur to provide an anatomical basis for the design of the proximal femoral plate. Anthropometric data on the proximal femur were performed utilizing three-dimensional computational modeling. Computed tomography images of healthy femurs in 53 women and 47 men were contributed to three-dimensional femur modeling. All data were compared between male and female femora. The results showed that mean values for male group were found to be greater in most of measured femoral dimensions. Oppositely, females demonstrated higher neck-shaft angle on anteroposterior view and femoral anteversion angle. The anthropometric data can be used for the anatomical shape design of femoral plates for osteosynthesis of fractures in the trochanteric regions. A distinct plate design may be necessary to accommodate differences between the genders. PMID:25530989

  3. Malachite green photosensitive plates.

    PubMed

    Solano, C

    1989-08-15

    An experimental study of the behavior of malachite green sensitized plates was carried out. The transmittance variation of the irradiated plates was taken as a parameter. It has been observed that photoreduction in the malachite green plates is present only when ammonium dichromate is added to the plates. The introduction of external electron donors does not improve the photochemical reaction. It has been determined that malachite green molecules form a weak complex with the dichromate molecules and this complex can only be destroyed photochemically. This effect can explain the limited response of the malachite green dichromated plates.

  4. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  5. Angular shear plate

    DOEpatents

    Ruda, Mitchell C [Tucson, AZ; Greynolds, Alan W [Tucson, AZ; Stuhlinger, Tilman W [Tucson, AZ

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  6. Problem-Solving Software

    NASA Technical Reports Server (NTRS)

    1992-01-01

    CBR Express software solves problems by adapting sorted solutions to new problems specified by a user. It is applicable to a wide range of situations. The technology was originally developed by Inference Corporation for Johnson Space Center's Advanced Software Development Workstation. The project focused on the reuse of software designs, and Inference used CBR as part of the ACCESS prototype software. The commercial CBR Express is used as a "help desk" for customer support, enabling reuse of existing information when necessary. It has been adopted by several companies, among them American Airlines, which uses it to solve reservation system software problems.

  7. A randomised study in all cervical hip fractures osteosynthesis with Hansson hook-pins versus AO-screws in 199 consecutive patients followed for two years.

    PubMed

    Mjørud, Jan; Skaro, Olav; Solhaug, Jan Helge; Thorngren, Karl-Göran

    2006-08-01

    A consecutive series of patients with all types of cervical hip fracture (both undisplaced and displaced) were randomised to osteosynthesis with Hansson hook-pins (n = 98) or AO-screws (n = 101). Background parameters, fracture type and reduction of the fracture did not differ significantly between the groups. Fifty-seven percent of the patients were operated on within 6 h of admission to hospital, 74% within 12 h and 92% within 24 h. The mean (median) time for operation was 36 (30) min for the hook-pins and 40 (35) min for the AO-screws. The devices were significantly better positioned in the hook-pin group (81% of cases good) compared to the AO-screws (66% good) (p = 0.04). In all, 72% of the patients had no deficiency either in reduction of the fracture, positioning of the implants or had drill penetration of the femoral head. Direct unrestricted weight bearing was encouraged in 92% of the hook-pin and 90% of the AO-screws group. The mean (median) hospital time was 13 (10) days with no significant difference between the groups. Following treatment, 5% walked without aids, 76% of the patients walked with some aids, and 16% could not walk. The walking ability was not known for 4%. At four months, 59% of the patients were living in their own home (64% before fracture), 18% (25% before) in a nursing home, 5% (11% before) in other accommodation and 18% were dead. After two years, 77% of the hook-pin patients had not needed any re-operation compared to 73% in the AO-screw group. In total a secondary hemi-arthroplasty had been performed in 7% and total hip arthroplasty in 12% of the patients. Extraction only of osteosynthesis material had been performed in 5%. The difference in the reoperation rates between the two methods was not significant. In the undisplaced fractures, 84% of the patients had not needed any reoperation after two years compared to 70% among the displaced fractures. Major reoperation had been performed in 10% (1% hemi and 9% total hip arthroplasty

  8. Paper microzone plates.

    PubMed

    Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

    2009-08-01

    This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader.

  9. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (Inventor)

    1984-01-01

    An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.

  10. [Wrist arthrodesis with a fixed-angle, "low-profile" fusion plate without carpometacarpal joint fixation].

    PubMed

    Köhler, S; Koch, K; Arsalan-Werner, A; Mehling, I M; Seegmüller, J; Krimmer, H; Sauerbier, Michael

    2017-09-12

    Total wrist arthrodesis to improve functional use of the hand by reducing pain and increasing grip strength. Painful destruction of the radio- and midcarpal joints. Analgesia and satisfactory hand function after motion-preserving surgical or conservative treatment. Chronic joint infection. Posterior approach to the wrist. Removal of articular surfaces destroyed all the way down to cancellous bone. Filling of defects with cancellous bone graft taken from distal radius or iliac crest. Osteosynthesis with fixed-angle wrist fusion plate without carpometacarpal (CMC) III joint fixation. Below-elbow cast for 2 weeks. Immediate active motion fingers exercises. X‑ray control 6 weeks postoperatively. Gradual increase of normal hand use in daily life after bony consolidation. Total wrist arthrodesis was performed using a fixed-angle fusion plate without CMC III joint fixation in 28 patients (21 men, 7 women). A follow-up of 14/28 patients was performed at a mean of 21 (3-39) months postoperatively. Grip strength improved from 14 (0-38) kg preoperatively to 22 (12-40) kg postoperatively. The average postoperative DASH score was 40 (6-72) points. Pain measured with the VAS scale (0-10) improved from an average of 7 (3-10) points preoperatively to 2 (0-6) points postoperatively. Overall, 13/14 patients were satisfied with the treatment; 26/28 patients achieved primary bony consolidation. Postoperative complications found in 9 of 28 patients: 2 nonunion, pain in the CMC II (n = 3) or III (n = 1) joints, 2 screw breakage, 1 postoperative bleeding and 1 infection. Both cases of nonunion healed after plate removal, re-osteosynthesis with a straight wrist arthrodesis plate, bridging the CMC III joint, and a bone graft from the iliac crest. All patients with CMC II joint pain were pain-free after removal of the protruding screw. One patient had chronic pain in the CMC III joint despite plate removal. In the 2 cases with screw breakage, no issues caused. In

  11. Problem Solving in Electricity.

    ERIC Educational Resources Information Center

    Caillot, Michel; Chalouhi, Elias

    Two studies were conducted to describe how students perform direct current (D-C) circuit problems. It was hypothesized that problem solving in the electricity domain depends largely on good visual processing of the circuit diagram and that this processing depends on the ability to recognize when two or more electrical components are in series or…

  12. Introspection in Problem Solving

    ERIC Educational Resources Information Center

    Jäkel, Frank; Schreiber, Cornell

    2013-01-01

    Problem solving research has encountered an impasse. Since the seminal work of Newell und Simon (1972) researchers do not seem to have made much theoretical progress (Batchelder and Alexander, 2012; Ohlsson, 2012). In this paper we argue that one factor that is holding back the field is the widespread rejection of introspection among cognitive…

  13. Problem Solving in Electricity.

    ERIC Educational Resources Information Center

    Caillot, Michel; Chalouhi, Elias

    Two studies were conducted to describe how students perform direct current (D-C) circuit problems. It was hypothesized that problem solving in the electricity domain depends largely on good visual processing of the circuit diagram and that this processing depends on the ability to recognize when two or more electrical components are in series or…

  14. Solving Common Mathematical Problems

    NASA Technical Reports Server (NTRS)

    Luz, Paul L.

    2005-01-01

    Mathematical Solutions Toolset is a collection of five software programs that rapidly solve some common mathematical problems. The programs consist of a set of Microsoft Excel worksheets. The programs provide for entry of input data and display of output data in a user-friendly, menu-driven format, and for automatic execution once the input data has been entered.

  15. Achievement in Problem Solving

    ERIC Educational Resources Information Center

    Friebele, David

    2010-01-01

    This Action Research Project is meant to investigate the effects of incorporating research-based instructional strategies into instruction and their subsequent effect on student achievement in the area of problem-solving. The two specific strategies utilized are the integration of manipulatives and increased social interaction on a regular basis.…

  16. On Solving Linear Recurrences

    ERIC Educational Resources Information Center

    Dobbs, David E.

    2013-01-01

    A direct method is given for solving first-order linear recurrences with constant coefficients. The limiting value of that solution is studied as "n to infinity." This classroom note could serve as enrichment material for the typical introductory course on discrete mathematics that follows a calculus course.

  17. Solving Problems Reductively

    ERIC Educational Resources Information Center

    Armoni, Michal; Gal-Ezer, Judith; Tirosh, Dina

    2005-01-01

    Solving problems by reduction is an important issue in mathematics and science education in general (both in high school and in college or university) and particularly in computer science education. Developing reductive thinking patterns is an important goal in any scientific discipline, yet reduction is not an easy subject to cope with. Still,…

  18. Problem Solving with Patents

    ERIC Educational Resources Information Center

    Moore, Jerilou; Sumrall, William J.

    2008-01-01

    Exploring our patent system is a great way to engage students in creative problem solving. As a result, the authors designed a teaching unit that uses the study of patents to explore one avenue in which scientists and engineers do science. Specifically, through the development of an idea, students learn how science and technology are connected.…

  19. [Problem Solving Activities.

    ERIC Educational Resources Information Center

    Wisconsin Univ. - Stout, Menomonie. Center for Vocational, Technical and Adult Education.

    The teacher directed problem solving activities package contains 17 units: Future Community Design, Let's Build an Elevator, Let's Construct a Catapult, Let's Design a Recreational Game, Let's Make a Hand Fishing Reel, Let's Make a Wall Hanging, Let's Make a Yo-Yo, Marooned in the Past, Metrication, Mousetrap Vehicles, The Multi System…

  20. Problem Solving with Patents

    ERIC Educational Resources Information Center

    Moore, Jerilou; Sumrall, William J.

    2008-01-01

    Exploring our patent system is a great way to engage students in creative problem solving. As a result, the authors designed a teaching unit that uses the study of patents to explore one avenue in which scientists and engineers do science. Specifically, through the development of an idea, students learn how science and technology are connected.…

  1. Problem Solving by Design

    ERIC Educational Resources Information Center

    Capobianco, Brenda M.; Tyrie, Nancy

    2009-01-01

    In a unique school-university partnership, methods students collaborated with fifth graders to use the engineering design process to build their problem-solving skills. By placing the problem in the context of a client having particular needs, the problem took on a real-world appeal that students found intriguing and inviting. In this article, the…

  2. On Solving Linear Recurrences

    ERIC Educational Resources Information Center

    Dobbs, David E.

    2013-01-01

    A direct method is given for solving first-order linear recurrences with constant coefficients. The limiting value of that solution is studied as "n to infinity." This classroom note could serve as enrichment material for the typical introductory course on discrete mathematics that follows a calculus course.

  3. Problem Solving Using Microcomputers.

    ERIC Educational Resources Information Center

    Demana, Franklin; Waits, Bert

    1987-01-01

    It is argued that microcomputer technology has evolved to the stage that it should be routinely used by mathematics students at all levels. It is shown how the use of microcomputers can change the way problems are solved. Computer-generated graphics are highlighted. (PK)

  4. Solving Problems through Circles

    ERIC Educational Resources Information Center

    Grahamslaw, Laura; Henson, Lisa H.

    2015-01-01

    Several problem-solving interventions that utilise a "circle" approach have been applied within the field of educational psychology, for example, Circle Time, Circle of Friends, Sharing Circles, Circle of Adults and Solution Circles. This research explored two interventions, Solution Circles and Circle of Adults, and used thematic…

  5. Inquiry and Problem Solving.

    ERIC Educational Resources Information Center

    Thorson, Annette, Ed.

    1999-01-01

    This issue of ENC Focus focuses on the topic of inquiry and problem solving. Featured articles include: (1) "Inquiry in the Everyday World of Schools" (Ronald D. Anderson); (2) "In the Cascade Reservoir Restoration Project Students Tackle Real-World Problems" (Clint Kennedy with Advanced Biology Students from Cascade High…

  6. Programming and Problem Solving.

    ERIC Educational Resources Information Center

    Elias, Barbara P.

    A study was conducted to examine computer programming as a problem solving activity. Thirteen fifth grade children were selected by their teacher from an above average class to use Apple IIe microcomputers. The investigator conducted sessions of 40-50 minutes with the children in groups of two or three. Four problems, incorporating the programming…

  7. Universal Design Problem Solving

    ERIC Educational Resources Information Center

    Sterling, Mary C.

    2004-01-01

    Universal design is made up of four elements: accessibility, adaptability, aesthetics, and affordability. This article addresses the concept of universal design problem solving through experiential learning for an interior design studio course in postsecondary education. Students' experiences with clients over age 55 promoted an understanding of…

  8. Problem Solving by Design

    ERIC Educational Resources Information Center

    Capobianco, Brenda M.; Tyrie, Nancy

    2009-01-01

    In a unique school-university partnership, methods students collaborated with fifth graders to use the engineering design process to build their problem-solving skills. By placing the problem in the context of a client having particular needs, the problem took on a real-world appeal that students found intriguing and inviting. In this article, the…

  9. Circumference and Problem Solving.

    ERIC Educational Resources Information Center

    Blackburn, Katie; White, David

    The concept of pi is one of great importance to all developed civilization and one that can be explored and mastered by elementary students through an inductive and problem-solving approach. Such an approach is outlined and discussed. The approach involves the following biblical quotation: "And he made a moltin sea ten cubits from one brim to…

  10. Solving Problems in Genetics

    ERIC Educational Resources Information Center

    Aznar, Mercedes Martinez; Orcajo, Teresa Ibanez

    2005-01-01

    A teaching unit on genetics and human inheritance using problem-solving methodology was undertaken with fourth-level Spanish Secondary Education students (15 year olds). The goal was to study certain aspects of the students' learning process (concepts, procedures and attitude) when using this methodology in the school environment. The change…

  11. Electric Current Solves Mazes

    ERIC Educational Resources Information Center

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  12. Electric Current Solves Mazes

    ERIC Educational Resources Information Center

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  13. Problem Solving Techniques Seminar.

    ERIC Educational Resources Information Center

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. Six problem-solving techniques are developed in the booklet to assist individuals and groups in making better decisions: problem identification, data gathering, data analysis, solution analysis,…

  14. Universal Design Problem Solving

    ERIC Educational Resources Information Center

    Sterling, Mary C.

    2004-01-01

    Universal design is made up of four elements: accessibility, adaptability, aesthetics, and affordability. This article addresses the concept of universal design problem solving through experiential learning for an interior design studio course in postsecondary education. Students' experiences with clients over age 55 promoted an understanding of…

  15. Solving Problems through Circles

    ERIC Educational Resources Information Center

    Grahamslaw, Laura; Henson, Lisa H.

    2015-01-01

    Several problem-solving interventions that utilise a "circle" approach have been applied within the field of educational psychology, for example, Circle Time, Circle of Friends, Sharing Circles, Circle of Adults and Solution Circles. This research explored two interventions, Solution Circles and Circle of Adults, and used thematic…

  16. Effective characteristics of corrugated plates

    NASA Astrophysics Data System (ADS)

    Arkhangel'skii, A. F.; Gorbachev, V. I.

    2007-06-01

    Corrugated plates are widely used in modern constructions and structures, because they, in contrast to plane plates, possess greater rigidity. In many cases, such a plate can be modeled by a homogeneous anisotropic plate with certain effective flexural and tensional rigidities. Depending on the geometry of corrugations and their location, the equivalent homogeneous plate can also have rigidities of mutual influence. These rigidities allow one to take into account the influence of bending moments on the strain in the midplane and, conversely, the influence of longitudinal strains on the plate bending [1]. The behavior of the corrugated plate under the action of a load normal to the midsurface is described by equations of the theory of flexible plates with initial deflection. These equations form a coupled system of nonlinear partial differential equations with variable coefficients [2]. The dependence of the coefficients on the coordinates is determined by the corrugation geometry. In the case of a plate with periodic corrugation, the coefficients significantly vary within one typical element and depend on the values of local variables determined in each of the typical elements. There is a connection between the local and global variables, and therefore, the functions of local coordinates are simultaneously functions of global coordinates, which are sometimes called rapidly oscillating functions [3]. One of the methods for solving the equations with rapidly oscillating coefficients is the asymptotic method of small geometric parameter. The standard procedure of this method usually includes preparatory stages. At the first stage, as a rule, a rectangular periodicity cell is distinguished to be a typical element. At the second stage, the scale of global coordinates is changed so that the rectangular structure periodicity cells became square cells of size l × l. The third stage consists in passing to the dimensionless global coordinates relative to the plate

  17. Is There Really A North American Plate?

    NASA Astrophysics Data System (ADS)

    Krill, A.

    2011-12-01

    elsewhere, such as S.J. Shand (1933), E.B. Bailey (1939), and Arthur Holmes (1944), presented continental drift as a working hypothesis that could elegantly solve important geological problems. Americans were preconditioned to dislike continental drift theory, ever since James Dwight Dana taught in his Manual of Geology (1863...1895) that North America was the type continent of the world, and that it had stood alone since earliest time. Such beliefs sometimes trump geologic evidence. As noted by Stephen Jay Gould (1999) Sigmund Freud had much insight into the psychology of scientific revolutions: they involve a scientific development that shows humans to have lesser status than previously perceived. In the Copernican revolution (geocentrism vs. heliocentrism) humans no longer inhabited the center of the universe. In the Darwinian revolution (creationism vs. evolutionism) humans were no longer uniquely created. In the Wegenerian revolution (fixism vs. mobilism) North America was no longer uniquely created; it was just other fragment from Pangaea. North American geologists were pleased when Press & Siever gave them their own lithospheric plate. Being a global-tectonic killjoy, I would like to take away that small consolation as well. Or at least pose the question: Is there really a North American Plate?

  18. Toward Solving the Problem of Problem Solving: An Analysis Framework

    ERIC Educational Resources Information Center

    Roesler, Rebecca A.

    2016-01-01

    Teaching is replete with problem solving. Problem solving as a skill, however, is seldom addressed directly within music teacher education curricula, and research in music education has not examined problem solving systematically. A framework detailing problem-solving component skills would provide a needed foundation. I observed problem solving…

  19. Toward Solving the Problem of Problem Solving: An Analysis Framework

    ERIC Educational Resources Information Center

    Roesler, Rebecca A.

    2016-01-01

    Teaching is replete with problem solving. Problem solving as a skill, however, is seldom addressed directly within music teacher education curricula, and research in music education has not examined problem solving systematically. A framework detailing problem-solving component skills would provide a needed foundation. I observed problem solving…

  20. Variational modeling of ionic polymer plate structures

    NASA Astrophysics Data System (ADS)

    Buechler, Miles A.; Leo, Donald J.

    2006-03-01

    Ionomeric polymers are a promising class of intelligent material which exhibit electromechanical coupling similar to that of piezoelectric bimorphs. Ionomeric polymers are much more compliant than piezoelectric ceramics or polymers and have been shown to produce actuation strain on the order of 5% at operating voltages between 1 V and 5 V. This performance indicates the potential for self-actuating devices manufactured from ionomeric polymers, such as deformable mirrors or low pressure pump diaphragms. This paper presents a variational approach to the dynamic modeling of ionic polymer plates in rectangular coordinates. A linear matrix equation, which relates displacement and charge to applied forces and voltage, is developed to determine the response of the structure to applied forces and applied potentials. The modeling method is based on the incorporation of empirically determined material properties, which have been shown to be highly frequency dependent. The matrices are calculated at discrete frequencies and solved frequency-by-frequency to determine the response of the ionomeric plate structures. A model of a thin rectangular plate is developed and validated experimentally. Simulated frequency response functions are compared to experimental results for several locations on the plate. The response of the plate at certain frequencies is computed and compared to experimentally-determined response shapes. The results demonstrate the validity of the modeling approach in predicting the dynamic response of the ionomeric plate structure. These spatial solutions are also compared to experimentally determined response shapes.

