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1

Locking versus nonlocking palmar plate fixation of distal radius fractures.  

PubMed

This study compared functional and radiological outcomes after treatment of extension-type distal radius fractures with conventional titanium nonlocking T-plates or titanium 1.5-mm locking plates. A total of 60 patients were included and followed for 4 to 7 years after receiving nonlocking T-plates (group A; n=30) or locking plates (group B; n=30) with and without dorsal bone grafting. Bone grafting was significantly more often performed in the nonlocking group to increase dorsal fracture fixation and stability (P<.003). Pre- and postoperative and follow-up values for palmar tilt, radial inclination, radial shortening, and ulnar variance were recorded. Age, sex, and fracture type were similarly distributed between the 2 groups. Postoperative and follow-up evaluation revealed equal allocation of intra-articular step formation and osteoarthritic changes to both groups. The overall complication rate was 25%. Compared with the nonlocking system, patients undergoing locking plate fixation presented with statistically significantly better values for postoperative palmar tilt (5.53° vs 8.15°; P<.02) and radial inclination (22.13° vs 25.03°; P<.02). However, forearm pronation was significantly better in group A (P<.005). At follow-up, radial inclination tended to approach a statistically significant difference in favor of group B. All clinical assessment, including Mayo wrist score, Disabilities of the Arm, Shoulder, and Hand score, Green and O'Brien score, Gartland and Werley score, visual analog scale score, and grip strength, yielded no statistically significant difference between the 2 groups. Locking plates seem to provide benefits regarding surgical technique and comfort, improvement in implant anchorage (especially in osteoporotic bone), and reduce the necessity of additional bone grafting. PMID:23127452

Osti, Michael; Mittler, Christoph; Zinnecker, Richard; Westreicher, Christoph; Allhoff, Clemens; Benedetto, Karl Peter

2012-11-01

2

Comparison of treatment of unstable intra articular fractures of distal radius with locking plate versus non-locking plate fixation  

PubMed Central

Introduction Unstable intra articular fractures of distal radius are frequently being managed with open reduction and internal fixation. Of late in some biomechanical studies locking plates have been shown to be better in terms of maintenance of radiological parameters in comparison to non-locking plates. We conducted this study to know whether this biomechanical superiority of locking plates is converted in to better clinical outcomes. Materials and methods A study was conducted in 60 patients (30 in each group) with unstable intra articular fractures of distal radius who were treated by open reduction and internal fixation with locking plates and non-locking plates. Patients were evaluated for radiological parameters (intra articular step off, radial height, radial tilt, volar tilt) and functional parameters (flexion, extension, radial deviation, ulnar deviation, pronation, supination grip strength) at two year follow up. Overall outcome was evaluated by scoring systems of Gartland and Werley and modified Green O' Brien. Results The change in radiological parameters from immediate post op to latest at two year in locking plate group was not significant for radial height, radial tilt, volar tilt, but ulnar variance whereas in non-locking plate there was significant change in radial height, volar tilt, ulnar variance but no significant change in radial inclination. In clinical and functional outcome no significant difference was found at two year follow up. Conclusions Locking plates maintain the radiological parameters better than non-locking plates but functional outcome are same for both plates at two year after surgery.

Kumar, Sunil; Chopra, R.K.; Sehrawat, Sunil; Lakra, Akshay

2014-01-01

3

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

PubMed

Metallic implants are often involved in the open reduction and internal fixation of fractures. Open reduction and internal fixation is commonly used in cases of trauma when the bone cannot be healed using external methods such as casting. The locking compression plate combines the conventional screw hole, which uses non-locking screws, with a locking screw hole, which uses locking head screws. This allows for more versatility in the application of the plate. There are many factors which affect the functionality of the plate (e.g., screw placement, screw choice, length of plate, distance from bone, etc.). This paper presents a review of the literature related to the biomechanics of locking compression plates and their use as internal fixators in fracture healing. Furthermore, this paper also addresses the materials used for locking compression plates and their mechanical behavior, parameters that control the overall success, as well as inherent bone quality results. PMID:17904257

Miller, Danielle L; Goswami, Tarun

2007-12-01

4

External Fixation Versus Open Reduction With Locked Volar Plating for Geriatric Distal Radius Fractures  

PubMed Central

The optimal management of displaced dorsal radius fractures (DRFs) in older patients remains an issue of debate. Bridging external fixation is a well-accepted treatment modality for severely comminuted DRFs, while open reduction and internal fixation with locked volar plating has emerged as a promising alternative in recent years. The current body of randomized trials supports the trend toward locked volar plating, as it allows for quicker improvement in subjective and functional outcomes. There is no clear evidence to suggest that one technique carries significantly less complications than the other. Locked volar plating should be considered in patients for whom an accelerated functional recovery would be advantageous. Otherwise, both external fixation and locked volar plating provide good long-term clinical outcomes. PMID:25360346

Lee, Daniel J.

2014-01-01

5

Stable fixation of osteoporotic fractures and nonunions in the upper limb - life before the "locking plate".  

PubMed

I have had a wonderful opportunity over the past 30 years to surgically reconstruct many complex fractures and non- unions in the upper limb in the elderly patient with underlying osteoporosis and prior to the development of the "locked plate". This article will present a number of specific techniques using standard LC-DCP and screw in a variety of applications to provide stable internal fixation. These include the use of long plates; creating a "waved plate" initially described by Blatter and Weber; double plating; 3.5 mm intramedullary plate combined with a larger plate on the cortex; custom and machi- ned blade plates as well as enhancement of screw fixation with bone cement and/ or Norian SRS cement. PMID:21040646

Jupiter, J B; Wyss, H

2010-10-01

6

Complications following volar locking plate fixation for distal radial fractures: a systematic review.  

PubMed

The purpose of this systematic review is to assess the prevalence of complications following volar locking plate fixation of distal radial fractures. A computer-based search was carried out using EMBASE and PUBMED/MEDLINE. Only prospective comparative and prospective cohort studies that presented data concerning complications after treatment of distal radial fractures with a volar locking plate in human adults with a minimal follow-up of 6 months were included. Two quality assessment tools were used to assess the methodological quality of the studies (level of evidence rating according to the Oxford Centre of Evidence Based Medicine and the modified version of the Cochrane Bone, Joint and Muscle Trauma Group's former quality assessment tool). Thirty three studies were eligible for final assessment. Most complications were problems with nerve and tendon function as well as complex regional pain syndrome. With an overall complication rate of 16.5%, most of which were 'minor' complications and low rates of nonunion and malunion, volar locking plate fixation can be considered a reasonably safe treatment option for patients with distal radial fractures. PMID:24262583

Bentohami, A; de Burlet, K; de Korte, N; van den Bekerom, M P J; Goslings, J C; Schep, N W L

2014-09-01

7

Comparison of functional outcomes of tibial plateau fractures treated with nonlocking and locking plate fixations: a nonrandomized clinical trial.  

PubMed

Fixation of tibial plateau fractures with plate has been widely used. This prospective study was planned to compare locking plate fixation of tibial plateau fracture with nonlocking methods in terms of their functional outcomes. The subjects of the study were selected from consecutive patients suffering from tibial plateau fractures referred to Kashani Hospital in Isfahan, Iran, between 2012 and 2013 and were candidate for surgery. The final included patients were assigned to two groups, those who were treated with locking plate (n = 20) and those who were treated with nonlocking plates (N = 21). The mean duration of follow-up was 13.4 months (ranging between 10 and 17 months). The mean of knee scores was significantly higher in locking plate group than in nonlocking plate group at the follow-up time (80.20 ± 10.21 versus 72.52 ± 14.75, P = 0.039). Also, the mean VAS pain severity score was significantly lower in locking plate group compared with nonlocking plate group (4.45 ± 2.50 versus 6.00 ± 2.59, P = 0.046). This study confirmed superiority of the locking plate method over nonlocking plate method with regard to knee score as well as VAS pain score. PMID:24967126

Tahririan, Mohammad Ali; Mousavitadi, Seyyed Hamid; Derakhshan, Mohsen

2014-01-01

8

Comparison of Functional Outcomes of Tibial Plateau Fractures Treated with Nonlocking and Locking Plate Fixations: A Nonrandomized Clinical Trial  

PubMed Central

Fixation of tibial plateau fractures with plate has been widely used. This prospective study was planned to compare locking plate fixation of tibial plateau fracture with nonlocking methods in terms of their functional outcomes. The subjects of the study were selected from consecutive patients suffering from tibial plateau fractures referred to Kashani Hospital in Isfahan, Iran, between 2012 and 2013 and were candidate for surgery. The final included patients were assigned to two groups, those who were treated with locking plate (n = 20) and those who were treated with nonlocking plates (N = 21). The mean duration of follow-up was 13.4 months (ranging between 10 and 17 months). The mean of knee scores was significantly higher in locking plate group than in nonlocking plate group at the follow-up time (80.20 ± 10.21 versus 72.52 ± 14.75, P = 0.039). Also, the mean VAS pain severity score was significantly lower in locking plate group compared with nonlocking plate group (4.45 ± 2.50 versus 6.00 ± 2.59, P = 0.046). This study confirmed superiority of the locking plate method over nonlocking plate method with regard to knee score as well as VAS pain score. PMID:24967126

Tahririan, Mohammad Ali; Mousavitadi, Seyyed Hamid; Derakhshan, Mohsen

2014-01-01

9

Biomechanical In Vitro - Stability Testing on Human Specimens of a Locking Plate System Against Conventional Screw Fixation of a Proximal First Metatarsal Lateral Displacement Osteotomy  

PubMed Central

Introduction: The aim of this study was to examine resistance to angulation and displacement of the internal fixation of a proximal first metatarsal lateral displacement osteotomy, using a locking plate system compared with a conventional crossed screw fixation. Materials and Methodology: Seven anatomical human specimens were tested. Each specimen was tested with a locking screw plate as well as a crossed cancellous srew fixation. The statistical analysis was performed by the Friedman test. The level of significance was p = 0.05. Results: We found larger stability about all three axes of movement analyzed for the PLATE than the crossed screws osteosynthesis (CSO). The Friedman test showed statistical significance at a level of p = 0.05 for all groups and both translational and rotational movements. Conclusion: The results of our study confirm that the fixation of the lateral proximal first metatarsal displacement osteotomy with a locking plate fixation is a technically simple procedure of superior stability. PMID:22675409

Arnold, Heino; Stukenborg-Colsman, Christina; Hurschler, Christof; Seehaus, Frank; Bobrowitsch, Evgenij; Waizy, Hazibullah

2012-01-01

10

Use of a locking compression plate as an external fixator for repair of a tarsometatarsal fracture in a bald eagle (Haliaeetus leucocephalus).  

PubMed

We describe the successful treatment of a tarsometatarsal fracture in a mature bald eagle (Haliaeetus leucocephalus) using a locking compression plate as an external fixator. The anatomy of the area (inelastic dermis and minimal subcutaneous space) and the high forces placed on a fracture at that site necessitated a unique approach to fixation. The unconventional use of a locking compression plate as an external fixator was minimally invasive, well tolerated by the eagle, and provided adequate stability in opposing fracture forces. This technique may serve as a method of fixation for tarsometatarsal fractures in other large avian species. PMID:21877449

Montgomery, Ronald D; Crandall, Elizabeth; Bellah, Jamie R

2011-06-01

11

Arthroscopic-assisted Locking Compression Plate clavicular hook fixation for unstable fractures of the lateral end of the clavicle: a prospective study  

Microsoft Academic Search

The aim of this prospective study was to assess the clinical outcomes of an unstable fracture of the lateral end of the clavicle\\u000a treated with an arthroscopic-assisted locking compressive plate (LCP) clavicular hook plate. Twenty-three patients underwent\\u000a arthroscopic assisted LCP clavicular hook plate fixation for these fractures. All patients achieved clinical and radiological\\u000a union over a mean of 4.2 months (range,

Kwang Won Lee; Sang Ki Lee; Kap Jung Kim; Yong In Kim; Won Cho Kwon; Won Sik Choy

2010-01-01

12

Internal fixation of proximal humeral fractures with locking proximal humeral plate (LPHP) in elderly patients with osteoporosis  

PubMed Central

Background Different operative techniques used for treating displaced proximal humeral fractures could result in malunion, non-union, osteonecrosis of humeral head, loosening of screw and loss of reduction particularly in comminuted and osteoporotic fractures. Locking compression plate (LPHP) has been proposed for open reduction and internal fixation of these fractures and is associated with less complication rate. Materials and methods We prospectively assessed the functional outcome and the complications after an average follow-up of 24.9 months in 25 patients of proximal humeral fractures with osteoporosis. Mean age was 62 years. Using AO classification, 48% were type A and 52% type B. Results Mean constant score was 80 points. According to constant score, 28% had excellent outcome, 64% had good functional outcome, and 8% had moderate outcome. When the results were related to grades of osteoporosis, grade IV osteoporotic fractures had highest average Constant–Murley score (83 points, range 78–88 points), followed by grade III osteoporotic fractures (80 points, range 71–92 points), followed by grade II osteoporotic fractures (78 points, range 66–88 points). Varus malalignment and subacromial impingement were observed in 8% patients. Loosening of implant and loss of reduction were observed in 4% patients. Superficial infection was observed in 4% patients. Conclusions Locking compression plate (LPHP) is an advantageous implant in proximal humeral fractures due to angular stability, particularly in comminuted fractures and in osteoporotic bones in elderly patients, thus allowing early mobilization. PMID:19384611

Singh, Roop; Rohilla, Rajesh Kumar; Kadian, Virender Singh; Sangwan, Sukhbir Singh; Dhanda, Manjeet

2008-01-01

13

Experimental and probabilistic analysis of distal femoral periprosthetic fracture: a comparison of locking plate and intramedullary nail fixation. Part A: experimental investigation.  

PubMed

The following is a two-part study. Part A evaluates biomechanically intramedullary (IM) nails vs. locking plates for fixation of femoral fractures in osteoporotic bone. Part B of this study introduces a deterministic finite element model of each construct type and investigates the probability of periprosthetic fracture of the locking plate compared with the retrograde IM nail using Monte Carlo simulation. For Part A, an extra-articular, metaphyseal wedge fracture pattern was created in 11 osteoporotic fourth-generation composite femurs. Fixation was performed with a locking plate or a retrograde IM nail. Axial, torsion and bending cyclic loading to simulate post-operative damage accumulation were performed followed by ramped load to failure. Locking plates proved to be more stable (using stiffness as the determining factor) in osteoporotic bone as observed under low load cycle conditions. However, some of these advantages were offset by a greater incidence of sudden periprosthetic fracture observed under ramped loading conditions. Cadaveric, osteoporotic femurs included as a case study also exhibited periprosthetic fracture, but failure was accompanied by catastrophic comminution of the cortex. Periprosthetic failure at the implant end including bone comminution is difficult to salvage with revision fixation. The weakened trabecular matrix and thinned cortex of osteoporotic bone may increase the incidence of periprosthetic fracture. It is, therefore, essential for the surgeon to consider all possible loading scenarios when recommending an ideal implant for the osteoporotic patient. PMID:21337222

Salas, Christina; Mercer, Deana; DeCoster, Thomas A; Reda Taha, Mahmoud M

2011-02-01

14

Locking plates for fixation of extra-articular fractures of the first metacarpal base: A series of 15 cases  

Microsoft Academic Search

Extra-articular fractures of the first metacarpal base may lead to retraction of the first web and weakness of the pinch. Conventional surgery (K-wire or non-locking plates) needs six weeks of immobilization. Our goal was to achieve the reduction of such fractures using locking mini-plates to allow early mobilization. Our series included 15 patients, with an average age of 35 years,

M. Diaconu; S. Facca; S. Gouzou; Ph. Liverneaux

2011-01-01

15

Fixation of subtrochanteric extending/derotational femoral osteotomies with the Locking Compression Plate in ambulatory neuro-orthopaedic patients  

PubMed Central

Purpose Patients with neuro-orthopaedic disorders often develop hip flexion contractures or rotational hip deformities. Increasing deformities impair the already diminished walking abilities and proximal femoral osteotomies are often performed to maintain/improve walking abilities. Fixation of the osteotomies with condylar plates has been successfully used but does often not allow immediate postoperative full weight bearing. To avoid a substantial postoperative rehabilitation deficit and additional bone loss due to inactivity, a postoperative treatment with full weight bearing is, therefore, wishful. Newer fixed-angled implants with stronger anchoring in osteopenic bone might fit these demands. The objective of this study was to evaluate bone healing and the complication rate after proximal extending and/or derotational femoral osteotomy fixed with 3.5/4.5 Locking Compression Plate (LCP; Synthes®) and postoperative full weight bearing in ambulatory neuro-orthopaedic patients. Methods Fifteen ambulatory neuro-orthopaedic patients (12 cerebral palsy [CP], 1 trisomy 21, 2 hemiparesis) with a mean age of 13.7 years (range 7–22) with hip flexion contractures and/or rotational deformities underwent subtrochanteric (n = 26) osteotomy between July 2004 and October 2007. All patients were allowed to bear their full weight postoperatively. We investigated the fusion rate, implant failure, and general complication rate until union had occurred. Results Fourteen patients (mean weight 42.0 kg [range 21.8–59]) uneventfully achieved solid fusion. One patient (19 years of age, 73 kg) needed revision surgery due to implant failure with consecutive varus deformity and achieved solid fusion after the second intervention. Besides one superficial wound infection, no other complications occurred. Conclusions Subtrochanteric extending and/or derotational osteotomies fixed with an LCP are a reliable procedure in neuro-orthopaedic patients. Most patients can be treated with early postoperative full weight bearing. However, in heavier patients, possible implant failure must be considered. PMID:21966306

Haefeli, Mathias; Huber, Hanspeter; Dierauer, Stefan

2010-01-01

16

Stainless steel versus titanium volar multi-axial locking plates for fixation of distal radius fractures: a randomised clinical trial  

PubMed Central

Background Distal radius fractures are among the most common fractures seen in the hospital emergency department. Of these, over 40% are considered unstable and require some form of fixation. In recent years with the advent of low profile plating, open reduction and internal fixation (ORIF) using volar plates has become the surgical treatment of choice in many hospitals. However, it is currently unknown which plating system has the lowest complication rate and/or superior clinical and radiological outcomes following surgery. Few studies have compared different types of plates, which may have various features, different plate and screw designs or may be manufactured from different materials (for example, stainless steel or titanium). This study will specifically investigate and compare the clinical and radiological outcomes and complication rates of two commonly used volar plating systems for fixation of distal radius fractures: one made from stainless steel (Trimed™ Volar Plate, Trimed™, California, USA) and the other made from titanium (Medartis® Aptus Volar Plate, Medartis®, Basel, Switzerland). The primary aim of this study is to determine if there is a difference on the Patient Reported Wrist Evaluation six months following ORIF using a volar plate for adult patients with a distal radius fracture. Methods/Design This study will implement a randomized prospective clinical trial study design evaluating the outcomes of two different types of volar plates: one plate manufactured from stainless steel (Trimed™ Volar Plate) and one plate manufactured from titanium (Medartis® Aptus Volar Plate). The surgery will be performed at a major trauma hospital in Brisbane, Australia. Outcome measures including function, adverse events, range of movement, strength, disability, radiological findings and health-related quality of life will be collected at 6 weeks, 3, 6, 12 and 24 months following surgery. A parallel economic analysis will also be performed. This randomized clinical trial is due to deliver results in December 2016. Discussion Results from this trial will contribute to the evidence on operative management of distal radius fractures and plate material type. Trial registration ACTRN12612000969864 PMID:24612524

2014-01-01

17

Treatment of reducible unstable fractures of the distal radius: randomized clinical study comparing the locked volar plate and external fixator methods: study protocol  

PubMed Central

Background Various treatments are available for reducible unstable fractures of the distal radius, such as closed reduction combined with fixation by external fixator (EF), and rigid internal fixation using a locked volar plate (VP). Although there are studies comparing these methods, there is no conclusive evidence indicating which treatment is best. The hypothesis of this study is that surgical treatment with a VP is more effective than EF from the standpoint of functional outcome (patient-reported). Methods/Design The study is randomized clinical trial with parallel groups and a blinded evaluator and involves the surgical interventions EF and VP. Patients will be randomly assigned (assignment ratio 1:1) using sealed opaque envelopes. This trial will include consecutive adult patients with an acute (up to 15 days) displaced, unstable fracture of the distal end of the radius of type A2, A3, C1, C2 or C3 by the Arbeitsgemeinschaft für Osteosynthesefragen–Association for the Study of Internal Fixation classification and type II or type III by the IDEAL32 classification, without previous surgical treatments of the wrist. The surgical intervention assigned will be performed by three surgical specialists familiar with the techniques described. Evaluations will be performed at 2, and 8 weeks, 3, 6 and 12 months, with the primary outcomes being measured by the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and measurement of pain (Visual Analog Pain Scale and digital algometer). Secondary outcomes will include radiographic parameters, objective functional evaluation (goniometry and dynamometry), and the rate of complications and method failure according to the intention-to-treat principle. Final postoperative evaluations (6 and 12 months) will be performed by independent blinded evaluators. For the Student’s t-test, a difference of 10 points in the DASH score, with a 95% confidence interval, a statistical power of 80%, and 20% sampling error results in 36 patients per group. Discussion Results from this study protocol will improve the current evidence regarding to the surgical treatment these fractures. Trial registration ISCRTN09599740 PMID:24597699

2014-01-01

18

Displaced proximal humeral fractures: an Indian experience with locking plates  

PubMed Central

Background The treatment of displaced proximal humerus fractures, especially in elderly, remains controversial. The objective of this study was to evaluate functional outcome of locking plate used for fixation of these fractures after open reduction. We also attempted to evaluate the complications and predictors of loss of fixation for such an implant. Methods Over two and a half years, 56 patients with an acute proximal humerus fracture were managed with locking plate osteosynthesis. 47 of these patients who completed a minimum follow up of 1 year were evaluated using Constant score calculation. Statistical analysis was done using SPSS 16 and a p value of less than 0.05 was taken as statistically significant. Results The average follow up period was around 21.5 months. Outcomes were excellent in 17%, good in 38.5%, moderate in 34% while poor in 10.5%. The Constant score was poorer for AO-OTA type 3 fractures as compared to other types. The scores were also inferior for older patients (> 65 years old). Complications included screw perforation of head, AVN, subacromial impingement, loss of fixation, axillary nerve palsy and infection. A varus malalignment was found to be a strong predictor of loss of fixation. Conclusion Locking plate osteosynthesis leads to satisfactory functional outcomes in all the patients. Results are better than non locking plates in osteoporotic fractures of the elderly. However the surgery has steep learning curve and various complications could be associated with its use. Nevertheless we believe that a strict adherence to the principles of locking plate use can ensure good result in such challenging fractures. PMID:20731844

2010-01-01

19

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

PubMed

The present study was performed to test the null hypothesis on no difference in stability of fixation after volar plating of intra-articular distal radius fractures (AO C2-C3) with either locking smooth pegs or locking screws in a clinical setting. A retrospective evaluation included adult patients with C2-C3 AO fractures treated with a volar plate with locking smooth pegs or locking screws. Radiographic assessment was performed to evaluate extra- and intra-articular parameters in the early postoperative period and after bone union. Twenty-seven consecutive patients were included. Thirteen cases had fixation with locking screws and 14 had fixation with locking smooth pegs. Both groups had bone fragment displacement after fixation. However, there were no significant differences between the groups either in extra- or intra-articular parameters defined by Kreder et al. (1996). Our study shows that, in a clinical setting, there is no difference in stability fixation between locking screws or smooth locking pegs in C2-C3 distal radius fractures. PMID:24401740

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

2014-09-01

20

Closed reduction and fixation of locked symphysis pubis using tubular external fixator: a case report.  

PubMed

Locked symphysis pubis is a kind of pelvic injury in which one pubic bone is jammed in the back of the other or opposite the obturator foramen following lateral compression forces. In this article, we present a 31-year-old female case of locked symphysis pubis which was treated by closed reduction using tubular external fixator. We believe that tubular external fixators are useful devices to perform closed reduction maneuvers for locked pelvic injuries and also help to reduce the need for open reduction and internal implant usage. PMID:23692202

Hal?c?, Mehmet; Karaman, ?brahim; Kafadar, ?brahim Halil; Argün, Ali Saltuk

2013-01-01

21

Endosteal Strut Augment Reduces Complications Associated With Proximal Humeral Locking Plates  

Microsoft Academic Search

Background  Locking-plate technology has renewed interest in plate fixation for treating proximal humerus fractures. Complications associated\\u000a with these devices, including loss of reduction, screw cutout, and intra-articular penetration, are frequent. Establishing\\u000a a second column of support may reduce complications and improve clinical outcome scores.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  We asked whether addition of an endosteal cortical allograft strut, used as an augment to locking-plate fixation

Andrew S. Neviaser; Carolyn M. Hettrich; Brandon S. Beamer; Joshua S. Dines; Dean G. Lorich

22

Biomechanical analysis of bicortical versus unicortical locked plating of mid-clavicular fractures  

Microsoft Academic Search

Objectives  Operative fixation of displaced mid-shaft clavicle fractures has been shown to improve the functional outcomes and decrease\\u000a the likelihood of non-union; however, little is known about the need for locking screws versus traditional screws. We, therefore,\\u000a evaluated the strength of unicortical locked plating versus traditional bicortical non-locking fixation methods.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Ten matched pairs of fresh, frozen cadaver clavicle specimens were obliquely

Daniel Hamman; Derek Lindsey; Jason Dragoo

2011-01-01

23

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

PubMed Central

Background Effective fixation of fracture requires careful selection of a suitable implant to provide stability and durability. Implant with a feature of locking plate (LP) has been used widely for treating distal fractures in femur because of its favourable clinical outcome, but its potential in fixing proximal fractures in the subtrochancteric region has yet to be explored. Therefore, this comparative study was undertaken to demonstrate the merits of the LP implant in treating the subtrochancteric fracture by comparing its performance limits against those obtained with the more traditional implants; angle blade plate (ABP) and dynamic condylar screw plate (DCSP). Materials and Methods Nine standard composite femurs were acquired, divided into three groups and fixed with LP (n?=?3), ABP (n?=?3) and DCSP (n?=?3). The fracture was modeled by a 20?mm gap created at the subtrochanteric region to experimentally study the biomechanical response of each implant under both static and dynamic axial loading paradigms. To confirm the experimental findings and to understand the critical interactions at the boundaries, the synthetic femur/implant systems were numerically analyzed by constructing hierarchical finite element models with nonlinear hyperelastic properties. The predictions from the analyses were then compared against the experimental measurements to demonstrate the validity of each numeric model, and to characterize the internal load distribution in the femur and load bearing properties of each implant. Results The average measurements indicated that the constructs with ABP, DCPS and LP respectively had overall stiffness values of 70.9, 110.2 and 131.4?N/mm, and exhibited reversible deformations of 12.4, 4.9 and 4.1?mm when the applied dynamic load was 400?N and plastic deformations of 11.3, 2.4 and 1.4?mm when the load was 1000?N. The corresponding peak cyclic loads to failure were 1100, 1167 and 1600?N. The errors between the displacements measured experimentally or predicted by the nonlinear hierarchical hyperelastic model were less than 18?%. In the implanted femur heads, the principal stresses were spatially heterogeneous for ABP and DCSP but more homogenous for LP, meaning LP had lower stress concentrations. Conclusion When fixed with the LP implant, the synthetic femur model of the subtrochancteric fracture consistently exceeds in the key biomechanical measures of stability and durability. These capabilities suggest increased resistance to fatigue and failure, which are highly desirable features expected of functional implants and hence make the LP implant potentially a viable alternative to the conventional ABP or DCSP in the treatment of subtrochancteric femur fractures for the betterment of clinical outcome. PMID:22545650

2012-01-01

24

Locking Compression Plate in Musculoskeletal Oncology 'a Friend in Need'  

PubMed Central

Background We are presenting our experience in the use of locking compression plate (LCP) after juxta-articular oncological resections in addition to its use in pathologic fracture. Methods A retrospective audit of skeletal reconstruction using LCP in 25 cases of long bone tumors was performed from 2008 to 2010. Reconstruction following limb salvage surgery was done in 17 patients and internal fixation of pathological fracture was done in 8 patients. All patients were available for > 12 months of follow-up, and thus assessed for union at the resected ends. Results There were 8 males and 17 females in the study. The average age at the time of surgery was 30 years (range, 9 to 66 years). The minimum follow-up was 12 months (range, 12 to 32 months). All patients except three went on to heal successfully. Complications occurred in those three patients: wound infection in one, nonunion in another, and periprosthetic fracture in the other patient. In the remaining patients, union was achieved at an average of 6.5 months after reconstruction in curative resection and 4.75 months after fixation of pathological fractures. Conclusions Joint sparing limb salvage surgery was made successfully possible after sekeletal reconstruction with LCP. Its use was also quite effective in pathological fractures with poor bone quality. Use of locking plates for musculoskeletal oncological reconstruction resulted in a good and predictable rate of union. PMID:24340153

Umer, Masood; Khan, Shahid; Rashid, Haroon ur

2013-01-01

25

Early complications of medial opening wedge high tibial osteotomy using autologous tricortical iliac bone graft and T-plate fixation  

Microsoft Academic Search

Despite several advantages of medial opening wedge high tibial osteotomy, this procedure has been noted to have a high rate of complications especially with the use of a spacer plate for fixation. We retrospectively evaluated the early complications of 138 medial opening wedge high tibial osteotomies done using autologous tricortical iliac bone graft and T-plate fixation(AO locking compression T-plate, Ti\\/3H

Dong Ju Chae; Gautam M. Shetty; Kook Hyun Wang; Antonio Santa Cruz Montalban Jr; Jong In Kim; Kyung Wook Nha

2011-01-01

26

Plate fixation of clavicle fractures : A comparative study between Reconstruction Plate and Dynamic Compression Plate  

Microsoft Academic Search

This study aimed at comparing the results of clavic- ular fracture fixation with AO Reconstruction (Recon) plate and Dynamic Compression Plate (DCP). The case notes of 39 patients with 40 acute and chronic clavicular fractures were retrospectively reviewed. The indications for fixation for acute cases comprised open fractures, the presence of sufficient skin tenting to risk skin integrity, neurovascular compromise

Rizwan SHAHID; Abid MUSHTAQ; Mohammad MAQSOOD; Lincoln LN

2007-01-01

27

Computational simulation of the early stage of bone healing under different configurations of locking compression plates.  