  1. Early results for treatment of two- and three-part fractures of the proximal humerus using Contours PHP (proximal humeral plate).

    PubMed

    Biazzo, Alessio; Cardile, Carlo; Brunelli, Luca; Ragni, Paolo; Clementi, Daniele

    2017-04-28

    The management of displaced 2- and 3-part fractures of the proximal humerus is controversial, both in younger and in elderly patients. The purpose of this paper is to evaluate the functional results of the Contours Proximal Humerus Plate (OrthofixR, Bussolengo,Verona, Italy), for the treatment of displaced 2- and 3-part fractures of the proximal humerus. We retrospectively reviewed 55 patients with proximal humerus fractures, who underwent osteosynthesis with Contours Proximal Humerus Plate from December 2011 to March 2015. We had 21 patients with 2-part fractures and with an average age of 67.1 years and 34 patients with 3-part fractures, with average age of 63.6 years. The average union time was 3 months. The mean Constant score was 67 for 2-part fracture group and 64.9 for 3-part fracture group. The difference was not statistically significant (p = 0.18). The overall complication rate was 14.5 %. Six patients underwent additional surgery (10.9%). The most frequent major complication was secondary loss of reduction following varus collapse of the fracture (2 cases). In these patients, there was loss of medial hinge integrity due to impaction and osteoporosis. The placement of the main locking screw in the calcar area to provide inferomedial support is the rational of the Contours Proximal Humerus Plate. Osteosynthesis with Contours Proximal Humerus Plate is a safe system for treating displaced 2- and 3-part fractures of the proximal humerus, with good functional results and complication rates comparable to those reported in the literature.

  2. Numerical analysis of eccentric orifice plate using ANSYS Fluent software

    NASA Astrophysics Data System (ADS)

    Zahariea, D.

    2016-11-01

    In this paper the eccentric orifice plate is qualitative analysed as compared with the classical concentric orifice plate from the point of view of sedimentation tendency of solid particles in the fluid whose flow rate is measured. For this purpose, the numerical streamlines pattern will be compared for both orifice plates. The numerical analysis has been performed using ANSYS Fluent software. The methodology of CFD analysis is presented: creating the 3D solid model, fluid domain extraction, meshing, boundary condition, turbulence model, solving algorithm, convergence criterion, results and validation. Analysing the numerical streamlines, for the concentric orifice plate can be clearly observed two circumferential regions of separated flows, upstream and downstream of the orifice plate. The bottom part of these regions are the place where the solid particles could sediment. On the other hand, for the eccentric orifice plate, the streamlines pattern suggest that no sedimentation will occur because at the bottom area of the pipe there are no separated flows.

  3. Inversion for the driving forces of plate tectonics

    NASA Technical Reports Server (NTRS)

    Richardson, R. M.

    1983-01-01

    Inverse modeling techniques have been applied to the problem of determining the roles of various forces that may drive and resist plate tectonic motions. Separate linear inverse problems have been solved to find the best fitting pole of rotation for finite element grid point velocities and to find the best combination of force models to fit the observed relative plate velocities for the earth's twelve major plates using the generalized inverse operator. Variance-covariance data on plate motion have also been included. Results emphasize the relative importance of ridge push forces in the driving mechanism. Convergent margin forces are smaller by at least a factor of two, and perhaps by as much as a factor of twenty. Slab pull, apparently, is poorly transmitted to the surface plate as a driving force. Drag forces at the base of the plate are smaller than ridge push forces, although the sign of the force remains in question.

  4. Ornament Problem Suppression in Indonesian License Plate Recognition Systems

    NASA Astrophysics Data System (ADS)

    Mahatmaputra Tedjojuwono, Samuel

    2017-03-01

    Based on the original work of fast performance algorithm in detecting Indonesian license plate, the proposed work will solve the error found in the license plate localization process caused by plate like pattern within the image, which was called the ornament problem. Although not in all cases, this problem could exist when a car has banner, regular pattern, car’s front grill, that could miss understood by the system as license plate letters. The proposed work will implement filtering systems instead of machine learning approach. The filtering methods will follows three steps: detection filter based on the number of elements in the vector, based on the letter proportion of a license plate number, and based on the distance between detected letters. This approach will maintain the fast properties of the original algorithm and will increase the accuracy of localizing the license plate within the given image.

  5. Influence of hooks and a lag screw on internal fixation plates for lateral malleolar fracture: a biomechanical and ergonomic study.

    PubMed

    Sakai, Rina; Uchino, Masataka; Yoneo, Terumasa; Ohtaki, Yasuaki; Minehara, Hiroaki; Matsuura, Terumasa; Gomi, Tsutomu; Ujihira, Masanobu

    2017-02-23

    For internal fixation of AO classification Type B lateral malleolar fracture, insertion of lag screws into the fracture plane and fixation with a one-third tubular plate as a neutralization plate are the standard treatment procedures. The one-third tubular plate is processed to a hook shape and hung on the distal end of the fibula. In this study, to compare the function of the hook and lag screws of a one-third tubular plate and LCP for osteosynthesis of lateral malleolar fracture, mechanical indices of internal fixation were compared among the one-third tubular plates with lag screws with and without the hook and a locking compression plate. As mechanical tests, a compression test was performed in which compression in the bone axis direction produced by supporting the body weight was simulated, and a torsion test was performed in which external rotation of the bone axis caused by plantar flexion of the ankle joint was simulated. Muscle strength during walking and the force and torque acting on the ankle and knee joints were determined using inverse dynamic analysis. Finite element analysis was performed to analyze the function of hooks and lag screws. The joint reaction force determined by inverse dynamic analysis was adopted as the loading condition of finite element analysis. A stiffness equivalent to that of healthy bone could be achieved by all three internal fixations. It was clarified that the presence of the hook does not make a difference in stiffness. Displacement of the one-third tubular plate was small regardless of the presence or absence of the hook compared with those of locking compression plates. The presence of the hook did not make any difference in stiffness, suggesting that active preparation of the hook is unnecessary. We also clarified that lag screws inhibit displacement.

  6. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  7. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  8. Electric current solves mazes

    NASA Astrophysics Data System (ADS)

    Ayrinhac, Simon

    2014-07-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question: how can the electric current choose the right way and avoid dead ends?

  9. Problem Solving and Reasoning.

    DTIC Science & Technology

    1984-02-01

    Sloan Foundation (HAS). This paper is a draft of a chapter to appear in R. C. Atkinson, R. Herrnstein, G. Lindzey, and R. D. Luce (Eds.), Stevens ...D. Luce (Eds.), Stevens ’ Handbook of Experimental Psychology, (Revised Edition). New York: John Wiley & Sons. PROBLEM SOLVING AND REASONING James G... LaBerge & S. J. Samuels (Eds.), Perception and comprehension. Hillsdale, NJ: Erlbaum. Anderson, J. R. (1982). Acquisition of cognitive skill

  10. Expertise in Problem Solving.

    DTIC Science & Technology

    1981-05-18

    use at each step of the solution process. By contrast, both Issac and Newton contain separate representations of the same physics knowledge for each...representation. Issac . Issac by Gordon Novak (1977) is a program that can read the problem statement. It does this for statics problems only. The key feature of...problem does not generate an efficient solution. Newton . Newton by Johann de Kleer (1977) does not have any language translation facility. It solves

  11. Numerical modelling of instantaneous plate tectonics

    NASA Technical Reports Server (NTRS)

    Minster, J. B.; Haines, E.; Jordan, T. H.; Molnar, P.

    1974-01-01

    Assuming lithospheric plates to be rigid, 68 spreading rates, 62 fracture zones trends, and 106 earthquake slip vectors are systematically inverted to obtain a self-consistent model of instantaneous relative motions for eleven major plates. The inverse problem is linearized and solved iteratively by a maximum-likelihood procedure. Because the uncertainties in the data are small, Gaussian statistics are shown to be adequate. The use of a linear theory permits (1) the calculation of the uncertainties in the various angular velocity vectors caused by uncertainties in the data, and (2) quantitative examination of the distribution of information within the data set. The existence of a self-consistent model satisfying all the data is strong justification of the rigid plate assumption. Slow movement between North and South America is shown to be resolvable.

  12. PLATES WITH OXIDE INSERTS

    DOEpatents

    West, J.M.; Schumar, J.F.

    1958-06-10

    Planar-type fuel assemblies for nuclear reactors are described, particularly those comprising fuel in the oxide form such as thoria and urania. The fuel assembly consists of a plurality of parallel spaced fuel plate mennbers having their longitudinal side edges attached to two parallel supporting side plates, thereby providing coolant flow channels between the opposite faces of adjacent fuel plates. The fuel plates are comprised of a plurality of longitudinally extending tubular sections connected by web portions, the tubular sections being filled with a plurality of pellets of the fuel material and the pellets being thermally bonded to the inside of the tubular section by lead.

  13. CALUTRON FACE PLATE

    DOEpatents

    Brobeck, W.M.

    1959-08-25

    The construction of a removable cover plate for a calutron tank is described. The plate is fabricated of a rectangular frame member to which is welded a bowed or dished plate of thin steel, reinforced with transverse stiffening ribs. When the tank is placed between the poles of a magnet, the plate may be pivoted away from the tank and magnet and is adapted to support the ion separation mechanism secured to its inner side as well as the vacuum load within the tank.

  14. Instability of a cantilevered flexible plate in viscous channel flow

    NASA Astrophysics Data System (ADS)

    Balint, T. S.; Lucey, A. D.

    2005-10-01

    The stability of a flexible cantilevered plate in viscous channel flow is studied as a representation of the dynamics of the human upper airway. The focus is on instability mechanisms of the soft palate (flexible plate) that cause airway blockage during sleep. We solve the Navier Stokes equations for flow with Reynolds numbers up to 1500 fully coupled with the dynamics of the plate motion solved using finite-differences. The study is 2-D and based upon linearized plate mechanics. When both upper and lower airways are open, the plate is found to lose its stability through a flutter mechanism and a critical Reynolds number exists. When one airway is closed, the plate principally loses its stability through a divergence mechanism and a critical flow speed exists. However, below the divergence-onset flow speed, flutter can exist for low levels of structural damping in the flexible plate. Our results serve to extend understanding of flow-induced instability of cantilevered flexible plates and will ultimately improve the diagnosis and treatment of upper-airway disorders.

  15. Efficacy of 3-Dimensional plates over Champys miniplates in mandibular anterior fractures

    PubMed Central

    Barde, Dhananjay H; Mudhol, Anupama; Ali, Fareedi Mukram; Madan, R S; Kar, Sanjay; Ustaad, Farheen

    2014-01-01

    Background: Mandibular fractures are treated surgically by either rigid or semi-rigid fixation, two techniques that reflect almost opposite concept of craniomaxillofacial osteosynthesis. The shortcomings of these fixations led to the development of 3 dimensional (3D) miniplates. This study was designed with the aim of evaluating the efficiency of 3D miniplate over Champys miniplate in anterior mandibular fractures. Materials & Methods: This study was done in 40 patients with anterior mandibular fractures. Group I consisting of 20 patients in whom 3D plates were used for fixation while in Group II consisting of other 20 patients, 4 holes straight plates were used. The efficacy of 3D miniplate over Champy’s miniplate was evaluated in terms of operating time, average pain, post operative infection, occlusion, wound dehiscence, post operative mobility and neurological deficit. Results: The mean operation time for Group II was more compared to Group I (statistically significant).There was significantly greater pain on day of surgery and at 2nd week for Group II patients but there was no significant difference between the two groups at 4th week. The post operative infection, occlusal disturbance, wound dehiscence, post operative mobility at facture site, neurological deficit was statistically insignificant (chi square test). Conclusion: The results of this study suggest that fixation of anterior mandibular fractures with 3D plates provides three dimensional stability and carries low morbidity and infection rates. The only probable limitation of these 3D plates may be excessive implant material, but they seem to be easy alternative to champys miniplate. How to cite the article: Barde DH, Mudhol A, Ali FM, Madan RS, Kar S, Ustaad F. Efficacy of 3-Dimensional plates over Champys miniplates in mandibular anterior fractures. J Int Oral Health 2014;6(1):20-6. PMID:24653598

  16. Biomechanical investigation of an alternative concept to angular stable plating using conventional fixation hardware

    PubMed Central

    2010-01-01

    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 < 0.001). All failures occurred due to breakage of the screw heads. 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. PMID:20492707

  17. Principal visual word discovery for automatic license plate detection.

    PubMed

    Zhou, Wengang; Li, Houqiang; Lu, Yijuan; Tian, Qi

    2012-09-01

    License plates detection is widely considered a solved problem, with many systems already in operation. However, the existing algorithms or systems work well only under some controlled conditions. There are still many challenges for license plate detection in an open environment, such as various observation angles, background clutter, scale changes, multiple plates, uneven illumination, and so on. In this paper, we propose a novel scheme to automatically locate license plates by principal visual word (PVW), discovery and local feature matching. Observing that characters in different license plates are duplicates of each other, we bring in the idea of using the bag-of-words (BoW) model popularly applied in partial-duplicate image search. Unlike the classic BoW model, for each plate character, we automatically discover the PVW characterized with geometric context. Given a new image, the license plates are extracted by matching local features with PVW. Besides license plate detection, our approach can also be extended to the detection of logos and trademarks. Due to the invariance virtue of scale-invariant feature transform feature, our method can adaptively deal with various changes in the license plates, such as rotation, scaling, illumination, etc. Promising results of the proposed approach are demonstrated with an experimental study in license plate detection.

  18. Plating Inc. Site

    EPA Pesticide Factsheets

    EPA will begin a hazardous waste cleanup at Plating Inc., an abandoned zinc and chromate plating facility at 888 N. Prior Ave. in St. Paul. The abandoned facility houses approximately 82 open chemical vats containing hazardous wastes such as cyanide, caust

  19. Earthquakes and plate tectonics

    USGS Publications Warehouse

    Spall, H.

    1977-01-01

    An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

  20. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  1. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  2. Planning and Problem Solving

    DTIC Science & Technology

    1982-10-01

    Artificial Intelig ~ence (Vol. III, edited by Paul R. Cohen and’ Edward A.. Feigenbaum)’, The chapter was written B’ Paul Cohen, with contributions... Artificial Intelligence (Vol. III, edited by Paul R. Cohen and EdWard A. Feigenbaum). The chapter was written by Paul R. Cohen, with contributions by Stephen...Wheevoats"EntermdI’ Planning and Problem ’Solving by Paul R. Cohen Chaptb-rXV-of Volumec III’of the Handbook of Artificial Intelligence edited by Paul R

  3. Solving crimes with hypnosis.

    PubMed

    Wester, William C; Hammond, D Corydon

    2011-04-01

    Following a brief review of the literature on hypnosis and memory, this paper overviews the procedures that are used in conducting forensic hypnosis interviews. Ten forensic hypnosis cases are then described. These real world cases are in stark contrast to research done in an artificial laboratory setting where the information to be recalled lacks personal relevance and was not associated with emotionally arousing situations. These cases illustrate how forensic hypnosis can result in obtaining important additional investigative leads which lead to the solving of crimes.

  4. Turbine vane plate assembly

    DOEpatents

    Schiavo Jr., Anthony L.

    2006-01-10

    A turbine vane assembly includes a turbine vane having first and second shrouds with an elongated airfoil extending between. Each end of the airfoil transitions into a shroud at a respective junction. Each of the shrouds has a plurality of cooling passages, and the airfoil has a plurality of cooling passages extending between the first and second shrouds. A substantially flat inner plate and an outer plate are coupled to each of the first and second shrouds so as to form inner and outer plenums. Each inner plenum is defined between at least the junction and the substantially flat inner plate; each outer plenum is defined between at least the substantially flat inner plate and the outer plate. Each inner plenum is in fluid communication with a respective outer plenum through at least one of the cooling passages in the respective shroud.

  5. Geometrically nonlinear behavior of piezoelectric laminated plates

    NASA Astrophysics Data System (ADS)

    Rabinovitch, Oded

    2005-08-01

    The geometrically nonlinear behavior of piezo-laminated plates actuated with isotropic or anisotropic piezoelectric layers is analytically investigated. The analytical model is derived using the variational principle of virtual work along with the lamination and plate theories, the von Karman large displacement and moderate rotation kinematic relations, and the anisotropic piezoelectric constitutive laws. A solution strategy that combines the approach of the method of lines, the advantages of the finite element concept, and the variational formulation is developed. This approach yields a set of nonlinear ordinary differential equations with nonlinear boundary conditions, which are solved using the multiple-shooting method. Convergence and verification of the model are examined through comparison with linear and nonlinear results of other approximation methods. The nonlinear response of two active plate structures is investigated numerically. The first plate is actuated in bending using monolithic piezoceramic layers and the second one is actuated in twist using macro-fiber composites. The results quantitatively reveal the complicated in-plane stress state associated with the piezoelectric actuation and the geometrically nonlinear coupling of the in-plane and out-of-plane responses of the plate. The influence of the nonlinear effects ranges from significant stiffening in certain combinations of electrical loads and boundary conditions to amplifications of the induced deflections in others. The paper closes with a summary and conclusions.

  6. [Fixed angle carbon fiber reinforced polymer composite plate for treatment of distal radius fractures : Pilot study on clinical applications].

    PubMed

    Behrendt, P; Kruse, E; Klüter, T; Fitschen-Oestern, S; Weuster, M; Menzdorf, L; Finn, J; Varoga, D; Seekamp, A; Müller, M; Lippross, S

    2017-02-01

    The clinical implementation of a new carbon-fiber-reinforced polyetheretherketon (PEEK) plate for distal radius fractures might offer advantageous properties over the conventional metallic devices. This includes similar elastic modulus to cortical bone, radiolucency, low artifacts on MRI scans and the lack of metal allergies. The aim of this study was to evaluate the clinical results at 6-week and 12-month follow-up using either a new fixed angle (monoaxial) PEEK plate system or a fixed angle (polyaxial) titanium plate. We included 26 patients (mean age 59.3) with displaced fractures of the distal radius (all AO types). Radiological and functional outcomes were measured prospectively at a 6-week and 12 month follow-up. We documented no cases of hardware breakage or significant loss of the surgically achieved fracture reduction with the usage oft the new PEEK device. Operating time was 101.0 min using PEEK versus 109.3 min in titanium plates, recorded times were including preparation, draping, and postoperative processing (ns, p 0.156). At the 6-week follow up the PEEK plate showed a trend for better range of motion and functional results (DASH-score, Mayo-wrist score, VAS) with no statistical significance. Results of 12 month follow up with PEEK showed comparable results with corresponding studies examining titanium plate after this period. First experience with PEEK plate osteosynthesis demonstrate quick clinical implementation with good clinical outcome and the advantage of excellent postoperative radiological assessment. At early follow-up PEEK even showed a trend for improved functional results.

  7. Solving Differential Equations in R: Package deSolve

    EPA Science Inventory

    In this paper we present the R package deSolve to solve initial value problems (IVP) written as ordinary differential equations (ODE), differential algebraic equations (DAE) of index 0 or 1 and partial differential equations (PDE), the latter solved using the method of lines appr...

  8. Solving Differential Equations in R: Package deSolve

    EPA Science Inventory

    In this paper we present the R package deSolve to solve initial value problems (IVP) written as ordinary differential equations (ODE), differential algebraic equations (DAE) of index 0 or 1 and partial differential equations (PDE), the latter solved using the method of lines appr...

  9. Geogebra for Solving Problems of Physics

    NASA Astrophysics Data System (ADS)

    Kllogjeri, Pellumb; Kllogjeri, Adrian

    Today is highly speed progressing the computer-based education, which allowes educators and students to use educational programming language and e-tutors to teach and learn, to interact with one another and share together the results of their work. In this paper we will be concentrated on the use of GeoGebra programme for solving problems of physics. We have brought an example from physics of how can be used GeoGebra for finding the center of mass(centroid) of a picture(or system of polygons). After the problem is solved graphically, there is an application of finding the center of a real object(a plate)by firstly, scanning the object and secondly, by inserting its scanned picture into the drawing pad of GeoGebra window and lastly, by finding its centroid. GeoGebra serve as effective tool in problem-solving. There are many other applications of GeoGebra in the problems of physics, and many more in different fields of mathematics.

  10. Absolute Plate Velocities from Seismic Anisotropy: Importance of Correlated Errors

    NASA Astrophysics Data System (ADS)

    Gordon, R. G.; Zheng, L.; Kreemer, C.

    2014-12-01

    The orientation of seismic anisotropy inferred beneath the interiors of plates may provide a means to estimate the motions of the plate relative to the deeper mantle. Here we analyze a global set of shear-wave splitting data to estimate plate motions and to better understand the dispersion of the data, correlations in the errors, and their relation to plate speed. The errors in plate motion azimuths inferred from shear-wave splitting beneath any one tectonic plate are shown to be correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. Our preferred set of angular velocities, SKS-MORVEL, is determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25±0.11º Ma-1 (95% confidence limits) right-handed about 57.1ºS, 68.6ºE. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ=19.2°) differs insignificantly from that for continental lithosphere (σ=21.6°). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ=7.4°) than for continental lithosphere (σ=14.7°). Two of the slowest-moving plates, Antarctica (vRMS=4 mm a-1, σ=29°) and Eurasia (vRMS=3 mm a-1, σ=33°), have two of the largest within-plate dispersions, which may indicate that a plate must move faster than ≈5 mm a-1 to result in seismic anisotropy useful for estimating plate motion.

  11. Earthquakes and plate tectonics.

    USGS Publications Warehouse

    Spall, H.

    1982-01-01

    Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author

  12. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1984-01-01

    The problem-solving strategy of making an organized list is highlighted, with a problem and suggestions for teaching the strategy. Other suggestions for teaching problem solving are then presented. (MNS)

  13. Pixelated neutron image plates

    NASA Astrophysics Data System (ADS)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  14. Polar Plate Theory for Orthogonal Anisotropy

    NASA Technical Reports Server (NTRS)

    Bailey, Michelle D.; Bower, Mark V.

    2000-01-01

    Laminated fiber-reinforced (or filamentary) composites are used today for their high strength-to-weight and stiffness-to-weight ratios. However, because of the anisotropic behavior of composites, determining the response on a macroscopic scale is challenging. This is particularly evident in the evaluation of the governing differential equations of a circular disk with the fibers of the lamina oriented with rectilinear orthogonality. This includes any situation involving a composite plate of circular geometry in which out-of-plane displacements due to load are desired, such as fastener pull through loading of a composite plate. Current analysis techniques use numerical methods with rectilinear coordinate systems to solve problems with circular geometry. These analyses over predict plate stiffness by 20% and underpredict failure by 70%. Consequently, there is a need to transform classical composite plate theory to a polar coordinate system. In order to better analyze structures with circular geometries the classical composite plate equations are transformed into the plate equations for a rectilinearly anisotropic composite in polar coordinates. A composite plate is typically a laminate of fibers in rectilinear directions. Subsequent to the lay-tip the necessary geometry is cut out of a rectangular plate. In a similar manner, the derivation of the plate equation starts with the fundamental definitions of strain, displacement and curvature and incorporates the material property angular dependence into the equilibrium equations for a differential polar element. In the transformed state, the stiffness coefficients are no longer constant, adding to the complexity of the governing differential equations. This paper discusses the new derivation and evaluation of the plate equations for a circular composite disk with orthogonal rectilinear anisotropy. The resultant new three partial differential equations, which describe the circular anisotropic plate, can be used to

  15. Tension plate for treatment of olecranon fractures: new surgical technique and case series study.

    PubMed

    Lukšic, Bruno; Juric, Ivo; Boschi, Vladimir; Pogorelic, Zenon; Bekavac, Josip

    2015-02-01

    Our aim was to determine the effectiveness of a new surgical technique for olecranon fractures using a tension plate (TP) designed by the operating surgeon. We included patients with olecranon fractures treated between September 2010 and August 2013 in our study. Treatment involved a new implant and operative technique, which combined the most favourable characteristics of 2 frequently used methods, tension band wiring and plate osteosynthesis, while eliminating their shortcomings. The new method was based on the newly constructed implant. Twenty patients participated in our study. We obtained the following functional results with our TP: median flexion 147.5° (interquartile range [IQR] 130°- 155°), median extension 135°/deficit 10° (IQR 135°-145°), median pronation 90° (IQR 81.3°-90°), median supination 90° (IQR 80°-90°). Implant-related complications were noted in 1 patient, and implants were removed in 3 patients. The mean functional Mayo elbow performance score was 94.8 (range 65-100). The removal of the implant was considerably less frequent in patients operated using the new method and implant than in patients operated using conventional methods at our institution (p < 0.001). Mean duration of follow-up was 8 months. Our TP for the treatment of olecranon fractures is safe and effective. Functional results are very good, with significantly decreased postoperative inconveniences and need to remove the implant. Less osteosynthetic material was used for TP construction, but stability was preserved.

  16. Early experience about Anteversa® plate for lateral femur fractures

    PubMed Central

    Bonicoli, Enrico; Andreani, Lorenzo; Piolanti, Nicola; Dolfi, Lorenzo; Lisanti, Michele

    2012-01-01

    Summary Introduction The hip fractures appear to be a real epidemic problem, especially in the western world, due primarily to higher average age. The social and economical impact is considerable with a continue social and health costs up-rising. The female-male ratio is approximately 8:1. Purpose The purpose of this report is to present a system of osteosynthesis for fractures of the lateral femoral neck. This system is a plate developed by INTRAUMA O'nil®, 3-hole plate with an 130° angle of valgus and 7° of anteversion. Materials and methods At the I Orthopedic Department at the University of Pisa from January 2009 to February 2012 were treated 52 fractures of the femur neck side with this system. All patients undergone to a clinical and X-ray evaluation according to the AO classification: 14 31-A1, 7 31-A2, 4 31-A3. Results The mean follow-up was 10 months, in all cases we did not have cut-outs with a TAD average of 23 mm. Conclusions This system offers the possibility to perform surgery quickly with low risk of cut-out thanks to 7° of anteversion. Ensures optimal fixation to the femoral shaft and an equitable distribution of forces, eliminating the risk of breakage of the implant and loosening of the screws. PMID:23289036

  17. Environmental problem solving

    SciTech Connect

    Miller, A.

    1999-06-01

    Human influences create both environmental problems and barriers to effective policy aimed at addressing those problems. In effect, environmental managers manage people as much as they manage the environment. Therefore, they must gain an understanding of the psychological and sociopolitical dimensions of environmental problems that they are attempting to resolve. The author reappraises conventional analyses of environmental problems using lessons from the psychosocial disciplines. The author combines the disciplines of ecology, political sociology and psychology to produce a more adaptive approach to problem-solving that is specifically geared toward the environmental field. Numerous case studies demonstrate the practical application of theory in a way that is useful to technical and scientific professionals as well as to policymakers and planners.

  18. Inverse characterization of plates using zero group velocity Lamb modes.

    PubMed

    Grünsteidl, Clemens; Murray, Todd W; Berer, Thomas; Veres, István A

    2016-02-01

    In the presented work, the characterization of plates using zero group velocity Lamb modes is discussed. First, analytical expressions are shown for the determination of the k-ω location of the zero group velocity Lamb modes as a function of the Poisson's ratio. The analytical expressions are solved numerically and an inverse problem is formulated to determine the unknown wave velocities in plates of known thickness. The analysis is applied to determine the elastic properties of tungsten and aluminum plates based on the experimentally measured frequency spectra. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Nonlinear vibrations of buckled plates by an asymptotic numerical method

    NASA Astrophysics Data System (ADS)

    Benchouaf, Lahcen; Boutyour, El Hassan

    2016-03-01

    This work deals with nonlinear vibrations of a buckled von Karman plate by an asymptotic numerical method and harmonic balance approach. The coupled nonlinear static and dynamic problems are transformed into a sequence of linear ones solved by a finite-element method. The static behavior of the plate is first computed. The fundamental frequency of nonlinear vibrations of the plate, about any equilibrium state, is obtained. To improve the validity range of the power series, Padé approximants are incorporated. A continuation technique is used to get the whole solution. To show the effectiveness of the proposed methodology, numerical tests are presented.

  20. Postbuckling of orthotropic composite plates loaded in compression

    NASA Technical Reports Server (NTRS)

    Stein, M.

    1982-01-01

    The nonlinear large deflection equations of von Karman are written for 'specially' orthotropic plates. The equations are then manipulated to determine the parameters required to establish postbuckling behavior. It is found that only two new parameters are needed beyond those required for buckling. By assuming trigonometric functions in one direction, the plate equations are converted into ordinary nonlinear differential equations which are solved numerically using a two point boundary problem solver that makes use of Newton's method. The postbuckling behavior is obtained for simply supported and clamped, long, rectangular, orthotropic plates covering the complete range of dimensions and material properties.

  1. Problem Solving and Beginning Programming.

    ERIC Educational Resources Information Center

    McAllister, Alan

    Based on current models of problem solving within cognitive psychology, this study focused on the spontaneous problem solving strategies used by children as they first learned LOGO computer programming, and on strategy transformations that took place during the problem solving process. The research consisted of a six weeks programming training…

  2. The Identity of Problem Solving

    ERIC Educational Resources Information Center

    Mamona-Downs, Joanna; Downs, Martin

    2005-01-01

    This paper raises issues motivated by considering the "identity" of problem solving. This means that we are concerned with how other mathematics education topics impinge on problem solving, and with themes that naturally arise within the problem-solving agenda. We claim that some of these issues need more attention by educational research, while…

  3. Dynamic behaviour of thin composite plates for different boundary conditions

    SciTech Connect

    Sprintu, Iuliana E-mail: rotaruconstantin@yahoo.com; Rotaru, Constantin E-mail: rotaruconstantin@yahoo.com

    2014-12-10

    In the context of composite materials technology, which is increasingly present in industry, this article covers a topic of great interest and theoretical and practical importance. Given the complex design of fiber-reinforced materials and their heterogeneous nature, mathematical modeling of the mechanical response under different external stresses is very difficult to address in the absence of simplifying assumptions. In most structural applications, composite structures can be idealized as beams, plates, or shells. The analysis is reduced from a three-dimensional elasticity problem to a oneor two-dimensional problem, based on certain simplifying assumptions that can be made because the structure is thin. This paper aims to validate a mathematical model illustrating how thin rectangular orthotropic plates respond to the actual load. Thus, from the theory of thin plates, new analytical solutions are proposed corresponding to orthotropic rectangular plates having different boundary conditions. The proposed analytical solutions are considered both for solving equation orthotropic rectangular plates and for modal analysis.

  4. Vibration suppression of composite laminated plate with nonlinear energy sink

    NASA Astrophysics Data System (ADS)

    Zhang, Ye-Wei; Zhang, Hao; Hou, Shuai; Xu, Ke-Fan; Chen, Li-Qun

    2016-06-01

    The composite laminated plate is widely used in supersonic aircraft. So, there are many researches about the vibration suppression of composite laminated plate. In this paper, nonlinear energy sink (NES) as an effective method to suppress vibration is studied. The coupled partial differential governing equations of the composite laminated plate with the nonlinear energy sink (NES) are established by using the Hamilton principle. The fourth-order Galerkin discrete method is used to truncate the partial differential equations, which are solved by numerical integration method. Meanwhile study about the precise effectiveness of the nonlinear energy sink (NES) by discussing the different installation location of the nonlinear energy sink (NES) at the same speed. The results indicate that the nonlinear energy sink (NES) can significantly suppress the severe vibration of the composite laminated plate with speed wind loadings in to protect the composite laminated plate from excessive vibration.

  5. Numerical solution of acoustic scattering by finite perforated elastic plates.

    PubMed

    Cavalieri, A V G; Wolf, W R; Jaworski, J W

    2016-04-01

    We present a numerical method to compute the acoustic field scattered by finite perforated elastic plates. A boundary element method is developed to solve the Helmholtz equation subjected to boundary conditions related to the plate vibration. These boundary conditions are recast in terms of the vibration modes of the plate and its porosity, which enables a direct solution procedure. A parametric study is performed for a two-dimensional problem whereby a cantilevered perforated elastic plate scatters sound from a point quadrupole near the free edge. Both elasticity and porosity tend to diminish the scattered sound, in agreement with previous work considering semi-infinite plates. Finite elastic plates are shown to reduce acoustic scattering when excited at high Helmholtz numbers k0 based on the plate length. However, at low k0, finite elastic plates produce only modest reductions or, in cases related to structural resonance, an increase to the scattered sound level relative to the rigid case. Porosity, on the other hand, is shown to be more effective in reducing the radiated sound for low k0. The combined beneficial effects of elasticity and porosity are shown to be effective in reducing the scattered sound for a broader range of k0 for perforated elastic plates.

  6. Numerical solution of acoustic scattering by finite perforated elastic plates

    PubMed Central

    2016-01-01

    We present a numerical method to compute the acoustic field scattered by finite perforated elastic plates. A boundary element method is developed to solve the Helmholtz equation subjected to boundary conditions related to the plate vibration. These boundary conditions are recast in terms of the vibration modes of the plate and its porosity, which enables a direct solution procedure. A parametric study is performed for a two-dimensional problem whereby a cantilevered perforated elastic plate scatters sound from a point quadrupole near the free edge. Both elasticity and porosity tend to diminish the scattered sound, in agreement with previous work considering semi-infinite plates. Finite elastic plates are shown to reduce acoustic scattering when excited at high Helmholtz numbers k0 based on the plate length. However, at low k0, finite elastic plates produce only modest reductions or, in cases related to structural resonance, an increase to the scattered sound level relative to the rigid case. Porosity, on the other hand, is shown to be more effective in reducing the radiated sound for low k0. The combined beneficial effects of elasticity and porosity are shown to be effective in reducing the scattered sound for a broader range of k0 for perforated elastic plates. PMID:27274685

  7. Numerical solution of acoustic scattering by finite perforated elastic plates

    NASA Astrophysics Data System (ADS)

    Cavalieri, A. V. G.; Wolf, W. R.; Jaworski, J. W.

    2016-04-01

    We present a numerical method to compute the acoustic field scattered by finite perforated elastic plates. A boundary element method is developed to solve the Helmholtz equation subjected to boundary conditions related to the plate vibration. These boundary conditions are recast in terms of the vibration modes of the plate and its porosity, which enables a direct solution procedure. A parametric study is performed for a two-dimensional problem whereby a cantilevered perforated elastic plate scatters sound from a point quadrupole near the free edge. Both elasticity and porosity tend to diminish the scattered sound, in agreement with previous work considering semi-infinite plates. Finite elastic plates are shown to reduce acoustic scattering when excited at high Helmholtz numbers k0 based on the plate length. However, at low k0, finite elastic plates produce only modest reductions or, in cases related to structural resonance, an increase to the scattered sound level relative to the rigid case. Porosity, on the other hand, is shown to be more effective in reducing the radiated sound for low k0. The combined beneficial effects of elasticity and porosity are shown to be effective in reducing the scattered sound for a broader range of k0 for perforated elastic plates.

  8. Solution of non-rectangular plates with macroelement method

    NASA Astrophysics Data System (ADS)

    Delyavskyy, Mykhaylo; Rosinski, Krystian

    2017-03-01

    New approach to static analysis of thin non-rectangular arbitrarily loaded plates, called the macroelement method, has been developed in this paper. Macroelement is a rectangular plate which entirely contains real plate. The mathematical model of macroelement was built. The equilibrium equations are performed for macroelement and boundary conditions are written on the line corresponding to contour of real plate in the nodes which are zero points of trigonometric functions, included in the macroelement model. The load is applied only to separate nodes on the surface of real plate, whereas the complement of a plate to macroelement is unloaded. Analysis of construction is reduced to solving a system of linear algebraic equations. The method provides better accuracy compared to finite element method and requires less equations. There is trapeze plate clamped at inclined edge and simply supported at opposite one considered in this paper. The other edges of the plate are free. Uniformly distributed load on the surface of real plate is taken into account.

  9. What's On Your Plate?

    MedlinePlus

    ... Table of Contents What's On Your Plate? Smart Food Choices for Healthy Aging www.nia.nih.gov/health/ ... calories in" and "calories out," and making good food choices as you age. Shopping Tips See how planning ...

  10. Reduction of astrometric plates

    NASA Technical Reports Server (NTRS)

    Stock, J.

    1984-01-01

    A rapid and accurate method for the reduction of comet or asteroid plates is described. Projection equations, scale length correction, rotation of coordinates, linearization, the search for additional reference stars, and the final solution are examined.

  11. Violin plate modes.

    PubMed

    Gough, Colin

    2015-01-01

    As the first step toward developing a generic model for the acoustically radiating vibrational modes of the violin and related instruments, the modes of both freely supported and edge-constrained top and back plates have been investigated as functions of shape, arching height, elastic anisotropy, the f-holes and associated island area, thickness graduations, and the additional boundary constraints of the ribs, soundpost, and bass-bar present in the assembled instrument. Comsol shell structure finite element software has been used as a quasi-experimental tool, with physical and geometric properties varied smoothly, often over several orders of magnitude, allowing the development of the plate modes to be followed continuously from those of an initially square plate to those of doubly-arched, guitar-shaped, orthotropic plates and their dependence on all the above factors.

  12. Reduction of astrometric plates

    NASA Technical Reports Server (NTRS)

    Stock, J.

    1984-01-01

    A rapid and accurate method for the reduction of comet or asteroid plates is described. Projection equations, scale length correction, rotation of coordinates, linearization, the search for additional reference stars, and the final solution are examined.

  13. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  14. Plate tectonics: Metamorphic myth

    NASA Astrophysics Data System (ADS)

    Korenaga, Jun

    2016-01-01

    Clear evidence for subduction-induced metamorphism, and thus the operation of plate tectonics on the ancient Earth has been lacking. Theoretical calculations indicate that we may have been looking for something that cannot exist.

  15. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  16. Designing Assemblies Of Plates

    NASA Technical Reports Server (NTRS)

    Williams, F. W.; Kennedy, D.; Butler, R.; Aston, G.; Anderson, M. S.

    1992-01-01

    VICONOPT calculates vibrations and instabilities of assemblies of prismatic plates. Designed for efficient, accurate analysis of buckling and vibration, and for optimum design of panels of composite materials. Written in FORTRAN 77.

  17. Flat plate solar oven

    SciTech Connect

    Parikh, M.

    1981-01-01

    The construction of an Indian Rs. 186 (US $20.33) flat-plate solar oven is described. Detailed drawings are provided and relevant information on cooking times and temperature for different foods is given.

  18. Mental maze solving.

    PubMed

    Crowe, D A; Averbeck, B B; Chafee, M V; Anderson, J H; Georgopoulos, A P

    2000-09-01

    We sought to determine how a visual maze is mentally solved. Human subjects (N = 13) viewed mazes with orthogonal, unbranched paths; each subject solved 200-600 mazes in any specific experiment below. There were four to six openings at the perimeter of the maze, of which four were labeled: one was the entry point and the remainder were potential exits marked by Arabic numerals. Starting at the entry point, in some mazes the path exited, whereas in others it terminated within the maze. Subjects were required to type the number corresponding to the true exit (if the path exited) or type zero (if the path did not exit). In all cases, the only required hand movement was a key press, and thus the hand never physically traveled through the maze. Response times (RT) were recorded and analyzed using a multiple linear regression model. RT increased as a function of key parameters of the maze, namely the length of the main path, the number of turns in the path, the direct distance from entry to termination, and the presence of an exit. The dependence of RT on the number of turns was present even when the path length was fixed in a separate experiment (N = 10 subjects). In a different experiment, subjects solved large and small mazes (N = 3 subjects). The former was the same as the latter but was scaled up by 1.77 times. Thus both kinds of mazes contained the same number of squares but each square subtended 1.77 degrees of visual angle (DVA) in the large maze, as compared to 1 DVA in the small one. We found that the average RT was practically the same in both cases. A multiple regression analysis revealed that the processing coefficients related to maze distance (i.e., path length and direct distance) were reduced by approximately one-half when solving large mazes, as compared to solving small mazes. This means that the efficiency in processing distance-related information almost doubled for scaled-up mazes. In contrast, the processing coefficients for number of turns and

  19. Salter-Harris type II metacarpal and metatarsal fracture in three foals. Treatment by minimally-invasive lag screw osteosynthesis combined with external coaptation.