PubMed

Flexible fixation or the so-called 'biological fixation' has been shown to encourage the formation of fracture callus, leading to better healing outcomes. However, the nature of the relationship between the degree of mechanical stability provided by a flexible fixation and the optimal healing outcomes has not been fully understood. In this study, we have developed a validated quantitative model to predict how cells in fracture callus might respond to change in their mechanical microenvironment due to different configurations of locking compression plate (LCP) in clinical practice, particularly in the early stage of healing. The model predicts that increasing flexibility of the LCP by changing the bone-plate distance (BPD) or the plate working length (WL) could enhance interfragmentary strain in the presence of a relatively large gap size (>3 mm). Furthermore, conventional LCP normally results in asymmetric tissue development during early stage of callus formation, and the increase of BPD or WL is insufficient to alleviate this problem. PMID:24261957

Miramini, Saeed; Zhang, Lihai; Richardson, Martin; Pirpiris, Marinis; Mendis, Priyan; Oloyede, Kunle; Edwards, Glenn

2015-06-01

28

Biomechanical Performance of Variable and Fixed Angle Locked Volar Plates for the Dorsally Comminuted Distal Radius  

PubMed Central

Background The ideal treatment strategy for the dorsally comminuted distal radius fracture continues to evolve. Newer plate designs allow for variable axis screw placement while maintaining the advantages of locked technology. The purpose of this study is to compare the biomechanical properties of one variable axis plate with two traditional locked constructs. Methods Simulated fractures were created via a distal 1 cm dorsal wedge osteotomy in radius bone analogs. The analogs were of low stiffness and rigidity to create a worst-case strength condition for the subject radius plates. This fracture-gap model was fixated using one of three different locked volar distal radius plates: a variable axis plate (Stryker VariAx) or fixed axis (DePuy DVR, Smith & Nephew Peri-Loc) designs. The constructs were then tested at physiologic loading levels in axial compression and bending (dorsal and volar) modes. Construct stiffness was assessed by fracture gap motion during the different loading conditions. As a within-study control, intact bone analogs were similarly tested. Results All plated constructs were significantly less stiff than the intact control bone models in all loading modes (p<0.040). Amongst the plated constructs, the VariAx was stiffest axially (p=0.032) and the Peri-Loc was stiffest in bending (p<0.024). Conclusion In this analog bone fracture gap model, the variable axis locking technology was stiffer in axial compression than other plates, though less stiff in bending. PMID:25328471

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

2014-01-01

29

Rotation and plate locking at the southern Cascadia subduction zone  

Microsoft Academic Search

Global Positioning System vectors and surface tilt rates are inverted simultaneously for the rotation of western Oregon and plate locking on the southern Cascadia subduction thrust fault. Plate locking appears to be largely offshore, consistent with earlier studies, and is sufficient to allow occasional great earthquakes inferred from geology. Clockwise rotation of most of Oregon about a nearby pole is

Robert McCaffrey; Maureen D. Long; Chris Goldfinger; Peter C. Zwick; John L. Nabelek; Cheryl K. Johnson; Curt Smith

2000-01-01

30

Lessons learned from a case of proximal humeral locked plating gone awry.  

PubMed

A 59-year-old woman underwent plate fixation of her 2-part anatomic neck proximal humerus fracture through an open anterolateral approach. The fixation subsequently failed, and the operation resulted in a dense axillary nerve palsy. Six weeks after her initial procedure, she was returned to the operating room. Exploration of the nerve revealed that it was compressed beneath the plate and irreparably damaged. Sural nerve cable grafting was required in an attempt to salvage deltoid function. The recent introduction of proximal humeral locking plates provides an opportunity for surgeons to reevaluate their methods of managing proximal humerus fractures. Indications for operative fixation have broadened, and a renewed interest in the anterolateral surgical approach has been reported. This case is the first description of an axillary nerve injury occurring in association with the open anterolateral approach when used for the treatment of a proximal humerus fracture and serves as a reminder that surgeons considering the use of a lateral approach must have a thorough understanding of axillary nerve anatomy. An additional review of the case provides a forum for discussion of the anterolateral approach to the proximal humerus and an opportunity to highlight the methods that can be used to optimize fixation when locked plates are employed. It must be emphasized that our enthusiasm for advances in technique and technology should not distract from basic surgical principles when treating these fractures. PMID:19704279

Nicandri, Gregg T; Trumble, Thomas E; Warme, Winston J

2009-09-01

31

Late extensor pollicis longus rupture following plate fixation in Galeazzi fracture dislocation  

PubMed Central

Late rupture of extensor pollicis longus (EPL) tendon after Galeazzi fracture dislocation fixation is an unknown entity though it is a well-established complication following distal radius fractures. We report the case of a 55-year old male who presented with late EPL tendon rupture 4 months following internal fixation of Galeazzi fracture dislocation with a Locking Compression Plate (LCP). He was managed with extensor indicis proprius (EIP) transfer to restore thumb extension. At 4 years followup, functional result of the transfer was good. We identify possible pitfalls with this particular patient and discuss how to avoid them in future. PMID:25143650

Sabat, Dhananjaya; Dabas, Vineet; Dhal, Anil

2014-01-01

32

Fixation of mandibular fractures with biodegradable plates and screws  

Microsoft Academic Search

Objective. Little data exist regarding the use of biodegradable plates and screws for the internal fixation of human mandibular fractures. The purpose of this study was to evaluate the stability of biodegradable, self-reinforced poly-L-lactide plates and screws for the internal fixation of fractures of the human mandible. Study Design. Twenty-two individuals (14 male, 8 female; average age, 26.3 years) with

Kaan C. Yerit; Georg Enislidis; Christian Schopper; Dritan Turhani; Felix Wanschitz; Arne Wagner; Franz Watzinger; Rolf Ewers

2002-01-01

33

Population-based design of mandibular fixation plates with bone quality and morphology considerations.  

PubMed

In this paper we present a new population-based implant design methodology, which advances the state-of-the-art approaches by combining shape and bone quality information into the design strategy. The method may enhance the mechanical stability of the fixation and reduces the intra-operative in-plane bending which might impede the functionality of the locking mechanism. The computational method is presented for the case of mandibular locking fixation plates, where the mandibular angle and the bone quality at screw locations are taken into account. The method automatically derives the mandibular angle and the bone thickness and intensity values at the path of every screw from a set of computed tomography images. An optimization strategy is then used to optimize the two parameters of plate angle and screw position. The method was applied to two populations of different genders. Results for the new design are presented along with a comparison with a commercially available mandibular locking fixation plate (MODUS(®) TriLock(®) 2.0/2.3/2.5, Medartis AG, Basel, Switzerland). The proposed designs resulted in a statistically significant improvement in the available bone thickness when compared to the standard plate. There is a higher probability that the proposed implants cover areas of thicker cortical bone without compromising the bone mineral density around the screws. The obtained results allowed us to conclude that an angle and screw separation of 129° and 9 mm for females and 121° and 10 mm for males are more suitable designs than the commercially available 120° and 9 mm. PMID:23053302

Bousleiman, Habib; Iizuka, Tateyuki; Nolte, Lutz-Peter; Reyes, Mauricio

2013-02-01

34

Comparison of outcome of unilateral locking plate and dual plating in the treatment of bicondylar tibial plateau fractures  

PubMed Central

Background Tibial plateau fracture (TPF) includes different fracture patterns with varied degrees of articular depression and displacement. Many kinds of fixators, including newly designed plate with locking screws, were applied to treat these complicated fractures. We intended to follow up the surgical outcomes of (1) unilateral locking plate, (2) classic dual plates, or (3) hybrid dual plates for TPF. Materials and methods We retrospectively reviewed 76 patients with TPF, Schatzker types V and VI, who we operated from June 2006 to May 2009 in our institute. Excluding patients who expired due to other medical conditions and without complete follow-up, 45 patients were sorted out in this series. The scheme of surgical intervention was designed by visiting staff, and 15 patients, as group I, were treated with unilateral locking plate. The other 19 patients, as group II, were treated with classic dual plates. The residual 11 patients, as group III, were treated with hybrid dual plates (one lateral approach locking compression plate (LCP)?+?medial anti-gliding plate). All patients were under periodic F/U at about 6 weeks interval for at least 18 months postoperatively. Results In group I, 13 cases achieved solid bony union without obvious traumatic OA change, limitation of ROM, or malalignment. In groups II and III, 15 and 10 patients reached the same goal, respectively. By analysis of the recorded parameters with statistical software (SPSS 12.0), there were five parameters with significant difference, including Schatzker classification, operation time, staged treatment or not, hospitalization period, and hardware impingement. Conclusions There was no significant statistical difference of union rate between these three groups in our series. Based on our clinical follow-up, several key points were emphasized: (1) Soft tissue problems should be kept in mind, and usage of locking plate can reduce the discomfort of hardware impingement effectively. (2) The single lateral approach technique for TPF with locking plate results in less operation time and shorter hospitalization period. (3) If the medial buttress cannot be established by reduction of the lateral fracture, then open reduction of the medial side is necessary and buttresses the medial fragment by dual plates. PMID:25038620

2014-01-01

35

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

PubMed Central

Background and purpose The Locking Compression Plate (LCP) is part of a new plate generation requiring an adapted surgical technique and new thinking about commonly used concepts of internal fixation using plates. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability and the risk of implant failure can best be controlled. Methods Upon validation, a finite element model of an LCP attached to a cylinder was developed to simulate and analyse the biomechanics of a transverse long bone fracture fixed with a locking plate. Of special interest were the factors influencing the mechanical conditions at the fracture site, the control of interfragmentary movement and implant failure. Results Several factors were shown to influence stability in compression. Increasing translation and/or fracture angle post fixation reduced construct stability. Axial stiffness was also influenced by the working length and plate-bone distance. The fracture gap had no effect on the construct stability when no bone contact occurred during loading. Stress analysis of the LCP demonstrated that the maximum Von Mises stresses were found in the innermost screws at the screw-head junction. Interpretation For the clinical use of the LCP as a locked internal fixator in fractures with an interfragmentary gap of 1 mm, at least two to four plate holes near the fracture gap should be omitted to allow fracture motion and bone contact to occur. This will also achieve a larger area of stress distribution on the plate and reduce the likelihood of fatigue failure due to cyclic loading. PMID:24403745

Nassiri, M.; MacDonald, B.; O'Byrne, J.M.

2013-01-01

36

Improving stability of locking compression plates through a design modification: a computational investigation.  

PubMed

Femoral shaft fractures are common in both the young and elderly due to high-impact trauma and low-impact trauma, respectively. Its treatment by indirect reduction through use of locking compression plates (LCPs) has been on the rise. The LCP possess several advantages in fracture fixation, combining angular stability through use of locking screws with misalignment correction and fracture reduction onto the plate through use of conventional screws. However, there have been cases of plate breakage and fracture non-unions to warrant a study to improve its stability. A design modification is suggested for mid-diaphyseal fractures, whereby unused screw holes are removed. The structural stability of the modified and commercially available LCP is computationally analyzed using finite element modelling and a comparison made in terms of mechanical performance across different fracture lengths. A critical fracture length for which the commercially available LCP is functional as a fixator for mid-diaphyseal fractures was established. The maximum von Mises' stress attained by the commercially available LCP rose to as high as 105 MPa, whereas for the modified LCP, it did not exceed 25 MPa. As expected, these stresses were also found at screw holes, nearest to the fracture site. Critical fracture length allows clinicians to quantitatively distinguish between mid-diaphyseal fractures that can or cannot be treated by the use of LCP fixation. It is also believed that the proposed design modification will substantially increase the fatigue life of the fixator, especially at screw holes nearest to the fracture region, where most fatigue fractures are known to occur and will consequently be functional for greater fracture lengths. PMID:23582021

Anitha, D; Das De, Shamal; Sun, Khong Kok; Doshi, Hitendra K; Lee, Taeyong

2015-02-01

37

Torsion properties of biological fixation utilizing a plate with and without an intramedullary rod  

E-print Network

failure. The research reported here analyzed this biological fixation technique during torsional loading. The strain values on the surface of the plate alone were compared to those of a plate with an intramedullary rod during simulated fracture fixation...

Keiser, Michael

2012-06-07

38

The Effects of Screw Length on Stability of Simulated Osteoporotic Distal Radius Fractures Fixed with Volar Locking Plates  

PubMed Central

Purpose Volar plating for distal radius fractures has caused extensor tendon ruptures secondary to dorsal screw prominence. This study was designed to determine the biomechanical impact of placing unicortical distal locking screws and pegs in an extra-articular fracture model. Methods Volar-locking distal radius plates were applied to 30 osteoporotic distal radius models. Radii were divided into 5 groups based on distal locking fixation: bicortical locked screws, 3 lengths of unicortical locked screws (abutting the dorsal cortex [full length], 75% length, and 50% length to dorsal cortex), and unicortical locked pegs. Distal radius osteotomy simulated a dorsally comminuted, extra-articular, fracture. Each constructs stiffness was determined under physiologic loads (axial compression, dorsal bending volar bending) before and after 1000 cycles of axial conditioning and prior to axial loading to failure (2mm of displacement) and subsequent catastrophic failure. Results Cyclic conditioning did not alter constructs stiffness. Stiffness to volar bending and dorsal bending forces were similar between groups. Final stiffness(N/mm) under axial load was statistically equivalent for all groups: bicortical screws(230), full-length unicortical screws(227), 75% length unicortical screws(226), 50% length unicortical screws(187), unicortical pegs(226). Force(N) at 2 mm displacement was significantly less for 50% length unicortical screws(311) compared to bicortical screws(460), full-length unicortical screws(464), 75% length unicortical screws(400), and unicortical pegs(356). Force(N) to catastrophic fracture was statistically equivalent between groups but mean values for pegs(749) and 50% length unicortical(702) screws were 16-21% less than means for bicortical(892), full-length unicortical(860), and 75% length(894) unicortical constructs. Discussion Locked unicortical distal screws of at least 75% length produce construct stiffness similar to bicortical fixation. Unicortical distal fixation for extra-articular distal radius fractures should be entertained to avoid extensor tendon injury since it does not appear to compromise initial fixation. Clinical Relevance Biomechanical comparison of distal fixation techniques during volar locked plating for distal radius fracture. PMID:22305729

Wall, Lindley B.; Brodt, Michael D.; Silva, Matthew J.; Boyer, Martin I.; Calfee, Ryan P.

2013-01-01

39

Fixation of zygomatic and mandibular fractures with biodegradable plates  

PubMed Central

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

Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

2013-01-01

40

Four-Screw Plate Fixation vs Conventional Fixation for Diaphyseal Fractures of the Forearm  

PubMed Central

Background: Standard treatment of diaphyseal fractures of the forearm is open reduction and fixation using dynamic compression plates (DCP) and screws. This technique uses screw placement in all 6 or more of the plate holes except the hole over the fracture line. We hypothesized that DCP with selective 4-screw bicortical placement can provide adequate fixation for these fractures. Objectives: The aim of this study was to evaluate the results of conventional 6 or more screw fixation versus 4 screw fixation for adults with diaphyseal fractures of the forearm. Patients and Methods: In this prospective study, 128 fractures of the ulna, radius or both bones of the forearm in 87 patients were treated in either one of these two groups: Open reduction and internal fixation (ORIF) with conventional DCP and screws or ORIF using DCP and selective 4- screw placement. Fractures were transverse or oblique in pattern without gross comminution. In a total of 41 patients with fractures, 28 single ulnar and 18 single radius fractures were included. Follow-up visits were done at 3-6 and 12-16 weeks and at 6 months. Outcome with respect to union an nonunion rates, union time, infection, and device failure was noted. Results: No change in alignment was noted in any patient. Union time in conventional and selective bicortical 4-screw fixation was 74.8 days and 73.6 days respectively which showed no significant difference (P = 0.064). Union rate and infection was 92.1% and 3.2% in conventional and 95.3% and 0% in the selective group respectively. Non-union was observed in 5 and 3 cases of fractures in conventional and the selective group respectively. Conclusions: For treatment of the transverse or oblique diaphyseal fractures of the forearm, fixation by a same length 3.5 mm DCP with selective 4-screw cortical fixation (2 screws on each side of the fracture site) had similar results in comparison with conventional 6 or more DCP screws. Because of lesser impact on host bone and smaller incision, the selective 4-screw insertion can be an alternative technique for treatment of these fractures. PMID:24829892

Mehdi Nasab, Seyed Abdolhossein; Sarrafan, Nasser; Sabahi, Saeed

2012-01-01

41

A new volar plate DiPhos-RM for fixation of distal radius fracture: preliminary report.  

PubMed

We analyzed the efficiency of a new plate DiPhos-RM in CFR-PEEK [carbon-fiber-reinforced poly (etheretherketone)] for the volar fixation of distal radius fractures. The new plate's composition has the advantage of x-ray absolute transparency, therefore allowing to monitor the healing of the fracture. The desired combination of high strength and low rigidity is obtained through the use of the polymer composites CFR-PEEK. In this preliminary study (from March 2012 to June 2012), 10 cases of intra-articular distal radius fractures were treated with DiPhos-RM produced by Lima Corporate (Italy). The fractures were classified according to the AO classification, 4 fractures were type C1, 3 type C2, and 3 were A2. A preoperative computed tomography scan was carried out in all patients. One patient also underwent a postoperative computed tomography scan. Grip strength, range of motion, and DASH score were evaluated at follow-up. There were no cases of hardware failure. Specifically, no loss of position or alignment of fixed-angle locking screws or breakage of the plate were observed. Radiographic union was present at an average of 6 weeks (range, 5 to 8 wk). The overall preliminary experience with this new plate is favorable. The new plate is easy to apply and provides the surgeon dual options of fixed-angle or variable-angle screws. It was rigid enough to maintain the reduction also in AO type C articular fractures. PMID:23423235

Tarallo, Luigi; Mugnai, Raffaele; Adani, Roberto; Catani, Fabio

2013-03-01

42

Analysis and design of an adjustable bone plate for mandibular fracture fixation  

E-print Network

This thesis presents the design, analysis and testing of a bone plate for mandibular fracture fixation. Conventional bone plates are commonly used to set fractures of the mandible in a surgical setting. If proper alignment ...

Cervantes, Thomas Michael

2011-01-01

43

Treatment of extra-articular and simple articular distal radial fractures with intramedullary nail versus volar locking plate.  

PubMed

The purpose of this prospective, randomized and blinded study was to compare the clinical outcomes of distal radial fractures treated with either an intramedullary nail or a volar locking plate. Sixty two patients were enrolled in the study and randomized to treatment with a MICRONAILTM (Group 1, 31 patients) or an adaptive plate (Group 2, 31 patients). Fracture types included were unstable extra-articular metaphyseal distal radial fractures and simple or multifragmentary sagittal articular distal radial fractures (AO classification types A2, A3, B1.1 and B1.2). All patients were evaluated at 6 weeks, 3 months and 12 months after surgery. Outcome measures included standard radiographic parameters, active wrist range of motion, the disabilities of the arm, shoulder and hand (DASH) and Mayo wrist scores. We concluded that treatment of this subset of distal radius fractures with minimally invasive intramedullary nailing gives better clinical outcomes at 6 weeks after surgery than treatment with a volar locking plate. By 3 and 12 months following surgery, there are no significant differences in outcome between the two treatment methods. Disadvantages of the MICRONAIL™ fixation system include risk of injury to the superficial branch of the radial nerve and a narrower spectrum of indications than volar locking plates. PMID:23442339

Safi, A; Hart, R; T?kn?džjan, B; Kozák, T

2013-09-01

44

Modified biplanar open-wedge high tibial osteotomy with rigid locking plate to treat varus knee*  

PubMed Central

Objective: To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat varus knee in young and active patients. Methods: Between June 2001 to July 2008, 18 patients with monocompartmental degeneration of the knee combined with a varus malalignment of the leg had the modified biplanar opening high tibial osteotomy and the osteotomy was fixed with the locking plates (Locking Compression Plate System). The mean varus deformity before operation was 11.5° (5°~19°) and no degenerative changes were found in other departments. Stability of the knee was normal in 15 patients, but ruptures in anterior cruciate ligaments or lateral collateral ligament were presented in the remaining 3 patients. Preoperative symptom was mainly limited in the pain of medial compartment. The preoperative and follow-up data for the range of motion and Lysholm score were determined. Subjective satisfactory examination was also applied to the patients for the operation they selected. Results: All of the patients were followed up with an average of 32.5 months (12~82 months). There was no ununion or delayed union in this group during the follow-up period. No complications like broken plate, nerve injury, or blood vessel injury occurred. The postoperative average corrected degree was 9.5° (5.5°~18°). No degenerations developed in the three departments of the knee. The Lysholm scores before and after surgery were 42.5 and 77.5, respectively (P<0.01). The overall fineness rate was 83.3%. The subjective satisfactory survey demonstrated that about 83.3% patients showed satisfactory on the operation. There was no obvious difference in the range of motion before and after operation, but significant changes were found in the Lysholm score and varus degree from preoperative to follow-up. Conclusion: Proximal opening high tibial osteotomy performed in conjunction with the special rigid locking plate yielded good results for symptomatic genu varum. This new classic technique can be effectively applied to the medial compartment degeneration of the knee in active young patients. PMID:19735102

Zhang, Hai-ning; Zhang, Jie; Lv, Cheng-yu; Leng, Ping; Wang, Ying-zhen; Wang, Xiang-da; Wang, Chang-yao

2009-01-01

45

Cerclage wire-plate composite for fixation of quadrilateral plate fractures of the acetabulum: a checkrein and pulley technique.  

PubMed

Acetabular fractures with complete or incomplete quadrilateral plate separation frequently present with central displacement of the femoral head. Failure of stable fixation of medial wall fractures leaves residual subluxation despite reduction of other fracture components. Several fixation techniques may be either technically demanding or insufficient for stable fixation in conditions of comminution, osteoporosis, or neglected injuries. The proposed wire-plate composite uses a reconstruction spring plate over the pelvic brim for medial wall buttressing. One hole on its true pelvic limb provides a pulley to deviate a cerclage wire or cable passed through the greater sciatic notch into the true pelvis. This enhances buttressing against medial protrusion. Application through anterior approaches is simple and fixation is reliable in difficult fractures without the risk of joint penetration because all quadrilateral plate buttressing implants remain extraosseous. PMID:20418739

Farid, Yasser R

2010-05-01

46

Design of Fracture Fixation Plate for Necessary and Sufficient Bone Stress Shielding  

NASA Astrophysics Data System (ADS)

The objective of treating the fractured bone is to achieve painless functioning of the bone and undisturbed healing at the fracture. Internal fixation by stiff bone-plate is one of the standard methods to achieve these objectives. Recently, there is considerable interest in the usage of compliant plates to enhance bone healing with reduced stress shielding. Herein, first an analytical solution is developed to determine screw forces in the bone-plate assembly that conforms the plate and the bone under bending load. Based on the analytical calculations, an optimal fixator plate selection criterion for necessary and sufficient stress shielding is proposed. Second, effectiveness of employing a non-homogeneous stiffness graded (SG) plate rather than a homogeneous stainless steel (SS) plate for stress shielding is investigated using a finite element method. It is found that stress shielding on bone by SG plate is less compared to SS plate.

Ramakrishna, Kotlanka; Sridhar, Idapalapati; Sivashanker, Sathiamoorthy; Khong, Kok Sun; Ghista, Dhanjoo N.

47

Compression plating of tibial fractures following primary external fixation  

Microsoft Academic Search

During the time period from May 1990 to December 1992, a total of 75 tibia fractures were treated in the Department of Traumatology at the University of Bonn. Thirtyeight patients with 40 tibial fractures were managed according to a regimen including primary stabilization, usually using external fixation, soft tissue reconstruction and delayed open reduction and internal fixation using an AO

C. H. Siebert; K.-P. Lehrbaß-Sökeland; F. Rinke; M. Hansis

1997-01-01

48

High Fusion Rates with Circular Plate Fixation for Four-corner Arthrodesis of the Wrist  

Microsoft Academic Search

Background   Scaphoid excision and four-corner fusion is commonly performed to reconstruct advanced scapholunate collapse and scaphoid\\u000a nonunion with collapse. Metallic plates were introduced for achieving fixation of the four carpal bones. Although the developer\\u000a reported high rates of fusion, several other early reports of circular plate fixation suggest higher complication rates and\\u000a inferior outcomes compared with traditional fixation techniques.\\u000a \\u000a \\u000a \\u000a Questions\\/Purposes  

Ben Bedford; S. Steven Yang

2010-01-01

49

Biomechanical stability of a supra-acetabular pedicle screw Internal Fixation device (INFIX) vs External Fixation and plates for vertically unstable pelvic fractures  

PubMed Central

Background We have recently developed a subcutaneous anterior pelvic fixation technique (INFIX). This internal fixator permits patients to sit, roll over in bed and lie on their sides without the cumbersome external appliances or their complications. The purpose of this study was to evaluate the biomechanical stability of this novel supraacetabular pedicle screw internal fixation construct (INFIX) and compare it to standard internal fixation and external fixation techniques in a single stance pelvic fracture model. Methods Nine synthetic pelves with a simulated anterior posterior compression type III injury were placed into three groups (External Fixator, INFIX and Internal Fixation). Displacement, total axial stiffness, and the stiffness at the pubic symphysis and SI joint were calculated. Displacement and stiffness were compared by ANOVA with a Bonferroni adjustment for multiple comparisons Results The mean displacement at the pubic symphysis was 20, 9 and 0.8?mm for external fixation, INFIX and internal fixation, respectively. Plate fixation was significantly stiffer than the INFIX and external Fixator (P?=?0.01) at the symphysis pubis. The INFIX device was significantly stiffer than external fixation (P?=?0.017) at the symphysis pubis. There was no significant difference in SI joint displacement between any of the groups. Conclusions Anterior plate fixation is stiffer than both the INFIX and external fixation in single stance pelvic fracture model. The INFIX was stiffer than external fixation for both overall axial stiffness, and stiffness at the pubic symphysis. Combined with the presumed benefit of minimizing the complications associated with external fixation, the INFIX may be a more preferable option for temporary anterior pelvic fixation in situations where external fixation may have otherwise been used. PMID:23017093

2012-01-01

50

Nicoya earthquake rupture anticipated by geodetic measurement of the locked plate interface  

NASA Astrophysics Data System (ADS)

The Nicoya Peninsula in Costa Rica is one of the few places on Earth where the seismically active plate interface of a subduction zone is directly overlaid by land rather than ocean. At this plate interface, large megathrust earthquakes with magnitudes greater than 7 occur approximately every 50 years. Such quakes occurred in 1853, 1900 and 1950, so another large earthquake had been anticipated. Land-based Global Positioning System (GPS) and seismic measurements revealed a region where the plate interface was locked and hence accumulated seismic strain that could be released in future earthquakes. On 5 September 2012, the long-anticipated Nicoya earthquake occurred in the heart of the previously identified locked patch. Here we report observations of coseismic deformation from GPS and geomorphic data along the Nicoya Peninsula and show that the magnitude 7.6 Nicoya earthquake ruptured the lateral and down-dip extent of the previously locked region of the plate interface. We also identify a previously locked part of the plate interface, located immediately offshore, that may not have slipped during the 2012 earthquake, where monitoring should continue. By pairing observations of the spatial extent of interseismic locking and subsequent coseismic rupture, we demonstrate the use of detailed near-field geodetic investigations during the late interseismic period for identifying future earthquake potential.

Protti, Marino; González, Victor; Newman, Andrew V.; Dixon, Timothy H.; Schwartz, Susan Y.; Marshall, Jeffrey S.; Feng, Lujia; Walter, Jacob I.; Malservisi, Rocco; Owen, Susan E.

2014-02-01

51

LCP external fixation - External application of an internal fixator: two cases and a review of the literature  

Microsoft Academic Search

The locking compression plate (LCP) is an angle-stable fixator intended for intracorporeal application. In selected cases, it can be applied externally in an extracorporeal location to function as a monolateral external fixator. We describe one patient with Schatzker V tibial plateau fracture and one patient with Gustillo IIIB open tibia shaft fracture treated initially with traditional external fixation for whom

Colin Yi-Loong Woon; Merng-Koon Wong; Tet-Sen Howe

2010-01-01

52

Application of lamina replantation with ARCH plate fixation in thoracic and lumbar intraspinal tumors  

PubMed Central

The aim of the present study was to investigate the clinical effects of lamina replantation with ARCH plate fixation on patients with thoracic and lumbar intraspinal tumors, following laminectomy. Thirteen patients with thoracic and lumbar intraspinal tumors underwent total lamina replantation with ARCH plate fixation and repair of the supraspinous ligaments, following laminectomy and tumor enucleation. To investigate the clinical effect of lamina replantation with ARCH plate fixation, pre- and postoperative visual analog scale (VAS), and Oswestry Disability Index (ODI) scores were determined, and pre- and postoperative X-ray and magnetic resonance imaging (MRI) examinations were conducted. Computed tomography (CT) examinations were also included in the follow-up. No complications were observed pre- or postoperatively. The VAS and ODI results 2 weeks following surgery and at the final follow-up examination demonstrated a significant improvement compared with the corresponding preoperative results. The X-ray examination results indicated a satisfactory internal fixation location, without any characteristics of a fracture, lumbar scoliosis, kyphosis or instability. Following the surgery, the CT and MRI examination results demonstrated that healing of the lamina bone and repair of the supraspinous ligament had occurred without tumor recurrence or spinal epidural scar recompression. Two of the 13 cases were lost to follow-up. The results indicated that in patients with thoracic and lumbar intraspinal tumors, lamina replantation with ARCH plate fixation following total laminectomy is effective and provides thoracolumbar stability. Furthermore, this has been identified to be an effective technique for preventing intraspinal scar proliferation. PMID:24137233

ZHOU, DONG; NONG, LU-MING; GAO, GONG-MIN; JIANG, YU-QIN; XU, NAN-WEI

2013-01-01

53

All levels versus alternate levels plate fixation in expansive open door cervical laminoplasty  

PubMed Central

Background: Expansive open door laminoplasty with the use of titanium miniplate is becoming popular. Usually, the plate is applied at each level to prevent re-closure of the opened lamina. However, it is also used at alternating levels (i.e., C3, C5 and C7) in clinical settings in order to reduce the cost. Whether they have any difference in clinical efficacy? There is a lack of comparative data between the two kinds of plate fixation in the literature. Materials and Methods: 83 patients who underwent cervical laminoplasty with alternating levels plate fixation (51 patients in Group A) or all levels plate fixation (32 patients in Group B) between January 2008 and October 2012 were evaluated in our institute retrospectively. Clinical and radiologic outcomes were assessed. Results: No statistical difference was found in the mean operation time, blood loss, incidence of significant axial symptoms and C5 palsy, preoperative anteroposterior diameter (APD) and preoperative Japanese Orthopedic Association score between the two groups. However, Group B showed a higher rate of neurologic recovery after surgery. Postoperative increased APD and open angle in Group B were significantly larger than Group A. The mean cost for Group B (12801 ± 460.6 USD) was higher than Group A (8906 ± 566.7 USD). Conclusions: Despite the higher cost of all level fixation, it is more effective in maintaining the expansion of the spinal canal and can obtain better clinical improvement compared to alternating levels fixation.

Wang, Zheng-Fei; Chen, Guang-Dong; Xue, Feng; Sheng, Xiao-Wen; Yang, Hui-Lin; Qian, Jun

2014-01-01

54

Processing and evaluation of long fiber thermoplastic composite plates for internal fixation  

NASA Astrophysics Data System (ADS)

The metallic plates used in internal fracture fixation may have up to ten times the elastic modulus of normal bone tissue, causing stress shielding-induced osteopenia in healed bone that can lead to re-fracture after plate removal and prolonged and painful recovery. Thermoplastic polymer matrix composites reinforced with long carbon fiber are promising alternative materials for internal fixation plates because they may be produced with relative ease and be tailored to have specific mechanical properties, alleviating the stress shielding problem. Long carbon fiber-reinforced polyetheretherketone (LCF PEEK) plates were produced using the extrusion / compression molding process. Static flexural testing determined that LCF PEEK plates with rectangular cross-section had an average flexural modulus of 12 GPa, or 23% of the flexural modulus of a stainless steel plate. The LCF PEEK plates also experienced negligible (14.7%, 14.5%, and 16.7%) reductions in modulus after fatigue testing at applied moments of 2.5, 3.0, and 3.5 N•m, respectively, over 106 load cycles. Aging the plates in 0.9% NaCl solution for four and eight weeks caused 0.34% and 0.28% increases in plate mass, respectively. No significant decrease of flexural properties due to aging was detected. Differential scanning calorimetry (DSC) revealed the PEEK matrix of the plates to be 24.5% crystalline, which is lower than typical PEEK crystallinity values of 30-35%. Scanning electron microscopy (SEM) revealed three times as many fiber pullout areas in LCF PEEK fracture surfaces as in fracture surfaces of long carbon fiber-reinforced polyphenylenesulfide (LCF PPS), another plate material tested. DSC and SEM data suggest that improvements in processing conditions and fiber/matrix bonding, along with higher carbon fiber fractions, would enhance LCF PEEK plate performance. LCF PEEK remains a promising alternative to stainless steel for internal fixation plates.