    PubMed

    Klopfenstein Bregger, Micaël D; Fürst, Anton E; Kircher, Patrick R; Kluge, Katharina; Kummer, Martin

    2016-05-18

    To describe minimally-invasive lag screw osteosynthesis combined with external coaptation for the treatment of Salter-Harris type II third metacarpal and third metatarsal bone fractures. Three foals aged two weeks to four months with a Salter-Harris type II third metacarpal or third metatarsal fracture. Surgery was carried out under general anaesthesia in lateral recumbency. After fracture reduction, the metaphyseal fragment was stabilized with two cortical screws placed in lag fashion under fluoroscopic control. A cast was applied for at least two weeks. All foals had a good outcome with complete fracture healing and return to complete soundness without any angular limb deformity. All foals had moderate transient digital hyperextension after cast removal. Internal fixation of Salter-Harris type II third metacarpal or third metatarsal fractures with two cortical screws in lag fashion, combined with external coaptation provided good stabilization and preserved the longitudinal growth potential of the injured physis.

  20. Positive battery plate

    NASA Technical Reports Server (NTRS)

    Rowlette, John R. (Inventor)

    1985-01-01

    The power characteristics of a lead acid battery are improved by incorporating a dispersion of 1 to 10% by weight of a thermodynamically stable conductivity additive, such as conductive tin oxide coated glass fibers (34) of filamentary glass wool (42) in the positive active layer (32) carried on the grid (30) of the positive plate (16). Positive plate potential must be kept high enough to prevent reduction of the tin oxide to tin by utilizing an oversized, precharged positive paste.

  1. Fractal multifiber microchannel plates

    NASA Technical Reports Server (NTRS)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  2. Computer Problem-Solving Coaches

    NASA Astrophysics Data System (ADS)

    Hsu, Leon; Heller, Kenneth

    2005-09-01

    Computers might be able to play an important role in physics instruction by coaching students to develop good problem-solving skills. Building on previous research on student problem solving and on designing computer programs to teach cognitive skills, we are developing a prototype computer coach to provide students with guided practice in solving problems. In addition to helping students become better problem solvers, such programs can be useful in studying how students learn to solve problems and how and if problem-solving skills can be transferred from a computer to a pencil-and-paper environment.

  3. Type II olecranon fractures in patients over 65. Tension band or pre-formed plate? Analysis and results.

    PubMed

    Liñán-Padilla, A; Cáceres-Sánchez, L

    The objective of this study was to compare the clinical outcomes of surgical treatment using tension band with needles and preformed plates in type ii olecranon fractures according to the Mayo classification in patients older than 65 years. A descriptive, retrospective study of 49 patients with a mean age of 75.1 years who underwent surgery olecranon fracture using 2 different fixing systems. The Mayo classification was used to define them, excluding type i and iii, and the VAS to assess postoperative pain. Patients were assessed functionally by the questionnaire Quick DASH. All measurement was performed with goniometer and joint balance serial radiographs at one month, 3, 6 and 12 months. Minimum follow-up was one year. In 26 patients the tension band was used and the preformed plates in 23. There were no statistically significant differences in functional outcomes, joint balance or postoperative VAS between the 2 groups. There were a greater proportion of patients who had to be operated because of problems related to osteosynthesis material in those in which preformed plates were used. Treatment of olecranon fractures with tension band with needles and cerclage remains the surgery of choice in patients older than 65 years. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Solving the Antibiotic Crisis.

    PubMed

    Wright, Gerard D

    2015-02-13

    Antibiotics are essential for both treating and preventing infectious diseases. Paradoxically, despite their importance as pillars of modern medicine, we are in danger of losing antibiotics because of the evolution and dissemination of resistance mechanisms throughout all pathogenic microbes. This fact, coupled with an inability to bring new drugs to market at a pace that matches resistance, has resulted in a crisis of global proportion. Solving this crisis requires the actions of many stakeholders, but chemists, chemical biologists, and microbiologists must drive the scientific innovation that is required to maintain our antibiotic arsenal. This innovation requires (1) a deep understanding of the evolution and reservoirs of resistance; (2) full knowledge of the molecular mechanisms of antibiotic action and resistance; (3) the discovery of chemical and genetic probes of antibiotic action and resistance; (4) the integration of systems biology into antibiotic discovery; and (5) the discovery of new antimicrobial chemical matter. Addressing these pressing scientific gaps will ensure that we can meet the antibiotic crisis with creativity and purpose.

  5. Cosmology Solved? Quite Possibly!

    NASA Astrophysics Data System (ADS)

    Turner, Michael S.

    1999-03-01

    The discovery of the cosmic microwave background (CMB) in 1964 by Penzias and Wilson led to the establishment of the hot big bang cosmological model some 10 years later. Discoveries made in 1998 may ultimately have as profound an effect on our understanding of the origin and evolution of the universe. Taken at face value, they confirm the basic tenets of inflation + cold dark matter, a bold and expansive theory that addresses all the fundamental questions left unanswered by the hot big bang model and holds that the universe is flat, slowly moving elementary particles provide the cosmic infrastructure, and quantum fluctuations seeded all the structure seen in the universe today. Just as it took a decade to establish the hot big bang model after the discovery of the CMB, it will likely take another 10 years to establish the latest addition to the standard cosmology and make the answer to ``Cosmology solved?'' ``YES!'' Whether or not 1998 proves to be a cosmic milestone, the coming avalanche of high-quality cosmological data promises to make the next 20 years an extremely exciting period for cosmology.

  6. Surgical fixation of sternal fractures: preoperative planning and a safe surgical technique using locked titanium plates and depth limited drilling.

    PubMed

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th; Mauerer, Andreas; Hennig, Friedrich F; Buder, Thomas

    2015-01-05

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture's morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology.

  7. Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

    PubMed Central

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th.; Mauerer, Andreas; Hennig, Friedrich F.; Buder, Thomas

    2015-01-01

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture’s morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology. PMID

  8. Complex AO type C3 distal femur fractures: Results after fixation with a lateral locked plate using modified swashbuckler approach

    PubMed Central

    Agrawal, Anuj; Kiyawat, Vivek

    2017-01-01

    Background: Complex AO type C3 fractures of the distal femur are challenging injuries, fraught with complications such as malunion and stiffness. We prospectively evaluated a consecutive series of patients with complex AO type C3 distal femur fractures to determine the clinicoradiological outcome after fixation with a single locked plate using modified swashbuckler approach. Materials and Methods: 12 patients with C3 type distal femur fractures treated with a lateral locked plate, using a modified swashbuckler approach, were included in the study. The extraarticular component was managed either by compression plating or bridge plating (transarticular approach and retrograde plate osteosynthesis) depending on the fracture pattern. Primary bone grafting was not done in any case. The clinical outcome at 1 year was determined using the Knee Society Score (KSS). The presence of any secondary osteoarthritis in the knee joint was noted at final followup. Results: All fractures united at a mean of 14.3 ± 4.7 weeks (range 6–26 weeks). There were no significant complications such as nonunion, deep infection, and implant failure. One of the patients underwent secondary bone grafting at 3 months. The mean range of motion of the knee was 120° ± 14.8° (range 105°–150°). Seven patients had excellent, three patients had good and two patients had a fair outcome according to the KSS at 1 year. At a mean followup of 17.6 months, three patients showed radiological evidence of secondary osteoarthritis of the knee joint. However, only one of these patients was symptomatic. Conclusion: The results of complex C3 type distal femur fractures, fixed with a single lateral locked plate using a modified swashbuckler approach, are encouraging, with a majority of patients achieving good to excellent outcome at 1 year. PMID:28216747

  9. Simulation of the stationary electrochemical surface treatment by two asymmetric cathode plates

    NASA Astrophysics Data System (ADS)

    Klokov, V. V.; Sergeev, D. E.

    2012-11-01

    The hydrodynamic analogy method was used to solve the problem of stationary electrochemical shaping with two semi-infinite cathode plates arranged arbitrarily relative to the feed direction. A feature of the problem is the multivalence of the velocity hodograph.

  10. Submuscular plating after distraction osteogenesis in children.

    PubMed

    Oh, Chang-Wug; Shetty, Gautam M; Song, Hae-Ryong; Kyung, Hee-Soo; Oh, Jong-Keon; Min, Woo-Kie; Lee, Byung-Woo; Park, Byung-Chul

    2008-09-01

    Although distraction osteogenesis has solved limb length discrepancies, many complications are inevitable from long duration of external fixation. Use of intramedullary nails for early removal of fixators has its own challenges especially in pediatric age group. To facilitate early removal of external fixators in children, we tried a novel method of submuscular plating over the distraction callus, which is described, and the results and complications of this technique are presented. In eight children (four girls and four boys), of limb lengthening (four cases) and bone transport (four cases) done in three femurs and five tibiae with external fixators (five Ilizarov ring fixators and three monofixators), submuscular plating was done over the distraction callus. The causes of limb length discrepancy included traumatic and septic growth arrest, congenital pseudoarthrosis of tibia, fibular hemimelia, tumor salvage, and Perthes' disease. The purpose of plating was to remove the external fixator earlier after achieving the target length. Mean age of plating procedure was 11.62 years, and mean amount of distraction was 5.47 cm. In all patients, the distraction callus healed on maintaining its length or correcting into the original alignment. The mean external fixation index was 26.93 days/cm and healing index was 52.01 days/cm. One complication of superficial pin-track infection occurred, which resolved completely with conservative treatment. None of the patients developed deep infection or implant failures. The mean follow-up after plating was 28 months (range, 18-62 months). Submuscular plating over the distraction callus may be a successful method that permits early removal of fixator with fewer complications. This method can be a useful alternative in children or when nailing is difficult.

  11. Caribbean plate interactions

    SciTech Connect

    Ball, M. )

    1993-02-01

    Vector analysis of plate motions, derived from studies of Atlantic magnetic lineations and fracture zone trends, indicates the following relative movements between the Caribbean, North American, and South American Plates. (1) During Early Jurassic to Early Cretaceous, the North American Plate moved 1900 km westward and 900 km northward relative to the South American Plate. A broad zone including the Caribbean region, i.e., the zone between the North and South America Plates, was a site of left-lateral shear and north-south extension. (2) During Early Cretaceous to Late Cretaceous, the North American Mate moved an additional 1200 km westward relative to South America across this zone. (3) During Late Cretaceous to the end of the Eocene, the North American Plate moved 200 km westward and 400 km northward relative to the South American Plate. (4) From the end of the Eocene to near the end of the Miocene, North America converged on South America some 200 km and moved 100 km eastward relative to it. Through the Mesozoic and earliest Tertiary history of the Caribbean, the region was a shear zone within which left-lateral displacement exceeded 3000 km and north-south extension exceeded 1300 km. In regard to time, 80% of the history of the Caribbean region is one of north-south extension and left-lateral shear. In terms of space, 97% of the shear is left-lateral and the ratio of divergence versus convergence is 7 to 1. Thus, characterizing the Caribbean region, and the Atlantic to its east, as a zone of north-south extension and left-lateral shear, is a fair generalization.

  12. Resource Scarcity: Problems Technology Cannot Solve; Problems Technology Can Solve.

    ERIC Educational Resources Information Center

    Meadows, Dennis; Castle, Emery N.

    1979-01-01

    Lists resource problems technology can and cannot solve, and emphasizes the need for considering and restructuring the social environments and institutions as well as developing new technologies. (CK)

  13. Wave interaction with dual circular porous plates

    NASA Astrophysics Data System (ADS)

    Mondal, Arpita; Gayen, R.

    2015-12-01

    In this paper we investigated the reflection and the transmission of a system of two symmetric circular-arc-shaped thin porous plates submerged in deep water within the context of linear theory. The hypersingular integral equation technique has been used to analyze the problem mathematically. The integral equations are formulated by applying Green's integral theorem to the fundamental potential function and the scattered potential function into a suitable fluid region, and then using the boundary condition on the porous plate surface. These are solved approximately using an expansion-cum-collocation method using the behaviour of the potential functions at the tips of the plates. This method ultimately produces a very good numerical approximation for the reflection and the transmission coefficients and hydrodynamic force components. The numerical results are depicted graphically against the wave number for a variety of layouts of the arc. Some results are compared with known results for similar configurations of dual rigid plate systems available in the literature with good agreement.

  14. BEPLATE emdash simulation of electrochemical plating

    SciTech Connect

    Giles, G.E. ); Gray, L.J. ); Bullock, J.S. IV )

    1990-09-01

    BEPLATE is a FORTRAN code that uses the boundary element method to simulate the electrochemical plating of material on parts, primarily rotating axisymmetric parts. A boundary element technique is used to solve for the local current density and thus the plating rate on the part, which is used to calculate the growth in the plated layer over a user-specified time step. The surface is moved to reflect this growth, and the new surface is used to generate the local current density. This cycle is repeated until the final time specified by the analyst, producing the final plated thickness. BEPLATE includes models for the polarization effects at both the part (cathode) and anode and allows the use of symmetry planes and nonconducting shields. For electroplating simulations, the part shape is normally assumed to be axisymmetric with a centerline along the z-axis. More general part shapes can be analyzed by BEPLATE if the surface growth simulation is not needed. In either case, the shield, anode, and tank geometries are not restricted to specific shapes. This report includes the information required to run BEPLATE, specifically, a brief description of the BEPLATE system including hardware and software requirements, a description of the complete simulation process, discussion of rules for generating models, and additional reference material. This system of codes consists of model generators (PIGS or PATRAN), input processor (BEPIN), the simulation code (BEPLATE) and postprocessing codes (PATRAN or CONPLOT).

  15. Cadmium plating replacements

    NASA Technical Reports Server (NTRS)

    Nelson, Mary J.; Groshart, Earl C.

    1995-01-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  16. Cadmium plating replacements

    SciTech Connect

    Nelson, M.J.; Groshart, E.C.

    1995-03-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  17. Wrinkling of reinforced plates subjected to shear stresses

    NASA Technical Reports Server (NTRS)

    Seydel, Edgar

    1931-01-01

    An analysis is made here of the problem of long plates with transverse stiffeners subject to shear. A typical example would be a long Wagner beam. The shear stress is calculated at which the web wrinkles and shear stress becomes a maximum. The equation is solved for both a condition of free support and rigidity of support on the edges.

  18. Incipient transition phenomena in compressible flows over a flat plate

    NASA Technical Reports Server (NTRS)

    Erlebacher, G.; Hussaini, M. Y.

    1986-01-01

    The full three-dimensional time-dependent compressible Navier-Stokes equations are solved by a Fourier-Chebyshev method to study the stability of compressible flows over a flat plate. After the code is validated in the linear regime, it is applied to study the existence of the secondary instability mechanism in the supersonic regime.

  19. The Importance of Lower Mantle Structure to Plate Stresses and Plate Motions

    NASA Astrophysics Data System (ADS)

    Holt, W. E.; Wang, X.; Ghosh, A.

    2016-12-01

    Plate motions and plate stresses are widely assumed as the surface expression of mantle convection. The generation of plate tectonics from mantle convection has been studied for many years. Lithospheric thickening (or ridge push) and slab pull forces are commonly accepted as the major driving forces for the plate motions. However, the importance of the lower mantle to plate stresses and plate motions remains less clear. Here, we use the joint modeling of lithosphere and mantle dynamics approach of Wang et al. (2015) to compute the tractions originating from deeper mantle convection and follow the method of Ghosh et al. (2013) to calculate gravitational potential energy per unit area (GPE) based on Crust 1.0 (Laske et al., 2013). Absolute values of deviatoric stresses are determined by the body force distributions (GPE gradients and traction magnitudes applied at the base of the lithosphere). We use the same relative viscosity model that Ghosh et al. (2013) used, and we solve for one single adjustable scaling factor that multiplies the entire relative viscosity field to provide absolute values of viscosity throughout the lithosphere. This distribution of absolute values of lithosphere viscosities defines the magnitudes of surface motions. In this procedure, the dynamic model first satisfies the internal constraint of no-net-rotation of motions. The model viscosity field is then scaled by the single factor until we achieve a root mean square (RMS) minimum between computed surface motions and the kinematic no-net-rotation (NNR) model of Kreemer et al. (2006). We compute plate stresses and plate motions from recently published global tomography models (over 70 based on Wang et al., 2015). We find that RMS misfits are significantly reduced when details of lower mantle structure from the latest tomography models are added to models that contain only upper and mid-mantle density distributions. One of the key reasons is that active upwelling from the Large Low Shear

  20. Models of space averaged energetics of plates

    NASA Technical Reports Server (NTRS)

    Bouthier, O. M.; Bernhard, R. J.

    1990-01-01

    The analysis of high frequency vibrations in plates is of particular interest in the study of structure borne noise in aircrafts. The current methods of analysis are either too expensive (finite element method) or may have a confidence band wider than desirable (Statistical Energy Analysis). An alternative technique to model the space and time averaged response of structural acoustics problems with enough detail to include all significant mechanisms of energy generation, transmission, and absorption is highly desirable. The focus of this paper is the development of a set of equations which govern the space and time averaged energy density in plates. To solve this equation, a new type of boundary value problem must be treated in terms of energy density variables using energy and intensity boundary conditions. A computer simulation verification study of the energy governing equation is performed. A finite element formulation of the new equations is also implemented and several test cases are analyzed and compared to analytical solutions.

  1. Solving Transportation Problems via Aggregation,

    DTIC Science & Technology

    1984-07-01

    AD-A144 219 SOLVING TRANSPORTATION PROBLEMS VIA AGGREGATION (U) i/l GEORGIA INST OF TECH ATLANTA PRODUCTION AND DISTRIBUTION RESEARCH CENTER R W...10 July 1984 SOLVING TRANSPORTATION PROBLEMS VIA AGGREGATION by" 4 Richard W. Taylort C. M. Shettytt PDRC 84-10 DTIC E L - TE~ School of Business...c UoaOO48--17 Rpouto spritein whol or pr for ny prpos of he U S. overment Abstract Solving Transportation Problems Via Aggregation 0

  2. Comparison of retrograde nailing and minimally invasive plating for treatment of periprosthetic supracondylar femur fractures (OTA 33-A) above total knee arthroplasty.

    PubMed

    Park, Jin; Lee, Ju Hong

    2016-03-01

    Retrograde intramedullary (IM) nailing and minimally invasive plate osteosynthesis (MIPO) using locking plate are typically considered the gold standards of treatment for periprosthetic supracondylar femoral fractures above total knee arthroplasty (TKA). Forty-one consecutive patients treated with either retrograde nailing (nail group, n = 20) or minimally invasive plating (plate group, n = 21) for periprosthetic supracondylar femoral fractures between March 2003 and January 2014 were retrospectively reviewed. Clinical functions [arc range of motion and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score] and bony outcomes (bony union and malunion) were evaluated. There was no statistical difference between the nail and plate groups in age (p = 0.665), one-year postoperative arc range of motion (p = 0.642), preoperative WOMAC score (p = 0.076), postoperative one-year WOMAC score (p = 0.135), and union time (p = 0.081). The mean union time of the nail group and the plate group was 4.3 months (range 3-12 months) and 3.6 months (range 3-5 months), respectively. There were three cases of malalignment in the nail group, whereas there was one case of malalignment in the plate group (p = 0.343). One case of nailing using a short nail demonstrated nail breakage. Although retrograde nailing was found to have a slightly higher rate of malunion compared to minimally invasive plating, there was no statistically significant difference between both treatment options in terms of clinical outcomes. Regardless of which implant is used, the proper application is essential in management of periprosthetic supracondylar femoral fractures above TKA.

  3. Bipolar battery plate

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1987-01-01

    A liquid-impermeable plate (10) having through-plate conductivity with essentially zero resistance comprises an insulator sheet (12) having a series of spaced perforations (14) each of which contains a metal element (16) sealingly received into the perforation (14). A low-cost plate can readily be manufactured by punching a thermoplastic sheet (40) such as polypropylene with a punching tool (52), filling the apertures with led spheres (63) having a diameter smaller than the holes (50) but larger than the thickness of the sheet, sweeping excess spheres (62) off the sheet with a doctor blade (60) and then pressing a heated platen (74) onto the sheet to swage the spheres into a cylindrical shape and melt the surrounding resin to form a liquid-impermeable collar (4) sealing the metal into the sheet.

  4. Problem Solving Style, Creative Thinking, and Problem Solving Confidence

    ERIC Educational Resources Information Center

    Houtz, John C.; Selby, Edwin C.

    2009-01-01

    Forty-two undergraduate and graduate students completed VIEW: An Assessment of Problem Solving Style, the non-verbal Torrance Test Thinking Creatively with Pictures, and the Problem Solving Inventory (PSI). VIEW assesses individuals' orientation to change, manner of processing, and ways of deciding, while the Torrance test measures several…

  5. Measuring Family Problem Solving: The Family Problem Solving Diary.

    ERIC Educational Resources Information Center

    Kieren, Dianne K.

    The development and use of the family problem-solving diary are described. The diary is one of several indicators and measures of family problem-solving behavior. It provides a record of each person's perception of day-to-day family problems (what the problem concerns, what happened, who got involved, what those involved did, how the problem…

  6. Lamb wave scattering by a surface-breaking crack in a plate

    NASA Technical Reports Server (NTRS)

    Datta, S. K.; Al-Nassar, Y.; Shah, A. H.

    1991-01-01

    An NDE method based on finite-element representation and modal expansion has been developed for solving the scattering of Lamb waves in an elastic plate waveguide. This method is very powerful for handling discontinuities of arbitrary shape, weldments of different orientations, canted cracks, etc. The advantage of the method is that it can be used to study the scattering of Lamb waves in anisotropic elastic plates and in multilayered plates as well.

  7. Plate-mantle coupling from post-Pangea plate kinematics

    NASA Astrophysics Data System (ADS)

    Zahirovic, Sabin; Dietmar Müller, R.; Seton, Maria; Flament, Nicolas

    2015-04-01

    Convection in the Earth's mantle that involves plates at the surfaces gives rise to plate velocities that vary through time and depend on the balance of plate boundary forces, with the present-day providing a snapshot of this ongoing process. However, present-day plate velocities do not capture plate behaviour over geologically representative timeframes and thus cannot be used to evaluate factors limiting plate velocities. Previous studies investigated the effects of continental keels on plate speeds by either using the present-day snapshot or a limited number of reconstructed plate configurations, often leading to conflicting results. For example, an early assumption was that continental keels (especially cratons) were unlikely to impede fast plate motions because India's velocity approached ~20 cm/yr in the Eocene prior to the collision with Eurasia. We employ a modern plate reconstruction approach with evolving global topological plate boundaries for the post-Pangea timeframe (since 200 Ma) to evaluate factors controlling plate velocities. Plate boundary configurations and plate velocities are extracted from the open-source and cross-platform plate reconstruction package GPlates (www.gplates.org) at 1 Myr intervals. For each plate, at each timestep, the area of continental and cratonic lithosphere is calculated to evaluate the effect on plate velocities. Our results support that oceanic plates tend to be 2-3 times faster than plates with large portion of continental plate area, consistent with predictions of numerical models of mantle convection. The fastest plates (~8.5 cm/yr RMS) are dominated by oceanic plate area and high subducting portion of plate perimeter, while the slowest plates (~2.6-2.8 cm/yr RMS) are dominated by continental plate area and bounded by transforms and mid-oceanic ridge segments. Importantly, increasing cratonic fractions (both Proterozoic and Archean lithosphere) significantly impede plate velocities, suggesting that deep continental

  8. Nitrided Metallic Bipolar Plates

    SciTech Connect

    Brady, Michael P; Tortorelli, Peter F; Pihl, Josh A; Toops, Todd J; More, Karren Leslie; Meyer III, Harry M; Vitek, John Michael; Wang, Heli; Turner, John; Wilson, Mahlon; Garzon, Fernando; Rockward, Tommy; Connors, Dan; Rakowski, Jim; Gervasio, Don

    2008-01-01

    The objectives are: (1) Develop and optimize stainless steel alloys amenable to formation of a protective Cr-nitride surface by gas nitridation, at a sufficiently low cost to meet DOE targets and with sufficient ductility to permit manufacture by stamping. (2) Demonstrate capability of nitridation to yield high-quality stainless steel bipolar plates from thin stamped alloy foils (no significant stamped foil warping or embrittlement). (3) Demonstrate single-cell fuel cell performance of stamped and nitrided alloy foils equivalent to that of machined graphite plates of the same flow-field design ({approx}750-1,000 h, cyclic conditions, to include quantification of metal ion contamination of the membrane electrode assembly [MEA] and contact resistance increase attributable to the bipolar plates). (4) Demonstrate potential for adoption in automotive fuel cell stacks. Thin stamped metallic bipolar plates offer the potential for (1) significantly lower cost than currently-used machined graphite bipolar plates, (2) reduced weight/volume, and (3) better performance and amenability to high volume manufacture than developmental polymer/carbon fiber and graphite composite bipolar plates. However, most metals exhibit inadequate corrosion resistance in proton exchange membrane fuel cell (PEMFC) environments. This behavior leads to high electrical resistance due to the formation of surface oxides and/or contamination of the MEA by metallic ions, both of which can significantly degrade fuel cell performance. Metal nitrides offer electrical conductivities up to an order of magnitude greater than that of graphite and are highly corrosion resistant. Unfortunately, most conventional coating methods (for metal nitrides) are too expensive for PEMFC stack commercialization or tend to leave pinhole defects, which result in accelerated local corrosion and unacceptable performance.

  9. Reduced Plating Ignitron

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A (Inventor); Pearson, J Boise (Inventor)

    2014-01-01

    An ignitron apparatus has an airtight tubular housing having a first sealed end and a second sealed end. An anode is connected at the first sealed end, projecting into the housing, and a recess at the second sealed and forms a well which contains a quantity of liquid gallium or gallium alloy making up the cathode. An ignitor projects through the liquid metal and into the housing. The inner surface of the housing includes at least one plating-reduction structure to prevent electrical shorting of the apparatus caused by plating of the liquid metal.

  10. License plate detection algorithm

    NASA Astrophysics Data System (ADS)

    Broitman, Michael; Klopovsky, Yuri; Silinskis, Normunds

    2013-12-01

    A novel algorithm for vehicle license plates localization is proposed. The algorithm is based on pixel intensity transition gradient analysis. Near to 2500 natural-scene gray-level vehicle images of different backgrounds and ambient illumination was tested. The best set of algorithm's parameters produces detection rate up to 0.94. Taking into account abnormal camera location during our tests and therefore geometrical distortion and troubles from trees this result could be considered as passable. Correlation between source data, such as license Plate dimensions and texture, cameras location and others, and parameters of algorithm were also defined.

  11. Plating under reduced pressure

    SciTech Connect

    Dini, J.W.; Beat, T.G.; Cowden, W.C. ); Ryan, L.E.; Hewitt, W.B. )

    1992-06-01

    Plating under reduced pressure was evaluated for both electroless nickel and electrodeposited copper systems. The objective was to reduce pitting of these coatings thereby further enhancing their usage for diamond turning applications. Cursory experiments with electroless nickel showed reduced porosity when deposition was done at around 500 torr. Detailed experiments with electrodeposited copper at around 100 torr provided similar results. Scanning tunneling microscopy was effectively used to show the improvement in the copper deposits plated under reduced pressure. Benefits included reduced surface roughness and finer and denser grain structure.

  12. NICKEL PLATING PROCESS

    DOEpatents

    Hoover, T.B.; Zava, T.E.

    1959-05-12

    A simplified process is presented for plating nickel by the vapor decomposition of nickel carbonyl. In a preferred form of the invention a solid surface is nickel plated by subjecting the surface to contact with a mixture containing by volume approximately 20% nickel carbonyl vapor, 2% hydrogen sulfide and .l% water vapor or 1% oxygen and the remainder carbon dioxide at room temperature until the desired thickness of nickel is obtained. The advantage of this composition over others is that the normally explosive nickel carbonyl is greatly stabilized.

  13. PCM Composite Cold Plate.

    DTIC Science & Technology

    1996-04-01

    packaging design for phase change materials (PCMs) used in thermal management. To control expansion stress, conventional PCM heat sinks have strong encapsulation that weighs more than the PCM they contain. The objective of this work is to develop PCM heat sinks configured as thin sandwich plates, in which the mass of the encapsulation is a small fraction of the PCM mass. The design is based on a lightweight carbon fiber core that has suitable mechanical, thermal, and capillary properties. PCM composite plates were fabricated with dimensions 15x15x0.6 cm3 and with a

  14. Bone healing in rabbits after compression osteosynthesis, studied by Tc-99m(Sn)polyphosphate scintimetry and autoradiography.

    PubMed

    Greiff, J

    1981-08-01

    The purpose of the present study was to determine the scintimetric time course (STC) for Tc-99m(Sn) polyphosphate in rabbit tibias after various osteosynthetic procedures, and to correlate the findings with those from serial radiographs and with autoradiographic and histologic evaluation of the bone. The STC was similar for all treatment groups, with a peak value within the second week after surgery. Significantly different levels of the STC were found after subperiosteal exploration, plate insertion, osteotomy and compression plating, or osteotomy and medullary nailing. The radiological, autoradiographic, and histological findings revealed that Tc-99m scintimetry monitors callus formation. The STC thus appears to be a valuable tool for the quantitative study of bone healing.

  15. Complications of appendicular fracture repair in cats and small dogs using locking compression plates.

    PubMed

    Vallefuoco, Rosario; Le Pommellet, Helene; Savin, Audrey; Decambron, Adeline; Manassero, Mathieu; Viateau, Véronique; Gauthier, Olivier; Fayolle, Pascal

    2016-01-01

    Our objectives were: 1) to review the complications associated with stabilization of appendicular fractures in cats and small dogs using locking compression plates (LCP), and 2) to identify factors that could influence fixation construct stability. Retrospective clinical study. Medical and radiographic records of cats and small dogs with appendicular fractures treated with LCP were reviewed. Only cases with adequate follow-up to document clinical union and cases for which complications appeared before the clinical union were included. Complications were classified as implant-related complications or other complications. Cases with implant-related complications were compared to cases with non-implant-related complications for differences in signalment (species, age, body weight, multiple fractures), fracture location and type (fractured bone, fracture localization, closed or open fracture), reduction method (open reduction and internal fixation [ORIF] or minimally invasive plate osteosynthesis [MIPO]) and fixation evaluations (implant size, plate-bridging ratio, plate span ratio, working length, plate screw density, number of screws and cortices engaged per plate and per main fragment, ratio between screw and bone diameter at the narrowest aspect of the bone, and presence of ancillary fixation). Seventy-five fractures from 63 cats (64 fractures) and 10 dogs (11 fractures) met the inclusion criteria. Eight humeral, 13 radio-ulnar, 26 femoral, and 28 tibio-fibular fractures were treated. Primary repair of the fracture was performed using 2.0 mm and 2.4 mm LCP in 22 and 53 fractures, respectively. Overall and implant-related complications were encountered in 13 and seven of 75 fractures, respectively. Fixation failure was not significantly associated with any aforementioned factor considered in this study, and in particular, there was no significant difference in the occurrence of fixation failure between fractures stabilized with two, or more than two, bicortical

  16. Intermittent Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Silver, P. G.; Behn, M. D.

    2006-12-01

    Intermittent Plate Tectonics A basic premise of Earth Science is that plate tectonics has been continuously operating since it began early in Earth's history. Yet, plate-tectonic theory itself, specifically the collisional phase of the Wilson Cycle, constitutes a process that is capable of stopping all plate motion. The plausibility of a plate-tectonic hiatus is most easily illustrated by considering the expected future of the present-day plate-tectonic configuration. Since the opening of the Atlantic at ~200 ma, the area of the Atlantic basin has been growing at the expense of the Pacific. If this trend continues, relative plate motion models predict that in ~350 my, the Pacific Ocean basin will effectively close leading to widespread continent-continent collisions. Since a continent-continent collision represents the termination of subduction locally, the accumulated effect of all collisions is to stop subduction globally. In this scenario, ridges would then stop spreading and young oceanic lithosphere would cool, reaching a steady-state thickness of 100 km in about 80 my, based on the properties of oceanic lithosphere today. This would constitute the stoppage of plate tectonics. The presumption that plate tectonics never stops in the face of continental collisions is equivalent to requiring that subduction flux is approximately constant through time, such that subduction initiation roughly balances subduction termination. Such a balance then raises several questions about the subduction initiation process. When and how does subduction initiate? Is there a detectible relationship between subduction cessation and subduction initiation? We can gain some guidance into these questions by examining the plate motion history over the last 200 my. Subduction initiation has occurred over the last 80 my in three intra- oceanic subduction zones: Aleutians, Marianas-Izu-Bonin and Tonga-Kermadec in the Pacific basin. In these cases, however, subduction initiation would not

  17. Shear buckling of specially orthotropic plates with centrally located cutouts

    NASA Technical Reports Server (NTRS)

    Owen, Vicki L.; Klang, Eric C.

    1990-01-01

    There is significant industry demand for a method of analyzing the shear buckling of composite plates with cutouts. This method should be able to easily accommodate frequent changes in model design; inflexibility is the major drawback to current finite element methods. The approach taken here is broken into two problems, prebuckling and buckling. To solve for the prebuckling stresses, complex variable equations are used in conjunction with boundary collocation. The least squares approach is utilized to improve the accuracy of the results. The buckling problem is solved using the Ritz method. A product of the Ritz method is a complicated integral equation which is solved using numerical integration. To date, the aforementioned method of determining the prebuckling stresses was verified against infinite plate theory and finite elements.

  18. Shear buckling of specially orthotropic plates with centrally located cutouts

    NASA Technical Reports Server (NTRS)

    Klang, Eric C.

    1991-01-01

    There is significant industry demand for a method of analyzing the shear buckling of composite plates with cutouts. This method should be able to easily accommodate frequent changes in model design; inflexibility being the major drawback to current finite element methods. The approach taken here is broken into two problems, prebuckling and buckling. To solve for the prebuckling stresses, complex variable equations are used in conjunction with boundary collocation. The least squares approach is utilized to improve the accuracy of the results. The buckling problem is solved using the Ritz method. A product of the Ritz method is a complicated integral equation which is solved using numerical integration. To date, the aforementioned method of determining the prebuckling stresses was verified against infinite plate theory and finite elements. Recent efforts have focused on reducing run time, improving accuracy and adding more boundary condition choices.

  19. Nuclear reactor alignment plate configuration

    SciTech Connect

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  20. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1984-01-01

    Presents a problem-solving activity in which students first guess and then check their answer. Also presents an activity to help students develop skill in understanding the question in a problem and a suggestion to help develop a classroom climate conducive to problem-solving. (JN)

  1. Problem Solving, Scaffolding and Learning

    ERIC Educational Resources Information Center

    Lin, Shih-Yin

    2012-01-01

    Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…

  2. Learning Impasses in Problem Solving

    NASA Technical Reports Server (NTRS)

    Hodgson, J. P. E.

    1992-01-01

    Problem Solving systems customarily use backtracking to deal with obstacles that they encounter in the course of trying to solve a problem. This paper outlines an approach in which the possible obstacles are investigated prior to the search for a solution. This provides a solution strategy that avoids backtracking.

  3. Problem Solving: Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G., Ed.; Schaaf, Oscar

    1986-01-01

    Describes: (1) a computation-oriented problem with procedures and some questions that might be asked of students; (2) four ways to help students develop positive problem-solving attitudes; (3) a strategy game; (4) a multiplication problem; and (5) several questions that will help students develop problem-solving skills. (JN)

  4. Creative Thinking and Problem Solving.

    ERIC Educational Resources Information Center

    Lacy, Grace

    The booklet considers the nature of creativity in children and examines classroom implications. Among the topics addressed are the following: theories about creativity; research; developments in brain research; the creative process; creative problem solving; the Structure of Intellect Problem Solving (SIPS) model; a rationale for creativity in the…

  5. Difficulties in Genetics Problem Solving.

    ERIC Educational Resources Information Center

    Tolman, Richard R.

    1982-01-01

    Examined problem-solving strategies of 30 high school students as they solved genetics problems. Proposes a new sequence of teaching genetics based on results: meiosis, sex chromosomes, sex determination, sex-linked traits, monohybrid and dihybrid crosses (humans), codominance (humans), and Mendel's pea experiments. (JN)

  6. Creative Thinking and Problem Solving.

    ERIC Educational Resources Information Center

    Lacy, Grace

    The booklet considers the nature of creativity in children and examines classroom implications. Among the topics addressed are the following: theories about creativity; research; developments in brain research; the creative process; creative problem solving; the Structure of Intellect Problem Solving (SIPS) model; a rationale for creativity in the…

  7. Multiple Ways to Solve Proportions

    ERIC Educational Resources Information Center

    Ercole, Leslie K.; Frantz, Marny; Ashline, George

    2011-01-01

    When solving problems involving proportions, students may intuitively draw on strategies that connect to their understanding of fractions, decimals, and percents. These two statements--"Instruction in solving proportions should include methods that have a strong intuitive basis" and "Teachers should begin instruction with more intuitive…

  8. A Personal Problem Solving Inventory.

    ERIC Educational Resources Information Center

    Heppner, P. Paul; Petersen, Chris H.

    Few studies have explicitly attended to the personal problem-solving process within the counseling literature, perhaps due in part to the dearth of relevant assessment instruments. To examine the dimensions underlying the applied problem-solving process, an exploratory factor analysis was conducted using data collected from four samples of college…

  9. Multiple Ways to Solve Proportions

    ERIC Educational Resources Information Center

    Ercole, Leslie K.; Frantz, Marny; Ashline, George

    2011-01-01

    When solving problems involving proportions, students may intuitively draw on strategies that connect to their understanding of fractions, decimals, and percents. These two statements--"Instruction in solving proportions should include methods that have a strong intuitive basis" and "Teachers should begin instruction with more intuitive…

  10. Difficulties in Genetics Problem Solving.

    ERIC Educational Resources Information Center

    Tolman, Richard R.

    1982-01-01

    Examined problem-solving strategies of 30 high school students as they solved genetics problems. Proposes a new sequence of teaching genetics based on results: meiosis, sex chromosomes, sex determination, sex-linked traits, monohybrid and dihybrid crosses (humans), codominance (humans), and Mendel's pea experiments. (JN)

  11. Problem Solving, Scaffolding and Learning

    ERIC Educational Resources Information Center

    Lin, Shih-Yin

    2012-01-01

    Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…

  12. The Future Problem Solving Program.

    ERIC Educational Resources Information Center

    Crabbe, Anne B.

    1989-01-01

    Describes the Future Problem Solving Program, in which students from the U.S. and around the world are tackling some complex challenges facing society, ranging from acid rain to terrorism. The program uses a creative problem solving process developed for business and industry. A sixth-grade toxic waste cleanup project illustrates the process.…

  13. Crime Solving Techniques: Training Bulletin.

    ERIC Educational Resources Information Center

    Sands, Jack M.

    The document is a training bulletin for criminal investigators, explaining the use of probability, logic, lateral thinking, group problem solving, and psychological profiles as methods of solving crimes. One chpater of several pages is devoted to each of the five methods. The use of each method is explained; problems are presented for the user to…

  14. Technological Problem Solving: A Proposal.

    ERIC Educational Resources Information Center

    Waetjen, Walter B.