Warren, Paul B.

55

A parametric analysis of bone fixation plates on fractured equine third metacarpal  

E-print Network

A P~TRIC ANALYSIS OI' BONE FIXATION PLATES ON FRACTURED EQUINE THIRD lKTACARPAL A Thesis by Donald Reagan Ray Submitted to tnk Graduate College of Texas A&N University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE Hay 1970 Major Subject: Civil Engineering A PARAMETRIC ANALYSIS OF BONE FIXATION PLATES ON FRACTURED EQUINE THIRD METACARPAL A Thesis Donald Reagan Ray Approved as to style and content by: (Cha of Committee) / I (Head of D artment...

Ray, Donald Reagan

2012-06-07

56

Arthroscopic evaluation for omalgia patients undergoing the clavicular hook plate fixation of distal clavicle fractures  

PubMed Central

Background The aim of this study is to investigate the anatomic changes in the shoulder joints responsible for omalgia after the clavicular hook plate fixation under arthroscope. Methods Arthroscopic examination was carried out for 12 omalgia patients who underwent clavicular hook plate fixation due to distal clavicle fractures. Functional outcome of shoulder was measured by the Japanese Orthopaedic Association (JOA) score before and after the withdrawal of the fixation plate. Results The rotator cuff compression by the clavicular hook was arthroscopically observed in 11 of the 12 cases. The JOA scores of the shoulder were significantly improved at 1 month after the withdrawal of the fixation plate (pain, 28?±?2.4 vs. 15?±?5.2; function, 19.2?±?1.0 vs. 11.7?±?1.9; range of movements, 26.8?±?2.6 vs. 14.8?±?3.4) compared with before. Conclusions The impingement of the hook to the rotator cuff may be the main cause for the omalgia. The appropriate hook and plate that fit to the curve of the clavicle as well as the acromion are necessary to decrease the severity of omalgia. PMID:24917508

2014-01-01

57

Analysis of gene expression profiles in healing rat fractures treated with nail and plate fixation.  

PubMed

To compare fracture healing therapies, the gene expression profiles of rat fracture samples treated with nail and plate fixation were analyzed at 1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after surgery. The gene expression profiles GSE1685, which include 19 samples, were downloaded from the Gene Expression Omnibus database. After preprocessing, the gene expression profiles were subjected to time series analysis using the Short Time-series Expression Miner software, and the significantly differentially expressed gene (DEG) sets were selected. Further, the distributions of those DEG sets on the corresponding chromosomes were identified using the functional classification tool. Finally, the DEGs were subjected to function and pathway enrichment analysis. DEG analysis indicated that the number of DEGs (854 genes) from nail fixation was significantly lower than that of DEGs (1029 genes) from plate fixation. The DEGs were mainly enriched in cell proliferation, cellular localization, and response to wounding functions. Several critical DEGs expressed during the fracture healing process were screened, and 2 common pathways were enriched for the DEGs in the nail fixation and plate fixation. These DEGs and pathways may be potential targets or predictive markers during fracture healing. PMID:25366739

Wang, S D; Li, X L; Liu, H P

2014-01-01

58

Limb alignment of pes valgus in a giant breed dog by plate-rod fixation.  

PubMed

A 2-year-old, female, neutered Newfoundland presented with pelvic limb lameness due to a distal tibial valgus deformity. A left distal fibula ostectomy and disto-medial tibial cuneiform ostectomy were performed with reduction and stabilisation using plate-rod internal fixation. Following surgical correction of the deformity the dog regained good functional mobility of the limb. PMID:17846693

Burton, N J; Owen, M R

2007-01-01

59

Interseismic locking of the plate interface in the northern Cascadia subduction zone, inferred from inversion of GPS data  

Microsoft Academic Search

We inverted GPS velocities from 20 continuous and 53 campaign sites in the northern Cascadia subduction zone using a Bayesian inverse method to estimate the locking state of the plate interface. The results are consistent with previous estimates based on thermal arguments and forward modeling. They suggest that the completely locked segment of the plate interface is offshore and that

Shoichi Yoshioka; Kelin Wang; Stephane Mazzotti

2005-01-01

60

The Mechanical Benefit of Medial Support Screws in Locking Plating of Proximal Humerus Fractures  

PubMed Central

Background The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures. Methods Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. Results Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001). When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P?0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. Conclusions Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure. PMID:25084520

Liu, Yanjie; Pan, Yao; Zhang, Wei; Zhang, Changqing; Zeng, Bingfang; Chen, Yunfeng

2014-01-01

61

To evaluate the efficacy of biodegradable plating system for fixation of maxillofacial fractures: A prospective study  

PubMed Central

Aims: The present study was undertaken to evaluate the efficacy of biodegradable plating system for fixation of maxillofacial fractures and to study the morbidity associated with the use of biodegradable plates and screws. Materials and Methods: This prospective study consisted of 10 patients with maxillofacial fractures requiring open reduction and internal fixation. Fractures with infection, comminuted and pathological fractures were excluded. All were plated with biodegradable system (Inion CPS) using standard plating principles and observed for a total period of 24 weeks. Characteristics of the fractures, ease of use of bioresorbable plate/screw system and post operative complications were assessed. Results: Of total 10 patients, eight patients were of midface fracture and two pediatric patients with mandibular fracture, with nine male and one female. The mean age was 32.8 years. Out of 20 plates and 68 screws applied to the 10 fractures sites; there were three incidences of screw breakage with no other intraoperative difficulties. Paresthesia of the infraorbital nerve was present in two patients, and recovered completely in four weeks after surgery. Fracture reduction was considered to be satisfactory in all cases. One patient developed postsurgical infection and was managed with oral antibiotics and analgesics. Conclusions: Favorable healing can be observed through the use of biodegradable plates and screws to stabilize selected midface fractures in patients of all ages, as well as mandible fractures in early childhood, however further studies with more sample size are required. PMID:24665170

Bali, Rishi K.; Sharma, Parveen; Jindal, Shalu; Gaba, Shivani

2013-01-01

62

Biomechanical evaluation of the impact of various facet joint lesions on the primary stability of anterior plate fixation in cervical dislocation injuries: a cadaver study.  

PubMed

Object Injuries of the subaxial cervical spine including facet joints and posterior ligaments are common. Potential surgical treatments consist of anterior, posterior, or anterior-posterior fixation. Because each approach has its advantages and disadvantages, the best treatment is debated. This biomechanical cadaver study compared the effect of different facet joint injuries on primary stability following anterior plate fixation. Methods Fractures and plate fixation were performed on 15 fresh-frozen intact cervical spines (C3-T1). To simulate a translation-rotation injury in all groups, complete ligament rupture and facet dislocation were simulated by dissecting the entire posterior and anterior ligament complex between C-4 and C-5. In the first group, the facet joints were left intact. In the second group, one facet joint between C-4 and C-5 was removed and the other side was left intact. In the third group, both facet joints between C-4 and C-5 were removed. The authors next performed single-level anterior discectomy and interbody grafting using bone material from the respective thoracic vertebral bodies. An anterior cervical locking plate was used for fixation. Continuous loading was performed using a servohydraulic test bench at 2 N/sec. The mean load failure was measured when the implant failed. Results In the group in which both facet joints were intact, the mean load failure was 174.6 ± 46.93 N. The mean load failure in the second group where only one facet joint was removed was 127.8 ± 22.83 N. In the group in which both facet joints were removed, the mean load failure was 73.42 ± 32.51 N. There was a significant difference between the first group (both facet joints intact) and the third group (both facet joints removed) (p < 0.05, Kruskal-Wallis test). Conclusions In this cadaver study, primary stability of anterior plate fixation for dislocation injuries of the subaxial cervical spine was dependent on the presence of the facet joints. If the bone in one or both facet joints is damaged in the clinical setting, anterior plate fixation in combination with bone grafting might not provide sufficient stabilization; additional posterior stabilization may be needed. PMID:25014498

Oberkircher, Ludwig; Born, Sebastian; Struewer, Johannes; Bliemel, Christopher; Buecking, Benjamin; Wack, Christina; Bergmann, Martin; Ruchholtz, Steffen; Krüger, Antonio

2014-10-01

63

Open reduction and internal fixation of posterior pilon fractures with buttress plate  

PubMed Central

Objective: Posterior pilon fractures are rare injuries and have not yet gained well recognition. The purpose of this study was to present the treatment outcome for patients with posterior pilon fractures treated with buttress plate. Method: In this retrospective study we identified patients with posterior pilon fractures of the distal tibia who had undergone open reduction and internal fixation at our institute. Between January 2007 and December 2009, 10 patients (mean age, 46.5 years) who had undergone buttress plating via either a posterolateral approach or a dual posterolateral-posteromedial approach, were selected. All 10 patients were available for follow-up. The clinical outcome was evaluated with the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the visual analogue scale (VAS). The radiological evaluation was performed using the osteoarthritis-score (OA-score). Results: Satisfactory reduction and stable fixation were accomplished in all patients. At a mean follow-up of 36.2 months, all patients had good radiological results and showed satisfactory clinical recovery. The mean AOFAS sore was 87.8, the mean OA-score was 0.6, and the mean VAS scores during rest, active motion, and weight-bearing walking were 0.6, 0.8, and 1.4, respectively. Conclusion: Buttress plating for posterior pilon fractures gave satisfactory clinical outcomes. It also ensured rigid fixation which in turn enabled earlier postoperative mobilization. Level of Evidence IV, Retrospective Study. PMID:24644421

Chen, Da-wei; Li, Bing; Aubeeluck, Ashwin; Yang, Yun-feng; Zhou, Jia-qian; Yu, Guang-rong

2014-01-01

64

Comparison of compressive strength between three different plates for mandibular angle fractures fixation.  

PubMed

The present study aims to compare three types of internal fixation for fractures of the mandibular angle. Mechanical testing was performed on replicas of polyurethane hemimandibles sectioned at the angle region to simulate a fracture and fixed with three different hardwares. Fixation devices enrolled on this survey included the grid plates with and without an intermediate bar and the method described by Champy and colleagues in 1978 and the sample consisted of 10 hemimandibles for each group. Vertical loadings were applied on each hemimandible and recorded after a vertical displacement of 3 and 5 mm. Statistical analysis was made by means of the variance analysis (ANOVA) and the Duncan test with a significance level of 5%. The Champy technique showed a statistically significant increased resistance when compared to the grid plates after vertical displacements of 3 and 5 mm. The results of this survey suggest that the Champy technique, when compared to the grid plate positioned at the middle of the mandibular bone (placement site selected for this study), is more resistant than the grid plate and that the inclusion or not of an intermediate bar to the grid plates does not improve its resistance after linear vertical loadings. PMID:24296119

Negreiros Lyrio, Mariana C; Monnazzi, Marcelo Silva; De Moraes, Marcio; Hochuli-Vieira, Eduardo; Nunes Reis, José Mauricio; Pereira-Filho, Valfrido Antonio

2014-07-01

65

The retromandibular transparotid approach for reduction and rigid internal fixation using two locking miniplates in mandibular condylar neck fractures.  

PubMed

We evaluated the safety, efficacy, and morbidity associated with the treatment of displaced mandibular condylar neck fractures using a retromandibular transparotid approach to reduce and rigidly fix using two 2.0-mm locking miniplates. Our surgical inclusion criteria were: patient selection of open reduction and fixation, displaced unilateral condylar fractures with derangement of occlusion, and bilateral condylar fractures with an anterior open bite. The study group consisted of 19 patients who underwent surgery for 19 mandibular condylar neck fractures; patients were analyzed prospectively, with more than 6 months of follow-up, and were evaluated in terms of functional results, scar formation, postoperative complications, and stability of fixation. The results showed that functional occlusion identical to the preoperative condition and correct anatomical reduction of the condylar segments in centric occlusion, followed by immediate functional recovery, was achieved in all patients. No patient suffered from any major or permanent complication postoperatively, although there were two cases (11%) of temporary facial nerve palsy, which resolved completely within 3 months. Surgical scars were barely visible. The retromandibular transparotid approach with open reduction and rigid internal fixation for displaced condylar neck fractures of the mandible is a feasible and safe, minimally invasive surgical technique that provides reliable clinical results. PMID:24070772

Kanno, T; Sukegawa, S; Tatsumi, H; Nariai, Y; Ishibashi, H; Furuki, Y; Sekine, J

2014-02-01

66

Reconstruction of the lumbar spine using AO DCP plate internal fixation.  

PubMed

Augmentation of lumbar spine fusion with internal fixation using pedicle screw systems has gained wide currency because it offers rigid stabilization to foster fusion healing. The AO DCP plate has been employed in Europe as a spinal implant with pedicle fixation using 6.5 mm, full-threaded cancellous bone screws with success. This report details the experience of using this device for lumbar spine fusion in a series of 46 North American patients with a mean follow-up of 1.25 years (range 1-2.5 years). Thirty-one patients had had prior lumbar spine surgery with poor outcomes, and 15 had had no prior surgery. All were treated surgically for lumbar degenerative disease with canal decompression, internal fixation with AO plates, and fusion with autologous bone grafting posterolaterally. Complications included two early and one delayed wound infection; five cases of screw loosening; three cases of screw breakage; and three cases of screw impingement upon a nerve. Results of surgery in 17 patients with failed interbody fusion included good to excellent pain relief in 59%, and solid fusion in 76%. In 14 patients with failed posterior surgery the good to excellent pain relief rate was 79%, and the fusion rate was 86%. In 15 patients undergoing primary surgery there was 89% good to excellent pain relief and a solid fusion rate of 87%. The benefits accruing from augmentation of the fusion with internal fixation using AO DCP plates are positive and justify its continued use. Complications encountered in the early experience have been significantly reduced in subsequent series, indicating the existence of a "learning curve" effect which would mandate specific training of spinal surgeons in the technique. PMID:2913675

Thalgott, J S; LaRocca, H; Aebi, M; Dwyer, A P; Razza, B E

1989-01-01

67

The design and analysis of a laminated partially degradable composite bone plate for fracture fixation.  

PubMed

During the early stages of fracture healing, rigid internal fixation maintains alignment and promotes primary osseous union. Unfortunately, as healing progresses rigid fixation from bone plating can cause bone in the region of the plate to undergo stress protection atrophy. This can result in significant loss of bone mass and osteoporosis. Refracture of the bone upon device removal is a widely reported complication. In an effort to minimize or eliminate stress protection atrophy, we have designed a partially absorbable, fiber-reinforced bone plate. Ideally, such a plate gradually loses rigidity as the fracture heals, increasingly transferring stress to the bone. Stress protection may be avoided and removal of the device after healing may be unnecessary. Composite theory was used to determine an optimum fiber layup for a composite bone plate. Composite analysis suggested the mechanical superiority of a 0 degree/ +/ -45 degree laminae layup. Given this laminated design, a thermoplastic absorbable polymer (polylactic acid polymer) was reinforced with high-modulus carbon fiber to produce a semiabsorbable composite. Implant evaluation included optimizing fabrication techniques, thorough mechanical device testing, and implantation on canine femurs to determine biocompatibility and efficacy. The composite design proved to have superior static and fatigue properties to laminated or random fiber designs used previously. Two techniques for hole fabrication were tested. The production of screw holes during the molding process rather than machining postmolding, improved the mechanical integrity of the finished plate. Although the 0 degree/ +/- 45 degree carbon/polylactic acid composite possessed superior mechanical properties, it was unsuccessful in the in vivo environment. Water absorption and subsequent delamination made the plate flexible. Hypertrophic nonunions developed. Further development to prevent water intrusion and premature loss of mechanical properties is necessary. PMID:3429470

Zimmerman, M; Parsons, J R; Alexander, H

1987-12-01

68

Rotation and plate locking at the southern Cascadia subduction zone, Geophys  

E-print Network

Abstract. Global Positioning System vectors and surface tilt rates are inverted simultaneously for the rotation of western Oregon and plate locking on the southern Cascadia subduction thrust fault. Plate locking appears to be largely offshore, consistent with earlier studies, and is sufficient to allow occasional great earthquakes inferred from geology. Clockwise rotation of most of Oregon about a nearby pole is likely driven by collapse of the Basin and Range and results in shortening in NW Washington State. The rotation pole lies along the Olympic- Wallowa lineament and explains the predominance of extension south of the pole and contraction north of it. using the GAMIT/GLOBK analysis software [King and Bock, 1999; Herring, 1998]. Site velocities and their covariances were estimated by linear regression of the time series of positions. Velocities were put in the North American (NA) reference frame by removing the NA-ITRF96 rotation [DeMets and Dixon, 1999], which agrees with our solution at the mm/a level for 16 NA sites. Convergence of the Juan de Fuca (JF) plate with NA is the sum of JF-Pacific [Wilson, 1993] and Pacific-NA [DeMets and Dixon, 1999] poles. The 71 horizontal GPS vectors (2 components each) and 4 tilt rates provide 146 observations for the inversion. Misfit is defined by 1.

Robert Mccaffrey; Maureen D. Long; Chris Goldfinger; Peter C. Zwick; John L. Nabelek; Cheryl K. Johnson; Curt Smith

2000-01-01

69

A video guided solution for screw insertion in orthopedic plate fixation  

NASA Astrophysics Data System (ADS)

In orthopedic and trauma surgery, metallic plates are used for reduction and fixation of bone fractures. In clinical practice, the intra-operative planning for screw fixation is usually based on fluoroscopic images. Screw fixation is then performed on a free-hand basis. As such, multiple attempts may be required in order to achieve an optimal positioning of the fixing screws. To help the physician insert the screws in accordance to the planned position, we propose a method for screw insertion guidance. Our approach uses a small video camera, rigidly placed on the drill, and a set of small markers that are rigidly fixed on a variable angle drill sleeve. In order to investigate the achievable accuracy of our setup, we simulate the estimation of the drill bit position under two different marker arrangements, planar and 3D, and different noise levels. Furthermore, we motivate our choices for marker design and position given the limited space available for marker positioning, the requirement for accurate position estimation of the drill bit and the illumination changes that could affect the surgical site. We also describe our proposed marker detection and tracking pipeline. Our simulation results let us conclude that we can achieve an accuracy of 1° and 1mm in the estimation of angular orientation and tip position of the drill bit respectively, provided that we have accurate marker detection.

Magaraggia, J.; Kleinszig, G.; Graumann, R.; Angelopoulou, E.; Hornegger, J.

2013-03-01

70

Achieving locked intramedullary fixation of long bone fractures: technology for the developing world.  

PubMed

Eighty per cent of severe fractures occur in developing countries. Long bone fractures are treated by conservative methods if proper implants, intraoperative imaging and consistent electricity are lacking. These conservative treatments often result in lifelong disability. Locked intramedullary nailing is the standard of care for long bone fractures in the developed world. The Surgical Implant Generation Network (SIGN) has developed technology that allows all orthopaedic surgeons to treat fracture patients with locked intramedullary nailing without the need for image intensifiers, fracture tables or power reaming. Introduced in 1999, SIGN nails have been used to treat more than 100,000 patients in over 55 developing world countries. SIGN instruments and implants are donated to hospitals with the stipulation that they will be used to treat the poor at no cost. Studies have shown that patients return to function more rapidly, hospital stays are reduced, infection rates are low and clinical outcomes excellent. Cost-effectiveness analysis has confirmed that the system not only provides better outcomes, but does so at a reduced cost. SIGN continues to develop new technologies, in an effort to transform lives and bring equality in fracture care to the poorest of regions. PMID:22847118

Phillips, Jonathan; Zirkle, Lewis G; Gosselin, Richard A

2012-10-01

71

Use of mineralized collagen bone graft substitutes and dorsal locking plate in treatment of elder metaphyseal comminuted distal radius fracture  

NASA Astrophysics Data System (ADS)

Bone graft may be needed to fill bone defect in elderly patients with a metaphyseal comminuted distal radius fracture. In this retrospective, nonrandomized, single-surgeon study, we evaluated the clinical and radiologic outcomes of using both dorsal locking plates with or without augmentation with mineralized collagen (MC) bone graft for elderly patients with dorsally metaphyseal comminuted radius fractures. Patients in group 1 ( n = 12) were treated with dorsal locking plates with MC bone graft application into the metaphyseal bone defect, and those in group 2 ( n = 12) only with dorsal locking plates. Clinical and radiologic parameters were determined at three and 12 months after surgery. At final follow-up, no significant difference was noted between the 2 groups in terms of palmar tilt and radial inclination ( p = 0.80); however, ulnar variance increased significantly in the group 2 treated with dorsal locking plates without augmentation ( p < 0.05). Functionally, there was no significant difference between the groups. Our preliminary study suggests that combination of MC as bone-graft substitutes and dorsal locking plates may be a usefully alternative for elderly patients with metaphyseal comminuted distal radius fracture.

Liu, Ke-Bin; Huang, Kui; Teng, Yu; Qu, Yan-Zheng; Cui, Wei; Huang, Zhen-Fei; Sun, Ting-Fang; Guo, Xiao-Dong

2014-03-01

72

Biomechanical analysis of the acetabular buttress-plate: are complex acetabular fractures in the quadrilateral area stable after treatment with anterior construct plate-1/3 tube buttress plate fixation?  

PubMed Central

OBJECTIVE: The acetabular buttress-plate has been widely used in treating difficult cases with satisfying clinical results. However, the biomechanical properties of a postoperative acetabular fracture fixed by the buttress-plate are not clear. The purpose of this study was to evaluate the biomechanical properties of stability after the anterior tube buttress-plate fixation of complex acetabular fractures in the quadrilateral area. METHODS: A construct was proposed based on anterior construct plate - 1/3 tube buttress plate fixation for acetabular both-column fractures. Two groups of six formalin-preserved cadaveric pelvises were analyzed: (1) group A, the normal pelvis and (2) group B, anterior construct plate-1/3 tube buttress plate with quadrilateral area fixation. The displacements were measured, and cyclical loads were applied in both standing and sitting simulations. RESULTS: As the load was added, the displacements were Aplate - 1/3 tube buttress plate fixation provided a better stable construct for early sitting. The standing mode yielded more significant differences between the groups. Placing a 1/3 tube buttress-plate via an anterior approach is a novel method of providing quadrilateral area support in this setting. PMID:23917670

Wu, Yong-De; Cai, Xian-Hua; Liu, Xi-Ming; Zhang, Hong-Xi

2013-01-01

73

Geometrical locking of the irreversible magnetic moment to the normal of a thin-plate superconductor  

SciTech Connect

We solve the Bean critical-state model for the screening current distribution in an infinite superconducting slab in a tilted magnetic field {bold H}, and calculate from it the magnitude and direction of the induced magnetic moment {bold m}. As the tilt angle increases, {bold m} remains directed close to the plate normal {bold n} until {bold H} is almost perpendicular to {bold n}, then {bold m} rotates very rapidly. We consider several generalizations of the model: finite length, a more realistic current-voltage characteristic, and critical-current anisotropy, but find that they have only a minor quantitative effect on the results derived for the simplest case. Also, we prove that the closure currents always contribute half the moment. Vector magnetic moment measurements of YBa{sub 2}Cu{sub 3}O{sub y} single crystals and an epitaxial film, and also on samples of conventional superconductors, confirm the model calculations. These geometrical effects are important for the analysis of the angular behavior of the critical currents and their anisotropy in HTS materials; also, they assist the observation of vortex locking to twin boundaries in HTS crystals, but tend to obscure vortex locking to CuO planes. {copyright} {ital 1997} {ital The American Physical Society}

Zhukov, A.A. [Physics Department, Moscow State University, Moscow 117234 (Russia)] [Physics Department, Moscow State University, Moscow 117234 (Russia); [Centre for High Temperature Superconductivity, Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom); Perkins, G.K.; Bugoslavsky, Y.V.; Caplin, A.D. [Centre for High Temperature Superconductivity, Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)] [Centre for High Temperature Superconductivity, Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

1997-08-01

74

Tidal Triggering of Earthquakes in and Around the Locked Zone of the Philippine Sea Plate in the Tokai Region, Japan  

Microsoft Academic Search

We investigated statistical correlation between the earth tide and earthquake occurrence in and around the locked zone, 80 km x 60 km, of the plate interface in the Tokai region, central Japan, where a large interplate earthquake may be impending. The data we used are the origin times, hypocenter coordinates and focal mechanisms of M >= 1.5 earthquakes occurring in

S. Tanaka; H. Sato; S. Matsumura; M. Ohtake

2003-01-01

75

Characterizing Plate Re-locking and Mantle Viscoelastic Response Following the 2010 Maule Mw 8.8 Megathrust Earthquake  

NASA Astrophysics Data System (ADS)

Following a subduction zone mega-earthquake we observe afterslip on the plate interface which is predominantly aseismic and can release as much as 20% of the moment release of the coseismic slip. However, as the postseismic period progresses the afterslip rate decays and the seismogenic zone begins to re-lock. Re-locking is manifested in the data by a turnaround of the GPS vectors from trenchwards to a convergence-parallel direction and a decrease in aftershock b-value. Due to the viscoelastic relaxation of the mantle we see a sustained trenchward displacement as we move futher away from the plate interface and into the backarc, concurrent with the turnaround of the stations closer to the plate interface. The excellent spatial coverage of continuous GPS stations in the region affected by the Maule Mw=8.8 2010 earthquake, combined with the proximity of the coast to the seismogenic zone, allows us to study subduction plate interface kinematics in unprecedented detail. Here we present geodetic evidence for re-locking of the seismogenic plate interface using over 3 years of postseismic data from continuous and campaign GPS stations close to the seismogenic zone. We attempt to characterize the process of re-locking using Finite Element Modelling of the South-Central Chilean subduction margin. Modelling proceeds by introducing a coseismic stress change and varying the parameters of rate-and-state friction along the plate interface to fit the vector turnaround of the near-field GPS stations. The data further towards the back-arc are used to constrain the linear Maxwell viscoelastic response of the mantle in a separate modeling step; the contribution of the viscoelastic relaxation to the surface displacement is then subtracted from the dataset to give a refined estimate of surface displacements due to plate interface kinematics. By analyzing the time dependent linear Maxwell viscoelastic parameters we attempt to deduce the most likely constitutive models of mantle viscoelasticity.

Bedford, Jonathan; Moreno, Marcos; Baez, Juan Carlos; Bartsch, Mitja; Heidbach, Oliver; Oncken, Onno; Rosenau, Matthias; Tilmann, Frederik; Tassara, Andrés

2014-05-01

76

Biomechanical evaluation with finite element analysis of the reconstruction of femoral tumor defects by using a double-barrel free vascularized fibular graft combined with a locking plate  

PubMed Central

The repair of large distal femoral tumor defects can be challenging for orthopedic surgeons. The combination of a double-barrel free vascularized fibular graft (DFVFG) with a locking plate is a viable option. However, the biomechanical influence of the fibular bone length on the locking plate attachment is unclear. We aimed to evaluate the stability of the distal femoral defect after reconstruction with fibular grafts of different lengths. A three-dimensional model of a healthy volunteer was developed using computed tomography images. A locking plate and bicortical screws were constructed and registered with CAD. Four models were defined (6 cm, 8 cm, 10 cm, and 12 cm bone grafts). The models were imported into finite element analysis software. Boundary-constrained and load conditions were applied. The model stress distribution and displacement were statistically analyzed. The Von Mises stress distributions were similar between the 6 cm, 8 cm, and 10 cm bone grafts and locking plate within each of those bone defect models (P > 0.05), while the Von Mises stress distribution was significantly higher in the 12 cm model than the other 3 lengths for both the bone graft and locking plate (P < 0.05). Significantly greater Von Mises stress was observed at the 12 cm bone graft and locking plate than with the shorter bone grafts. Therefore, we recommend that, to avoid complications, the bone graft should not exceed 12 cm when using FVFG in combination with a locking plate while treating a distal femoral tumor defect. PMID:25356094

Ma, Limin; Zhou, Ye; Zhang, Yu; Zhou, Xia; Yao, Zilong; Huang, Wenhan; Qiao, Guoqing; Xia, Hong

2014-01-01

77

Does medial support decrease major complications of unstable proximal humerus fractures treated with locking plate?  

PubMed Central

Background The purpose of this study was to evaluate the role of medial support and clinical factors responsible on outcomes and major complications associated with treatment of unstable proximal humerus fractures using a locking plate and suture augmentation. Methods Sixty-three cases in 62 patients (42 female, 20 male) were evaluated between September 2004 and October 2008. Cases were divided into either a medial support group (36 cases) or non-medial support group (27 cases). Clinical and radiographic evaluations included Neer’s evaluation criteria, the neck-shaft angle using the Paavolainen method, and complications. We analyzed the correlation between bone- and fracture- related complications and three independent clinical variables, such as the presence of medial support, fracture type, and osteoporosis by way of multivariate logistic regression. Results There were statistically significant differences in the overall incidence of complications based on the presence of medial support (p = 0.014) and preoperative fracture type (p = 0.018), but no differences based on the presence of osteoporosis (p = 0.157). According to multivariate logistic regression analysis, the restoration of medial support was the most reliable factor to prevent bone- and fracture- related complications. In addition, when we compared the incidence of bone- and fracture-related complications in the presence or absence of medial support among 30 patients with osteoporosis, the group with restoration of medial support had only one complication of humeral head osteonecrosis despite the presence of osteoporosis (5.9% vs. 46.2%, p = 0.025). According to Neer’s criteria, excellent or satisfactory clinical results accounted for seventy-three percent of the total cases (46 of 63 cases). Seventy-eight percent (49 of 55 cases) showed good radiographic results by the Paavolainen method. There were 14 complications in 13 of 63 cases (20.6%). Conclusions In the treatment of unstable proximal humerus fractures with locking plate technology and suture augmentation, we suggest that obtaining medial support is an important factor in preventing major bone- and fracture-related postoperative complications such as reduction loss or nonunion. PMID:23517539

2013-01-01

78

Comparison of Functional Recovery in the Very Early Period After Surgery Between Plate and Nail Fixation for Correction of Stable Femoral Intertrochanteric Fractures  

PubMed Central

Purpose: This study aimed to compare the differences in functional recovery between patients undergoing plate and nail fixation in the very early period after surgery. Method: This study was designed as a controlled clinical trial that included 18 patients who were surgically treated with either dynamic hip screw as plate fixation or proximal femoral nail as nail fixation for stable intertrochanteric fractures. In particular, all patients selected for the study reported walking completely independently without the use of walking aids prior to sustaining their initial fracture. In all, 8 patients (mean age, 73.8 years; range, 65-89 years) were treated with plate fixation (group plate) and 10 patients (mean age, 79.7 years; range, 70-90 years) were treated with nail fixation (group nail). Functional evaluations were assessed every week after surgery using the Japanese Orthopaedic Association (JOA) hip functional scores and active range of motion (ROM) of the hip joint. Results: The recovery of activities of daily living (ADLs) according to JOA hip functional scores at week 4 after surgery was significantly better in group nail than in group plate (P = .03), whereas active ROM of hip flexion improved significantly in group plate than in group nail at weeks 3 and 4 after surgery (P = .04 and P = .02, respectively). Conclusions: The results suggested that nail fixation may provide a more rapid recovery of ADLs than that of plate fixation in the very early period after surgery. However, plate fixation may provide better ROM of hip flexion than that of nail fixation.

Fushimi, Kazunari; Shirai, Goshi; Fukuta, Masashi

2014-01-01

79

A laboratory investigation to assess the influence of cement augmentation of screw and plate fixation in a simulation of distal femoral fracture of osteoporotic and non-osteoporotic bone.  

PubMed

The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017). PMID:24078541

Wähnert, D; Lange, J H; Schulze, M; Gehweiler, D; Kösters, C; Raschke, M J

2013-10-01

80

Did the 2010 Chile earthquake change the locking degree at neighboring plate interface segments of the Andean subduction zone?  