    Examination of newer technology education materials reveals two recurring themes: one relates to curriculum content, familiarizing students with technology, and another to a technique of classroom instruction, i.e., problem solving. A problem-solving framework for technical education has the following components: (1) define the problem; (2)…

  15. The Plate Tectonics Project

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  16. The Plate Tectonics Project

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  17. INL HIP Plate Fabrication

    SciTech Connect

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  18. Unitary plate electrode

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor); Clough, Thomas J. (Inventor); Josefowicz, Jack Y. (Inventor); Sibert, John W. (Inventor)

    1985-01-01

    The unitary electrode (10) comprises a porous sheet (12) of fiberglass the strands (14) of which contain a coating (16) of conductive tin oxide. The lower portion of the sheet contains a layer (18) of resin and the upper layer (20) contains lead dioxide forming a positive active electrode on an electrolyte-impervious layer. The strands (14) form a continuous conduction path through both layers (16, 18). Tin oxide is prevented from reduction by coating the surface of the plate facing the negative electrode with a conductive, impervious layer resistant to reduction such as a thin film (130) of lead or graphite filled resin adhered to the plate with a layer (31) of conductive adhesive. The plate (10) can be formed by casting a molten resin from kettle (60) onto a sheet of glass wool (56) overlying a sheet of lead foil and then applying positive active paste from hopper (64) into the upper layer (68). The plate can also be formed by passing an assembly of a sheet ( 80) of resin, a sheet (86) of sintered glass and a sheet (90) of lead between the nip (92) of heated rollers (93, 95) and then filling lead oxide into the pores (116) of the upper layer (118).

  19. Mono- versus polyaxial locking plates in distal femur fractures: a prospective randomized multicentre clinical trial.

    PubMed

    Hanschen, Marc; Aschenbrenner, Ina M; Fehske, Kai; Kirchhoff, Sonja; Keil, Leonhard; Holzapfel, Boris M; Winkler, Sebastian; Fuechtmeier, Bernd; Neugebauer, Rainer; Luehrs, Sven; Liener, Ulrich; Biberthaler, Peter

    2014-04-01

    Treatment of complex fractures of the distal femur utilizing monoaxial locking plates (e.g. Less Invasive Stabilisation System, LISS®, Synthes) is considered to be superior to conventional plating systems. Due to the limitation that the thread forces the screw into pre-determined positions, modifications have been made to allow screw positioning within a range of 30° (Non Contact Bridging, NCB®-DF, Zimmer). For the first time, this multicenter prospective randomized clinical trial (RCT) investigates the outcome of LISS® vs. NCB®-DF treatment following complex fractures of the distal femur. Since June 2008, 27 patients with a fracture of the distal femur (AO ASIF 33-A-C and periprosthetic fractures) were enrolled in this study by four university trauma centres in southern Germany. Clinical (e.g. range of motion, Oxford knee score, Tegner score) and radiological (e.g. axis deviation, secondary loss of realignment) follow-ups were conducted one and six weeks, as well as three, six, and 12 months after the operation. This study comprises data of 27 patients (8 male, 19 female; 15 NCB®-DF, 12 LISS®). Polyaxial osteosynthesis using the NCB® system tended to result in better functional knee scores and a higher range of motion. Interestingly, fracture union tended to be more rapid using the polyaxial plating system. We present the analysis of a multicenter prospective RCT to compare the monoaxial LISS® vs. the polyaxial NCB®-DF treatment following complex fractures of the distal femur. NCB®-DF treatment tended to result in better functional and radiological outcomes than LISS® treatment. Level I.

  20. MHD free convective flow past a vertical plate

    NASA Astrophysics Data System (ADS)

    Raihan Mohamad Asimoni, Nor; Farahain Mohammad, Nurul; Kasim, Abdul Rahman Mohd; Shafie, Sharidan

    2017-09-01

    The free convective flow in incompressible viscous fluid past a vertical plate is studied under the presence of magnetic field. The flow is considered along the vertical plate at x – axis in upward direction and y – axis is taken normal to it. The governing equations are written in vector form. Afterwards, the equations are solved numerically using finite element method with automated solution techniques. Later, the effects of magnetic field strength to the velocity and temperature of the fluid are obtained. It is found that for heated plate, the velocity and the temperature of the fluid decreases when the magnetic field strength increases. Meanwhile for cooled plate, the velocity decreases but the temperature increases when the magnetic field strength increases.

  1. Buckling of Fiber Reinforced Composite Plates with Nanofiber Reinforced Matrices

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Murthy, Pappu L. N.

    2010-01-01

    Anisotropic composite plates were evaluated with nanofiber reinforced matrices (NFRM). The nanofiber reinforcement volumes ratio in the matrix was 0.01. The plate dimensions were 20 by 10 by 1.0 in. (508 by 254 by 25.4 mm). Seven different loading condition cases were evaluated: three for uniaxial loading, three for pairs of combined loading, and one with three combined loadings. The anisotropy arose from the unidirectional plates having been at 30 from the structural axis. The anisotropy had a full 6 by 6 rigidities matrix which were satisfied and solved by a Galerkin buckling algorithm. The buckling results showed that the NFRM plates buckled at about twice those with conventional matrix.

  2. Pulsating Star Mystery Solved

    NASA Astrophysics Data System (ADS)

    2010-11-01

    By discovering the first double star where a pulsating Cepheid variable and another star pass in front of one another, an international team of astronomers has solved a decades-old mystery. The rare alignment of the orbits of the two stars in the double star system has allowed a measurement of the Cepheid mass with unprecedented accuracy. Up to now astronomers had two incompatible theoretical predictions of Cepheid masses. The new result shows that the prediction from stellar pulsation theory is spot on, while the prediction from stellar evolution theory is at odds with the new observations. The new results, from a team led by Grzegorz Pietrzyński (Universidad de Concepción, Chile, Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), appear in the 25 November 2010 edition of the journal Nature. Grzegorz Pietrzyński introduces this remarkable result: "By using the HARPS instrument on the 3.6-metre telescope at ESO's La Silla Observatory in Chile, along with other telescopes, we have measured the mass of a Cepheid with an accuracy far greater than any earlier estimates. This new result allows us to immediately see which of the two competing theories predicting the masses of Cepheids is correct." Classical Cepheid Variables, usually called just Cepheids, are unstable stars that are larger and much brighter than the Sun [1]. They expand and contract in a regular way, taking anything from a few days to months to complete the cycle. The time taken to brighten and grow fainter again is longer for stars that are more luminous and shorter for the dimmer ones. This remarkably precise relationship makes the study of Cepheids one of the most effective ways to measure the distances to nearby galaxies and from there to map out the scale of the whole Universe [2]. Unfortunately, despite their importance, Cepheids are not fully understood. Predictions of their masses derived from the theory of pulsating stars are 20-30% less than predictions from the theory of the

  3. Finite element study of plate buckling induced by spatial temperature gradients

    NASA Technical Reports Server (NTRS)

    Thornton, Earl A.; Kolenski, James D.; Marino, Robert P.

    1993-01-01

    Finite element analyses of thermal buckling of thin metallic plates with prescribed spatial temperature distributions are described. Thermally induced compressive membrane stresses and transverse plate displacement imperfections initiate plates buckling. A finite element formulation based on von Karman plate theory is presented. The resulting nonlinear equations are solved for incremental temperature increases by Newton-Raphson iteration. The computational method is used to investigate the buckling response of rectangular plates with steady and unsteady spatially varying temperature distributions. The role of initial plate imperfections and temperature distributions on the nonlinear response of plate displacements and stresses is described. The relatively high levels of stress induced by spatial temperature gradients should be considered carefully in the postbuckling design of panels for aerospace vehicles subjected to combined mechanical and thermal loads.

  4. Finite element study of plate buckling induced by spatial temperature gradients

    SciTech Connect

    Thornton, E.A.; Kolenski, J.D.; Marino, R.P.

    1993-01-01

    Finite element analyses of thermal buckling of thin metallic plates with prescribed spatial temperature distributions are described. Thermally induced compressive membrane stresses and transverse plate displacement imperfections initiate plates buckling. A finite element formulation based on von Karman plate theory is presented. The resulting nonlinear equations are solved for incremental temperature increases by Newton-Raphson iteration. The computational method is used to investigate the buckling response of rectangular plates with steady and unsteady spatially varying temperature distributions. The role of initial plate imperfections and temperature distributions on the nonlinear response of plate displacements and stresses is described. The relatively high levels of stress induced by spatial temperature gradients should be considered carefully in the postbuckling design of panels for aerospace vehicles subjected to combined mechanical and thermal loads. 31 refs.

  5. Thermal buckling analysis of composite laminated plates by the finite-element method

    SciTech Connect

    Chen, Lienwen; Chen, Leiyi )

    1989-01-01

    The thermal buckling behavior of laminated plates subjected to a nonuniform temperature field is investigated by the finite-element method. Being nonuniformly distributed over the plate, the thermal stresses should be determined before solving the buckling problem. The stiffness matrix, geometry matrix, and load vector are derived based on the principle of minimum potential energy. The assumed displacement state over the middle surface of the plate element is expressed as the products of one-dimensional, first-order Hermite polynomials. Numerical results show that the thermal buckling strength of a clamped plate is higher than that of a simply supported plate, and the influence of lamination angle, plate aspect ratio, and modulus ratio on thermal buckling are found to be significant for laminated plates. 21 refs.

  6. Minimally invasive plating versus either open reduction and plate fixation or intramedullary nailing of humeral shaft fractures: a systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Hohmann, Erik; Glatt, Vaida; Tetsworth, Kevin

    2016-10-01

    The purpose of this study was to perform a meta-analysis comparing the clinical outcomes and complications between anterior humeral minimally invasive plate osteosynthesis (MIPO) and the 2 standard techniques, either open reduction and plating or humeral nailing. We performed a systematic review of Medline, Embase, Scopus, and Google Scholar to identify relevant randomized controlled trials in the English- and German-language literature. Eligibility criteria included randomized controlled trials comparing at least 1 surgical intervention with MIPO and reporting the primary clinical outcome using a validated functional scoring system and description of complications. Publication bias was assessed by funnel plot, and the risk of bias was established using the Cochrane Collaboration's Risk of Bias Tool. Heterogeneity was assessed using χ(2) and I(2) statistics. Eight prospective randomized studies (N = 376) met the eligibility criteria and were included in the analysis. The pooled estimate for clinical outcome showed that MIPO resulted in a significantly better outcome (standardized mean difference, 0.366; 95% confidence interval, 0.16 to 0.571; P = .0001; I(2) = 61%). The pooled estimate for all complications showed that the open reduction-internal fixation/nail group had a significantly higher complication rate (odds ratio, 0.507; 95% confidence interval, 0.285 to 0.905; P = .021; I(2) = 97%). Current evidence indicates the MIPO approach has better clinical outcomes with a lower rate of complications compared with alternative surgical techniques. However, the results of this meta-analysis are limited by problems inherent in the primary studies, including poor reporting of randomization protocols, as well as possible attrition bias and reporting bias, of the primary studies. Future publications may therefore change the trend of the pooled estimate in either direction. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees

  7. Shear buckling of specially orthotropic plates with centrally located cutouts

    NASA Technical Reports Server (NTRS)

    Klang, Eric C.; Owen, Vicki

    1989-01-01

    The shear loading of a composite rectangular plate with a centrally located circular cutout was analyzed in order to predict the buckling load of the plate. The first step in this analysis is to calculare the in-plane stress distribution of the plate prior to buckling. This problem can be solved using finite element methods, but a quicker and more cost efficient method is desired. The method chosen to determine the pre-buckling stresses is that of boundary collocation using complex variables. The real valued force functions are written in terms of two complex valued functions, each of which is a function of a different complex variable. The solution of the generalized biharmonic function is a superposition of functions of these two complex variables. For this analysis, the force functions are represented with a Laurent series. The constants in these series are found using boundary collocation. Two force equations for complex variables are satisfied over the plate boundaries to obtain these constants. The stresses in the plate are then known for any particular locations on the plate given the applied shear on the edges of the plate.

  8. Regenerate metal-plating baths to cut waste and save

    SciTech Connect

    1995-03-01

    During electrode-based metal plating of equipment components, the formation of an electrical field causes metal deposits to be thicker at edges and seams, and thinner on flat surfaces. And, electrode-based methods consume large amounts of energy. Electroless-nickel (EN) -- or autocatalytic -- plating systems were pioneered in the 1940s to solve these problems. EN plating produces a more uniform coating, irrespective of the complexity of the part, and it consumes less electricity, since to electric current is required during plating. Plating in an EN system results from a chemical reaction between nickel in the bath and the substrate of the equipment component. The downside of electroless plating, however, is the limited life of the nickel bath, and the large volume of metal waste produced by bath disposal. Ionsep Corp. (Wilmington, Del.) has developed an electrodialytic system that continuously reforms the EN plating baths, to give them longer life. Its patented system has been successfully laboratory tested in a 1-ft{sup 2} cell, and the firm recently won a $250,000 grant from the US Dept. of Energy (Washington, D.C.) and Environmental Protection Agency (Washington, D.C.), to design and engineer a commercial-scale version of the system.

  9. What Are Growth Plate Injuries?

    MedlinePlus

    ... for growth plate injuries are:  Falling down  Competitive sports (like football)  Recreational activities. Other reasons for growth plate injuries are:  Child abuse  Injury from extreme cold (for example, frostbite)  Radiation (used to treat ...

  10. Renewable liquid reflecting zone plate

    DOEpatents

    Toor, Arthur; Ryutov, Dmitri D.

    2003-12-09

    A renewable liquid reflecting zone plate. Electrodes are operatively connected to a dielectric liquid in a circular or other arrangement to produce a reflecting zone plate. A system for renewing the liquid uses a penetrable substrate.

  11. Managing Vancouver B1 fractures by cerclage system compared to locking plate fixation - a biomechanical study.

    PubMed

    Gordon, Katharina; Winkler, Martin; Hofstädter, Thomas; Dorn, Ulrich; Augat, Peter

    2016-06-01

    With increasing life expectancy and number of total hip arthroplasties (THA), the need for revision surgery is increasing too. The aim of this study was to evaluate the optimal fracture treatment for a clinically characteristic Vancouver B1 fracture. We hypothesized that locking plate fixation has biomechanical advantages over fixation with a simple cerclage system. Additionally, we hypothesized that removal of the primary short stem and revision with a long stem would show biomechanical benefit. The biomechanical testing was performed with a static and a dynamic loading protocol on twenty 4th Generation sawbones. These were divided into four different groups (n = 5 each). In group 1, the primary uncemented short stem remained and the fracture was stabilized with a locking plate. In group 2, the primary stem remained and the fracture was stabilized with a cerclage stabilization system containing two stabilizers and four cerclages. In group 3, the primary stem was replaced by an uncemented long revision stem and the fracture was fixed with a locking plate. In group 4, the short stem was replaced by a long revision stem and the fracture was fixed with the cerclage system. Static testing revealed that the revision of the short stem with the long stem caused a 2-fold (p < 0.001, ANOVA) increase of axial stiffness. In dynamic testing, the number of cycles to failure was 4 times (p < 0.001, ANOVA) higher with the long revision stem. Compared to locked plating cerclage wiring demonstrated a 26% more cycles to failure (p = 0.031, ANOVA). The load to failure was 91% larger (p < 0.001, ANOVA) with the long revision stem and 11% smaller with locked plating (p < 0.001, ANOVA). In conclusion, the present biomechanical study indicates that periprosthetic Vancouver B1 fractures can be sufficiently fixed by simple cerclage systems. Revision with a long replacement stem provides a superior mechanical stability regardless of type of osteosynthesis fixation and is therefore a viable

  12. Long-term results after treatment of pertrochanteric femoral fractures with percutaneous compression plate (PCCP).

    PubMed

    Crespo, E; Gómez, S; Palacios, V; Galvez, J; Tenías, J M; Cano, I; Peñuela, R; Arcas, A; Crespo, R

    2016-08-01

    This study sought to evaluate the long-term osteosynthesis results for AO/OTA 31.A1-A2 pertrochanteric fractures treated with the percutaneous compression plate (PCCP). This investigation was a retrospective observational descriptive study of 335 patients, with a minimum follow-up of 2 years and a maximum follow-up of 8 years (2004-2011). The average post-operative hospital stay was 6.2 days, and the average decrease in haemoglobin levels after the intervention was 2.7 mg/dL, with transfusion required for one-third of the patients. Complications related to the implant were observed in 4.2 % of patients; the most notable complication was cut-out (2.4 % of patients), and 3 cases involved pseudarthrosis with breakage of the implant (0.9 % of patients). From the results obtained in this study and an analysis of previously published work, we believe that the PCCP may be the implant of choice for AO/OTA 31.A1-A2 fractures.

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

    NASA Astrophysics Data System (ADS)

    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

  14. Microchannel plate streak camera

    DOEpatents

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  15. North American plate dynamics

    NASA Technical Reports Server (NTRS)

    Richardson, Randall M.; Reding, Lynn M.

    1991-01-01

    Deformation within the North American plate in response to various tectonic processes is modeled using an elastic finite element analysis. The tectonic processes considered in the modeling include ridge forces associated with the normal thermal evolution of oceanic lithosphere, shear and normal stresses transmitted across transforms, normal stresses transmitted across convergent boundaries, stresses due to horizontal density contrasts within the continent, and shear tractions applied along the base of the plate. Model stresses are calculated with respect to a lithostatic reference stress state. Shear stresses transmitted across transform boundaries along the San Andreas and Caribbean are small, of the order of 5-10 MPa. Also, compressive stresses of the order of 5-10 MPa transmitted across the major transforms improve the fit to the data. Compressive stresses across convergent margins along the Aleutians and the Middle America trench are important.

  16. Bipolar battery plate

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1985-01-01

    A liquid-impermeable plate (10) having throughplate conductivity with essentially zero resistance comprises an insulator sheet (12) having a series of spaced perforations (14) each of which contains a metal element (16) sealingly received into the perforation (14). A low-cost plate can readily be manufactured by punching a thermoplastic sheet (40) such as polypropylene with a punching tool (52), filling the apertures with lead spheres (63) having a diameter smaller than the holes (50) but larger than the thickness of the sheet, sweeping excess spheres (62) off the sheet with a doctor blade (60) and then pressing a heated platen (74) onto the sheet to swage the spheres into a cylindrical shape and melt the surrounding resin to form a liquid-impermeable collar (4) sealing the metal into the sheet.

  17. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1984-09-28

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (uv to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 keV x-rays.

  18. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1989-03-21

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras is disclosed. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1,000 KeV x-rays. 3 figs.

  19. Mechanisms in Thermal Mechanical Forming of Plates.

    DTIC Science & Technology

    1987-05-01

    specific locations within the plate is discussed, and recommendations for further research are made. Keywords: Metal plates; Ship plates; Material forming; Thermomechanics; Edge effect ; Laser line heating.

  20. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1985-01-01

    The focus is on the problem-solving strategy of find a pattern, with a problem explored to illustrate how to use the strategy. Other tips concern classroom climate, checking skills, research, and type of problems. (MNS)

  1. Problem Solving Tips for Teachers.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.

    1984-01-01

    The strategy of making a table is highlighted. A problem is given and the procedure for setting up and using the table are explained. Other suggestions for teaching problem solving are also included. (MNS)

  2. Modeling Applied to Problem Solving

    NASA Astrophysics Data System (ADS)

    Pawl, Andrew; Barrantes, Analia; Pritchard, David E.

    2009-10-01

    Modeling Applied to Problem Solving (MAPS) is a pedagogy that helps students transfer instruction to problem solving in an expert-like manner. Declarative and Procedural syllabus content is organized and learned (not discovered) as a hierarchy of General Models. Students solve problems using an explicit Problem Modeling Rubric that begins with System, Interactions and Model (S.I.M.). System and Interactions are emphasized as the key to a strategic description of the system and the identification of the appropriate General Model to apply to the problem. We have employed the pedagogy in a three-week review course for students who received a D in mechanics. The course was assessed by a final exam retest as well as pre and post C-LASS surveys, yielding a one standard deviation improvement in the students' ability to solve final exam problems and a statistically significant positive shift in 7 of the 9 categories in the C-LASS.

  3. Student Problem-Solving Behaviors

    NASA Astrophysics Data System (ADS)

    Harper, Kathleen A.

    2006-04-01

    Kathy Harper is director of undergraduate curriculum development in the physics department at The Ohio State University. She has been involved in local and national workshops for in-service teachers and conducts research in student problem solving.

  4. The Problems of Problem Solving

    ERIC Educational Resources Information Center

    Watson, Charles E.

    1976-01-01

    Discusses some common pitfalls in problem-solving and outlines three basic approaches to successfully identifying problems and their causes. (Available from Business Horizons, School of Business, Indiana University, Bloomington, Indiana 47401; $2.50, single copy) (Author/JG)

  5. Problem Solving with General Semantics.

    ERIC Educational Resources Information Center

    Hewson, David

    1996-01-01

    Discusses how to use general semantics formulations to improve problem solving at home or at work--methods come from the areas of artificial intelligence/computer science, engineering, operations research, and psychology. (PA)

  6. The Plate Overlap Technique.

    DTIC Science & Technology

    1978-07-31

    INTRODUCTION 1 II. NOTATION 2 III. THE GNOMONIC PROJECTION 4 IV . THE PLATE OVERLAP TECHNIQUE 6 A. MOTIVATION 6 B. FORNULATION 9 C. ON STATISTICAL RIGOR 14 D...and new hardware. Since this aim was clearly recognized long ago, wherever possible in earlier documents or software development flexibility was...reader should see 1, 2, and 3. The procedures one should use to update stellar positions are discussed in 4 with applica- tions to the SAOC in 5. Non

  7. Plated wire memory subsystem

    NASA Technical Reports Server (NTRS)

    Reynolds, L.; Tweed, H.

    1972-01-01

    The work performed entailed the design, development, construction and testing of a 4000 word by 18 bit random access, NDRO plated wire memory for use in conjunction with a spacecraft imput/output unit and central processing unit. The primary design parameters, in order of importance, were high reliability, low power, volume and weight. A single memory unit, referred to as a qualification model, was delivered.

  8. Elastic plate spallation

    NASA Technical Reports Server (NTRS)

    Oline, L.; Medaglia, J.

    1972-01-01

    The dynamic finite element method was used to investigate elastic stress waves in a plate. Strain displacement and stress strain relations are discussed along with the stiffness and mass matrix. The results of studying point load, and distributed load over small, intermediate, and large radii are reported. The derivation of finite element matrices, and the derivation of lumped and consistent matrices for one dimensional problems with Laplace transfer solutions are included. The computer program JMMSPALL is also included.

  9. Smov FOS Plate Scale

    NASA Astrophysics Data System (ADS)

    Kinney, Anne

    1994-01-01

    The goal is to measure the precise plate scale and orientation. This will be acheived by performing a raster step and dwell sequence in the 4.3 arcsec aperture. The edges of the aperture should be avoided to prevent vignetting effects. An aperture map is required at each step of the dwell sequence. This test has to be conducted for both the RED and BLUE detectors. We will also determine the offset between the two detectors.

  10. Electronic Equipment Cold Plates

    DTIC Science & Technology

    1976-04-01

    equations for such a flow regiae. For laainar flow and Moderate teaperature differwwe« between the well «nd coolant, a aodifled Sieder -Tate...con- figuration. The heat-transfer coefficients, therefore, were determined by using both the Sieder -Tate and McAdams equations and the coaputed...values used In the analytical predictions. As with th* previous cold Plates, the Sieder -Tate equation gave too low of values for the heat- transfer

  11. Martian plate tectonics

    NASA Astrophysics Data System (ADS)

    Sleep, N. H.

    1994-03-01

    The northern lowlands of Mars have been produced by plate tectonics. Preexisting old thick highland crust was subducted, while seafloor spreading produced thin lowland crust during late Noachian and Early Hesperian time. In the preferred reconstruction, a breakup margin extended north of Cimmeria Terra between Daedalia Planum and Isidis Planitia where the highland-lowland transition is relatively simple. South dipping subduction occured beneath Arabia Terra and east dipping subduction beneath Tharsis Montes and Tempe Terra. Lineations associated with Gordii Dorsum are attributed to ridge-parallel structures, while Phelegra Montes and Scandia Colles are interpreted as transfer-parallel structures or ridge-fault-fault triple junction tracks. Other than for these few features, there is little topographic roughness in the lowlands. Seafloor spreading, if it occurred, must have been relatively rapid. Quantitative estimates of spreading rate are obtained by considering the physics of seafloor spreading in the lower (approx. 0.4 g) gravity of Mars, the absence of vertical scarps from age differences across fracture zones, and the smooth axial topography. Crustal thickness at a given potential temperature in the mantle source region scales inversely with gravity. Thus, the velocity of the rough-smooth transition for axial topography also scales inversely with gravity. Plate reorganizations where young crust becomes difficult to subduct are another constraint on spreading age. Plate tectonics, if it occurred, dominated the thermal and stress history of the planet. A geochemical implication is that the lower gravity of Mars allows deeper hydrothermal circulation through cracks and hence more hydration of oceanic crust so that more water is easily subducted than on the Earth. Age and structural relationships from photogeology as well as median wavelength gravity anomalies across the now dead breakup and subduction margins are the data most likely to test and modify hypotheses

  12. Plate motion and deformation

    SciTech Connect

    Minster, B.; Prescott, W.; Royden, L.

    1991-02-01

    Our goal is to understand the motions of the plates, the deformation along their boundaries and within their interiors, and the processes that control these tectonic phenomena. In the broadest terms, we must strive to understand the relationships of regional and local deformation to flow in the upper mantle and the rheological, thermal and density structure of the lithosphere. The essential data sets which we require to reach our goal consist of maps of current strain rates at the earth's surface and the distribution of integrated deformation through time as recorded in the geologic record. Our success will depend on the effective synthesis of crustal kinematics with a variety of other geological and geophysical data, within a quantitative theoretical framework describing processes in the earth's interior. Only in this way can we relate the snapshot of current motions and earth structure provided by geodetic and geophysical data with long-term processes operating on the time scales relevant to most geological processes. The wide-spread use of space-based techniques, coupled with traditional geological and geophysical data, promises a revolution in our understanding of the kinematics and dynamics of plate motions over a broad range of spatial and temporal scales and in a variety of geologic settings. The space-based techniques that best address problems in plate motion and deformation are precise space-geodetic positioning -- on land and on the seafloor -- and satellite acquisition of detailed altimetric and remote sensing data in oceanic and continental areas. The overall science objectives for the NASA Solid Earth Science plan for the 1990's, are to Understand the motion and deformation of the lithosphere within and across plate boundaries'', and to understand the dynamics of the mantle, the structure and evolution of the lithosphere, and the landforms that result from local and regional deformation. 57 refs., 7 figs., 2 tabs.

  13. Armor Plate Surface Roughness Measurements

    DTIC Science & Technology

    2005-04-01

    Armor Plate Surface Roughness Measurements by Brian Stanton, William Coburn, and Thomas J. Pizzillo ARL-TR-3498 April 2005... Armor Plate Surface Roughness Measurements Brian Stanton, William Coburn and Thomas J. Pizzillo Sensors and Electron Devices Directorate...October 2004 5a. CONTRACT NUMBER 5b. GRANT NUMBER 4. TITLE AND SUBTITLE Armor Plate Surface Roughness Measurements 5c. PROGRAM ELEMENT NUMBER

  14. Buckling of trapezoidal plates

    SciTech Connect

    Radloff, H.D.; Hyer, M.W.; Nemeth, M.P.

    1995-12-31

    This study focuses on the buckling response of flat composite plates with an isosceles planform, as shown below. The study consisted of both analytical and experimental phases. In the study the parallel edges x = 0 and L were clamped or simply supported. Clamped parallel edges were used in the experimental phase of the study. The nonparallel edges were simply supported. The parallel edges were assumed to remain straight and buckling was assumed to occur because these edges moved toward each other. A Rayleigh-Ritz approach was used, with the finite-element code ABAQUS being used to check specific cases. The buckling displacements were assumed to be in the form of harmonic functions. The prebuckling force resultant N{sub x} was assumed to be given by N{sub x}(x,y) = P/W(x), where P is the applied load and W(x) is the varying width of the plate. N{sub y}(x,y) and N{sub x,y}(x,y) were taken to be zero. Experiments were conducted on a number of laminates and a number of plate geometries, and the results were compared to predictions of the Rayleigh-Ritz scheme. In general correlation was good, though the analysis underpredicted the number of buckling half-waves.

  15. Program solves line flow equation

    SciTech Connect

    McCaslin, K.P.

    1981-01-19

    A program written for the TI-59 programmable calculator solves the Panhandle Eastern A equation - an industry-accepted equation for calculating pressure losses in high-pressure gas-transmission pipelines. The input variables include the specific gravity of the gas, the flowing temperature, the pipeline efficiency, the base temperature and pressure, the inlet pressure, the pipeline's length and inside diameter, and the flow rate (SCF/day); the program solves for the discharge pressure.

  16. Origin of Small Tectonic Plates

    NASA Astrophysics Data System (ADS)

    Mallard, C.; Coltice, N.; Seton, M.; Müller, D.; Tackley, P.

    2015-12-01

    The plate tectonic theory allowed to split the Earth surface into 6 (Le Pichon 1968) to 52 tectonic plates (Bird 2003). These plates are separated into two groups: the first of 7 large plates and the second of numerous smaller plates (Morra et al 2013). Previous studies using the reconstruction of the past 200 My, suggest that the size of large plates is driven by mantle flow. But the tools employed are descriptive (Morra et al 2013, Sornette and Pisarenko 2003), hence ignoring forces and physical principles within the lithosphere and the mantle. The processes at the origin of small plates remain unknown. We developed a new approach to explain the plate sizes. We demonstrate that the physics of convection drives it. We applied plate tectonics theory on 3D spherical convection models generating plate-like motions, which give access to a complete survey of data: velocities, viscosity and heat flow. Our data show that (1) the large plates depend on the dominating scale of the convective flow due to the initiation or the shutdown of subductions; (2) the smaller plates are generated thanks to large variability of regional stresses along subduction zone by slab pull and suction influenced by the geometry of trenches. Our results are consistent with the quick reorganizations of back-arc basins occuring synchronously with the modification of subduction zones geometry around the Pacific plate (Sdrolias et al 2004). Hence, we conclude that (1) the decreasing number of small plates in the plate reconstructions back in time is an artifact induced by their short lifetime, that is why they are artificially ignored; (2) the geometry of past trenches is simplified leading to an underestimation of the length of subduction zones.

  17. Nonlinear effects in the coupled response of tiles bonded to a plate

    NASA Technical Reports Server (NTRS)

    El-Raheb, M.; Wagner, P.

    1985-01-01

    The coupled response to a large impulse on tiles bonded to a finite plate is studied. The analysis includes geometric nonlinearity born from boundary restraint in the plane, which stiffens the plate transversely. It also includes material nonlinearities born from plasticity of the plate's material and from properties of a polymer bond including memory and dissipation. The equations of motion are solved by the Galerkin method using linearized eigenfunctions of the system as trial functions. A strip of plate which is one tile wide is modeled.

  18. Tangram solved? Prefrontal cortex activation analysis during geometric problem solving.

    PubMed

    Ayaz, Hasan; Shewokis, Patricia A; Izzetoğlu, Meltem; Çakır, Murat P; Onaral, Banu

    2012-01-01

    Recent neuroimaging studies have implicated prefrontal and parietal cortices for mathematical problem solving. Mental arithmetic tasks have been used extensively to study neural correlates of mathematical reasoning. In the present study we used geometric problem sets (tangram tasks) that require executive planning and visuospatial reasoning without any linguistic representation interference. We used portable optical brain imaging (functional near infrared spectroscopy--fNIR) to monitor hemodynamic changes within anterior prefrontal cortex during tangram tasks. Twelve healthy subjects were asked to solve a series of computerized tangram puzzles and control tasks that required same geometric shape manipulation without problem solving. Total hemoglobin (HbT) concentration changes indicated a significant increase during tangram problem solving in the right hemisphere. Moreover, HbT changes during failed trials (when no solution found) were significantly higher compared to successful trials. These preliminary results suggest that fNIR can be used to assess cortical activation changes induced by geometric problem solving. Since fNIR is safe, wearable and can be used in ecologically valid environments such as classrooms, this neuroimaging tool may help to improve and optimize learning in educational settings.

  19. [The influence of hypersensitivity to nickel, chrome and cobalt on the process of fracture healing in patients treated operatively by stable osteosynthesis].

    PubMed

    Dobiecki, Konrad; Zietek, Paweł; Kołodziej, Lukasz; Brzosko, Marek; Bohatyrewicz, Andrzej; Kedzierski, Michał

    2009-01-01

    The aim of the study was to evaluate the frequency of occurrence of the hypersensitivity to nickel, chrome and cobalt in patients with longbone fractures. Two groups of patients were compared. The first group was composed of those treated operatively by stable osteosynthesis with the use of metal implants. The control group consisted of patients who have never been operated. Additionally, the influence of recognized hypersensitivity on the process of fracture healing was estimated. The study group consisted of 80 and the control group of 65 patients. All patients were patch tested with metal salts. The correlation was sought between hypersensitivity to metal in the study group, and incidence of complications relating to fracture healing. There was no significant difference observed both in frequency of occurrence of hypersensitivity to nickel, chrome and cobalt among patients treated operatively, and those treated conservatively, as well. There was no correlation between occurrence of hypersensitivity to the ions of metals, and complications in the process of fracture healing.

  20. Symmetries in laminated composite plates

    NASA Technical Reports Server (NTRS)

    Noor, A. K.

    1976-01-01

    The different types of symmetry exhibited by laminated anisotropic fibrous composite plates are identified and contrasted with the symmetries of isotropic and homogeneous orthotropic plates. The effects of variations in the fiber orientation and the stacking sequence of the layers on the symmetries exhibited by composite plates are discussed. Both the linear and geometrically nonlinear responses of the plates are considered. A simple procedure is presented for exploiting the symmetries in the finite element analysis. Examples are given of square, skew and polygonal plates where use of symmetry concepts can significantly reduce the scope and cost of analysis.

  1. Plate tectonics conserves angular momentum

    NASA Astrophysics Data System (ADS)

    Bowin, C.

    2009-03-01

    A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4 E+27 kgm2s-1). Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates). Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth). The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant velocity on the crests of convection cells driven by rising heat. These results imply that spreading centers are primarily passive reactive features, and fracture zones (and wedge-shaped sites

  2. Sudden stretching of a four layered composite plate

    NASA Technical Reports Server (NTRS)

    Sih, G. C.; Chen, E. P.

    1980-01-01

    An approximate theory of laminated plates is developed by assuming that the extensioral and thickness mode of vibration are coupled. The mixed boundary value crack problem of a four layered composite plate is solved. Dynamic stress intensity factors for a crack subjected to suddenly applied stress are found to vary as a function of time and depend on the material properties of the laminate. Stress intensification in the region near the crack front can be reduced by having the shear modulus of the inner layers to be larger than that of the outer layers.

  3. The new applications of sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1977-01-01

    The potential industrial applications of sputtering and ion plating are strictly governed by the unique features these methods possess. The outstanding features of each method, the resultant coating characteristics and the various sputtering modes and configurations are discussed. New, more complex coatings and deposits can be developed such as graded composition structures (metal-ceramic seals), laminated and dispersion strengthened composites which improve the mechanical properties and high temperature stability. Specific industrial areas where future effort of sputtering and ion plating will concentrate to develop intricate alloy or compound coatings and solve difficult problem areas are discussed.

  4. Fuel cell end plate structure

    DOEpatents

    Guthrie, Robin J.; Katz, Murray; Schroll, Craig R.

    1991-04-23

    The end plates (16) of a fuel cell stack (12) are formed of a thin membrane. Pressure plates (20) exert compressive load through insulation layers (22, 26) to the membrane. Electrical contact between the end plates (16) and electrodes (50, 58) is maintained without deleterious making and breaking of electrical contacts during thermal transients. The thin end plate (16) under compressive load will not distort with a temperature difference across its thickness. Pressure plate (20) experiences a low thermal transient because it is insulated from the cell. The impact on the end plate of any slight deflection created in the pressure plate by temperature difference is minimized by the resilient pressure pad, in the form of insulation, therebetween.

  5. Hypervelocity impact on shielded plates

    NASA Technical Reports Server (NTRS)

    Smith, James P.

    1993-01-01

    A ballistic limit equation for hypervelocity impact on thin plates is derived analytically. This equation applies to cases of impulsive impact on a plate that is protected by a multi-shock shield, and it is valid in the range of velocity above 6 km/s. Experimental tests were conducted at the NASA Johnson Space Center on square aluminum plates. Comparing the center deflections of these plates with the theoretical deflections of a rigid-plastic plate subjected to a blast load, one determines the dynamic yield strength of the plate material. The analysis is based on a theory for the expansion of the fragmented projectile and on a simple failure criterion. Curves are presented for the critical projectile radius versus the projectile velocity, and for the critical plate thickness versus the velocity. These curves are in good agreement with curves that have been generated empirically.

  6. The surface and through crack problems in layered orthotropic plates

    NASA Technical Reports Server (NTRS)

    Erdogan, Fazil; Wu, Binghua

    1991-01-01

    An analytical method is developed for a relatively accurate calculation of Stress Intensity Factors in a laminated orthotropic plate containing a through or part-through crack. The laminated plate is assumed to be under bending or membrane loading and the mode 1 problem is considered. First three transverse shear deformation plate theories (Mindlin's displacement based first-order theory, Reissner's stress-based first-order theory, and a simple-higher order theory due to Reddy) are reviewed and examined for homogeneous, laminated and heterogeneous orthotropic plates. Based on a general linear laminated plate theory, a method by which the stress intensity factors can be obtained in orthotropic laminated and heterogeneous plates with a through crack is developed. Examples are given for both symmetrically and unsymmetrically laminated plates and the effects of various material properties on the stress intensity factors are studied. In order to implement the line-spring model which is used later to study the surface crack problem, the corresponding plane elasticity problem of a two-bonded orthotropic plated containing a crack perpendicular to the interface is also considered. Three different crack profiles: an internal crack, an edge crack, and a crack terminating at the interface are considered. The effect of the different material combinations, geometries, and material orthotropy on the stress intensity factors and on the power of stress singularity for a crack terminating at the interface is fully examined. The Line Spring model of Rice and Levy is used for the part-through crack problem. The surface crack is assumed to lie in one of the two-layered laminated orthotropic plates due to the limitation of the available plane strain results. All problems considered are of the mixed boundary value type and are reduced to Cauchy type of singular integral equations which are then solved numerically.

  7. Vibration characteristics of rectangular plate in compressible inviscid fluid

    NASA Astrophysics Data System (ADS)

    Liao, Chan-Yi; Ma, Chien-Ching

    2016-02-01

    This paper presents a mathematical derivation of the vibration characteristics of an elastic thin plate placed at the bottom of a three dimensional rectangular container filled with compressible inviscid fluid. A set of beam functions is used as the admissible functions of the plate in a fluid-plate system, and the motion of the fluid induced by the deformation of the plate is obtained from a three-dimensional acoustic equation. Pressure from the fluid over the fluid-plate interface is integrated to form a virtual mass matrix. The frequency equation of the fluid-plate system is derived by combining mass, stiffness, and the virtual mass matrix. Solving the frequency equation makes it possible to obtain the dynamic characteristic of the fluid-plate system, such as resonant frequencies, corresponding mode shapes, and velocity of the fluid. Numerical calculations were performed for plates coupled with fluids with various degrees of compressibility to illustrate the difference between compressible and incompressible fluids in a fluid-plate system. The proposed method could be used to predict resonant frequencies and mode shapes with accuracy compared to that of incompressible fluid theory (IFT). The proposed method can be used to analyze cases involving high value of sound velocity, such as incompressible fluids. When the sound velocity approaches infinity, the results obtained for compressible fluids are similar to those of incompressible fluids. We also examined the influence of fluid compressibility on vibration characteristics in which a decrease in sound velocity was shown to correspond to a decrease in resonant frequency. Additional modes, not observed in incompressible fluids, were obtained in cases of low sound velocity, particularly at higher resonant frequencies. Fluid velocity plots clearly reveal that the additional resonant modes can be attributed to the compressible behavior of the fluid.