NASA Astrophysics Data System (ADS)

A widely held view is that lateral extents and magnitudes of great earthquakes are fundamentally controlled by the stress build-up along the plate interface as inferred from the degree of locking. Therefore, inferring the distribution of locking and its along-strike variations has become an essential tool for seismic and tsunami hazard assessment. Recent studies have explored the main parameters affecting the spatial distribution of locking degree, but the time evolution of locking has not yet been clearly documented. Here we used time-series of continuous GPS at adjacent segments (> 500 km distance) to the rupture zone of the 2010 Chile (Mw=8.8) earthquake to explore the differences in locking degree before (2008-2010) and after (2010-2013) this event. Results suggest that the interseismic velocity (landward displacements) increased both in the northern (27°S-32°S) and southern (41°S-45°S) unruptured segments. The variations of displacements can be explained by an increase and homogenization of the locking degree at areas that were creeping before the 2010 earthquake. The estimated increase of locking degrees have peaks of about 20% and 100% for the northern and southern regions respectively. The b-value, which parameterizes the frequency-magnitude distribution of seismicity, decreased after the 2010 earthquake in the northern segment (in the southern segment there is not enough seismicity for estimating b-value) from 1.2 to 0.7 indicating a tendency for asperities to be brought closer to failure due to increase of shear stresses on the plate interface. By means of a 3D thermo-mechanical subduction model we are able to simulate the dynamic response of the system and study the stress variations before and after the earthquake, supporting the rearrangment of shear stresses at adjacent segments. Our results suggest that locking degree can evolve over a short timescale due to the change of the stress regime induced by great earthquakes. We propose that the seismic cycle along a margin is a self-organized system in the sense of a lateral connected evolution of build-up and release of stress at different seismotectonic segments. Importantly, the 2010 earthquake may have increased the seismic potential of the northern and southern neighboring plate interface segments, which broke last in 1922 and 1960, respectively.

Moreno, Marcos; Báez, Juan Carlos; Bedford, Jonathan; Quinteros, Javier; Tassara, Andres; Melnick, Daniel; Oncken, Onno; Vigny, Christophe; Bartsch, Mitja; Bevis, Michael; Soto, Hugo; Barrientos, Sergio; Ortega, Ismael; Valderas, Maria

2014-05-01

81

Augmentation of implant fixation in osteoporotic bone.  

PubMed

Osteoporosis presents a dilemma for the orthopedic surgeon. Screw fixation within the bone is crucial for mechanical stabilization, maintenance of reduction, and ultimately, fracture healing. For the patient, soft bones and physiological fragility usually benefit from immediate weight bearing and mobility to avoid further disuse osteoporosis, deconditioning, and immobility. For implant companies, traditional screws, plates, and nails function for simple fractures and compliant patients. Locked plating has improved screw purchase in osteoporotic bone and has expanded fracture fixation capabilities but is not the panacea for all fractures. For orthopedic surgeons, traditional surgical augmentation for osteoporosis consisting of dual plating, augmentation with polymethyl methacrylate, joint replacement, and now locked plating are beneficial. In order to advance orthopedic care in the expanding population of elderly osteoporotic patients, modern solutions utilizing the dual properties of secure fixation and relatively flexible implants are required. Endosteal substitution, extraosteal substitution, and combined nail/plate combinations are methods of utilizing traditional implants in a nontraditional way. Nonsurgical augmentation of fracture fixation is also paramount. PMID:23054960

Jones, Clifford B

2012-12-01

82

Walking ability of children with a hexapod external ring fixator (TSF®) and foot plate mounting at the lower leg.  

PubMed

Wearing an external fixator for several months can be expected to profoundly affect the ability to walk, but, in principle, full weight-bearing is possible during corrective procedures with the Taylor Spatial Frame (TSF). The present prospective cohort study was conducted to assess whether patients are able to walk with or without crutches during treatment with a TSF on the lower leg. Twenty-four patients (10 girls, 14 boys; average age 11 years, range 6-17) scheduled for fixator surgery with osteotomies in the lower leg and foot mounting were included. Dynamic foot loading during free walking was measured with plantar pressure measurements. The contact area, contact time and contact pressure on the foot plate were recorded and normalized to body weight. In the first postoperative week, all patients needed crutches and 67% showed partial weight-bearing. At the second measurement, about 6 weeks after surgery, 21% of the patients could walk without crutches and 58% were partially weight-bearing with crutches. On the day before fixator removal, 50% of the patients were fully weight-bearing without crutches and 38% were partially weight-bearing, but 12% could not bear any weight or were unable to walk. When a ring fixator is used to correct lower leg deformity and prevent equinus, there is minimal risk of complete dependence and abasia. This study shows that up to 88% of the pediatric patients are able to walk while wearing the fixator. Already a few days after surgery, two-thirds of the patients were partially weight-bearing with crutches, and only 12% needed a wheelchair and were not able to walk with the fixator. PMID:22682788

Schiedel, F; Vogt, B; Wacker, S; Pöpping, J; Bosch, K; Rödl, R; Rosenbaum, D

2012-07-01

83

Biomechanical in vitro assessment of fixed angle plating using a new concept of locking for the treatment of osteoporotic proximal humerus fractures  

Microsoft Academic Search

Locked plating attempts to improve mechanical stability via better anchorage of the screws in the bone. In 22 paired osteoporotic\\u000a humeri an AO\\/ASIF 11-B 1 fracture was created. Locked and conventional plating using the same device of the latest generation\\u000a was performed. Torsional loading around three axes (x = varus\\/valgus, y = flexion\\/extension, z = axial rotation) with an increasing

Götz Röderer; Florian Gebhard; Gert Krischak; Hans-Joachim Wilke; Lutz Claes

2011-01-01

84

Biomechancis of biological fixation utilizing a plate with and without an intramedullary rod  

E-print Network

of fracture fixation using these devices is to achieve appropriate stability, while allowing the fractured bone to bear loads at some fraction of that of the unbroken bone. This research reported here involved developing a new concept of biological internal...

Nori, Meera

2012-06-07

85

Plating of a periarticular medial clavicle fracture.  

PubMed

This article describes a case of a 23-year-old man who sustained a far medial fracture dislocation of the medial clavicle. We performed an open reduction and internal fixation of the fragment back to the remaining medial fragment using a small locking plate. This fracture can be problematic and usually requires reduction due to the potential vascular or airway compromise. Because the fracture often occurs at the medial physis, it is difficult to secure in place to prevent displacement. Historically, fixation of this fracture has been problematic with sutures and K-wires. Failure of fixation and migration of K-wires have been reported. In the past, plates have been inadequate or too large for this area to provide fixation. With the development of locking plates, a fixed-angle construct can be created to secure a small periarticular portion of bone as in the distal radius. In our case, the small distal radius locking plate was able to secure the lateral shaft to the medial piece with good stability in the medial clavicle. We were able to get multiple screws in the medial fragment in a low-profile plate. Postoperatively, the patient was permitted to use his arm for most activities but was restricted from pushing, pulling, or lifting heavy objects for 4 weeks. He recovered well and returned to normal activities of daily living with no restriction. Therefore, these plates may have a role in fixation of periarticular fractures. PMID:19472950

McKenna, Mark

2009-05-01

86

Fusion and failure following anterior cervical plating with dynamic or rigid plates: 6-months results of a multi-centric, prospective, randomized, controlled study  

Microsoft Academic Search

Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior\\u000a cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide\\u000a a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is

Jan Stulik; Tobias Rainer Pitzen; Jan Chrobok; Sabine Ruffing; Jörg Drumm; Laurentius Sova; Ravel Kucera; Tomas Vyskocil; Wolf Ingo Steudel

2007-01-01

87

Use of a single 2.0-mm locking AO reconstruction titanium plate in linear, non-comminuted, mandible fractures  

PubMed Central

Purpose: The aim of the following study is to prospectively evaluate the use of a single Arbeitsgemeinschaft für Osteosynthesefragen (AO) 2.0-mm locking reconstruction plate for linear non-comminuted mandibular fractures without the use of a second plate. Materials and Methods: This study consisted of a sample of 10 patients who reported to the department with fractures of the mandible and were treated over a period of 24 months from November 2010 to November 2012. Out of these, there were 8 male patients and 2 female patients. There were four cases of isolated parasymphysis fractures, 1 of the case had a parasymphysis fracture associated with subcondylar fracture, 4 had a body fracture and 2 had a symphysis fracture. Results: All patients had satisfactory fracture reduction and a successful treatment outcome without major complications. Only one patient (10%) developed minor complications. Conclusion: The study has demonstrated that treating linear non-comminuted mandibular fractures with a single AO 2.0-mm locking reconstruction plate provides excellent stability at the fracture site which in turn leads to sound bone healing and early functional rehabilitation. PMID:24987599

Parmar, Babu S.; Makwana, Kalpesh G.; Patel, Aditi M.; Tandel, Ramanuj C.; Shah, Jay

2014-01-01

88

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

PubMed

The importance of osteoporosis in proximal humerus fractures is well recognized. However, the local distribution of bone quality in the humeral head may also have a significant effect because it remains unclear in what quality of bone screws of standard implants purchase. The goal of this study was to investigate whether the failure of proximal humerus locked plating can be predicted by the DensiProbe (ARI, Davos, Switzerland). A 2-part fracture with metaphyseal impaction was simulated in 12 fresh-frozen human cadaveric humeri. Using the DensiProbe, local bone quality was determined in the humeral head in the course of 6 proximal screws of a standard locking plate (Philos; Synthes GmbH, Solothurn, Switzerland). Cyclic mechanical testing with increasing axial loading until failure was performed. Bone mineral density (BMD) significantly correlated with cycles until failure. Head migration significantly increased between 1000 and 2000 loading cycles and significantly correlated with BMD after 3000 cycles. DensiProbe peak torque in all screw positions and their respective mean torque correlated significantly with the BMD values. In 3 positions, the peak torque significantly correlated with cycles to failure; here BMD significantly influenced mechanical stability. The validity of the DensiProbe was proven by the correlation between its peak torque measurements and BMD. The correlation between the peak torque and cycles to failure revealed the potential of the DensiProbe to predict the failure of locked plating in vitro. This method provides information about local bone quality, potentially making it suitable for intraoperative use by allowing the surgeon to take measures to improve stability. PMID:24025003

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

2013-09-01

89

Comparison of two different double-plate fixation methods with olecranon osteotomy for intercondylar fractures of the distal humeri of young adults  

PubMed Central

Although several studies have demonstrated good results with open reduction and internal fixation of intercondylar fractures of the distal humerus, few have specifically addressed the results of such surgical fixation in young adults. The purpose of this study was to compare the clinical outcomes in patients with intercondylar fractures of the distal humerus treated using two different double-plating methods. Twenty-five patients with distal humeral fractures classified as type C according to the Association for Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF) classification system, who were admitted to the Second Hospital Affiliated to Anhui Medical University (Hefei, China) from October 2008 to October 2011, were included in the study. The patients were treated with two different double-plate fixation and olecranon osteotomy methods. Thirteen patients were treated by perpendicular plating (group I) and twelve patients by Y-shaped double-plating in the coronal plane (group II). All the patients were followed up for 12–38 months, with an average of 19.2±7.1 months in group I and 18.3±4.0 months in group II. All the osteotomies and fractures had healed by the final follow-up. Complications developed in 4 patients in group I and 3 patients in group II. According to the Mayo Elbow Performance Scores (MEPS), 84.6% of patients in group I and 83.3% in group II had excellent or good scores. No significant differences were identified between the clinical outcomes of the two plating methods. The olecranon osteotomy approach with double-plate fixation is a good choice for the surgical treatment of type C intercondylar fractures in young adult distal humeri. The two plating methods provide solid fixation, permit early rehabilitation and result in satisfactory clinical outcomes. PMID:23935736

TIAN, DASHENG; JING, JUEHUA; QIAN, JUN; LI, JIANMING

2013-01-01

90

Biological fixation of fracture shaft femur in children.  

PubMed

The aim of this work was to assess the results of biological fixation of fracture shaft femur in children with locked plates. Twenty-eight fractures in 26 children with closed fractures of the shaft of the femur were managed with biological plating using locked plates bridging the fracture site applied submuscularly through two small incisions above and below the fracture site. The mean age of the patients was 11.2 years; all patients had radiological union within a mean time of 11.9 weeks (8-14 weeks); the average follow-up was 31 months (14-40 months). No patient had frontal or sagittal plane deformity more than 10° or limb length discrepancy more than 1.5 cm. There was no infection, delayed union, nonunion or clinically evident malrotation. A significant positive correlation between the age and the time to healing (p = 0.03) was detected, whereas there was no significant correlation between time to healing and patient sex, fracture level, fracture type, mechanism of injury. Also there was no significant correlation between limb length discrepancy and patient age, sex, fracture level, fracture type, and mechanism of injury. Biological fixation of fractures of the femoral shaft in children with locked plates is a reliable method of fixation with excellent healing potential and fixation mechanics without complications. PMID:23412246

Elgohary, Hatem S A

2014-01-01

91

[Osteosynthesis with plates for full sternal dehiscence (Titanium Sternal Fixation System Synthes) -- first use in Hungary].  

PubMed

The prevalence of deep sternal infection after cardiac surgery is between 0,5 and 5%, with an average mortality up to 50%. The authors present the case of the rst sternal osteosynthesis carried out in Hungary after postoperative deep sternal infection. Using this orthopedic reconstructive surgical technique in this patient group, an anatomical reconstruction and reposition of the sternum is feasible. With the Titanium Sternal Fixation Synthes system reconstruction of total or partial sternal absence is possible. PMID:19386566

Hartyánszky, István; Veres, Gábor; Hüttl, Tivadar; Moravcsik, Endre; Kayser, Sándor; Daróczi, László; Vida, Kata; Gálffy, Ildikó; Szudi, László; Szabolcs, Zoltán

2009-04-01

92

Biomechanical analysis and clinical effects of bridge combined fixation system for femoral fractures.  

PubMed

This work aimed to compare the stress distribution and mechanical properties of our bridge combined fixation system and commonly used metal locking plate screw system by finite element analysis and by using the Zwick/Z100 testing machine. In addition, we also investigated the clinical outcome of our bridge combined fixation system for femoral fractures in 59 patients from June 2005 to January 2013. As a result, the stress distribution in the bone plate and screws of metal locking plate screw system during walking and climbing stairs was significantly lower than that of metal locking plate screw system. No significant difference in the displacement was observed between two systems. The equivalent bending stiffness of bridge combined fixation system was significantly lower than that of metal locking plate screw system. There were no significant differences in the bending strength, yield load, and maximum force between two systems. All the cases were followed up for 12-24 months (average 18 months). The X-ray showed bone callus was formed in most patients after 3 months, and the fracture line was faint and disappeared at 6-9 months postoperatively. No serious complications, such as implant breakage and wound infection, occurred postoperatively. According to self-developed standard for bone healing, clinical outcomes were rated as excellent or good in 55 out of 59 patients (success rate: 93.2%). Therefore, our findings suggest that our bridge combined fixation system may be a promising approach for treatment of long-bone fractures. PMID:25201264

Wang, Da-Xing; Xiong, Ying; Deng, Hong; Jia, Fu; Gu, Shao; Liu, Bai-Lian; Li, Qun-Hui; Pu, Qi; Zhang, Zhong-Zi

2014-09-01

93

Modified biplanar open-wedge high tibial osteotomy with rigid locking plate to treat varus knee  

Microsoft Academic Search

Objective  To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat varus knee\\u000a in young and active patients.\\u000a \\u000a \\u000a \\u000a Methods  Between June 2001 to July 2008, 18 patients with monocompartmental degeneration of the knee combined with a varus malalignment\\u000a of the leg had the modified biplanar opening high tibial osteotomy and the osteotomy was fixed with the

Hai-ning Zhang; Jie Zhang; Cheng-yu Lv; Ping Leng; Ying-zhen Wang; Xiang-da Wang; Chang-yao Wang

2009-01-01

94

Noncomminuted lateral end clavicle fractures associated with coracoclavicular ligament disruption: Technical considerations for optimal anatomic fixation and stability.  

PubMed

Distal clavicle fractures associated with coracoclavicular ligament disruption are potentially unstable and necessitate surgical treatment. Current fixation techniques are nonanatomic and do not address relevant aspects of the pathoanatomy. We have developed a technique that uses a unique combination of implants; this permits minimally invasive fixation and stable reduction with a lateral fragment size as small as 5 mm. The surgical technique consists of (1) neutralization of muscular forces on the proximal fragment using a minimally invasive ligament repair device (TightRope™, Arthrex, FL, USA) and (2) internal fixation using a contour-matched locking plate (2.4 mm LCP(®) Distal radius plates, Synthes, USA). Technical tips to optimize this new procedure are discussed. The technique can be extended to an "arthroscopic-assisted" method involving arthroscopic coracoclavicular fixation followed by a mini-open plate fixation of the clavicular fragments. PMID:25258500

Page, Richard S; Bhatia, Deepak N

2014-07-01

95

Design and development of a biomechanical apparatus to test the integrity of the Luque orthopaedic internal bone-plate fixation system.  

PubMed

This paper describes the design and construction of a biomechanical model that will determine the pull-out strengths and fatigue failure of internal fixation devices used at the lumbosacral junction. Fusions at this junction have the highest failure rate. It is suggested that devices that successfully fix this vertebral unit will be effective at other levels of the spine. A model that tests any device designed for use at the lumbosacral junction will therefore provide a uniform measure of the effectiveness of different kinds of instrumentation at the L5-S1 vertebral unit. It will also provide predictive values for fixation systems at other spinal levels. A real-time data-acquisition system was also designed and used to define and determine the failure of the Luque orthopaedic bone-plate fixation device. PMID:8295224

Sadeghipour, K; Baren, R; Ortiz, B A; Clements, D H

1993-01-01

96

Evaluation of 2.0-mm Titanium Three-Dimensional Curved Angle Strut Plate in the Fixation of Mandibular Angle Fractures-A Prospective Clinical and Radiological Analysis.  

PubMed

The aim of the study was to evaluate the efficacy and complication rate with use of 2.0-mm titanium three-dimensional (3D) curved angle strut plate for mandibular angle fractures. Twenty cases requiring internal fixation of the mandibular angle by 2.0-mm titanium 3D curved angle strut plates were evaluated. Postoperative clinical and radiological analyses were done on 1st, 2nd, 4th, and 6th weeks, which included wound healing, transmitted movements, difficulty in function and occlusion, and neurosensory changes, if any. Reasonable level of success in terms of immediate jaw function was noted in all cases. Transient inferior alveolar nerve dysfunction was observed in three cases, which recovered gradually in 2 months, and surgical site infection was observed in two cases, which resolved with appropriate course of antibiotics and wound care. Fixation of mandibular angle fractures with a 2.0-mm titanium 3D curved angle strut plate is predictable, expeditious, and has less complication rate. PMID:25050147

Chhabaria, Gaurav; Halli, Rajshekhar; Chandan, Sanjay; Joshi, Samir; Setiya, Sneha; Shah, Anand

2014-06-01

97

Use of a proximal humeral plate for a paediatric peri-prosthetic femoral fracture  

PubMed Central

In this case an 18-year-old female with cerebral palsy sustained a peri-prosthetic femoral fracture adjacent to a blade plate previously inserted for a femoral varus osteotomy. The injury was treated using a long proximal humeral locking plate. The existing blade plate was removed. The fracture was reduced and held, and a 10-hole PHILOS™ plate applied with near anatomical reduction. There were no post-operative complications. Radiographic union was confirmed at 11 months. To our knowledge, this is the first reported use of a PHILOS™ plate in the management of a femoral peri-prosthetic fracture and successfully demonstrated a straightforward method for revision fixation. PMID:24986984

Shaw, C.R.; Badhesha, J.; Ayana, G.; Abu-Rajab, R.

2014-01-01

98

Hook plate fixation of acute displaced lateral clavicle fractures: mid-term results and a brief literature overview  

PubMed Central

Background The clavicle hook plate achieves like most other operative techniques, a high percentage of union and a low percentage of complications however concerns about long term complications still exist, particularly the involvement of the acromioclavicular joint. Methods To evaluate the results and long term effects in use of this plate we performed a retrospective analysis with a mean follow up of 65 months (5.4 years) of 28 consecutive patients with acute displaced lateral clavicle fractures, treated with the clavicle hook plate. Results Short term functional results in all patients were good to excellent. All but one patient had a united fracture (96%). Nine patients (32%) developed impingement symptoms and in 7 patients (25%) subacromial osteolysis was found. These findings resolved after plate removal. Twenty-four patients were re-evaluated at a mean follow-up period of 5.4 years. The Constant-Murley score was 97 and the DASH score was 3.5. Four patients (14%) developed acromioclavicular joint arthrosis of which one was symptomatic. Three patients (11%) had extra articular ossifications of which one was symptomatic. There was no relation between the impingement symptoms, subacromial osteolysis and development of acromioclavicular joint arthrosis or extra articular ossifications. Conclusions The clavicle hook plate is a good primary treatment option for the acute displaced lateral clavicle fracture with few complications. At mid term the results are excellent and no long term complications can be addressed to the use of the plate. PMID:22236647

2012-01-01

99

Osteotomy and fracture fixation in children and teenagers.  

PubMed

Significant changes have occurred recently in fixation methods following fracture or osteotomy in children and teenagers. Children have benefited the most from these advances. A child's growth is anatomically and physiologically ensured by the growth plate and periosteum. The need to keep the periosteum intact during trauma cases has led to the introduction of flexible intramedullary nailing. We will review the basic principles of this safe, universally adopted technique, and also describe available material, length and diameter options. The problems and the limitations of this method will be discussed extensively. In orthopedics, the desire to preserve the periosteum has led to the use of locking compression plates. Because of their low profile and high stability, they allow the micromovements essential for bone union. These new methods reduce the immobilization period and allow autonomy to be regained more quickly, which is especially important in children with neurological impairment. The need to preserve the growth plate, which is well known in pediatric surgery, is reviewed with the goal of summarizing current experimental data on standard fracture and osteotomy fixation methods. Adjustable block stop wires provide better control over compression. These provide an alternate means of fixation between K-wires and screws (now cannulated) and have contributed to the development of minimally invasive surgical techniques. The aim of this lecture is to provide a rationale for the distinct technical features of pediatric surgery, while emphasizing the close relationship between the physiology of growth, bone healing and technical advances. PMID:24394918

de Billy, B; Gindraux, F; Langlais, J

2014-02-01

100

A case of hypertrophic ischial tuberosity non-union treated by closed wedge osteotomy and plate and screws fixation.  

PubMed

We report a case of a 21-year-old male with massive hypertrophic ischial tuberosity non-union. Among multiple other lesions, the patient suffered an open avulsion of the ischial tuberosity in a severe traffic accident in adolescence. A conservative treatment was decided for the avulsion. Because of sciatic pain and difficulties while sitting since the age of 19, X-rays were realised and showed a massive hypertrophic non-union of the ischial tuberosity. To preserve hamstring origin with bone attachment, the non-union was mobilised, reduced by osteotomy and fixed by plate and screws. At the follow up of one year, the patient sits without pain and can work without interruption. Avulsion of the ischial tuberosity is infrequent and the diagnosis is often missed (Gidwani et al., BMJ 329:99-100, 2004; Hamada, Clin Orthop 31:117-130, 1963). This lesion is more often seen in adolescence as the consequence of a sport injury (Gidwani et al., BMJ 329:99-100, 2004). Treatment is generally conservative and outcome good. Surgical therapy is only needed in cases with severe displacement. Long-term problems are seldom and surgical therapy to solve these problems is the exception. PMID:23411936

Putman, S; Rommens, P M

2013-04-01

101

Improving greater trochanteric reattachment with a novel cable plate system.  

PubMed

Cable-grip systems are commonly used for greater trochanteric reattachment because they have provided the best fixation performance to date, even though they have a rather high complication rate. A novel reattachment system is proposed with the aim of improving fixation stability. It consists of a Y-shaped fixation plate combined with locking screws and superelastic cables to reduce cable loosening and limit greater trochanter movement. The novel system is compared with a commercially available reattachment system in terms of greater trochanter movement and cable tensions under different greater trochanteric abductor application angles. A factorial design of experiments was used including four independent variables: plate system, cable type, abductor application angle, and femur model. The test procedure included 50 cycles of simultaneous application of an abductor force on the greater trochanter and a hip force on the femoral head. The novel plate reduces the movements of a greater trochanter fragment within a single loading cycle up to 26%. Permanent degradation of the fixation (accumulated movement based on 50-cycle testing) is reduced up to 46%. The use of superelastic cables reduces tension loosening up to 24%. However this last improvement did not result in a significant reduction of the grater trochanter movement. The novel plate and cables present advantages over the commercially available greater trochanter reattachment system. The plate reduces movements generated by the hip abductor. The superelastic cables reduce cable loosening during cycling. Both of these positive effects could decrease the risks related to grater trochanter non-union. PMID:22749768

Baril, Yannick; Bourgeois, Yan; Brailovski, Vladimir; Duke, Kajsa; Laflamme, G Yves; Petit, Yvan

2013-03-01

102

Treatment of segmental tibial fractures with supercutaneous plating.  

PubMed

Segmental tibial fractures usually follow a high-energy trauma and are often associated with many complications. The purpose of this report is to describe the authors' results in the treatment of segmental tibial fractures with supercutaneous locking plates used as external fixators. Between January 2009 and March 2012, a total of 20 patients underwent external plating (supercutaneous plating) of the segmental tibial fractures using a less-invasive stabilization system locking plate (Synthes, Paoli, Pennsylvania). Six fractures were closed and 14 were open (6 grade IIIa, 2 grade IIIb, 4 grade II, and 2 grade I, according to the Gustilo classification). When imaging studies confirmed bone union, the plates and screws were removed in the outpatient clinic. Average time of follow-up was 23 months (range, 12-47 months). All fractures achieved union. Median time to union was 19 weeks (range, 12-40 weeks) for the proximal fractures and 22 weeks (range, 12-42 weeks) for the distal fractures. Functional results were excellent in 17 patients and good in 3. Delayed union of the fracture occurred in 2 patients. All patients' radiographs showed normal alignment. No rotational deformities and leg shortening were seen. No incidences of deep infection or implant failures occurred. Minor screw tract infection occurred in 2 patients. A new 1-stage protocol using supercutaneous plating as a definitive fixator for segmental tibial fractures is less invasive, has a lower cost, and has a shorter hospitalization time. Surgeons can achieve good reduction, soft tissue reconstruction, stable fixation, and high union rates using supercutaneous plating. The current patients obtained excellent knee and ankle joint motion and good functional outcomes and had a comfortable clinical course. PMID:25102507

He, Xianfeng; Zhang, Jingwei; Li, Ming; Yu, Yihui; Zhu, Limei

2014-08-01

103

Comparative evaluation of bite forces in patients after treatment of mandibular fractures with miniplate osteosynthesis and internal locking miniplate osteosynthesis  

PubMed Central

Aims and Objectives: The aim of present study was to compare the stability of fractured mandibular fragments under functional load, when fixed with conventional miniplate and internal locking miniplate. Materials and Methods: Bite force (in kg) recorded in twenty mandible fractured patients and fifty normal healthy individuals. Bite force was measured at incisor and molar regions. Comparative evaluation of bite force generated was performed between 10 cases treated with conventional miniplates and 10 cases treated with internal locking miniplates. Bite force generated by patients in mandibular fracture between symphysis and the angle of mandible was recorded in incisor and molar regions preoperatively. The fracture fragments were fixed using the above fixation techniques. Then same recording was undertaken on the 7th, 14th, 21st, 28th, and 90th days postoperatively. Results: Bite force generated by patients treated with locking plates at the 7th, 14th, 21st, 28th, and 90th postoperative days was significantly higher as compared to those in patients treated with miniplates. Conclusion: It was observed in our study that the locking plate/screw system offers significant advantages over the conventional plating system. There are no intraoperative difficulties associated with placement of the plate.

Kumar, Saurab; Gattumeedhi, Shashank Reddy; Sankhla, Bharat; Garg, Akshay; Ingle, Ekta; Dagli, Namrata

2014-01-01

104

Effectiveness of 2.0 mm Standard and 2.0 mm Locking Miniplates in Management of Mandibular Fractures: A Clinical Comparative Study.  

PubMed

To compare and evaluate the effectiveness of 2.0 mm locking miniplates versus 2.0 mm standard miniplates in treatment of mandible fractures. Sixty randomly selected patients who sustained mandibular fractures were selected for this study. The fractured fragments were stabilized using 2.0 mm locking miniplates in 30 cases and in the remaining 30 cases the fractured fragments were fixed with conventional 2.0 mm miniplates. Post-operative stability was assessed with radiographs at 7th day, 1st, and 3rd months. The stability of the reduced fracture was assessed clinically and both the types of plates were assessed with an OPG or conventional radiographs. This study shows favorable results on use of locking miniplates in mandibular fractures. The results show that there were no significant differences in the post-operative complications between the conventional and the locking plate/screw mandibular systems. The locking plate/screw system was more rigid than conventional plate/screw system, thereby reducing the need and duration of intermaxillary fixation (IMF). PMID:24644396

Shaik, Mahaboob; Subba Raju, T; Rao, N Koteswara; Reddy, Chandra Kiran

2014-03-01

105

Fixation of a Periprosthetic Intertrochanteric Hip Fracture below a Birmingham Hip Resurfacing  

PubMed Central

This case report involves a 56-year-old female (Mrs X) with a traumatic intertrochanteric hip fracture with subtrochanteric extension below a previous Birmingham hip resurfacing. Periprosthetic fractures following hip resurfacing are usually subcapital and treated with a revision or conservative management. We present an unusual surgical problem with an interesting solution stabilising the fracture using a proximal femoral locking compression plate (LCP). Eight months following surgery the patient is able to walk pain free and there is good fixation and stability. PMID:24995142

Macdonald, J.; Robinson, A.; Brown, I.

2014-01-01

106

Two fixation methods for acromioclavicular joint reduction during coracoclavicular ligament reconstruction: a biomechanical analysis.  

PubMed

One specimen from each of six pairs of cadaveric shoulders underwent a semitendinosus coracoclavicular ligament reconstruction with a hook plate used for acromioclavicular joint reduction, while on the other specimen a polydioxanone (PDS) suture braid was utilized. Cyclical loading followed by maximal load-to-failure testing was performed. Displacement during cyclical loading, loads to 50% and 100% displacement, stiffness, and maximal load to failure were determined for all specimens. Results showed that the locking hook plate allowed significantly less displacement of the coracoclavicular interval during cyclical loading (3.41 vs. 9.67 mm, p = .0081) and withstood significantly higher loads before both 50% (225.5 vs. 107.7 N, p = .0197) and 100% displacement (410.6 vs. 240.1 N, p = .0077). The locking hook plate was found to be significantly stiffer than the PDS suture braid (28.2 vs. 18.4 N/mm, p = .0029), but there was no difference in maximal load to failure between the two fixation methods (hook plate, 434.4 N; PDS, 476.7 N; p = .76). PMID:25153813

Dierckman, Brian D; Karas, Spero G; Hammond, Kyle E; Brantley, Steven P; Hutton, William C

2014-01-01

107

GEOPHYSICAL RESEARCH LETTERS, VOL. 27, NO. 19, PAGES 3117-3120, OCTOBER 1, 2000 Rotation and plate locking at the southern  

E-print Network

satellite orbits 1Rensselaer Polytechnic Institute, Troy, New York 2Oregon State University, Corvallis offshore, consistent with earlier studies, and is sufficient to allow occasional great earthquakes inferred- tributed permanent deformation within the overriding plate. Evidence for large thrust earthquakes

Goldfinger, Chris

108

Biologic fixation through bridge plating for comminuted shaft fracture of the clavicle: technical aspects and prospective clinical experience with a minimum of 12-month follow-up.  