  8. Changes in mechanical properties of poly-l-lactic acid mini-plate under functional load simulating sagittal splitting ramus osteotomy.

    PubMed

    Mizuhashi, H; Suga, K; Uchiyama, T; Oda, Y

    2008-02-01

    The purpose of this study was to investigate how the characteristics of a poly-l-lactic acid mini-plate changed with dynamic loading in an environment with hydrolytic degradation. A mandible osteosynthesis model was prepared with specimen poly-l-lactic acid mini-plates to simulate sagittal splitting ramus osteotomy. The model was then subjected to dynamic loading, and changes in specimen shape and surface quality were observed. Specimen bending strength was then measured, and degree of hydrolytic degradation estimated. Neither dynamic loading nor degree of load clearly affected degree of hydrolytic degradation. The specimens maintained their original shape and bending strength for up to 4 weeks with dynamic loading of 40 N or less in an environment with hydrolytic degradation. At 8 weeks, under the same conditions, the specimens showed cracks or fractures, or both, together with a clear decrease in bending strength. The results suggest that dynamic loading causes cracking in a poly-l-lactic acid mini-plate, and that growth of these cracks decreases bending strength over time, leading to fatigue fracture.

  9. Plated wire memory subsystem

    NASA Technical Reports Server (NTRS)

    Carpenter, K. H.

    1974-01-01

    The design, construction, and test history of a 4096 word by 18 bit random access NDRO Plated Wire Memory for use in conjunction with a spacecraft input/output and central processing unit is reported. A technical and functional description is given along with diagrams illustrating layout and systems operation. Test data is shown on the procedures and results of system level and memory stack testing, and hybrid circuit screening. A comparison of the most significant physical and performance characteristics of the memory unit versus the specified requirements is also included.

  10. Shuttle plate braiding machine

    NASA Technical Reports Server (NTRS)

    Huey, Jr., Cecil O. (Inventor)

    1994-01-01

    A method and apparatus for moving yarn in a selected pattern to form a braided article. The apparatus includes a segmented grid of stationary support elements and a plurality of shuttles configured to carry yarn. The shuttles are supported for movement on the grid assembly and each shuttle includes a retractable plunger for engaging a reciprocating shuttle plate that moves below the grid assembly. Such engagement at selected times causes the shuttles to move about the grid assembly in a selected pattern to form a braided article of a particular geometry.

  11. The vibroacoustic response and sound absorption performance of multilayer, microperforated rib-stiffened plates

    NASA Astrophysics Data System (ADS)

    Zhou, Haian; Wang, Xiaoming; Wu, Huayong; Meng, Jianbing

    2017-04-01

    The vibroacoustic response and sound absorption performance of a structure composed of multilayer plates and one rigid back wall are theoretically analyzed. In this structure, all plates are two-dimensional, microperforated, and periodically rib-stiffened. To investigate such a structural system, semianalytical models of one-layer and multilayer plate structures considering the vibration effects are first developed. Then approaches of the space harmonic method and Fourier transforms are applied to a one-layer plate, and finally the cascade connection method is utilized for a multilayer plate structure. Based on fundamental acoustic formulas, the vibroacoustic responses of microperforated stiffened plates are expressed as functions of a series of harmonic amplitudes of plate displacement, which are then solved by employing the numerical truncation method. Applying the inverse Fourier transform, wave propagation, and linear addition properties, the equations of the sound pressures and absorption coefficients for the one-layer and multilayer stiffened plates in physical space are finally derived. Using numerical examples, the effects of the most important physical parameters—for example, the perforation ratio of the plate, sound incident angles, and periodical rib spacing—on sound absorption performance are examined. Numerical results indicate that the sound absorption performance of the studied structure is effectively enhanced by the flexural vibration of the plate in water. Finally, the proposed approaches are validated by comparing the results of stiffened plates of the present work with solutions from previous studies.

  12. Earth's Decelerating Tectonic Plates (Invited)

    NASA Astrophysics Data System (ADS)

    Forte, A. M.; Moucha, R.; Rowley, D. B.; Quere, S.; Mitrovica, J. X.; Simmons, N. A.; Grand, S. P.

    2009-12-01

    We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data (Simmons et al., GJI 2009) to explore the impact of time-dependent changes in mantle buoyancy forces on tectonic plate accelerations. This plate-coupled mantle convection model incorporates a viscosity structure that reconciles both glacial isostatic adjustment and global convection-related data sets (Mitrovica & Forte, EPSL 2004) and it successfully reproduces present-day plate velocities, global surface gravity and topography data. This convection model predicts the recent deceleration of several major plates in the Pacific and Indo-Atlantic hemispheres. Independent verification of these predictions is a fundamental test of the plausibility of the buoyancy forces and rheological structure in the convection model. To this end, we consider marine magnetic anomaly and space geodetic constraints on tectonic plate motions to determine a new global map of present-day rates of change of plate velocities. This map shows that several major plates, such as the Pacific, Africa and Nazca plates are presently decelerating and that they contribute to a globally-averaged slowdown in tectonic plate speeds. These joint geologic-geodetic inferences of plate decelerations are consistent with those predicted by our tomography-based convection model.

  13. Large Angle Unsteady Aerodynamic Theory of a Flat Plate

    NASA Astrophysics Data System (ADS)

    Manar, Field; Jones, Anya

    2016-11-01

    A purely analytical approach is taken for the evaluation of the unsteady loads on a flat plate. This allows for an extremely low cost theoretical prediction of the plate loads in the style of Wagner and Theodorsen, without making the assumption of small angle of attack or small disturbance flow. The forces and moments are evaluated using the time rate of change of fluid momentum, expressed as an integral of the vorticity field. The flow is taken as inviscid and incompressible with isolated vorticity bound to the plate and in the shed wake. The bound vorticity distribution on the plate is solved exactly using conformal mapping of the plate to a cylinder. In keeping with the original assumption of Wagner, the wake vorticity is assumed to remain stationary in an inertial reference frame and convection is disregarded. Formulation in this manner allows for a closed form solution of Wagner's problem valid at all angles of attack. Separation from the leading edge of the plate can also be included to further increase the fidelity of the model at high angles.

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

    PubMed Central

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

    2016-01-01

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

  15. Tension plate for treatment of olecranon fractures: new surgical technique and case series study

    PubMed Central

    Lukšic, Bruno; Juric, Ivo; Boschi, Vladimir; Pogorelic, Zenon; Bekavac, Josip

    2015-01-01

    Background Our aim was to determine the effectiveness of a new surgical technique for olecranon fractures using a tension plate (TP) designed by the operating surgeon. Methods We included patients with olecranon fractures treated between September 2010 and August 2013 in our study. Treatment involved a new implant and operative technique, which combined the most favourable characteristics of 2 frequently used methods, tension band wiring and plate osteosynthesis, while eliminating their shortcomings. The new method was based on the newly constructed implant. Results Twenty patients participated in our study. We obtained the following functional results with our TP: median flexion 147.5° (interquartile range [IQR] 130°–155°), median extension 135°/deficit 10° (IQR 135°–145°), median pronation 90° (IQR 81.3°–90°), median supination 90° (IQR 80°–90°). Implant-related complications were noted in 1 patient, and implants were removed in 3 patients. The mean functional Mayo elbow performance score was 94.8 (range 65–100). The removal of the implant was considerably less frequent in patients operated using the new method and implant than in patients operated using conventional methods at our institution (p < 0.001). Mean duration of follow-up was 8 months. Conclusion Our TP for the treatment of olecranon fractures is safe and effective. Functional results are very good, with significantly decreased postoperative inconveniences and need to remove the implant. Less osteosynthetic material was used for TP construction, but stability was preserved. PMID:25427338

  16. Customer-centered problem solving.

    PubMed

    Samelson, Q B

    1999-11-01

    If there is no single best way to attract new customers and retain current customers, there is surely an easy way to lose them: fail to solve the problems that arise in nearly every buyer-supplier relationship, or solve them in an unsatisfactory manner. Yet, all too frequently, companies do just that. Either we deny that a problem exists, we exert all our efforts to pin the blame elsewhere, or we "Band-Aid" the problem instead of fixing it, almost guaranteeing that we will face it again and again.

  17. Robot, computer problem solving system

    NASA Technical Reports Server (NTRS)

    Becker, J. D.

    1972-01-01

    The development of a computer problem solving system is reported that considers physical problems faced by an artificial robot moving around in a complex environment. Fundamental interaction constraints with a real environment are simulated for the robot by visual scan and creation of an internal environmental model. The programming system used in constructing the problem solving system for the simulated robot and its simulated world environment is outlined together with the task that the system is capable of performing. A very general framework for understanding the relationship between an observed behavior and an adequate description of that behavior is included.

  18. Plating on difficult-to-plate metals: what's new

    SciTech Connect

    Wiesner, H.J.

    1980-07-30

    Some of the changes since 1970 in procedures for plating on such materials as titanium, molybdenum, silicon, aluminum, and gallium arsenide are summarized. While basic procedures for plating some of these materials were developed as many as 30 to 40 years ago, changes in the end uses of the plated products have necessitated new plating processes. In some cases, vacuum techniques - such as ion bombardment, ion implantation, and vacuum metallization - have been introduced to improve the adhesion of electrodeposits. In other cases, these techniques have been used to deposit materials upon which electrodeposits are required.

  19. Modeling of composite beams and plates for static and dynamic analysis

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.

    1992-01-01

    A rigorous theory and the corresponding computational algorithms were developed for through-the-thickness analysis of composite plates. This type of analysis is needed in order to find the elastic stiffness constants of a plate. Additionally, the analysis is used to post-process the resulting plate solution in order to find approximate three-dimensional displacement, strain, and stress distributions throughout the plate. It was decided that the variational-asymptotical method (VAM) would serve as a suitable framework in which to solve these types of problems. Work during this reporting period has progressed along two lines: (1) further evaluation of neo-classical plate theory (NCPT) as applied to shear-coupled laminates; and (2) continued modeling of plates with nonuniform thickness.

  20. Localised Plate Motion on Venus

    NASA Astrophysics Data System (ADS)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.

  1. Tectonics of the Easter plate

    NASA Technical Reports Server (NTRS)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  2. The Photodynamic Bone Stabilization System: a minimally invasive, percutaneous intramedullary polymeric osteosynthesis for simple and complex long bone fractures.

    PubMed

    Vegt, Paul; Muir, Jeffrey M; Block, Jon E

    2014-01-01

    The treatment of osteoporotic long bone fractures is difficult due to diminished bone density and compromised biomechanical integrity. The majority of osteoporotic long bone fractures occur in the metaphyseal region, which poses additional problems for surgical repair due to increased intramedullary volume. Treatment with internal fixation using intramedullary nails or plating is associated with poor clinical outcomes in this patient population. Subsequent fractures and complications such as screw pull-out necessitate additional interventions, prolonging recovery and increasing health care costs. The Photodynamic Bone Stabilization System (PBSS) is a minimally invasive surgical technique that allows clinicians to repair bone fractures using a light-curable polymer contained within an inflatable balloon catheter, offering a new treatment option for osteoporotic long bone fractures. The unique polymer compound and catheter application provides a customizable solution for long bone fractures that produces internal stability while maintaining bone length, rotational alignment, and postsurgical mobility. The PBSS has been utilized in a case series of 41 fractures in 33 patients suffering osteoporotic long bone fractures. The initial results indicate that the use of the light-cured polymeric rod for this patient population provides excellent fixation and stability in compromised bone, with a superior complication profile. This paper describes the clinical uses, procedural details, indications for use, and the initial clinical findings of the PBSS.

  3. The Photodynamic Bone Stabilization System: a minimally invasive, percutaneous intramedullary polymeric osteosynthesis for simple and complex long bone fractures

    PubMed Central

    Vegt, Paul; Muir, Jeffrey M; Block, Jon E

    2014-01-01

    The treatment of osteoporotic long bone fractures is difficult due to diminished bone density and compromised biomechanical integrity. The majority of osteoporotic long bone fractures occur in the metaphyseal region, which poses additional problems for surgical repair due to increased intramedullary volume. Treatment with internal fixation using intramedullary nails or plating is associated with poor clinical outcomes in this patient population. Subsequent fractures and complications such as screw pull-out necessitate additional interventions, prolonging recovery and increasing health care costs. The Photodynamic Bone Stabilization System (PBSS) is a minimally invasive surgical technique that allows clinicians to repair bone fractures using a light-curable polymer contained within an inflatable balloon catheter, offering a new treatment option for osteoporotic long bone fractures. The unique polymer compound and catheter application provides a customizable solution for long bone fractures that produces internal stability while maintaining bone length, rotational alignment, and postsurgical mobility. The PBSS has been utilized in a case series of 41 fractures in 33 patients suffering osteoporotic long bone fractures. The initial results indicate that the use of the light-cured polymeric rod for this patient population provides excellent fixation and stability in compromised bone, with a superior complication profile. This paper describes the clinical uses, procedural details, indications for use, and the initial clinical findings of the PBSS. PMID:25540600

  4. Human Problem Solving in 2006

    ERIC Educational Resources Information Center

    Pizlo, Zygmunt

    2007-01-01

    This paper presents a bibliography of a little more than 100 references related to human problem solving, arranged by subject matter. The references were taken from PsycInfo and Compendex databases. Only journal papers, books and dissertations are included. The topics include human development, education, neuroscience, research in applied…

  5. Time Out for Problem Solving.

    ERIC Educational Resources Information Center

    Champagne, Audrey B.; And Others

    Teachers in elementary schools, supervisors of instruction, and other educational practitioners are the primary audience for this publication. The paper presents philosophical, psychological, and practical reasons for including a problem-solving approach in elementary school instruction. It draws on the writings of John Dewey, Jean Piaget, James…

  6. Problem Solving through Paper Folding

    ERIC Educational Resources Information Center

    Wares, Arsalan

    2014-01-01

    The purpose of this article is to describe a couple of challenging mathematical problems that involve paper folding. These problem-solving tasks can be used to foster geometric and algebraic thinking among students. The context of paper folding makes some of the abstract mathematical ideas involved relatively concrete. When implemented…

  7. Students' Problem Solving and Justification

    ERIC Educational Resources Information Center

    Glass, Barbara; Maher, Carolyn A.

    2004-01-01

    This paper reports on methods of students' justifications of their solution to a problem in the area of combinatorics. From the analysis of the problem solving of 150 students in a variety of settings from high-school to graduate study, four major forms of reasoning evolved: (1) Justification by Cases, (2) Inductive Argument, (3) Elimination…

  8. Problem-Solving Test: Pyrosequencing

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2013-01-01

    Terms to be familiar with before you start to solve the test: Maxam-Gilbert sequencing, Sanger sequencing, gel electrophoresis, DNA synthesis reaction, polymerase chain reaction, template, primer, DNA polymerase, deoxyribonucleoside triphosphates, orthophosphate, pyrophosphate, nucleoside monophosphates, luminescence, acid anhydride bond,…

  9. Human Problem Solving in 2012

    ERIC Educational Resources Information Center

    Funke, Joachim

    2013-01-01

    This paper presents a bibliography of 263 references related to human problem solving, arranged by subject matter. The references were taken from PsycInfo and Academic Premier data-base. Journal papers, book chapters, and dissertations are included. The topics include human development, education, neuroscience, and research in applied settings. It…

  10. Quantitative Reasoning in Problem Solving

    ERIC Educational Resources Information Center

    Ramful, Ajay; Ho, Siew Yin

    2015-01-01

    In this article, Ajay Ramful and Siew Yin Ho explain the meaning of quantitative reasoning, describing how it is used in the to solve mathematical problems. They also describe a diagrammatic approach to represent relationships among quantities and provide examples of problems and their solutions.

  11. Human Problem Solving in 2008

    ERIC Educational Resources Information Center

    Pizlo, Zygmunt

    2008-01-01

    This paper presents a bibliography of more than 200 references related to human problem solving, arranged by subject matter. The references were taken from PsycInfo database. Journal papers, book chapters, books and dissertations are included. The topics include human development, education, neuroscience, research in applied settings, as well as…

  12. Solving DAEs using block method

    NASA Astrophysics Data System (ADS)

    Abasi, Naghmeh; Suleiman, Mohamed; Ibrahim, Zarina Bibi

    2013-04-01

    This paper is on solving semi-explicit index-one Differential Algebraic Equations (DAEs). The block method suggested computes the solutions of the DAE at 2-point simultaneously. The numerical results obtained are compared with non-block backward differentiation method (BDF). The comparison of the numerical results confirms that the block method developed is more efficient and accurate.

  13. Human Problem Solving in 2008

    ERIC Educational Resources Information Center

    Pizlo, Zygmunt

    2008-01-01

    This paper presents a bibliography of more than 200 references related to human problem solving, arranged by subject matter. The references were taken from PsycInfo database. Journal papers, book chapters, books and dissertations are included. The topics include human development, education, neuroscience, research in applied settings, as well as…

  14. Robot computer problem solving system

    NASA Technical Reports Server (NTRS)

    Becker, J. D.

    1972-01-01

    Continuing research is reported in a program aimed at the development of a robot computer problem solving system. The motivation and results are described of a theoretical investigation concerning the general properties of behavioral systems. Some of the important issues which a general theory of behavioral organization should encompass are outlined and discussed.

  15. Teaching through Collaborative Problem Solving.

    ERIC Educational Resources Information Center

    Blandford, A. E.

    1994-01-01

    Discussion of a prototype intelligent education system called WOMBAT (Weighted Objectives Method by Arguing with the Tutor) focuses on dialogue and negotiation in collaborative problem solving. The results of a formative evaluation, in which the system was used by 10 subjects who commented on various aspects of the design, are presented. (Contains…

  16. Error Patterns in Problem Solving.

    ERIC Educational Resources Information Center

    Babbitt, Beatrice C.

    Although many common problem-solving errors within the realm of school mathematics have been previously identified, a compilation of such errors is not readily available within learning disabilities textbooks, mathematics education texts, or teacher's manuals for school mathematics texts. Using data on error frequencies drawn from both the Fourth…

  17. Gender and Mathematical Problem Solving.

    ERIC Educational Resources Information Center

    Duffy, Jim; Gunther, Georg; Walters, Lloyd

    1997-01-01

    Studied the relationship between gender and mathematical problem solving in 83 male and 76 female high achieving Canadian 12-year-olds. Gender differences were found on the Canadian Test of Basic Skills but not on the GAUSS assessment. Implications for the discussion of the origin of gender differences in mathematics are discussed. (SLD)

  18. Problem-Solving Test: Pyrosequencing

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2013-01-01

    Terms to be familiar with before you start to solve the test: Maxam-Gilbert sequencing, Sanger sequencing, gel electrophoresis, DNA synthesis reaction, polymerase chain reaction, template, primer, DNA polymerase, deoxyribonucleoside triphosphates, orthophosphate, pyrophosphate, nucleoside monophosphates, luminescence, acid anhydride bond,…

  19. Common Core: Solve Math Problems

    ERIC Educational Resources Information Center

    Strom, Erich

    2012-01-01

    The new common core standards for mathematics demand that students (and teachers!) exhibit deeper conceptual understanding. That's music to the ears of education professor John Tapper, who says teachers have overemphasized teaching procedures--and getting right answers. In his new book, "Solving for Why," he makes a powerful case for moving beyond…

  20. Customer Service & Team Problem Solving.

    ERIC Educational Resources Information Center

    Martin, Sabrina Budasi

    This curriculum guide provides materials for a six-session, site-specific training course in customer service and team problem solving for the Claretian Medical Center. The course outline is followed the six lesson plans. Components of each lesson plan include a list of objectives, an outline of activities and discussion topics for the lesson,…