PubMed

For comminuted shaft fracture of clavicle, the operative goal, aside from sound bone healing without complications of direct reduction, is maintenance of the original length in order to maintain the normal biomechanics of adjacent joint. Our bridge plating technique utilizing distraction through a lumbar spreader was expected to be effective for restoring clavicular length with soft tissue preservation. However, there are two disadvantages. First, there is more exposure to radiation compared to conventional plating; and second, it is difficult to control the rotational alignment. Despite these disadvantages, our technique has important benefits, in particular, the ability to preserve clavicular length without soft tissue injury around the fracture site. PMID:24340154

Jung, Gu Hee; Park, Chang-Min; Kim, Jae-Do

2013-12-01

109

A new adhesive technique for internal fixation in midfacial surgery  

Microsoft Academic Search

BACKGROUND: The current surgical therapy of midfacial fractures involves internal fixation in which bone fragments are fixed in their anatomical positions with osteosynthesis plates and corresponding screws until bone healing is complete. This often causes new fractures to fragile bones while drilling pilot holes or trying to insert screws. The adhesive fixation of osteosynthesis plates using PMMA bone cement could

Kira Endres; Rudolf Marx; Joachim Tinschert; Dieter Christian Wirtz; Christian Stoll; Dieter Riediger; Ralf Smeets

2008-01-01

110

Comparison of unreamed nailing and external fixation of tibial diastases––mechanical conditions during healing and biological outcome  

Microsoft Academic Search

Locked intramedullary nailing and external fixation are alternatives for the stabilization of tibial shaft fractures. The goal of this study was to determine to what extent the mechanical conditions at the fracture site influence the healing process after unreamed tibial nailing compared to external fixation. A standardized tibial diastasis was stabilized with either a locked unreamed tibial nail or a

P. Klein; M. Opitz; H. Schell; W. R. Taylor; M. O. Heller; J.-P. Kassi; F. Kandziora; G. N. Duda

2004-01-01

111

12. VIEW OF TYPICAL CELL LOCKING MECHANISM, BUILDING 220 CELL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. VIEW OF TYPICAL CELL LOCKING MECHANISM, BUILDING 220 CELL BLOCK 'A'. THE FACE PLATE OF THE CELL LOCK IS SHOWN REMOVED, EXPOSING THE ELECTROMAGNETIC LOCKING MECHANISM COMPRISING OF 2 MICROSWITCHES FOR LOCK POSITION INDICATION (FRONT LEFT CENTER AND REAR RIGHT CENTER OF PANEL); KEY SLOT MECHANICAL LOCK; LOCK SPRING (UPPER RIGHT OF PANEL); ELECTRIC SOLENOID (BOTTOM RIGHT CORNER OF PANEL); AND MISCELLANEOUS MECHANICAL LINKAGES. - U.S. Naval Base, Pearl Harbor, Brig, Neville Way near Ninth Street at Marine Barracks, Pearl City, Honolulu County, HI

112

Low-profile titanium plate construct for early weightbearing with first metatarsophalangeal joint arthrodesis.  

PubMed

First metatarsophalangeal joint arthrodesis is a useful procedure for various first ray pathologic entities. Multiple constructs for fixation have provided successful fusion. A retrospective study of 21 feet (18 patients) was performed after first metatarsophalangeal joint fusion using crossed Kirschner wires or compression fixation with cannulated screws followed by the application of a 2-hole low-profile partially locking titanium plate. The median age was 59 (range 41 to 76) years, and we had 4 smokers and 3 patients with diabetes in our series. Postoperatively, a compression dressing with a posterior splint was applied. The patients then transitioned to a controlled ankle motion walker, and all patients reported full weightbearing by 2 weeks postoperatively. The mean follow-up duration was 11.43 (range 6 to 27) months. The overall primary fusion rate was 95.24% (20 of 21). Two nonunions occurred; one was asymptomatic and successfully consolidated at 12 months. The second nonunion required revisional surgery with an autogenous bone graft to heal successfully. This patient was noncompliant with the postoperative regimen and had a 48-pack year history of tobacco usage. Our results have shown early weightbearing after first metatarsophalangeal joint arthrodesis can be successfully initiated with splintage or lag screw fixation and a 2-hole, low-profile, partially locking titanium plate. PMID:23632068

Mann, Joshua J; Moon, Jared L; Brosky, Thomas A

2013-01-01

113

Development and mechanical testing of a short intramedullary nail for fixation of femoral rotational osteotomy in cerebral palsy patients  

PubMed Central

Background Rotational osteotomy is frequently indicated to correct excessive femoral anteversion in cerebral palsy patients. Angled blade plate is the standard fixation device used when performed in the proximal femur, but extensile exposure is required for plate accommodation. The authors developed a short locked intramedullary nail to be applied percutaneously in the fixation of femoral rotational osteotomies in children with cerebral palsy and evaluated its mechanical properties. Methods The study was divided into three stages. In the first part, a prototype was designed and made based on radiographic measurements of the femoral medullary canal of ten-year-old patients. In the second, synthetic femoral models based on rapid-prototyping of 3D reconstructed images of patients with cerebral palsy were obtained and were employed to adjust the nail prototype to the morphological changes observed in this disease. In the third, rotational osteotomies were simulated using synthetic femoral models stabilized by the nail and by the AO-ASIF fixed-angle blade plate. Mechanical testing was done comparing both devices in bending-compression and torsion. Results The authors observed proper adaptation of the nail to normal and morphologically altered femoral models, and during the simulated osteotomies. Stiffness in bending-compression was significantly higher in the group fixed by the plate (388.97 ± 57.25 N/mm) than in that fixed by the nail (268.26 ± 38.51 N/mm) as torsional relative stiffness was significantly higher in the group fixed by the plate (1.07 ± 0.36 Nm/°) than by the nail (0.35 ± 0.13 Nm/°). Conclusions Although the device presented adequate design and dimension to fit into the pediatric femur, mechanical tests indicated that the nail was less stable than the blade plate in bending-compression and torsion. This may be a beneficial property, and it can be attributed to the more flexible fixation found in intramedullary devices. PMID:21711560

2011-01-01

114

Variable Angle Locking Intercarpal Fusion System for Four-Corner Arthrodesis: Indications and Surgical Technique  

PubMed Central

Four-corner fusion (4CF) is an accepted and regularly performed procedure when managing posttraumatic degenerative disorders in the wrist. This procedure consists of excision of the entire scaphoid in association with midcarpal fusion of the remaining four ulnar carpal bones (hamate, capitate, lunate, and triquetrum). In the majority of cases, the long-term outcome is a functional painless wrist. However, the exact procedure to best achieve a rapid solid bone union of the fusion mass without hardware complications remains controversial. The authors have developed a precise system to ensure precise positioning, firm fixation, and fusion at the midcarpal joint together with an early postoperative recovery, avoiding some of the issues reported with other implants used for 4CF. The described implant is a circular plate accommodating variable angle locking screws as well as compression screws that can firmly fix the plate to the carpal bones. The locking technology produces a very solid construct. A special reaming-distraction-compression guide has also been developed to both countersink the plate on the underlying carpal bone mass and allow distraction of the midcarpal joint for debridement and cancellous bone graft interposition. The features of the implant, its surgical technique, and a relevant case are described. PMID:23904983

González del Pino, Juan; Campbell, Douglas; Fischer, Thomas; Vázquez, Fiesky Núñez; Jupiter, Jesse B.; Nagy, Ladislav

2012-01-01

115

Automatic locking orthotic knee device  

NASA Technical Reports Server (NTRS)

An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

Weddendorf, Bruce C. (inventor)

1993-01-01

116

Early postoperative failure of a new intramedullary fixation device for midshaft clavicle fractures.  

PubMed

The Sonoma CRx device (Sonoma Orthopedic Products, Santa Rosa, California) is a recently introduced intramedullary device with a flexible shaft that becomes rigid once actuated to allow deployment within the sigmoidal contour of the clavicular shaft. Medial intramedullary cortical purchase is obtained by grippers and lateral purchase through a locking bicortical buttressing screw. This article describes 2 cases of early hardware failure using this device. In both cases, early postoperative radiographs demonstrate adequate initial fracture reduction and implant position. Both patients sustained repeat injuries, one under low physiologic load and the other after returning to mixed martial arts 4 months postoperatively. Implant failure was noted after reinjury in both cases. Complete healing and full return to function was documented for both patients at 2 years. Proper patient selection and counseling regarding the limitations of this intramedullary fixation device are important. Biomechanical comparison of this implant to plate fixation under physiologic loads of combined axial compression and torsion may shed light on differences in fixation stability. PMID:24200452

Wilson, David J; Weaver, DeWayne L; Balog, Todd P; Arrington, Edward D

2013-11-01

117

Intramedullary screw fixation of lateral malleolus fractures.  

PubMed

A biomechanical evaluation of intramedullary versus buttress plate and lag screw fixation of lateral malleolus fractures is combined with a clinical evaluation of 44 patients with lateral malleolus fractures who underwent intramedullary screw fixation. The biomechanical study was performed in experimentally produced, Weber B, supination-eversion ankle fractures. The fractures were fixed with one of the two above fixation methods and then placed under a torsional load to failure. Sixteen cadaver ankles were tested as compared with native bone. The intramedullary screw provided 66.5% the resistance of torsion, and the buttress plate and lag screw provided 61.5% the resistance to torsion. There was no statistical difference between these two groups. The 44 fractures treated with an intramedullary screw were reviewed retrospectively. There was one failure of fixation, and one prominent hardware problem. Time to full weightbearing averaged 7.2 weeks. These results suggest that intramedullary screw fixation of noncomminuted lateral malleolus fractures provides stable fixation with good clinical results. This technique has the advantages of providing dynamic intramedullary fixation with limited surgical dissection and no subcutaneous hardware. PMID:7849975

Bankston, A B; Anderson, L D; Nimityongskul, P

1994-11-01

118

Zero-profile hybrid fusion construct versus 2-level plate fixation to treat adjacent-level disease in the cervical spine.  

PubMed

Object Single-level anterior cervical discectomy and fusion (ACDF) is an established surgical treatment for cervical myelopathy. Within 10 years of undergoing ACDF, 19.2% of patients develop symptomatic adjacent-level degeneration. Performing ACDF adjacent to prior fusion requires exposure and removal of previously placed hardware, which may increase the risk of adverse outcomes. Zero-profile cervical implants combine an interbody spacer with an anterior plate into a single device that does not extend beyond the intervertebral disc space, potentially obviating the need to remove prior hardware. This study compared the biomechanical stability and adjacent-level range of motion (ROM) following placement of a zero-profile device (ZPD) adjacent to a single-level ACDF against a standard 2-level ACDF. Methods In this in vitro biomechanical cadaveric study, multidirectional flexibility testing was performed by a robotic spine system that simulates flexion-extension, lateral bending, and axial rotation by applying a continuous pure moment load. Testing conditions were as follows: 1) intact, 2) C5-6 ACDF, 3) C4-5 ZPD supraadjacent to simulated fusion at C5-6, and 4) 2-level ACDF (C4-6). The sequence of the latter 2 test conditions was randomized. An unconstrained pure moment of 1.5 Nm with a 40-N simulated head weight load was applied to the intact condition first in all 3 planes of motion and then using the hybrid test protocol, overall intact kinematics were replicated subsequently for each surgical test condition. Intersegmental rotations were measured optoelectronically. Mean segmental ROM for operated levels and adjacent levels was recorded and normalized to the intact condition and expressed as a percent change from intact. A repeated-measures ANOVA was used to analyze the ROM between test conditions with a 95% level of significance. Results No statistically significant differences in immediate construct stability were found between construct Patterns 3 and 4, in all planes of motion (p > 0.05). At the operated level, C4-5, the zero-profile construct showed greater decreases in axial rotation (-45% vs -36%) and lateral bending (-55% vs -38%), whereas the 2-level ACDF showed greater decreases in flexion-extension (-40% vs -34%). These differences were marginal and not statistically significant. Adjacent-level motion was nearly equivalent, with minor differences in flexion-extension. Conclusions When treating degeneration adjacent to a single-level ACDF, a zero-profile implant showed stabilizing potential at the operated level statistically similar to that of the standard revision with a 2-level plate. Revision for adjacent-level disease is common, and using a ZPD in this setting should be investigated clinically because it may be a faster, safer alternative. PMID:25170655

Healy, Andrew T; Sundar, Swetha J; Cardenas, Raul J; Mageswaran, Prasath; Benzel, Edward C; Mroz, Thomas E; Francis, Todd B

2014-11-01

119

Open reduction technique for overlapping and locked pubic symphysis.  

PubMed

A locked pubic symphysis can occur following a lateral compression injury of the pelvic ring when one pubic bone becomes entrapped behind the contralateral pubis or obturator foramen. In selecting the treatment modality, it is important to know the mechanism of injury. We presented the use of an open reduction technique in the treatment of a locked pubic symphysis in which open reduction external fixation application failed in the emergency department. PMID:22441457

Botanlio?lu, Hüseyin; Bilsel, Nafiz; Kaynak, Gökhan; Unlü, Mehmet Can

2012-01-01

120

Seismicity near the slip maximum of the 1960 Mw 9.5 Valdivia earthquake (Chile): Plate interface lock and reactivation of the subducted Valdivia Fracture Zone  

NASA Astrophysics Data System (ADS)

Understanding the processes behind subduction-related hazards is an important responsibility and major challenge for the Earth sciences. Few areas demonstrate this as clearly as south-central Chile, where some of the largest earthquakes in human history have occurred. We present the first observation of local seismicity in the Villarrica region (39°-40°S), based on a temporary local network of 55 stations installed from the Chilean coast into the Argentinian back-arc for one year. While consistent with the Chilean national catalog (SSN), our results allow us to observe smaller magnitudes with a completeness of about 2.0 and image the geometry of the Wadati-Benioff Zone from the Chile Trench down to 200 km. Offshore, a gap in interplate seismicity is observed in the region of the 1960 Valdivia earthquake slip. Above the interface, two offshore seismicity clusters possibly indicate ongoing stress relaxation. In the subducting Nazca Plate, we find a prominent seismicity cluster along the extrapolated trace of the oceanic Valdivia Fracture Zone (VFZ). The seismicity cluster is observed between 70 and 130 km depth and comprises mainly strike-slip events. It indicates weakening and reactivation of the major VFZ by dehydration of oceanic crust and mantle. Interpreting the subducted VFZ section as a localized reservoir of potential fluid release offers an explanation for the Villarrica volcanic complex that is located above the reactivated VFZ and shows the highest volcanic activity in South America. Crustal seismicity is observed near Puyehue volcano, which recently started to erupt (June 2011).

Dzierma, Yvonne; Thorwart, Martin; Rabbel, Wolfgang; Siegmund, Claudia; Comte, Diana; Bataille, Klaus; Iglesia, Paula; Prezzi, Claudia

2012-06-01

121

Safety lock-out device for electrical appliances  

DOEpatents

A safety lock-out device prevents the insertion of an electrical power cord into an electrical power cord receptacle of an electrical appliance. The device comprises a mounting plate fastened to the appliance and a hinged cover plate attached to the appliance. The cover plate is movable between a first position and a second position such that, in the first position, the cover plate covers and prevents insertion of a power cord into the appliance receptacle. In said second position, the appliance receptacle is uncovered to permit insertion of a power cord into the receptacle. Extending a lock shank through aligned openings formed in flange members extending from the mounting plate, the cover plate locks the cover plate in the first position. 15 figs.

Cliff, P.L. Jr.

1996-07-09

122

Safety lock-out device for electrical appliances  

DOEpatents

A safety lock-out device prevents the insertion of an electrical power cord into an electrical power cord receptacle of an electrical appliance. The devise comprises a mounting plate fastened to the appliance and a cover plate hingedly attached to the appliance. The cover plate is movable between a first position and a second position such that, in the first position, the cover plate covers and prevents insertion of a power cord into the appliance receptacle. In said second position, the appliance receptacle is uncovered to permit insertion of a power cord into the receptacle. Extending a lock shank through aligned openings formed in flange members extending from the mounting plate and the cover plate locks the cover plate in the first position.

Cliff, Jr., Paul L. (Bloomingdale, IL)

1996-01-01

123

Surgical Treatment of Extra-articular or Simple Intra-articular Distal Tibial Fractures: MIPO Versus Supercutaneous Plating.  

PubMed

Minimally invasive plate osteosynthesis (MIPO) has become a widely accepted technique to treat distal tibial fractures. Recently, the novel application of a locking plate used as an external fixator (supercutaneous plating) was introduced for the management of open fractures and infected nonunions and even as an adjunct in distraction osteogenesis, which is considered another less invasive method. The aim of this study was to compare the results of supercutaneous plating with closed reduction and minimally invasive plating in the treatment of distal tibial fractures. Forty-eight matched patients were divided according to age, sex, Injury Severity Score, and fracture pattern into the MIPO group and the supercutaneous plating group. Minimum follow-up was 12 months (mean, 18.5 months; range, 12-26 months). No patient had nonunion, hardware breakdown, or deep infection. Patients in the supercutaneous plating group had a significantly shorter mean operative time (65.6±13.2 vs 85.9±14.0 minutes; P=.000), hospital stay (7.5±2.0 vs 13.0±4.4 days; P=.000), and union time (15.2±2.4 vs 17.0±2.8 weeks; P=.000). In the MIPO group, 15 (62.5%) patients reported implant impingement or discomfort and there was 1 incidence of stripping of 15.6% at the time of locking screw removal, whereas in the supercutaneous plating group, no patient reported skin irritation, and removal of the supercutaneous plate was easily performed in clinic without anesthesia. Distal tibial fractures may be treated successfully with MIPO or supercutaneous plating. However, the supercutaneous plating technique may represent a superior surgical option because it offers advantages in terms of mean operative time, hospital stay, and union time; skin irritation; and implant removal. PMID:25275982

He, Xianfeng; Zhang, Jingwei; Li, Ming; Yu, Yihui; Zhu, Limei

2014-09-01

124

Assessment of plate use for mandibular reconstruction: Has changing technology made a difference?  

Microsoft Academic Search

Reconstruction of mandibular defects with a variety of alloplastic materials during a 22-year period was reviewed. Outcomes were examined to determine whether specific plating technology affected the incidence of plate-related complications including plate exposure, plate fracture, and plate removal. Repair with the miniplate, reconstruction plate, titanium hollow screw reconstruction plate, and locking reconstruction plate was evaluated. Although the incidence of

DOUGLAS W. KLOTCH; THOMAS J. GAL; ROBIN L. GAL

1999-01-01

125

Fast flux locked loop  

DOEpatents

A flux locked loop for providing an electrical feedback signal, the flux locked loop employing radio-frequency components and technology to extend the flux modulation frequency and tracking loop bandwidth. The flux locked loop of the present invention has particularly useful application in read-out electronics for DC SQUID magnetic measurement systems, in which case the electrical signal output by the flux locked loop represents an unknown magnetic flux applied to the DC SQUID.

Ganther, Jr., Kenneth R. (Olathe, KS); Snapp, Lowell D. (Independence, MO)

2002-09-10

126

Overview of locking systems  

SciTech Connect

The purpose of this document is to present technical information that should be useful for understanding and applying locking systems for physical protection and control. There are major sections on hardware for locks, vaults, safes, and security containers. Other topics include management of lock systems and safety considerations. This document also contains notes on standards and specifications and a glossary.

Gee, K.T.; Scott, S.H.; Wilde, M.G. [Sandia National Labs., Albuquerque, NM (United States); Highland, S.E. [Albuquerque Safe Co., Albuquerque, NM (United States)

1993-12-01

127

Lock For Valve Stem  

NASA Technical Reports Server (NTRS)

Simple, cheap device locks valve stem so its setting cannot be changed by unauthorized people. Device covers valve stem; cover locked in place with standard padlock. Valve lock made of PVC pipe and packing band. Shears, drill or punch, and forming rod only tools needed.

Burley, Richard K.; Guirguis, Kamal S.

1991-01-01

128

Dynamic-locking-screw (DLS)–leads to less secondary screw perforations in proximal humerus fractures  

PubMed Central

Background Loss of reduction and screw perforation causes high failure rates in the treatment of proximal humerus fractures. The purpose of the present study was to evaluate the early postoperative complications using modern Dynamic Locking Screws (DLS 3.7) for plating of proximal humerus fractures. Methods Between 03/2009 and 12/2010, 64 patients with acute proximal humerus fractures were treated by angular stable plate fixation using DLSs in a limited multi-centre study. Follow-up examinations were performed three, six, twelve and twenty-four weeks postoperatively and any complications were carefully collected. Results 56 of 64 patients were examined at the six-month follow-up. Complications were observed in 12 patients (22%). In five cases (9%), a perforation of the DLS 3.7 occurred. Conclusions Despite the use of modern DLS 3.7, the early complications after plating of proximal humerus fractures remain high. The potential advantage of the DLS 3.7 regarding secondary screw perforation has to be confirmed by future randomized controlled trials. PMID:24894637

2014-01-01

129

Lock mandrel latch assembly  

SciTech Connect

This patent describes a latch assembly for preliminarily latching a lock mandrel into a locking annulus in a landing nipple in a wellbore. The latch assembly being disposed in a window in a sidewall of the lock mandrel; the latch assembly further comprises a pawl rotatably mounted about an axis traversing the window, a shear pin traversing the window below the pawl, and means for biasing the pawl against the shear pin; the pawl being further adapted to extend radially outward through the window in the sidewall of the lock mandrel to engage the locking annulus in the landing nipple when the pawl is biased against the shear pin.

Welch, W.R.

1991-03-05

130

How A Lock Works  

NSDL National Science Digital Library

Ships travelling between Lake Ontario and Lake Erie use the Welland Canal. Beginning with a conversation between characters Mathise, Geo, and Trig, they explain how a lock in the canal operates by gravity alone, without pumps. The characters use mathematics to solve problems such as how long the locks take to fill and how to express the volume and flow of water in more common terms (bathtubs of water per second). They also ask why the lower lock door is much larger and heavier than the upper one, a question which users can answer by watching the animation of the lock's operation.

131

38. VIEW OF AUXILIARY LOCK MITER GATE, WITH MAIN LOCK ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

38. VIEW OF AUXILIARY LOCK MITER GATE, WITH MAIN LOCK UPSTREAM MITER GATE AND UPSTREAM GUIDEWALL IN BACKGROUND, LOOKING WEST - Upper Mississippi River 9-Foot Channel Project, Lock & Dam No. 5, Minneiska, Winona County, MN

132

West Branch Pennsylvania Canal, Lock No. 34 Lock Keeper's House, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

West Branch Pennsylvania Canal, Lock No. 34 Lock Keeper's House, South of State Route 664 along North bank of West Branch of Susquehanna River, 2,000 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

133

Fixation systems of greater trochanteric osteotomies: biomechanical and clinical outcomes.  

PubMed

The development of cerclage systems for fixation of greater trochanteric osteotomies has progressed from monofilament wires to multifilament cables to cable grip and cable plate systems. Cerclage wires and cables have various clinical indications, including fixation for fractures and for trochanteric osteotomy in hip arthroplasty. To achieve stable fixation and eventual union of the trochanteric osteotomy, the implant must counteract the destabilizing forces associated with pull of the peritrochanteric musculature. The material properties of cables and cable grip systems are superior to those of monofilament wires; however, potential complications with the use of cables include debris generation and third-body polyethylene wear. Nevertheless, the cable grip system provides the strongest fixation and results in lower rates of nonunion and trochanteric migration. Cable plate constructs show promise but require further clinical studies to validate their efficacy and safety. PMID:17916785

Jarit, Gregg J; Sathappan, Sathappan S; Panchal, Anand; Strauss, Eric; Di Cesare, Paul E

2007-10-01

134

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

PubMed

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

Vl?ek, Martin; Jaganjac, Edib; Pech, Jan; Jonáš, David; Kebrle, Radek

2014-05-01

135

The Digital Locke Project  

NSDL National Science Digital Library

The influence of John Locke on human thought is hard to overstate, and scholars continue to mine his substantial corpus for insights into the ways that humans interact. This delightful website brings together a scholarly text edition of many of his works. The project is being overseen by Professor Paul Schuurman, and the database here includes multiple drafts of some of Locke's most powerful works, such as the seminal "An Essay Concerning Human Understanding." Visitors can get started by clicking on the "Texts" button to find the text of his works, along with an "About" area that gives some background material on each work. Those persons who might not be familiar with Locke might also appreciate the "About Locke" area of the site.

136

PEEK and LOCK  

E-print Network

This memo describes two small utility programs that are of assistance in using the ITS 1.4 (see A.I. 161, MAC-M-377) time sharing system. LOCK performs miscellaneous utility functions while PEEK displays, with periodic ...

III, Donald Eastlake

1968-11-01

137

Adapter plate assembly for adjustable mounting of objects  

DOEpatents

An adapter plate and two locking discs are together affixed to an optic table with machine screws or bolts threaded into a fixed array of internally threaded holes provided in the table surface. The adapter plate preferably has two, and preferably parallel, elongated locating slots each freely receiving a portion of one of the locking discs for secure affixation of the adapter plate to the optic table. A plurality of threaded apertures provided in the adapter plate are available to attach optical mounts or other devices onto the adapter plate in an orientation not limited by the disposition of the array of threaded holes in the table surface. An axially aligned but radially offset hole through each locking disc receives a screw that tightens onto the table, such that prior to tightening of the screw the locking disc may rotate and translate within each locating slot of the adapter plate for maximum flexibility of the orientation thereof.

Blackburn, Robert S. (Albuquerque, NM)

1987-01-01

138

Adapter plate assembly for adjustable mounting of objects  

DOEpatents

An adapter plate and two locking discs are together affixed to an optic table with machine screws or bolts threaded into a fixed array of internally threaded holes provided in the table surface. The adapter plate preferably has two, and preferably parallel, elongated locating slots each freely receiving a portion of one of the locking discs for secure affixation of the adapter plate to the optic table. A plurality of threaded apertures provided in the adapter plate are available to attach optical mounts or other devices onto the adapter plate in an orientation not limited by the disposition of the array of threaded holes in the table surface. An axially aligned but radially offset hole through each locking disc receives a screw that tightens onto the table, such that prior to tightening of the screw the locking disc may rotate and translate within each locating slot of the adapter plate for maximum flexibility of the orientation thereof.

Blackburn, R.S.

1986-05-02

139

Locke and botany.  

PubMed

This paper argues that the English philosopher John Locke, who has normally been thought to have had only an amateurish interest in botany, was far more involved in the botanical science of his day than has previously been known. Through the presentation of new evidence deriving from Locke's own herbarium, his manuscript notes, journal and correspondence, it is established that Locke made a modest contribution to early modern botany. It is shown that Locke had close and ongoing relations with the Bobarts, keepers of the Oxford Botanic Garden, and that Locke distributed seeds and plant parts to other botanists, seeds of which the progeny almost certainly ended up in the most important herbaria of the period. Furthermore, it is claimed that the depth of Locke's interest in and practice of botany has a direct bearing on our understanding of his views on the correct method of natural philosophy and on the interpretation of his well known discussion of the nature of species in Book III of his Essay concerning human understanding. PMID:16769554

Anstey, Peter R; Harris, Stephen A

2006-06-01

140

Improving Carbon Fixation Pathways  

PubMed Central

A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing and enhancing photosynthetic reactions in a species independent manner. Furthermore, the elucidation of alternative carbon-fixation routes distinct from the Calvin cycle raises possibilities that alternative pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials. PMID:22647231

Ducat, Daniel C.

2012-01-01

141

Spiral Intermaxillary Fixation  

PubMed Central

Intermaxillary fixation (IMF) remains an important component in the management of many facial fractures. During IMF, dental occlusion plays an important role as a guide and therapeutic tool. Since time immemorial there is a constant quest of oral and maxillofacial surgeons to find a quick way for IMF. The desire to develop an alternate interdental fixation technique, which not only would decrease the risk to the operator and gingival trauma but also accurately satisfy dental occlusion, lead to the development of this novel technique of “spiral IMF.” PMID:23730425

Kumar, Yuvika Raj; Chaudhary, Zainab; Sharma, Pankaj

2012-01-01

142

Mechanical properties of two canine iliac fracture fixation systems  

E-print Network

. Computer generated plots of force versus displace- ment were made for determination of the stiffness and failure strength of the specimen. Failure was defined as exceedance of ultimate strength or fracture gap propaga- tion of greater than 2 mm. Failed.... Either situation is considered exceedance of ultimate strength. In all plated specimens in all testing modes failure was defined in terms of fracture gap propagation greater than 2 mm. In torsional testing the bone plate fixation system usually...

VanGundy, Thomas Eugene

2012-06-07

143

Biomechanical Study of Acetabular Tridimensional Memoryalloy Fixation System  

NASA Astrophysics Data System (ADS)

We developed the acetabular tridimensional memoryalloy fixation system (ATMFS), which is made of NiTi shape memory alloy, according to the specific mechanical properties of biological memory material, NiTi shape memory alloy and measured distribution of contact area and pressure between the acetabulum and the femoral head of cadaveric pelvis. Seven formalin-preserved cadaveric pelves were used for this investigation. Pressure-sensitive film was used to measure contact area and pressure within the anterior, superior, and posterior regions of the acetabulum. The pelves were loaded under the following four conditions: (1) intact; (2) following a creation posterior wall fracture defect; (3) following reduction and standard internal fixation with reconstruction plate; and (4) following reduction and internal fixation with a new shape memory alloy device named ATMFS. A posterior wall fracture was created along an arc of 40° to 90° about the acetabulur rim. Creation of a posterior wall defect resulted in increased load in the superior acetabulum (1485 N) as compared to the intact condition (748 N, P = 0.009). Following reduction and internal fixation, the load distributed to the superior acetabulum (1545 N) was not statistically different from the defect condition. Following the fixation with ATMFS, the load seen at the superior region of the actabulum (964 N) was familiar with fixation with reconstruction plate and was not different from intact state ( P = 0.45). These data indicate that the use of ATMFS as a fracture internal fixation device resulted a partial restoration of joint loading parameters toward the intact state. ATMFS fixation may result in a clinical benefit.

Liu, Xin-Wei; Xu, Shuo-Gui; Zhang, Yun-Tong; Zhang, Chun-Cai

2011-07-01

144

The effect of external fixation stiffness on early healing of transverse osteotomies.  

PubMed

The effect of bending stiffness of external fixators on the early healing of transverse tibial osteotomies was studied in a canine model to determine whether there is a particular range of fixation stiffness where healing is poor. Five unilateral fixators with different stiffnesses were developed and employed along with a dynamic compression plate to fix experimental osteotomies of dog tibias and the contralateral intact tibias served as controls. The six experimental fixation devices were: plate (P), stainless steel sidebar fixator (SS), stiff aluminum sidebar fixator (SA), intermediate aluminum sidebar fixator (IA), flexible aluminum sidebar fixator (FA), and Delrin sidebar fixator (D). Compared with human tibial fixation methods, the fixators ranged from a rigidity greater than a plate on a human tibia to a flexibility similar to a plaster cast on a human lower leg. Sixty-four adult male mongrel dogs (29 +/- 3 kg) underwent surgery and 52 completed the 9-week study, leaving 7 to 10 dogs in each experimental group (P = 8, SS = 7, SA = 9, IA = 9, FA = 10, D = 9). After the 9-week survival period the experimental tibias were radiographed and callus area was digitized. Both the experimental and control tibias were then tested to failure in four-point bending, and failure moment, stiffness, and energy to failure were determined. Of the 52 osteotomies, only four developed nonunions: 3 of 10 in the FA group and 1 of 7 in the SS group. Using analysis of variance, no statistical differences were detected in failure force, stiffness, or energy to failure as a function of fixator groups.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2703930

Gilbert, J A; Dahners, L E; Atkinson, M A

1989-01-01

145

Update: Biological Nitrogen Fixation.  

ERIC Educational Resources Information Center

Updates knowledge on nitrogen fixation, indicating that investigation of free-living nitrogen-fixing organisms is proving useful in understanding bacterial partners and is expected to lead to development of more effective symbioses. Specific areas considered include biochemistry/genetics, synthesis control, proteins and enzymes, symbiotic systems,…

Wiseman, Alan; And Others

1985-01-01

146

Lock 4 View east of lock wall and adjacent ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Lock 4 - View east of lock wall and adjacent roadway built atop tow path. The gate pocket can be seen at center. - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

147

49 CFR 236.337 - Locking faces of mechanical locking; fit.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit squarely...

2013-10-01

148

49 CFR 236.337 - Locking faces of mechanical locking; fit.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit squarely...

2010-10-01

149

49 CFR 236.337 - Locking faces of mechanical locking; fit.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit squarely...

2012-10-01

150

49 CFR 236.337 - Locking faces of mechanical locking; fit.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit squarely...

2011-10-01

151

Self Locking Fasteners  

NASA Technical Reports Server (NTRS)

Detroit Tool Industries' Spiralock threading tool solves a major industrial problem, fasteners coming loose under vibration. Loosening is caused between the flanks of the bolt and nut threads. This lateral movement releases the locking friction that holds the joint together. Spiralock is a uniquely designed female thread form which used with male fasteners of standard thread form provides a self locking action that prevents the lateral movement, and thus makes the threaded joint highly resistant to the effects of vibration. Additionally, a thread contract runs the entire length of the nut, offering greater stress resistance than earlier fasteners.

1987-01-01

152

Posterior transodontoid fixation: A new fixation (Kotil) technique.  

PubMed

Anterior odontoid screw fixation or posterior C1-2 fusion techniques are routinely used in the treatment of Type II odontoid fractures, but these techniques may be inadequate in some types of odontoid fractures. In this new technique (Kotil technique), through a posterior bilateral approach, transarticular screw fixation was performed at the non-dominant vertebral artery (VA) side and posterior transodontoid fixation technique was performed at the dominant VA side. C1-2 complex fusion was aimed with unilateral transarticular fixation and odontoid fixation with posterior transodontoid screw fixation. Cervical spinal computed tomography (CT) of a 40-year-old male patient involved in a motor vehicle accident revealed an anteriorly dislocated Type II oblique dens fracture, not reducible by closed traction. Before the operation, the patient was found to have a dominant right VA with Doppler ultrasound. He was operated through a posterior approach. At first, transarticular screw fixation was performed at the non-dominant (left) side, and then fixation of the odontoid fracture was achieved by directing the contralateral screw (supplemental screw) medially and toward the apex. Cancellous autograft was scattered for fusion without the need for structural bone graft or wiring. Postoperative cervical spinal CT of the patient revealed that stabilization was maintained with transarticular screw fixation and reduction and fixation of the odontoid process was achieved completely by posterior transodontoid screw fixation. The patient is at the sixth month of follow-up and complete fusion has developed. With this new surgical technique, C1-2 fusion is maintained with transarticular screw fixation and odontoid process is fixed by concomitant contralateral posterior transodontoid screw (supplemental screw) fixation; thus, this technique both stabilizes the C1-2 complex and fixes the odontoid process and the corpus in atypical odontoid fractures, appearing as an alternative new technique among the previously defined C1-C2 fixation techniques in eligible cases. PMID:22013375

Kotil, Kad?r; Köksal, Neslihan Sütpideler; Kayac?, Selim

2011-01-01

153

Posterior transodontoid fixation: A new fixation (Kotil) technique  

PubMed Central

Anterior odontoid screw fixation or posterior C1-2 fusion techniques are routinely used in the treatment of Type II odontoid fractures, but these techniques may be inadequate in some types of odontoid fractures. In this new technique (Kotil technique), through a posterior bilateral approach, transarticular screw fixation was performed at the non-dominant vertebral artery (VA) side and posterior transodontoid fixation technique was performed at the dominant VA side. C1-2 complex fusion was aimed with unilateral transarticular fixation and odontoid fixation with posterior transodontoid screw fixation. Cervical spinal computed tomography (CT) of a 40-year-old male patient involved in a motor vehicle accident revealed an anteriorly dislocated Type II oblique dens fracture, not reducible by closed traction. Before the operation, the patient was found to have a dominant right VA with Doppler ultrasound. He was operated through a posterior approach. At first, transarticular screw fixation was performed at the non-dominant (left) side, and then fixation of the odontoid fracture was achieved by directing the contralateral screw (supplemental screw) medially and toward the apex. Cancellous autograft was scattered for fusion without the need for structural bone graft or wiring. Postoperative cervical spinal CT of the patient revealed that stabilization was maintained with transarticular screw fixation and reduction and fixation of the odontoid process was achieved completely by posterior transodontoid screw fixation. The patient is at the sixth month of follow-up and complete fusion has developed. With this new surgical technique, C1-2 fusion is maintained with transarticular screw fixation and odontoid process is fixed by concomitant contralateral posterior transodontoid screw (supplemental screw) fixation; thus, this technique both stabilizes the C1-2 complex and fixes the odontoid process and the corpus in atypical odontoid fractures, appearing as an alternative new technique among the previously defined C1-C2 fixation techniques in eligible cases. PMID:22013375

Kotil, Kad?r; Köksal, Neslihan sütpideler; Kayac?, Selim

2011-01-01

154

Hot topics in biomechanically directed fracture fixation.  

PubMed

The evolution of locking plates and modern nail constructs provides the orthopaedic trauma surgeon with a myriad of options with regard to implant selection for common fractures. There is a significant amount of biomechanical literature comparing modern constructs with those conventionally used. A basic understanding of this literature is required to make informed decisions with regard to implant selection in the management of these injuries. This article reviews the most recent biomechanical literature regarding implant selection and application for a variety of commonly treated injuries, including fractures of the clavicle, proximal humerus, distal humerus, intertrochanteric hip region, distal femur, and bicondylar tibial plateau. PMID:24464098

Bonyun, Marissa; Nauth, Aaron; Egol, Kenneth A; Gardner, Michael J; Kregor, Philip J; McKee, Michael D; Wolinsky, Philip R; Schemitsch, Emil H

2014-01-01

155

Integrated optical phase locked loop.  

SciTech Connect

A silicon photonics based integrated optical phase locked loop is utilized to synchronize a 10.2 GHz voltage controlled oscillator with a 509 MHz mode locked laser, achieving 32 fs integrated jitter over 300 kHz bandwidth.

Lentine, Anthony L.; Kim, Jungwon (Massachusetts Institute of Technology, Cambridge, MA); Trotter, Douglas Chandler; DeRose, Christopher T.; Kartner, Franz X. (Massachusetts Institute of Technology, Cambridge, MA); Byun, Hyunil (Massachusetts Institute of Technology, Cambridge, MA); Nejadmalayeri, Amir H. (Massachusetts Institute of Technology, Cambridge, MA); Watts, Michael R.; Zortman, William A.

2010-12-01

156

Distal radius fixation through a mini-invasive approach of 15 mm. PART 1: a series of 144 cases.  

PubMed

The volar Henry approach is becoming the gold standard for distal radius fracture fixation. It decreases the incidence of nonunion, limits complications especially complex regional pain syndrome (CRPS) type I, and allows early mobilization of the wrist. Nonetheless, it has some disadvantages such as the size of the incision, which is not esthetically pleasing, and the loss of ligamentotaxis. This is why some authors have developed a mini-invasive approach. The aim of this work was to evaluate the feasibility of the anterior mini-invasive approach of 15 mm in a clinical series of 144 cases of distal radius fracture. All patients were operated under regional anesthesia using the same techniques by five surgeons of the same team. According to the AO classification, there were 83 type A fractures, 2 type B, and 59 type C. A volar plate (Step One(®), Newclip Technics™, Haute-Goulaine, France) was used in all cases. The 2 proximal metaphyseal screws and the 2 distal central epiphyseal screws were monoaxial locking. The 2 distal ulnar and radial epiphyseal screws were placed in polyaxial locking at 20° angulation maximum. Skin closure without drainage was performed. No postoperative immobilization was prescribed, and patients were encouraged to use their upper limb immediately postoperative. No postoperative physiotherapy was prescribed. The mean follow-up was 4.1 months. The final size of the incision was on average 16.1 mm. Mean pain score was 1.8. The Quick DASH score was average 25. Average range of motion was more than 85 %, and global force of the hand was 67 % compared with contralateral side. On X-ray, the mean radial slope was 22°, the mean radial tilt was 8.3°, and the mean radioulnar variance/index was -0.4 mm. There were nine cases of CRPS type I, which all resolved. Specific complications included two secondary displacements and nine tenosynovitis cases. No tendon rupture was noted. Two intra-articular distal radioulnar joint screws had to be removed at 3 months. One epiphyseal screw required removal 1 month postoperative due to loosening. There were no intra-articular radiocarpal screws. Distal radius fracture fixation using a mini-invasive approach is a reliable and reproducible procedure with few complications. It allows anatomical reduction in the distal radius fractures including intra-articular ones. It can be associated with arthroscopy, scaphoid screw fixation or even percutaneous pinning. Thus, most traumatic lesions of the wrist bony or soft tissue can be treated through this mini-invasive approach. PMID:24258689

Lebailly, Frédéric; Zemirline, Ahmed; Facca, Sybille; Gouzou, Stéphanie; Liverneaux, Philippe

2014-08-01

157

Excel: Locking Cell References  

NSDL National Science Digital Library

In this animated and interactive object, students read how to lock a cell that is being referenced in a formula so that it does not automatically show an increment when the formula is copied. Target Audience: 2-4 Year College Students

Hoppe, Patrick

2009-10-14

158

Locked-In Syndrome  

MedlinePLUS

... for locked-in syndrome, nor is there a standard course of treatment. A therapy called functional neuromuscular stimulation, which uses ... endorsement by or an official position of the National Institute of Neurological ... Advice on the treatment or care of an individual patient should be ...

159

Roller Locking Brake  

NASA Technical Reports Server (NTRS)

Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

Vranish, John M.

1993-01-01

160

Positioning and locking apparatus  

DOEpatents

A positioning and locking apparatus including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member.

Hayward, Milton L. (2305 Greenbrook Blvd., Richland, WA 99352); Harper, William H. (1454 Amon Dr., Richland, WA 99352)

1987-01-01

161

Positioning and locking apparatus  

DOEpatents

A positioning and locking apparatus are disclosed including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member. 6 figs.

Hayward, M.L.; Harper, W.H.

1987-06-30

162

Novel posterior fixation keratoprosthesis  

NASA Astrophysics Data System (ADS)

The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

Lacombe, Emmanuel

1992-08-01

163

CARBON DIOXIDE FIXATION.  

SciTech Connect

Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

FUJITA,E.

2000-01-12

164

Parallel analysis of finite element model controlled trial and retrospective case control study on percutaneous internal fixation for vertical sacral fractures  

PubMed Central

Background Although percutaneous posterior-ring tension-band metallic plate and percutaneous iliosacral screws are used to fix unstable posterior pelvic ring fractures, the biomechanical stability and compatibility of both internal fixation techniques for the treatment of Denis I, II and III type vertical sacral fractures remain unclear. Methods Using CT and MR images of the second generation of Chinese Digitized Human “male No. 23”, two groups of finite element models were developed for Denis I, II and III type vertical sacral fractures with ipsilateral superior and inferior pubic ramus fractures treated with either a percutaneous metallic plate or a percutaneous screw. Accordingly, two groups of clinical cases that were fixed using the above-mentioned two internal fixation techniques were retrospectively evaluated to compare postoperative effect and function. Parallel analysis was performed with a finite element model controlled trial and a case control study. Results The difference of the postoperative Majeed standards and outcome rates between two case groups was no statistically significant (P?>?0.05). Accordingly, the high values of the maximum displacements/stresses of the plate-fixation model group approximated those of the screw-fixation model group. However, further simulation of Denis I, II and III type fractures in each group of models found that the biomechanics of the plate-fixation models became increasingly stable and compatible, whereas the biomechanics of the screw-fixation models maintained tiny fluctuations. When treating Denis III fractures, the biomechanical effects of the pelvic ring of the plate-fixation model were better than the screw-fixation model. Conclusions Percutaneous plate and screw fixations are both appropriate for the treatment of Denis I and II type vertical sacral fractures; whereas percutaneous plate fixation appears be superior to percutaneous screw fixation for Denis III type vertical sacral fracture. Biomechanical evidence of finite element evaluations combined with clinical evidence will contribute to our ability to distinguish between indications that require plate or screw fixation for vertical sacral fractures. PMID:23879618

2013-01-01

165

Plating of patella fractures: techniques and outcomes.  

PubMed

Operative treatment of displaced patella fractures with tension band fixation remains the gold standard, but is associated with a significant rate of complications and symptomatic implants. Despite the evolution of tension band fixation to include cannulated screws, surprisingly little other development has been made to improve overall patient outcomes. In this article, we present the techniques and outcomes of patella plating for displaced patella fractures and patella nonunions. PMID:24343252

Taylor, Benjamin C; Mehta, Sanjay; Castaneda, Joaquin; French, Bruce G; Blanchard, Chris

2014-09-01

166

Posterior fixation of the upper cervical spine: contemporary techniques.  

PubMed

Instrumentation in the upper cervical spine has changed considerably in the past two decades. Previous stand-alone wiring techniques have been made largely obsolete with the development of occipital segmental plating, transarticular screws, and C1 lateral mass screws, as well as a myriad of C2 fixation options, including pedicle, pars, and translaminar screws. Polyaxial screws and segmental fixation are more user-friendly than stand-alone wiring and provide a stronger construct. Awareness of the risks and benefits associated with the use of modern instrumentation and thorough familiarity with the anatomy of the upper cervical spine are essential to avoid complications and optimize outcomes. PMID:21292929

Bransford, Richard J; Lee, Michael J; Reis, Abilio

2011-02-01

167

The treatment of fractures with a dynamic axial fixator.  

PubMed

The results obtained with a lightweight dynamic axial fixator in the treatment of fractures are reported. The apparatus comprises a single bar with articulating ends which clamp self-tapping screws and can be locked at an angle appropriate for axial alignment. A telescopic facility allows ready conversion from rigid to dynamic fixation once periosteal callus formation has commenced. Reduction and controlled distraction or compression are achieved by means of a detachable compressor unit. We treated 288 patients with fresh fractures and 50 with ununited fractures. The success rate for fresh fractures was 94%, with average healing times ranging from 3.4 to 6.5 months. In ununited fractures also, the success rate was 94% with average healing times ranging from 4.7 to 6.5 months. Complications were minimal. The device is versatile and can be applied in an average of 15 minutes. It permits ambulatory fracture care without sacrificing a sound anatomical result. PMID:6746689

De Bastiani, G; Aldegheri, R; Renzi Brivio, L

1984-08-01

168

The Mechanics of External Fixation  

Microsoft Academic Search

External fixation has evolved from being used primarily as a last resort fixation method to becoming a main stream technique\\u000a used to treat a myriad of bone and soft tissue pathologies. Techniques in limb reconstruction continue to advance largely\\u000a as a result of the use of these external devices. A thorough understanding of the biomechanical principles of external fixation\\u000a is

Austin T. Fragomen; S. Robert Rozbruch

2007-01-01

169

Data port security lock  

DOEpatents

In a security apparatus for securing an electrical connector, a plug may be fitted for insertion into a connector receptacle compliant with a connector standard. The plug has at least one aperture adapted to engage at least one latch in the connector receptacle. An engagement member is adapted to partially extend through at least one aperture and lock to at least one structure within the connector receptacle.

Quinby, Joseph D. (Albuquerque, NM); Hall, Clarence S. (Albuquerque, NM)

2008-06-24

170

Ilizarov hybrid external fixation for fractures of the distal radius: Part II. Internal fixation versus ilizarov hybrid external fixation: Stability as assessed by cadaveric simulated motion testing  

Microsoft Academic Search

The in vitro stability of an Ilizarov hybrid external fixator was compared with that of a dorsal 3.5-mm AO T-plate in 8 unpaired, fresh-frozen upper extremities. A specially designed testing device that used computer-controlled pneumatic actuators was used to simulate active finger, wrist, and forearm motions by applying loads to relevant tendons. A comminuted extra-articular distal radius fracture was modelled

Cynthia E Dunning; Christopher S Lindsay; Ryan T Bicknell; James A Johnson; Graham J. W King; Stuart D Patterson

2001-01-01

171

Definitive Bone Fixation and Reconstruction: Conversion from Temporary External Fixation to Internal Fixation Methods  

Microsoft Academic Search

\\u000a Temporary external fixation is frequently employed in the military combat theater of operations to temporize devastating extremity\\u000a injuries and facilitate transport of the wounded soldier. Multiple civilian and a few military studies have provided helpful\\u000a insight into the staged treatment of these injuries including conversion of temporary external fixation to definitive stabilization\\u000a with internal fixation. Diaphyseal fractures of the long

Craig S. Bartlett; Benjamin Geer; David L. Helfet

172

49 CFR 236.306 - Facing point lock or switch-and-lock movement.  

Code of Federal Regulations, 2012 CFR

...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

2012-10-01

173

49 CFR 236.306 - Facing point lock or switch-and-lock movement.  

Code of Federal Regulations, 2013 CFR

...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

2013-10-01

174

49 CFR 236.306 - Facing point lock or switch-and-lock movement.  

Code of Federal Regulations, 2011 CFR

...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

2011-10-01

175

49 CFR 236.306 - Facing point lock or switch-and-lock movement.  

Code of Federal Regulations, 2010 CFR

...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

2010-10-01

176

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.  

Code of Federal Regulations, 2012 CFR

...accordance with locking sheet and dog chart. 236.338 Section 236.338 Transportation...accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

2012-10-01

177

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.  

Code of Federal Regulations, 2011 CFR

...accordance with locking sheet and dog chart. 236.338 Section 236.338 Transportation...accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

2011-10-01

178

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.  

Code of Federal Regulations, 2013 CFR

...accordance with locking sheet and dog chart. 236.338 Section 236.338 Transportation...accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

2013-10-01

179

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.  

Code of Federal Regulations, 2010 CFR

...accordance with locking sheet and dog chart. 236.338 Section 236.338 Transportation...accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

2010-10-01

180

Escaping carbon lock-in  

Microsoft Academic Search

This article explores the climate policy implications of the arguments made in “Understanding carbon lock-in” (Unruh, 2000), which posited that industrial countries have become locked-into fossil fuel-based energy systems through path dependent processes driven by increasing returns to scale. Carbon lock-in arises through technological, organizational, social and institutional co-evolution, “culminating” in what was termed as techno-institutional complex (TIC). In order

Gregory C. Unruh

2002-01-01

181

Fixation Time for Evolutionary Graphs  

NASA Astrophysics Data System (ADS)

Evolutionary graph theory (EGT) is recently proposed by Lieberman et al. in 2005. EGT is successful for explaining biological evolution and some social phenomena. It is extremely important to consider the time of fixation for EGT in many practical problems, including evolutionary theory and the evolution of cooperation. This study characterizes the time to asymptotically reach fixation.

Nie, Pu-Yan; Zhang, Pei-Ai

182

Eighth international congress on nitrogen fixation  

SciTech Connect

This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

Not Available

1990-01-01

183

Robust Photon Locking  

SciTech Connect

We experimentally demonstrate a strong-field coherent control mechanism that combines the advantages of photon locking (PL) and rapid adiabatic passage (RAP). Unlike earlier implementations of PL and RAP by pulse sequences or chirped pulses, we use shaped pulses generated by phase modulation of the spectrum of a femtosecond laser pulse with a generalized phase discontinuity. The novel control scenario is characterized by a high degree of robustness achieved via adiabatic preparation of a state of maximum coherence. Subsequent phase control allows for efficient switching among different target states. We investigate both properties by photoelectron spectroscopy on potassium atoms interacting with the intense shaped light field.

Bayer, T.; Wollenhaupt, M.; Sarpe-Tudoran, C.; Baumert, T. [Universitaet Kassel, Institut fuer Physik und CINSaT, Heinrich-Plett-Str. 40, D-34132 Kassel (Germany)

2009-01-16

184

Plate Tectonics  

NSDL National Science Digital Library

Students will go over the main points of plate tectonics, including the theory of continental drift, different types of plate boundaries, seafloor spreading, and convection currents. We have been spending time learning about plate tectonics. We have discussed the theory of continental drift, we have talked about the different types of plate boundaries, we have also learned about seafloor spreading and convection currents. Plate Boundary Diagram Now is your chance ...

Rohlfing, Mrs.

2011-02-03

185

49 CFR 236.330 - Locking dog of switch-and-lock movement.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

2010-10-01

186

49 CFR 236.330 - Locking dog of switch-and-lock movement.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

2011-10-01

187

49 CFR 236.330 - Locking dog of switch-and-lock movement.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

2012-10-01

188

49 CFR 236.330 - Locking dog of switch-and-lock movement.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

2013-10-01

189

49 CFR 236.765 - Locking, mechanical.  

Code of Federal Regulations, 2013 CFR

... 4 2013-10-01 2013-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other...DEVICES, AND APPLIANCES Definitions § 236.765 Locking, mechanical. An arrangement of locking bars, dogs, tappets,...

2013-10-01

190

49 CFR 236.376 - Mechanical locking.  

Code of Federal Regulations, 2013 CFR

...4 2013-10-01 2013-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation...Interlocking Inspection and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall...

2013-10-01

191

49 CFR 236.765 - Locking, mechanical.  

Code of Federal Regulations, 2010 CFR

... 4 2010-10-01 2010-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other...DEVICES, AND APPLIANCES Definitions § 236.765 Locking, mechanical. An arrangement of locking bars, dogs, tappets,...

2010-10-01

192

49 CFR 236.376 - Mechanical locking.  

Code of Federal Regulations, 2010 CFR

...4 2010-10-01 2010-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation...Interlocking Inspection and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall...

2010-10-01

193

49 CFR 236.376 - Mechanical locking.  

Code of Federal Regulations, 2012 CFR

...4 2012-10-01 2012-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation...Interlocking Inspection and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall...

2012-10-01

194

49 CFR 236.765 - Locking, mechanical.  

Code of Federal Regulations, 2011 CFR

... 4 2011-10-01 2011-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other...DEVICES, AND APPLIANCES Definitions § 236.765 Locking, mechanical. An arrangement of locking bars, dogs, tappets,...

2011-10-01

195

49 CFR 236.376 - Mechanical locking.  

Code of Federal Regulations, 2011 CFR

...4 2011-10-01 2011-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation...Interlocking Inspection and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall...

2011-10-01

196

49 CFR 236.765 - Locking, mechanical.  

Code of Federal Regulations, 2012 CFR

... 4 2012-10-01 2012-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other...DEVICES, AND APPLIANCES Definitions § 236.765 Locking, mechanical. An arrangement of locking bars, dogs, tappets,...

2012-10-01

197

John Locke and Public Administration  

Microsoft Academic Search

John Locke, whose thought greatly influenced the American founding, makes an important contribution to contemporary public administration theory and to our understanding of the history of American public administration. Locke's theory gives an account of why it is legitimate for public administrators to sometimes perform functions that are legislative or judicial in nature and encourages public administrators to interpret directives

Alex Tuckness

2008-01-01

198

Deformation and stress change associated with plate interaction at subduction zones: a kinematic modelling  

Microsoft Academic Search

The interseismic deformation associated with plate coupling at a subduction zone is commonly simulated by the steady-slip model in which a reverse dip-slip is imposed on the down-dip extension of the locked plate interface, or by the backslip model in which a normal slip is imposed on the locked plate interface. It is found that these two models, although totally

Shaorong Zhao; Shuzo Takemoto

2000-01-01

199

Phase-Locked Loops  

NSDL National Science Digital Library

Phase-locked loops (PLL) are unique feedback control circuits that offer many useful features and benefits in electronic applications. PLLs are available either in integrated circuit (IC) form for general applications or built into larger system IC chips. Today, PLLs are found in virtually all types of electronic equipment from PCs to consumer products like TV sets and cell phones. This module provides an introduction to the PLL and its applications. It begins with an overview of the main components of a PLL and how these components work together. It then describes PLL specifications and a description of the most widely used applications including frequency synthesizers, clock multipliers, clock and data recovery circuits, FM demodulators, and filters.

2012-09-06

200

Evaluation of Bone Fixation Implants  

E-print Network

This research investigates the effects of the human body on the mechanical, chemical, and morphological properties of the surface of internal fixation devices. Stainless steel and titanium devices that had failed were provided from the Shandong...

Perkins, Luke 1990-

2012-12-10

201

Plate Tectonics  

NSDL National Science Digital Library

Create a poster all about Plate Tectonics! Directions: Make a poster about Plate Tectonics. (20 points) Include at least (1) large picture (15 points) on your poster complete with labels of every part (10 points). (15 points) Include at least three (3) facts about Plate Tectonics. (5 points ...

Walls, Mrs.

2011-01-30

202

Plate Tectonics  

NSDL National Science Digital Library

This interactive Flash explores plate tectonics and provides an interactive map where users can identify plate boundaries with name and velocities as well as locations of earthquakes, volcanoes, and hotspots. The site also provides animations and supplementary information about plate movement and subduction. This resource is a helpful overview or review for introductory level high school or undergraduate physical geology or Earth science students.

Smoothstone; Company, Houghton M.

203

49 CFR 236.766 - Locking, movable bridge.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Locking, movable bridge. 236.766 Section 236.766 Transportation... Definitions § 236.766 Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers,...

2012-10-01

204

49 CFR 236.766 - Locking, movable bridge.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Locking, movable bridge. 236.766 Section 236.766 Transportation... Definitions § 236.766 Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers,...

2011-10-01

205

49 CFR 236.766 - Locking, movable bridge.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Locking, movable bridge. 236.766 Section 236.766 Transportation... Definitions § 236.766 Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers,...

2013-10-01

206

49 CFR 236.766 - Locking, movable bridge.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Locking, movable bridge. 236.766 Section 236.766 Transportation... Definitions § 236.766 Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers,...

2010-10-01

207

A magnetorheological fluid locking device  

NASA Astrophysics Data System (ADS)

A magnetorheological fluid (MRF) device is designed to provide a static locking force caused by the operation of a controllable MRF valve. The intent is to introduce an MRF device which provides the locking force of a fifth wheel coupler while maintaining the "powerless" locking capability when required. A passive magnetic field supplied by a permanent magnet provides a powerless locking resistance force. The passively closed MRF valve provides sufficient reaction force to eliminate axial displacement to a pre-defined force value. Unlocking of the device is provided by means of an electromagnet which re-routes the magnetic field distribution along the MR valve, and minimizes the resistance. Three dimensional electromagnetic finite element analyses are performed to optimize the MRF lock valve performance. The MRF locking valve is fabricated and tested for installation on a truck fifth wheel application. An experimental setup, resembling actual working conditions, is designed and tests are conducted on vehicle interface schemes. The powerless-locking capacity and the unlocking process with minimal resistance are experimentally demonstrated.

Kavlicoglu, Barkan; Liu, Yanming

2011-04-01

208

Plate Tectonics  

NSDL National Science Digital Library

The Plate Tectonics SciPack explores the various materials that make up Earth and the processes they undergo to provide a framework for understanding how continents are created and change over time. The focus is on Standards and Benchmarks related to Earth's layers, oceanic and continental plates and the interactions between plates.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:� Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. � Access to one-on-one support via e-mail to content "Wizards".� Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Plate Tectonics: Layered Earth� Identify that Earth has layers (not necessarily name them), and that the interior is hotter and more dense than the crust.� Identify the crust as mechanically strong, and the underlying mantle as deformable and convecting.Plate Tectonics: Plates� Identify that the outermost layer of Earth is made up of separate plates.� Choose the correct speed of the motion of plates.� Identify the ocean floor as plate, in addition to the continents (to combat the common idea that only continents are plates, floating around on the oceans).� Recognize that oceans and continents can coexist on the same plate.Plate Tectonics: Plate Interactions� Identify the different interactions between plates.� Discuss what happens as a result of those interactions.Plate Tectonics: Consequences of Plate Interactions� Explain why volcanoes and earthquakes occur along plate boundaries. � Explain how new sea floor is created and destroyed.� Describe features that may be seen on the surface as a result of plate interactions.Plate Tectonics: Lines of Evidence� Use plate tectonics to explain changes in continents and their positions over geologic time.� Provide evidence for the idea of plates, including the location of earthquakes and volcanoes, continental drift, magnetic orientation of rocks in the ocean floor, etc.

National Science Teachers Association (NSTA)

2007-03-21

209

Lock cohorting: A general technique for designing NUMA locks  

E-print Network

Multicore machines are quickly shifting to NUMA and CC-NUMA architectures, making scalable NUMA-aware locking algorithms, ones that take into account the machines' non-uniform memory and caching hierarchy, ever more ...

Dice, David

210

Open reduction and internal fixation versus casting for highly comminuted and intra-articular fractures of the distal radius (ORCHID): protocol for a randomized clinical multi-center trial  

PubMed Central

Background Fractures of the distal radius represent the most common fracture in elderly patients, and often indicate the onset of symptomatic osteoporosis. A variety of treatment options is available, including closed reduction and plaster casting, K-wire-stabilization, external fixation and open reduction and internal fixation (ORIF) with volar locked plating. The latter is widely promoted by clinicians and hardware manufacturers. Closed reduction and cast stabilization for six weeks is a simple, convenient, and ubiquitously available intervention. In contrast, ORIF requires hospitalization, but allows for functional rehabilitation. Given the lack of randomized controlled trials, it remains unclear whether ORIF leads to better functional outcomes one year after injury than closed reduction and casting. Methods/Design ORCHID (Open reduction and internal fixation versus casting for highly comminuted intra-articular fractures of the distal radius) is a pragmatic, randomized, multi-center, clinical trial with two parallel treatment arms. It is planned to include 504 patients in 15 participating centers throughout Germany over a three-year period. Patients are allocated by a central web-based randomization tool. The primary objective is to determine differences in the Short Form 36 (SF-36) Physical Component Score (PCS) between volar locked plating and closed reduction and casting of intraarticular, comminuted distal radius fractures in patients > 65 years of age one year after the fracture. Secondary outcomes include differences in other SF-36 dimensions, the EuroQol-5D questionnaire, the Disability of the Arm, Shoulder, and Hand (DASH) instrument. Also, the range of motion in the affected wrist, activities of daily living, complications (including secondary ORIF and revision surgery), as well as serious adverse events will be assessed. Data obtained during the trial will be used for later health-economic evaluations. The trial architecture involves a central statistical unit, an independent monitoring institute, and a data safety monitoring board. Following approval by the institutional review boards of all participating centers, conduct and reporting will strictly adhere to national and international rules, regulations, and recommendations (e.g., Good Clinical Practice, data safety laws, and EQUATOR/CONSORT proposals) Discussion To our knowledge, ORCHID is the first multicenter RCT designed to assess quality of life and functional outcomes following operative treatment compared to conservative treatment of complex, intra-articular fractures of the distal radius in elderly patients. The results are expected to influence future treatment recommendations and policies on an international level. Trial registration ISRCTN: ISRCTN76120052 Registration date: 31.07.2008; Randomization of first patient: 15.09.2008 PMID:21426543

2011-01-01

211

Abortable Reader-Writer Locks are No More Complex Than Abortable Mutex Locks  

E-print Network

Abortable Reader-Writer Locks are No More Complex Than Abortable Mutex Locks Dartmouth Computer on designing abortable mutual exclusion locks, and fairly efficient algorithms of O(log n) RMR complexity have). The abort feature is just as important for a reader-writer lock as it is for a mutual exclusion lock

212

Cavity-locked ring down spectroscopy  

DOEpatents

Distinct locking and sampling light beams are used in a cavity ring-down spectroscopy (CRDS) system to perform multiple ring-down measurements while the laser and ring-down cavity are continuously locked. The sampling and locking light beams have different frequencies, to ensure that the sampling and locking light are decoupled within the cavity. Preferably, the ring-down cavity is ring-shaped, the sampling light is s-polarized, and the locking light is p-polarized. Transmitted sampling light is used for ring-down measurements, while reflected locking light is used for locking in a Pound-Drever scheme.

Zare, Richard N. (Stanford, CA); Paldus, Barbara A. (Stanford, CA); Harb, Charles C. (Palo Alto, CA); Spence, Thomas (Union City, CA)

2000-01-01

213

John locke on personal identity.  

PubMed

John Locke speaks of personal identity and survival of consciousness after death. A criterion of personal identity through time is given. Such a criterion specifies, insofar as that is possible, the necessary and sufficient conditions for the survival of persons. John Locke holds that personal identity is a matter of psychological continuity. He considered personal identity (or the self) to be founded on consciousness (viz. memory), and not on the substance of either the soul or the body. PMID:21694978

Nimbalkar, Namita

2011-01-01

214

Nitrogen Fixation (Acetylene Reduction) Associated with Duckweed (Lemnaceae) Mats  

PubMed Central

Duckweed (Lemnaceae) mats in Texas and Florida were investigated, using the acetylene reduction assay, to determine whether nitrogen fixation occurred in these floating aquatic macrophyte communities. N2-fixing microorganisms were enumerated by plating or most-probable-number techniques, using appropriate N-free media. Results of the investigations indicated that substantial N2-fixation (C2H2) was associated with duckweed mats in Texas and Florida. Acetylene reduction values ranged from 1 to 18 ?mol of C2H4 g (dry weight)?1 day?1 for samples incubated aerobically in light. Dark N2 fixation was always two- to fivefold lower. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea (7 to 10 ?M) reduced acetylene reduction to levels intermediate between light and dark incubation. Acetylene reduction was generally greatest for samples incubated anaerobically in the light. It was estimated that 15 to 20% of the N requirement of the duckweed could be supplied through biological nitrogen fixation. N2-fixing heterotrophic bacteria (105 cells g [wet weight]?1 and cyanobacteria (105 propagules g [wet weight]?1 were associated with the duckweed mats. Azotobacter sp. was not detected in these investigations. One diazotrophic isolate was classified as Klebsiella. PMID:16345992

Zuberer, D. A.

1982-01-01

215

Tibial plafond fractures: limited incision reduction with percutaneous fixation.  

PubMed

This study was a retrospective review of 18 patients with 19 pilon fractures treated with limited incision reduction and percutaneous plate fixation of the tibia. Patients were treated with either a 1- or 2-stage protocol. The latter consisted of placement of an external fixator followed by definitive reduction. The emphasis of analysis was placed on the identification of complications to the soft tissue envelope or bone-healing problems within the first 6 months after surgery. A major complication was defined as an unplanned operation within the first 6 months. Minor complications were any superficial wound defects that did not require operative intervention to resolve or any malunion or delayed union. With this protocol, no major complications were encountered. Minor complications were identified in 4 patients (4 fractures) of which 2 were minor wound problems. One patient developed a malunion, and the other had a delayed union. Four patients requested removal of prominent hardware. These results indicate that limited incision reduction and percutaneous plate fixation lead to safe methods of stabilization. The authors also provide guidance and strategies for the consistent execution of this technique. PMID:17586439

Salton, Heather L; Rush, Shannon; Schuberth, John

2007-01-01

216

Design of a textile composite bone plate using 3D-finite element method  

Microsoft Academic Search

Bone plates are the most common devices used for long bone fracture fixations. Metallic bone plates are conventionally used for load bearing regions suffer the disadvantages that they usually needs to be removed 1–2years after surgery due to stress shielding and ion releasing effects. One solution to overcome these problems is to use bone plates made of composite materials with

A. Zargar Kharazi; M. H. Fathi; F. Bahmany

2010-01-01

217

Experimental and theoretical study of the passively mode-locked ytterbium-doped double-clad fiber laser  

NASA Astrophysics Data System (ADS)

We consider a Yb-doped double-clad fiber laser in a unidirectional ring cavity containing a polarizer placed between two half-wave plates. Depending on the orientation of the phase plates, the laser operates in continuous, Q-switch, mode-lock, or unstable self-pulsing regime. An experimental study of the stability of the mode-locking regime is realized versus the orientation of the half-wave plates. A model for the stability of self-mode-locking and cw operation is developed starting from two-coupled nonlinear Schrödinger equations in a gain medium. The model is reduced to a master equation in which the coefficients are explicitly dependent on the orientation angles of the phase plates. Analytical solutions are given together with their stability versus the angles.

Leblond, Hervé; Salhi, Mohamed; Hideur, Ammar; Chartier, Thierry; Brunel, Marc; Sanchez, François

2002-06-01

218

A new adhesive technique for internal fixation in midfacial surgery  

PubMed Central

Background The current surgical therapy of midfacial fractures involves internal fixation in which bone fragments are fixed in their anatomical positions with osteosynthesis plates and corresponding screws until bone healing is complete. This often causes new fractures to fragile bones while drilling pilot holes or trying to insert screws. The adhesive fixation of osteosynthesis plates using PMMA bone cement could offer a viable alternative for fixing the plates without screws. In order to achieve the adhesive bonding of bone cement to cortical bone in the viscerocranium, an amphiphilic bone bonding agent was created, analogous to the dentin bonding agents currently on the market. Methods The adhesive bonding strengths were measured using tension tests. For this, metal plates with 2.0 mm diameter screw holes were cemented with PMMA bone cement to cortical bovine bone samples from the femur diaphysis. The bone was conditioned with an amphiphilic bone bonding agent prior to cementing. The samples were stored for 1 to 42 days at 37 degrees C, either moist or completely submerged in an isotonic NaCl-solution, and then subjected to the tension tests. Results Without the bone bonding agent, the bonding strength was close to zero (0.2 MPa). Primary stability with bone bonding agent is considered to be at ca. 8 MPa. Moist storage over 42 days resulted in decreased adhesion forces of ca. 6 MPa. Wet storage resulted in relatively constant bonding strengths of ca. 8 MPa. Conclusion A new amphiphilic bone bonding agent was developed, which builds an optimizied interlayer between the hydrophilic bone surface and the hydrophobic PMMA bone cement and thus leads to adhesive bonding between them. Our in vitro investigations demonstrated the adhesive bonding of PMMA bone cement to cortical bone, which was also stable against hydrolysis. The newly developed adhesive fixing technique could be applied clinically when the fixation of osteosynthesis plates with screws is impossible. With the detected adhesion forces of ca. 6 to 8 MPa, it is assumed that the adhesive fixation system is able to secure bone fragments from the non-load bearing midfacial regions in their orthotopic positions until fracture consolidation is complete. PMID:18489785

Endres, Kira; Marx, Rudolf; Tinschert, Joachim; Wirtz, Dieter Christian; Stoll, Christian; Riediger, Dieter; Smeets, Ralf

2008-01-01

219

Plate Tectonics  

NSDL National Science Digital Library

In this lesson, students are introduced to the theory of plate tectonics and explore how the theory was developed and supported by evidence. Through class discussion, videos, and activities, students seek connections between tectonic activity and geologic features and investigate how the theory of plate tectonics evolved.

2006-01-01

220

NCI-Frederick PHL - Fixatives and Solutions  

Cancer.gov

Services Price List Courier Services & Shipment Procedures Scheduling Contact Information Related Links Establishing an Account PHL Forms PHL Portal Fixatives and Solutions Routine fixatives: 10% Neutral Buffered Formalin (NBF) 37 - 40% Formaldehyde………………………………………1000mL distilled

221

Repositioning and stabilization of the radial styloid process in comminuted fractures of the distal radius using a single approach: the radio-volar double plating technique  

PubMed Central

Background A possible difficulty in intra-articular fracture of the distal radius is the displacement tendency of the radial styloid process due to the tension of the brachioradialis tendon. Methods Ten patients treated within one year for complex distal radius fractures by double-plating technique with a radial buttress plate and volar locking plate, through a single volar approach, were followed prospectively during 24 months. Outcome measures included radiographic follow-up, range of motion, grip strength and score follow-up (VAS, Gartland-Werley score and patient-rated wrist evaluation). Results Ten patients with intraarticular distal radius fractures with dislocation of the radial styloid process were treated with this technique. This resulted after 24 months in good clinical outcome (mean visual analog scale 0.9; almost symmetric range of motion; mean Gartland-Werley score 2 ± 3; mean patient-rated wrist evaluation 3.2 ± 2.4). Radiologic evaluation according to the Dresdner Score revealed anatomic reduction without secondary dislocation during the follow-up and uneventful consolidation. Conclusions The described technique strongly facilitates anatomic reduction and stable fixation of intra-articular distal radius fractures with dislocation of the radial styloid process and leads to satisfactory clinical and radiographic outcome. PMID:20701799

2010-01-01

222

Medicine in John Locke's philosophy.  

PubMed

John Locke's philosophy was deeply affected by medicine of his times. It was specially influenced by the medical thought and practice of Thomas Sydenham. Locke was a personal friend of Sydenham, expressed an avid interest in his work and shared his views and methods. The influence of Sydenham's medicine can be seen in the following areas of Locke's philosophy: his "plain historical method"; the emphasis on observation and sensory experience instead of seeking the essence of things; the rejection of hypotheses and principles; the refusal of research into final causes and inner mechanisms; the ideal of irrefutable evidence and skepticism on the possibilities of certainty in science. The science which for Locke held the highest paradigmatic value in his theory of knowledge was precisely medicine. To a great extent, Locke's Essay on Human Understanding can be understood as an attempt to justify, substantiate, and promote Sydenham's medical method. This method, generalized, was then proposed as an instrument for the elaboration of all natural sciences. PMID:2290077

Sanchez-Gonzalez, M A

1990-12-01

223

Evaluation of Bite Force After Open Reduction and Internal Fixation Using Microplates  

PubMed Central

The primary aim of this study is to determine maximum bite force in molar and incisor regions of healthy individuals, to evaluate the bite force after open reduction and internal fixation of mandibular fractures using micro plates, for a period of up to 6 weeks and to determine the rate of recovery of maximum bite force in an Indian population. PMID:24910656

Kumar, S Tharani; Saraf, Saurabh; Devi, S Prasanna

2013-01-01

224

Hinged external fixation of the elbow.  

PubMed

Hinged external fixation of the elbow provides the advantages of static fixation with the benefits of continued motion through the joint. Indications for the use of this method of fixation include traumatic instability, distraction interposition arthroplasty, instability after contracture release, and instability after excision of heterotopic ossification. Orthopedic surgeons should be familiar with hinged fixators and their application when faced with an unstable ulnohumeral joint. PMID:20670807

Chen, Neal C; Julka, Abhishek

2010-08-01

225

The healing philosopher: John Locke's medical ethics.  

PubMed

This article examines a heretofore unexplored facet of John Locke's philosophy. Locke was a medical doctor and he also wrote about medical issues that are controversial today. Despite this, Locke's medical ethics has yet to be studied. An analysis of Locke's education and his teachers and colleagues in the medical profession, of the 17th century Hippocratic Oath, and of the reaction to the last recorded outbreak of the bubonic plague in London, shines some light on the subject of Locke's medical ethics. The study of Locke's medical ethics confirms that he was a deontologist who opposed all suicide and abortion through much of pregnancy. PMID:15709441

Short, Bradford William

2004-01-01

226

Options for acetabular fixation surfaces.  

PubMed

Aseptic loosening is the most common cause for revision total hip arthroplasty (THA). Due to poor long-term results with cemented acetabular components, cementless implants that rely on biologic fixation became popular in the United States for both primary and revision procedures in the early 1980s. Cementless acetabular components used in THA have been reported to have superior radiographic performance compared with cemented fixation, although the optimal method of acetabular fixation remains controversial. Cementless acetabular components require initial implant stability to allow for bone ingrowth and remodeling into the acetabular shell, providing long-term durability of the prosthesis. Many improved implant materials are available to facilitate bone growth and remodeling, including the 3 most common surface treatments; fibermesh, sintered beads, and plasma spray coatings. Recently added to these are porous metal surfaces, which have increased porosity and optimal pore sizes when compared with titanium fibermesh. The most studied of these materials is the titanium fibermesh fixation surface, which has demonstrated a mechanical failure rate of 1% at 10 to 15 years. This technology utilizes the diffusion bonding process to attach fiber metal pads to a titanium substrate using heat and pressure. The sintered bead fixation surface offers a porous coating of various sizes of spherical beads, achieved by the sintering process, and has been shown to provide long-term fixation. While there are less long-term published data regarding the titanium plasma spray surface, its early results have provided evidence of its durability, even in the face of significant osteolysis. The most recently added alternative fixation surface is porous tantalum metal, which offers potentially greater bone ingrowth and bone graft incorporation due to its high porosity (80%) and low modulus of elasticity (3 MPa). Porous tantalum implants have shown early favorable clinical results and have been reported to have excellent bone graft incorporation of the acetabular component based on serial radiograph data at a minimum 1-year follow-up. Tritanium is a porous metal, which has emerged as a promising new surface technology for acetabular shells. While no clinical data are yet available, basic science research has demonstrated enhanced bone ingrowth and mechanical strength. PMID:19023943

Klika, Alison K; Murray, Trevor G; Darwiche, Hussein; Barsoum, Wael K

2007-01-01

227

Parallel Plate Antenna.  

National Technical Information Service (NTIS)

The invention as disclosed is a parallel plate antenna having a number of stacked horizontal plates and two vertical plates. Alternating ones of the horizontal plates are electrically coupled to one vertical plate such that the horizontal plates coupled t...

D. F. Rivera

2009-01-01

228

Understanding Nitrogen Fixation  

SciTech Connect

The purpose of our program is to explore fundamental chemistry relevant to the discovery of energy efficient methods for the conversion of atmospheric nitrogen (N{sub 2}) into more value-added nitrogen-containing organic molecules. Such transformations are key for domestic energy security and the reduction of fossil fuel dependencies. With DOE support, we have synthesized families of zirconium and hafnium dinitrogen complexes with elongated and activated N-N bonds that exhibit rich N{sub 2} functionalization chemistry. Having elucidated new methods for N-H bond formation from dihydrogen, C-H bonds and Broensted acids, we have since turned our attention to N-C bond construction. These reactions are particularly important for the synthesis of amines, heterocycles and hydrazines with a range of applications in the fine and commodity chemicals industries and as fuels. One recent highlight was the discovery of a new N{sub 2} cleavage reaction upon addition of carbon monoxide which resulted in the synthesis of an important fertilizer, oxamide, from the diatomics with the two strongest bonds in chemistry. Nitrogen-carbon bonds form the backbone of many important organic molecules, especially those used in the fertilizer and pharamaceutical industries. During the past year, we have continued our work in the synthesis of hydrazines of various substitution patterns, many of which are important precursors for heterocycles. In most instances, the direct functionalization of N{sub 2} offers a more efficient synthetic route than traditional organic methods. In addition, we have also discovered a unique CO-induced N{sub 2} bond cleavage reaction that simultaneously cleaves the N-N bond of the metal dinitrogen compound and assembles new C-C bond and two new N-C bonds. Treatment of the CO-functionalized core with weak Broensted acids liberated oxamide, H{sub 2}NC(O)C(O)NH{sub 2}, an important slow release fertilizer that is of interest to replace urea in many applications. The synthesis of ammonia, NH{sub 3}, from its elements, H{sub 2} and N{sub 2}, via the venerable Haber-Bosch process is one of the most significant technological achievements of the past century. Our research program seeks to discover new transition metal reagents and catalysts to disrupt the strong N {triple_bond} N bond in N{sub 2} and create new, fundamental chemical linkages for the construction of molecules with application as fuels, fertilizers and fine chemicals. With DOE support, our group has discovered a mild method for ammonia synthesis in solution as well as new methods for the construction of nitrogen-carbon bonds directly from N{sub 2}. Ideally these achievements will evolve into more efficient nitrogen fixation schemes that circumvent the high energy demands of industrial ammonia synthesis. Industrially, atmospheric nitrogen enters the synthetic cycle by the well-established Haber-Bosch process whereby N{sub 2} is hydrogenated to ammonia at high temperature and pressure. The commercialization of this reaction represents one of the greatest technological achievements of the 20th century as Haber-Bosch ammonia is responsible for supporting approximately 50% of the world's population and serves as the source of half of the nitrogen in the human body. The extreme reaction conditions required for an economical process have significant energy consequences, consuming 1% of the world's energy supply mostly in the form of pollution-intensive coal. Moreover, industrial H{sub 2} synthesis via the water gas shift reaction and the steam reforming of methane is fossil fuel intensive and produces CO{sub 2} as a byproduct. New synthetic methods that promote this thermodynamically favored transformation ({Delta}G{sup o} = -4.1 kcal/mol) under milder conditions or completely obviate it are therefore desirable. Most nitrogen-containing organic molecules are derived from ammonia (and hence rely on the Haber-Bosch and H{sub 2} synthesis processes) and direct synthesis from atmospheric nitrogen could, in principle, be more energy-efficient. This is particularly attractive giv

Paul J. Chirik

2012-05-25

229

Osmolarity of osmium tetroxide and glutaraldehyde fixatives  

Microsoft Academic Search

Synopsis  The evidence available to date for the importance of fixative osmolarity is considered together with some observations on the volume changes of crab axons after fixation by osmium tetroxide and glutaraldehyde. The results obtained are compared with those obtained from crab axons and from amphioxus skin cells which had been processed and examined with the electron microscope after initial fixation

Q. Bone; K. P. Ryan

1972-01-01

230

Tissue fixation and the effect of molecular fixatives on downstream staining procedures  

PubMed Central

It is impossible to underplay the importance of fixation in histopathology. Whether the scientist is interested in the extraction of information on lipids, proteins, RNA or DNA, fixation is critical to this extraction. This review aims to give a brief overview of the current “state of play” in fixation and focus on the effect fixation, and particularly the effect of the newer brand of “molecular fixatives” have on morphology, histochemistry, immunohistochemistry and RNA/DNA analysis. A methodology incorporating the creation of a fixation tissue microarray for the study of the effect of fixation on histochemistry is detailed. PMID:24561827

Howat, William J.; Wilson, Beverley A.

2014-01-01

231

Proximal tibia medial open-wedge osteotomy using plates with wedges: early results in 58 cases  

Microsoft Academic Search

We evaluated in this study indications, surgical technique, and results of wedge plates for fixation in proximal tibia medial opening wedge osteotomy. Fifty-eight knees in 56 consecutive patients (9 men, 47 women; mean age 52 years; ranging between 36 and 66 years) with medial compartment osteoarthrosis were treated with proximal tibia medial open-wedge osteotomy. For fixation, plates which were designed by the

Irfan Esenkaya; Nurzat Elmali

2006-01-01

232

Plate Motions  

NSDL National Science Digital Library

To prepare for this exercise students read the Chapter on plate tectonics in their text book. In class, they are given a color isochron map of the sea floor. They are given 4 tasks: Answer basic questions about the timing and rate of opening of the N. and S. Atlantic; Determine what has happened to the oceanic crust that is created on the eastern side of the East Pacific Rise; Determine what type of plate boundary existed on the western edge of the N. America plate before the San Andreas Fault and when this transition occurred; and Reconstruct the motion of the plates over the last 40 Ma assuming that the surface area of the Earth has not changed.

Nunn, Jeffrey

233

72. LOCK ELECTRICAL SYSTEM CONTROL SWITCH CABINET ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

72. LOCK - ELECTRICAL SYSTEM - CONTROL SWITCH CABINET - PANEL ARRANGEMENT AND DETAILS (ML-5-29/33-FS), March 1934 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam No. 5, Minneiska, Winona County, MN

234

49 CFR 236.769 - Locking, traffic.  

Code of Federal Regulations, 2010 CFR

...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.769 Locking, traffic. Electric locking which prevents the manipulation of levers or other devices for changing the direction of traffic on a section of track while that section is occupied or...

2010-10-01

235

49 CFR 236.762 - Locking, indication.  

Code of Federal Regulations, 2011 CFR

...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.762 Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe condition for a train movement if a signal, switch, or other operative unit...

2011-10-01

236

Plate Tectonics  

NSDL National Science Digital Library

This data tip from Bridge, the Ocean Sciences Education Teacher Resource Center archive, includes a variety of educational sites to visit on plate tectonic theory. Learners can use underwater earthquake data to identify plate boundaries with links to the National Oceanic and Atmospheric Administration's Acoustic Monitoring Program Ocean Seismicity data. Data from the Northeast Pacific, eastern Equatorial Pacific, and North Atlantic are examined in more detail.

2002-09-01

237

On the similarity between pre-seismic locking and coseismic slip during the 2010 Maule earthquake (Invited)  

Microsoft Academic Search

The M8.8 Maule earthquake of 27 Feb. 2010 in Chile was the largest earthquake that ruptured a mature seismic gap in a subduction zone, monitored with a dense space-geodetic network. This provides an image of the pre-seismically locked state of the plate interface of unprecedented high resolution, allowing for an assessment of the spatial correlation of interseismic locking and coseismic

M. Moreno; M. Rosenau; D. Melnick; O. Oncken; M. Keiding; J. C. Baez; M. G. Bevis; J. Chen; A. Tassara; M. Motagh; A. Socquet; M. Cisternas; K. Bataille; H. Hase

2010-01-01

238

Simulation of the Illinois Waterway locks system  

Microsoft Academic Search

A computer simulation model of the locks system on the Illinois Waterway is described. The model was developed using ProModel for Windows and includes boats and barge tows traveling through the locks system and operation of the locks. Entities with attributes are used to simulate the boats and barge tows that enter the system, travel either upstream or downstream through

D. Brent Bandy

1996-01-01

239

49 CFR 236.742 - Dog, locking.  

Code of Federal Regulations, 2010 CFR

...Transportation 4 2010-10-01 2010-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

2010-10-01

240

49 CFR 236.742 - Dog, locking.  

Code of Federal Regulations, 2013 CFR

...Transportation 4 2013-10-01 2013-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

2013-10-01

241

49 CFR 236.742 - Dog, locking.  

Code of Federal Regulations, 2012 CFR

...Transportation 4 2012-10-01 2012-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

2012-10-01

242

49 CFR 236.742 - Dog, locking.  

Code of Federal Regulations, 2011 CFR

...Transportation 4 2011-10-01 2011-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

2011-10-01

243

Locking and wavelength selection of an ultra-collimated single-mode diode laser bar by a volume holographic grating.  

PubMed

Wavelength-locking by a volume holographic grating (VHG) is reported for a diode laser bar with 49 single mode emitters, fitted with a dual-axis collimation phase-plate for smile elimination and excellent beam pointing correction. The much-improved VHG feedback with the ultra-collimated array beam gives 100% wavelength locking at 975 nm over a 17°C temperature range and external cavity lengths up to 110 mm. This enables a folded cavity configuration to provide a fully-locked array with wavelength selection into 200 pm channels over an 8 nm band, suitable for multi-bar dense wavelength-combining. PMID:23481984

Trela, Natalia; Baker, Howard J; Hall, Denis R

2013-02-25

244

Dynamic Holographic Lock-In Imaging of Ultrasonic Waves  

SciTech Connect

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

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

1999-05-01

245

Efficacy analysis of pedicle screw internal fixation of fractured vertebrae in the treatment of thoracolumbar fractures  

PubMed Central

The present study aimed to discuss the method and effect of posterior internal fixation of thoracolumbar fractures strengthened by the vertical stress pedicle screw fixation of fractured vertebrae. Patients with single thoracolumbar fractures were examined retrospectively. Fourteen patients (group A) had been treated with vertical stress pedicle screw fixation of a fractured vertebra and sixteen patients (group B) received traditional double-plate fixation, as a control. All patients were diagnosed with fresh fractures with a complete unilateral or bilateral pedicle and no explosion of the inferior half of the vertebral body or inferior endplate. In group A, patients received conventional posterior distraction and lumbar lordosis restoration, as well as pedicle screws in the fractured vertebra in a vertical direction to relieve stress to achieve a local stress balance. All patients were followed up postoperatively for 4–18 months (average, 12.6 months). The vertical stress pedicle screw fixation assisted in the reduction of vertebrae fracture, which reduced the postoperative Cobb’s angle loss. There was a significant difference in the change of Cobb’s angle between the two groups one year after surgery (P<0.01). Conditional application of pedicle screws in a single thoracolumbar fracture enhances the stability of the internal fixation system and is conducive to the correction of kyphosis and maintenance of the corrective effects. PMID:23407593

HUANG, WEIJIE; LUO, TAO

2013-01-01

246

Three-dimensional load displacement properties of posterior lumbar fixation.  

PubMed

Pedicular fixation devices for the posterior treatment of segmental spinal instability are thought to offer enhanced stabilization compared with sublaminar wire systems, while avoiding the immobilization of multiple normal motion segments. We compared the performance of three dissimilar stabilization systems: the Hartshill rectangle, the Acromed/Steffee interpedicular screw and plate, and the Synthes/Dick fixateur interne. Human cadaveric lumbosacral specimens were first tested intact, then after a laminectomy and a facetectomy at the L3/L4 level, and finally after the fixation devices were sequentially attached. Constructs spanning two to four vertebral levels were compared for stabilization of the resected lumbar spine segments. When tested in compression, the Acromed/Steffee system with pedicular screws at L2-L5 allowed significantly less intersegmental distraction than the Synthes/Dick construct with screws at L2 and L5 only, and less than the intact and the destabilized uninstrumented spine. When sagittally rotated, the Acromed/Steffee construct with screws at L2-L5, or at L2 and L5, allowed significantly less distraction than the intact or destabilized segments, and the construct with screws at L2 through L5 allowed less distraction than the Synthes/Dick constructs with screws at L3/L4 or L2/L5. With the exception of the Acromed/Steffee system with screws at four levels, there were no significant differences in distraction allowed between the Synthes/Dick and Acromed/Steffee constructs, or between the multisegment and single segment constructs. There were no significant differences in stiffness across levels L3/L4 with the various implants. Results indicate that the use of posterior spine constructs significantly augment the stability of posterior segmental defects. Pedicular fixation immediately cephalad and caudad to the defect provided stable fixation in this application. PMID:1762002

Shea, M; Edwards, W T; Clothiaux, P L; Crowell, R R; Nachemson, A L; White, A A; Hayes, W C

1991-01-01

247

Performance of arm locking in LISA  

SciTech Connect

For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. D 78, 082001 (2008)] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time-delay error of 3 ns (equivalent of 1 m interspacecraft ranging error), time-delay interferometry (TDI) is capable of suppressing 300 Hz/{radical}(Hz) of laser frequency noise to the required level. We show that if no interspacecraft laser links fail, arm locking alone surpasses this noise performance for the entire mission. If one interspacecraft laser link fails, arm locking alone will achieve this performance for all but approximately 1 h per year, when the arm length mismatch of the two remaining arms passes through zero. Therefore, the LISA sensitivity can be realized with arm locking and time-delay interferometry only, without any form of prestabilization.

McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

2009-11-15

248

Performance of arm locking in LISA  

NASA Astrophysics Data System (ADS)

For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. DPRVDAQ1550-7998 78, 082001 (2008)10.1103/PhysRevD.78.082001] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time-delay error of 3 ns (equivalent of 1 m interspacecraft ranging error), time-delay interferometry (TDI) is capable of suppressing 300Hz/Hz of laser frequency noise to the required level. We show that if no interspacecraft laser links fail, arm locking alone surpasses this noise performance for the entire mission. If one interspacecraft laser link fails, arm locking alone will achieve this performance for all but approximately 1 h per year, when the arm length mismatch of the two remaining arms passes through zero. Therefore, the LISA sensitivity can be realized with arm locking and time-delay interferometry only, without any form of prestabilization.

McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A.

2009-11-01

249

Fixational eye movements and binocular vision  

PubMed Central

During attempted visual fixation, small involuntary eye movements–called fixational eye movements–continuously change of our gaze’s position. Disagreement between the left and right eye positions during such motions can produce diplopia (double vision). Thus, the ability to properly coordinate the two eyes during gaze fixation is critical for stable perception. For the last 50 years, researchers have studied the binocular characteristics of fixational eye movements. Here we review classical and recent studies on the binocular coordination (i.e., degree of conjugacy) of each fixational eye movement type: microsaccades, drift and tremor, and its perceptual contribution to increasing or reducing binocular disparity. We also discuss how amblyopia and other visual pathologies affect the binocular coordination of fixational eye movements. PMID:25071480

Otero-Millan, Jorge; Macknik, Stephen L.; Martinez-Conde, Susana

2014-01-01

250

Plate TectonicsPlate Tectonics Plate TectonicsPlate Tectonics  

E-print Network

ridge systems #12;Concentration of earthquakes #12;Mid-ocean ridge systems #12;Deep Sea Drilling Project, transform boundaries ­ travel 1 to 11 cm/yr relative to one another #12;14 tectonic plates today #12;Mid-ocean

Siebel, Wolfgang

251

Self-locking threaded fasteners  

DOEpatents

A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures. A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy.

Glovan, Ronald J. (Butte, MT); Tierney, John C. (Butte, MT); McLean, Leroy L. (Butte, MT); Johnson, Lawrence L. (Butte, MT)

1996-01-01

252

Self-locking threaded fasteners  

DOEpatents

A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures. A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy. 13 figs.

Glovan, R.J.; Tierney, J.C.; McLean, L.L.; Johnson, L.L.

1996-01-16

253

Beyond Plate Tectonics: “Plate ” Dynamics  

E-print Network

Plate tectonics dogma has resulted in a variety of theories that frequently violate first principles. In this article it is suggested that ridges are in compression, not tension from convection cells, triple junctions cause hot spots (not vice versa), mantle plumes do not cause hot spot tracks, chord push creates pressures well in excess of lithostatic load, the arch effect demonstrates that rifts form both in compression and tension, surging (i.e. the sudden and rapid motion of the plates) occurs episodically, the presence of a basal shear zone a few meters thick during surging, the preferred initiation of subduction zones at the ridge, revision of the Wilson Cycle, the conformance of “old ” school geologists and plate tectonicians, earth-based non bolide impact mass extinctions, the loss of the earth’s magnetic field and its subsequent reappearance, additional application of the least work (or maximum

Richard Moody

254

Analysis of Flow in the Lock-up Clutch of an Automotive Torque Converter  

NASA Astrophysics Data System (ADS)

The flow through the single-plate lock-up clutch in an automotive torque converter with a 250-mm nominal diameter was numerically investigated using a CFD code. The flow was computed under various clearances between the lock-up piston and the torque converter cover. The stable location of the lock-up piston was determined so that the thrust acting on it became zero. The computation results showed that the fluid flowed outwards in the narrow channel between the lock-up clutch facing and the converter cover, whereas the flow reversed inwards near the lock-up piston surface upstream and downstream of the narrow channel in most cases. Along the outer surface of the axial flow channel near the exit, the flow also reversed far upstream of the channel. The computation results well predicted the stable position of the lock-up piston. It is noteworthy that the sharp increase in clearance in the coupling range can be clearly captured with this method.

Ejiri, Eiji

255

A possible nitrogen crisis for Archaean life due to reduced nitrogen fixation by lightning.  

PubMed

Nitrogen is an essential element for life and is often the limiting nutrient for terrestrial ecosystems. As most nitrogen is locked in the kinetically stable form, N2, in the Earth's atmosphere, processes that can fix N2 into biologically available forms-such as nitrate and ammonia-control the supply of nitrogen for organisms. On the early Earth, nitrogen is thought to have been fixed abiotically, as nitric oxide formed during lightning discharge. The advent of biological nitrogen fixation suggests that at some point the demand for fixed nitrogen exceeded the supply from abiotic sources, but the timing and causes of the onset of biological nitrogen fixation remain unclear. Here we report an experimental simulation of nitrogen fixation by lightning over a range of Hadean (4.5-3.8 Gyr ago) and Archaean (3.8-2.5 Gyr ago) atmospheric compositions, from predominantly carbon dioxide to predominantly dinitrogen (but always without oxygen). We infer that, as atmospheric CO2 decreased over the Archaean period, the production of nitric oxide from lightning discharge decreased by two orders of magnitude until about 2.2 Gyr. After this time, the rise in oxygen (or methane) concentrations probably initiated other abiotic sources of nitrogen. Although the temporary reduction in nitric oxide production may have lasted for only 100 Myr or less, this was potentially long enough to cause an ecological crisis that triggered the development of biological nitrogen fixation. PMID:11452304

Navarro-González, R; McKay, C P; Mvondo, D N

2001-07-01

256

Intermaxillary fixation screw for endotracheal tube fixation in the edentulous patient with facial burns.  

PubMed

Endotracheal tube fixation in patients with severe facial burns and edentulism is a challenge. We describe a simple and elegant method to secure the endotracheal tube in such patients by means of an intermaxillary fixation screw. PMID:24948409

Fleissig, Y; Rushinek, H; Regev, E

2014-10-01

257

Modeling fixation locations using spatial point processes.  

PubMed

Whenever eye movements are measured, a central part of the analysis has to do with where subjects fixate and why they fixated where they fixated. To a first approximation, a set of fixations can be viewed as a set of points in space; this implies that fixations are spatial data and that the analysis of fixation locations can be beneficially thought of as a spatial statistics problem. We argue that thinking of fixation locations as arising from point processes is a very fruitful framework for eye-movement data, helping turn qualitative questions into quantitative ones. We provide a tutorial introduction to some of the main ideas of the field of spatial statistics, focusing especially on spatial Poisson processes. We show how point processes help relate image properties to fixation locations. In particular we show how point processes naturally express the idea that image features' predictability for fixations may vary from one image to another. We review other methods of analysis used in the literature, show how they relate to point process theory, and argue that thinking in terms of point processes substantially extends the range of analyses that can be performed and clarify their interpretation. PMID:24084942

Barthelmé, Simon; Trukenbrod, Hans; Engbert, Ralf; Wichmann, Felix

2013-01-01

258

Image recorder with microwave fixation  

SciTech Connect

The present invention is directed to improvement in an image recorder for recording developed images or toner images by microwave fixation. According to the invention there is used a novel thermoplastic developer comprising of two components. The first component contains a dielectric material which is able to absorb microwave and generate heat by dielectric loss. The second component contains magnetic loss exothermic material. The microwave absorbing power of the first component is improved by heating the first component with heat generated from the second component.

Hosono, N.; Isaka, K.

1984-11-13

259

Symbiotic N 2 -fixation in alpine tundra: ecosystem input and variation in fixation rates among communities  

Microsoft Academic Search

Annual inputs of symbiotic N2-fixation associated with 3 species of alpine Trifolium were estimated in four alpine communities differing in resource supplies. We hypothesized that fixation rates would vary according to the degree of N, P, and water limitation of production, with the higher rates of fixation in N limited communities (dry meadow, moist meadow) and lower rates in P

William D. Bowman; James C. Schardt; Steven K. Schmidt

1996-01-01

260

2010 Maule earthquake slip correlates with pre-seismic locking of Andean subduction zone.  

PubMed

The magnitude-8.8 Maule (Chile) earthquake of 27 February 2010 ruptured a segment of the Andean subduction zone megathrust that has been suspected to be of high seismic potential. It is the largest earthquake to rupture a mature seismic gap in a subduction zone that has been monitored with a dense space-geodetic network before the event. This provides an image of the pre-seismically locked state of the plate interface of unprecedentedly high resolution, allowing for an assessment of the spatial correlation of interseismic locking with coseismic slip. Pre-seismic locking might be used to anticipate future ruptures in many seismic gaps, given the fundamental assumption that locking and slip are similar. This hypothesis, however, could not be tested without the occurrence of the first gap-filling earthquake. Here we show evidence that the 2010 Maule earthquake slip distribution correlates closely with the patchwork of interseismic locking distribution as derived by inversion of global positioning system (GPS) observations during the previous decade. The earthquake nucleated in a region of high locking gradient and released most of the stresses accumulated in the area since the last major event in 1835. Two regions of high seismic slip (asperities) appeared to be nearly fully locked before the earthquake. Between these asperities, the rupture bridged a zone that was creeping interseismically with consistently low coseismic slip. The rupture stopped in areas that were highly locked before the earthquake but where pre-stress had been significantly reduced by overlapping twentieth-century earthquakes. Our work suggests that coseismic slip heterogeneity at the scale of single asperities should indicate the seismic potential of future great earthquakes, which thus might be anticipated by geodetic observations. PMID:20829792

Moreno, Marcos; Rosenau, Matthias; Oncken, Onno

2010-09-01

261

Optimized Control of Vortex Shedding from an Inclined Flat Plate  

E-print Network

vortex shedding in order to maximize lift. A two-dimensional flat plate model is considered at a high to robustly estimate the phase of vortex shedding and achieve phase-locked, high lift flow states. Finally to account for high lift at high angles of attack unanswered by `quasi-steady' aerodynamic models.1, 2

Dabiri, John O.

262

Axillary artery pseudoaneurysm after plate osteosynthesis for a clavicle nonunion: A case report and literature review  

PubMed Central

Neurovascular complications have been reported from both plate osteosynthesis and intramedullary fixation of midshaft clavicle fractures. We wish to report a case of limb threatening ischemia from screw penetration of the axillary artery after plate osteosynthesis for a clavicle nonunion. A literature review of vascular trauma from midshaft clavicle fractures is presented. PMID:21472068

Bain, Gregory I.; Galley, Ian J.; Keogh, Angus R. E.; Durrant, Adam W.

2010-01-01

263

Increased Fusion Rates With Cervical Plating for Two Level Anterior Cervical Discectomy and Fusion  

Microsoft Academic Search

Study Design. A retrospective review of all patients surgically treated with a two-level anterior cervical disc- ectomy and fusion with and without anterior plate fixa- tion by a single surgeon. Objectives. To compare the clinical and radiographic success of two-level discectomy and the effect of anterior cervical plate fixation. Summary of Background Data. Prior studies of multi- segment fusions have

Jeffrey C. Wang; Paul W. McDonough; Kevin K. Endow; Rick B. Delamarter

264

Is one hair lock really representative?  

PubMed

When investigating someone's hair a single lock is cut, washed, extracted and analysed. The forensic institutes in Switzerland agreed to retain a second lock for a possible reassessment. We were interested in the reproducibility of the concentrations of analytes in hair locks taken from different areas of the head of the same person covering the same time period. Therefore we analysed ethyl glucuronide and caffeine as model substances in 10 hair locks from three individuals categorised as social drinkers. The individual coefficients of variation varied between 14% and 28% for ethyl glucuronide and between 13% and 62% for caffeine corresponding to factors of 1.6 to 4.2 for the highest to the lowest concentrations between the hair locks. This finding has a significant importance both when the second hair lock has to be analysed in a forensic case and if the interpretation of the result is depending on a cut-off value. PMID:24817042

Dussy, Franz; Carson, Nicholas; Hangartner, Sarah; Briellmann, Thomas

2014-06-01

265

Fatigue strength of common tibial intramedullary nail distal locking screws  

PubMed Central

Background Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative and qualitative measures of the relative performance of these screws. Methods Fatigue tests were conducted to simulate a comminuted fracture that was treated by IM nailing assuming that all load was carried by the screws. Each screw type was tested ten times in a single screw configuration. One screw type was tested an additional ten times in a two-screw parallel configuration. Fatigue tests were performed using a servohydraulic materials testing system and custom fixturing that simulated screws placed in the distal region of an appropriately sized tibial IM nail. Fatigue loads were estimated based on a seventy-five kilogram individual at full weight bearing. The test duration was one million cycles (roughly one year), or screw fracture, whichever occurred first. Failure analysis of a representative sample of titanium alloy and stainless steel screws included scanning electron microscopy (SEM) and quantitative metallography. Results The average fatigue life of a single screw with a diameter of 4.0 mm was 1200 cycles, which would correspond roughly to half a day of full weight bearing. Single screws with a diameter of 4.5 mm or larger have approximately a 50 percent probability of withstanding a week of weight bearing, whereas a single 5.0 mm diameter screw has greater than 90 percent probability of withstanding more than a week of weight bearing. If two small diameter screws are used, our tests showed that the probability of withstanding a week of weight bearing increases from zero to about 20 percent, which is similar to having a single 4.5 mm diameter screw providing fixation. Conclusion Our results show that selecting the system that uses the largest distal locking screws would offer the best fatigue resistance for an unstable fracture pattern subjected to full weight bearing. Furthermore, using multiple screws will substantially reduce the risk of premature hardware failure. PMID:19371438

Griffin, Lanny V; Harris, Robert M; Zubak, Joseph J

2009-01-01

266

Verifying Parameterized taDOM+ Lock Managers  

Microsoft Academic Search

taDOM* protocols are designed to provide lock-based approach to handle multiple access to XML databases. The notion of taDOM+\\u000a protocol is formalized and generalized and a formal model of taDOM+ lock manager that is parameterized in the number of transactions\\u000a and in the size of database is represented. An important class of safety properties of taDOM+ lock managers were proven

Antti Siirtola; Michal Valenta

2008-01-01

267

Parameter ranges for CW passive mode locking  

Microsoft Academic Search

CW passive mode locking of a homogeneously broadened laser is considered. In the coordinate plane, whose abscissa is proportional to the small-signal saturable absorber loading, and whose ordinate is proportional to the small-signal gain, the following regimes are laid out: 1) steady-state single-pulse mode-locking solutions; 2) stability against relaxation oscillations; 3) self-starting of mode locking. The assumption is made that

H. Haus

1976-01-01

268

21 CFR 888.3010 - Bone fixation cerclage.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Bone fixation cerclage. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage...

2011-04-01

269

21 CFR 888.3010 - Bone fixation cerclage.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Bone fixation cerclage. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage...

2010-04-01

270

21 CFR 888.3010 - Bone fixation cerclage.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 false Bone fixation cerclage. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage...

2012-04-01

271

21 CFR 888.3010 - Bone fixation cerclage.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Bone fixation cerclage. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage...

2013-04-01

272

All-Arthroscopic Suprapectoral Long Head of Biceps Tendon Tenodesis With Interference Screw-Like Tendon Fixation After Modified Lasso-Loop Stitch Tendon Securing  

PubMed Central

Arthroscopic suprapectoral techniques for tenodesis of the long head of the biceps tendon (LHB) are appropriate for the treatment of proximal biceps lesions. Several types of techniques and fixation devices have been described and evaluated in biomechanical studies regarding primary stability. In this technical note, we describe an all-arthroscopic suprapectoral technique using the 6.25-mm Bio-SwiveLock device (Arthrex, Naples, FL) for an interference screw–like bony fixation after having armed the tendon with a lasso-loop stitch. Both the interference screw fixation and securing of the lasso-loop tendon have been well described and approved in biomechanical tests concerning the primary stability. One advantage of this technique performed from the glenohumeral space, in addition to the strong and secure fixation with ingrowth of the tendon in a bony canal, is the avoidance of touching the soft tissue above the bicipital groove, which results in a smooth fitting of the tendon into its natural canal and therefore avoids mechanical irritation of the stump at the rotator interval. In conclusion, the all-arthroscopic suprapectoral LHB tenodesis performed from the glenohumeral space with the modified lasso-loop stitch for securing of the tendon and the 6.25-mm Bio-SwiveLock suture anchor for interference screw–like bony tendon fixation is an appropriate technique for the treatment of LHB-associated lesions. PMID:23766976

Patzer, Thilo; Kircher, Jorn; Krauspe, Ruediger

2012-01-01

273

Phase-lock loop frequency control and the dropout problem  

NASA Technical Reports Server (NTRS)

Technique automatically sets the frequency of narrow band phase-lock loops within automatic lock-in-range. It presets a phase-lock loop to a desired center frequency with a closed loop electronic frequency discriminator and holds the phase-lock loop to that center frequency until lock is achieved.

Attwood, S.; Kline, A. J.

1968-01-01

274

Fixation and the Road Not Taken  

Microsoft Academic Search

In this article, the psychic and existential impact that fixation has on an individual's life is addressed. A person may drift through years that are dictated by the circuitous path of a fixation and its vicissitude of the repetition compulsion. When such \\

Peter Shabad

1987-01-01

275

Bioabsorbable fixation in orthopaedic surgery and traumatology  

Microsoft Academic Search

Bioabsorbable internal fixation devices were introduced clinically in the treatment of fractures and osteotomies of the extremities at the Department of Orthopaedics and Traumatology, Helsinki University, in 1984. Since November 5, 1984, a total of 3200 patients were managed using bone or ligament fixation devices made of self-reinforced (matrix and fibres of the same polymer) bioabsorbable alpha-hydroxy polyesters. The devices

Pentti U Rokkanen; Ole Böstman; Eero Hirvensalo; E. Antero Mäkelä; Esa K Partio; Hannu Pätiälä; Seppo Vainionpää; Kimmo Vihtonen; Pertti Törmälä

2000-01-01

276

Nitrogen fixation in Lake Mendota, Madison, Wisconsin  

Microsoft Academic Search

The cffccts of various environmental conditions, and of ccl1 composition, heterocyst con- tent, and nitrogen content of algal s'amples, on fixation of N, by colonial and filamentous algae in Lake Mendota were investigated. IIctcrocyst content and temperature were significantly and positively related to accty- lcnc recluction activity ( NB fixation); depth of sample collection was negatively related. Rvailablc data do

MARGUERITE SHERMAN TORREY; G. F. LEE

1976-01-01

277

Original article The economics of nitrogen fixation  

E-print Network

. Of course, soil type and climate also affect the value of nitrogen, but so do fertiliser and crop and animalOriginal article The economics of nitrogen fixation Steven SCHILIZZI*, David J. PANNELL Agriculture the economic value of nitrogen fixation in a Mediterranean-type farming system in Western Australia, as well

Paris-Sud XI, Université de

278

Phase locking between Josephson soliton oscillators  

NASA Astrophysics Data System (ADS)

We report observations of phase-locking phenomena between two Josephson soliton (fluxon) oscillators biased in self-resonant modes. The locking strength was measured as a function of bias conditions. A frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. Two coupled perturbed sine-Gordon equations were derived from an equivalent circuit consisting of inductively coupled, nonlinear, lossy transmission lines. These equations were solved numerically to find the locking regions. Good qualitative agreement was found between the experimental results and the calculations based on the model.

Holst, T.; Hansen, J. Bindslev; Grnbech-Jensen, N.; Blackburn, J. A.

1990-07-01

279

Robust quantum data locking from phase modulation  

NASA Astrophysics Data System (ADS)

Quantum data locking is a uniquely quantum phenomenon that allows a relatively short key of constant size to (un)lock an arbitrarily long message encoded in a quantum state, in such a way that an eavesdropper who measures the state but does not know the key has essentially no information about the message. The application of quantum data locking in cryptography would allow one to overcome the limitations of the one-time pad encryption, which requires the key to have the same length as the message. However, it is known that the strength of quantum data locking is also its Achilles heel, as the leakage of a few bits of the key or the message may in principle allow the eavesdropper to unlock a disproportionate amount of information. In this paper we show that there exist quantum data locking schemes that can be made robust against information leakage by increasing the length of the key by a proportionate amount. This implies that a constant size key can still lock an arbitrarily long message as long as a fraction of it remains secret to the eavesdropper. Moreover, we greatly simplify the structure of the protocol by proving that phase modulation suffices to generate strong locking schemes, paving the way to optical experimental realizations. Also, we show that successful data locking protocols can be constructed using random code words, which very well could be helpful in discovering random codes for data locking over noisy quantum channels.

Lupo, Cosmo; Wilde, Mark M.; Lloyd, Seth

2014-08-01

280

Eighth international congress on nitrogen fixation. Final program  

SciTech Connect

This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

Not Available

1990-12-31

281

Locking mechanism for orthopedic braces  

NASA Technical Reports Server (NTRS)

A locking mechanism for orthopedic braces is described which automatically prevents or permits the relative pivotable movement between a lower brace member and an upper brace member. The upper and lower brace members are provided with drilled bores within which a slidable pin is disposed, and depending upon the inclination of the brace members with respect to a vertical plane, the slidable pin will be interposed between both brace members. The secondary or auxiliary latching device includes a spring biased, manually operable lever bar arrangement which is manually unlatched and automatically latched under the influence of the spring.

I-Lechao, J.; Epps, C. H., Jr. (inventors)

1976-01-01

282

Green River Locks and Dams 3, 4, 5, 6 and Barren River Lock and Dam 1 Disposition, Kentucky  

E-print Network

Green River Locks and Dams 3, 4, 5, 6 and Barren River Lock and Dam 1 Disposition, Kentucky 16 September 2014 ABSTRACT: Green River Locks and Dams 3 through 6 and Barren River Lock and Dam 1 were. The Green River Locks and Dams 5 and 6 ceased operations in 1951 due to a marked decline in navigation

US Army Corps of Engineers

283

Inactivation of Influenza A virus, Adenovirus, and Cytomegalovirus with PAXgene tissue fixative and formalin.  

PubMed

Formalin fixation is known to inactivate most viruses in a vaccine production context, but nothing is published about virus activity in tissues treated with alternative, non-crosslinking fixatives. We used a model assay based on cell culture to test formalin and PAXgene Tissue fixative for their virus-inactivating abilities. MDCK, A549, and MRC-5 cells were infected with Influenza A virus, Adenovirus, and Cytomegalovirus, respectively. When 75% of the cells showed a cytopathic effect (CPE), the cells were harvested and incubated for 15?min, or 1, 3, 6, or 24 hours, with PBS (positive control), 4% formalin, or PAXgene Tissue Fix. The cells were disrupted and the released virus was used to infect fresh MDCK, A549, and MRC-5 cells cultured on cover slips in 24-well plates. The viral cultures were monitored for CPE and by immunocytochemistry (ICC) to record viral replication and infectivity. Inactivation of Adenovirus by formalin occurred after 3?h, while Influenza A virus as well as Cytomegalovirus were inactivated by formalin after 15?min. All three virus strains were inactivated by PAXgene Tissue fixative after 15?min. We conclude that PAXgene Tissue fixative is at least as effective as formalin in inactivating infectivity of Influenza A virus, Adenovirus, and Cytomegalovirus. PMID:24845590

Kap, Marcel; Arron, Georgina I; Loibner, M; Hausleitner, Anja; Siaulyte, Gintare; Zatloukal, Kurt; Murk, Jean-Luc; Riegman, Peter

2013-08-01

284

Dinitrogen fixation in aphotic oxygenated marine environments  

PubMed Central

We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO?3)-rich, waters of the oligotrophic Levantine Basin (LB) and the Gulf of Aqaba (GA). N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L?1 d?1 to 0.38 nmol N L?1 d?1. N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as photic depths. Dissolved free amino acid amendments to whole water from the GA enhanced bacterial productivity by 2–3.5 fold and N2 fixation rates by ~2-fold in samples collected from aphotic depths while in amendments to water from photic depths bacterial productivity increased 2–6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP and heterotrophic N2 fixation were carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particle (TEP) concentrations and N2 fixation rates. This suggests that sinking organic material and high carbon (C): nitrogen (N) micro-environments (such as TEP-based aggregates or marine snow) could support high heterotrophic N2 fixation rates in oxygenated surface waters and in the aphotic zones. Indeed, our calculations show that aphotic N2 fixation accounted for 37 to 75% of the total daily integrated N2 fixation rates at both locations in the Mediterranean and Red Seas with rates equal or greater to those measured from the photic layers. Moreover, our results indicate that that while N2 fixation may be limited in the surface waters, aphotic, pelagic N2 fixation may contribute significantly to new N inputs in other oligotrophic basins, yet it is currently not included in regional or global N budgets. PMID:23986748

Rahav, Eyal; Bar-Zeev, Edo; Ohayon, Sarah; Elifantz, Hila; Belkin, Natalia; Herut, Barak; Mulholland, Margaret R.; Berman-Frank, Ilana

2013-01-01

285

Skin damage probabilities using fixation materials in high-energy photon beams  

Microsoft Academic Search

Introduction: Patient fixation, such as thermoplastic masks, carbon-fibre support plates and polystyrene bead vacuum cradles, is used to reproduce patient positioning in radiotherapy. Consequently low-density materials may be introduced in high-energy photon beams. The aim of the this study was to measure the increase in skin dose when low-density materials are present and calculate the radiobiological consequences in terms of

Jesper Carl; Anne Vestergaard

2000-01-01

286

DOWNSTREAM LOCK GATE DETAIL VIEW WITH DOG HOUSE. NOTE CONTROL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DOWNSTREAM LOCK GATE DETAIL VIEW WITH DOG HOUSE. NOTE CONTROL ARM AND GEAR FOR GATE. LOOKING NORTHWEST. - Illinois Waterway, Dresden Island Lock and Dam , 7521 North Lock Road, Channahon, Will County, IL

287

UPSTREAM LOCK GATE DETAIL AND DOG HOUSE. NOTE ARM AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

UPSTREAM LOCK GATE DETAIL AND DOG HOUSE. NOTE ARM AND GEARING FOR CONTROLLING LOCK GATE. LOOKING WEST SOUTHWEST. - Illinois Waterway, Brandon Road Lock and Dam , 1100 Brandon Road, Joliet, Will County, IL

288

10. Detail of bridge underside showing gears for locking mechanism ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Detail of bridge underside showing gears for locking mechanism at south end of bridge. View to east. - Locke Avenue Bridge, Locke Avenue (County Route 671) Spanning Raccoon Creek, Swedesboro, Gloucester County, NJ

289

Arthroscopic coracoclavicular ligament reconstruction using biologic and suture fixation.  

PubMed

Presented in this report is a modified arthroscopic approach to acromioclavicular joint reconstruction via suture and allograft fixation. An arthroscopic approach is used to expose the base of the coracoid by use of electrocautery. After an open distal clavicle excision is performed, clavicular and coracoid tunnels are created under arthroscopic visualization as previously described by Wolf and Pennington. The myotendinous end of a semitendinosus allograft is sutured to a Spider plate (Kinetikos Medical, San Diego, CA). The tendinous end of the graft is prepared with a running baseball stitch. A Nitinol wire with a loop end (Arthrex, Naples, FL) is used to pass 2 free FiberTape sutures (Arthrex) and the leading sutures from the tendinous end of the graft through the clavicular and coracoid tunnels, exiting out the anterior portal. One of the FiberTape sutures is retrieved with a grasper and passed over the anterior aspect of the distal clavicle. The second FiberTape suture and the allograft are passed over the distal end of the resected clavicle. While the acromioclavicular joint is held reduced, the FiberTape sutures are tied to the plate and the allograft is tensioned medially until the plate is embedded against the superior surface of the clavicle. The tendinous end of the graft is secured to the superior surface of the clavicle with a Bio-tenodesis screw (Arthrex) medial to the clavicular tunnel. PMID:17637416

Pennington, William T; Hergan, David J; Bartz, Brian A

2007-07-01

290

Robust quantum data locking from phase modulation  

E-print Network

Quantum data locking is a unique quantum phenomenon that allows a relatively short key to (un)lock an arbitrarily long message encoded in a quantum state, in such a way that an eavesdropper who measures the state but does not know the key has essentially no information about the encrypted message. The application of quantum data locking in cryptography would allow one to overcome the limitations of the one-time pad encryption, which requires the key to have the same length as the message. However, it is known that the strength of quantum data locking is also its Achilles heel, as the leakage of a few bits of the key or the message may in principle allow the eavesdropper to unlock a disproportionate amount of information. In this paper we show that there exist quantum data locking schemes that can be made robust against information leakage by increasing the length of the shared key by a proportionate amount. This implies that a constant size key can still encrypt an arbitrarily long message as long as a fraction of it remains secret to the eavesdropper. Moreover, we greatly simplify the structure of the protocol by proving that phase modulation suffices to generate strong locking schemes, paving the way to optical experimental realizations. Also, we show that successful data locking protocols can be constructed using random codewords, which very well could be helpful in discovering random codes for data locking over noisy quantum channels.

Cosmo Lupo; Mark M. Wilde; Seth Lloyd

2013-11-20

291

49 CFR 236.793 - Rod, lock.  

Code of Federal Regulations, 2012 CFR

...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

2012-10-01

292

49 CFR 236.793 - Rod, lock.  

Code of Federal Regulations, 2013 CFR

...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

2013-10-01

293

49 CFR 236.793 - Rod, lock.  

Code of Federal Regulations, 2011 CFR

...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

2011-10-01

294

49 CFR 236.793 - Rod, lock.  

Code of Federal Regulations, 2010 CFR

...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

2010-10-01

295

VIEW LOOKING NORTHEAST FROM THE PINE STREET BRIDGE. THE LOCK ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW LOOKING NORTHEAST FROM THE PINE STREET BRIDGE. THE LOCK ACCESS ROAD (FORMER TOW PATH) IS AT THE EXTREME LEFT, AND LOCKS 69 THROUGH 67 ARE IN THE CENTER LEFT, THE LOCK MACHINE SHOP IS IN THE MID-GROUND CENTER, AND THE ERIE CANAL MUSEUM (FORMER LOCK POWER PLANT) IN THE BACKGROUND CENTER. THE BARGE CANAL LOCK 34 IS AT THE EXTREME RIGHT. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

296

BulletinoftheSeismologicalSocietyofAmerica,Vol.73,No.5,pp.1415-1434,October1983 PRECURSORY SURFACE DEFORMATION IN GREAT PLATE  

E-print Network

observed that the majority of great shallow earthquakes occur at tectonic plate boundaries, and that some-dependent processes preceding seismic rupture at such a plate segment under increasing tectonic load. These processes, tectonic loading causes the accumulation of elastic strain (near a locked segment along a plate boundary

297

Plate Tectonics II: Plates, plate boundaries, and driving forces  

NSDL National Science Digital Library

The distribution of earthquakes and volcanoes around the world confirmed the theory of plate tectonics first proposed by Wegener. These phenomena also help categorize plate boundaries into three different types: convergent, divergent, and transform.

Egger, Anne

2003-03-18

298

Locking apparatus for gate valves  

DOEpatents

A locking apparatus for fluid operated valves having a piston connected to the valve actuator which moves in response to applied pressure within a cylinder housing having a cylinder head, a catch block is secured to the piston, and the cylinder head incorporates a catch pin. Pressure applied to the cylinder to open the valve moves the piston adjacent to the cylinder head where the catch pin automatically engages the catch block preventing futher movement of the piston or premature closure of the valve. Application of pressure to the cylinder to close the valve, retracts the catch pin, allowing the valve to close. Included are one or more selector valves, for selecting pressure application to other apparatus depending on the gate valve position, open or closed, protecting such apparatus from damage due to premature closing caused by pressure loss or operational error.

Fabyan, Joseph (Livermore, CA); Williams, Carl W. (Manteca, CA)

1988-01-01

299

Monocular fixation with the optic nerve head: a case report  

E-print Network

was an 80-year-old male with left ET from early childhood. Retinal tracking monocular fixation measurements the fixation. This patient does not have the blind spot syndrome (Swan, 1948). We propose the use of a retinal perimeter for documentation of eccentric fixation in strabismus. Keywords: blind spot, eccentric fixation

Peli, Eli

300

Mechanistic models of oceanic nitrogen fixation  

E-print Network

Oceanic nitrogen fixation and biogeochemical interactions between the nitrogen, phosphorus and iron cycles have important implications for the control of primary production and carbon storage in the ocean. The biological ...

Monteiro, Fanny

2009-01-01

301

Triple fixation of Bacillus subtilis dormant spores.  

PubMed Central

A triple-fixation method with a sequential application of 5% glutaraldehyde, 1% osmium tetroxide, and 2% potassium permanganate gave superior preservation of the ultrastructure of Bacillus subtilis dormant spores with a thick spore coat. Images PMID:6413496

Kozuka, S; Tochikubo, K

1983-01-01

302

ORIGINAL ARTICLE Sulfur oxidizers dominate carbon fixation  

E-print Network

ORIGINAL ARTICLE Sulfur oxidizers dominate carbon fixation at a biogeochemical hot spot in the dark clade of marine gamma-proteobacterial sulfur oxidizers (GSOs) are distributed throughout proteins for sulfur oxidation (adenosine phosphosulfate reductase, sox (sulfur oxidizing system

Hansell, Dennis

303

Fixation of Ejaculated Spermatozoa for Electron Microscopy  

Microsoft Academic Search

EJACULATED spermatozoa cannot be preserved satisfactorily by conventional fixation procedures for electron microscopy. Osmium tetroxide (OsO4) fixation of crude ejaculate consistently produces a variety of artefacts such as separation of the plasma membrane from the acrosome, widening of nuclear vacuoles, erosion of the acrosome, and swelling of mitochondria1-3. These alterations could be the consequence of the rapid destruction of the

Mario Stefanini; Cesare De Martino; Luciano Zamboni

1967-01-01

304

Morbus-Locke's early essay on disease.  

PubMed

John Locke engaged in a systematic study of medicine from the late 1650's. In this period he acquainted himself with the three main competing natural philosophical theories of the time -Galenism, Paracelsianism and Mechanism. He was particularly interested in the work of Sennert, Helmont and Doyle. In 1666, just after the publication of Boyle's The Origine of Formes and Qualities, Locke wrote a short paper entitled Morbus. This paper gave Locke's own view of the nature of disease. Locke went out of his way to criticise Boyle's attempts to give mechanical explanations for biological phenomena. He endorsed Helmont's theory that disease was caused by "ferments" and "Archei" and re-introduced Galenic temperaments as factors of susceptibility in seminal diseases. Locke did not endorse a mechanical corpuscularianism at this stage in his career, when his contact with Boyle was most frequent. Consequently, Locke's espousal of the corpuscular philosophy in the Essay cannot be attributed to Locke's association with Boyle at this time. PMID:15025079

Walmsley, J

2000-01-01

305

A new generation of lock and tag  

SciTech Connect

The safety culture of an organization needs to change to achieve full implementation of Chapter 9, ``Lockout and Tagouts`` of DOE Order 5480.19, Conduct of Operations Requirements for DOE Facilities (DOE 1990). You can implement this change of culture through Conduct of Operations training in the classroom, in organized group discussions, and with on-the-job training. In many facilities, lock and tag is viewed as an administration function that is not directly tied to individual employee safety. Often, lock and tag is seen as an obstacle to getting the job done, a roadblock in the way of progress that has been placed there by unseen forces for unknown reasons. Because lock and tag is not always viewed as part of the personal safety standards of the employee, the necessary attention to detail is lacking. We are presenting you with three useful methods for introducing and reinforcing a new generation of safety culture and lock and tag safety. The method will help your fellow workers view lock and tag and as a safety tool. Lock and tag will become part of their safety foundation. However, you may need to do some foundation building regarding safety, personal standards, and worker attitude before the principles of lock and tag training can become an integral part of your safety culture.

Wells, P.A.; Bickford, J.C.

1992-04-01

306

A new generation of lock and tag  

SciTech Connect

The safety culture of an organization needs to change to achieve full implementation of Chapter 9, Lockout and Tagouts'' of DOE Order 5480.19, Conduct of Operations Requirements for DOE Facilities (DOE 1990). You can implement this change of culture through Conduct of Operations training in the classroom, in organized group discussions, and with on-the-job training. In many facilities, lock and tag is viewed as an administration function that is not directly tied to individual employee safety. Often, lock and tag is seen as an obstacle to getting the job done, a roadblock in the way of progress that has been placed there by unseen forces for unknown reasons. Because lock and tag is not always viewed as part of the personal safety standards of the employee, the necessary attention to detail is lacking. We are presenting you with three useful methods for introducing and reinforcing a new generation of safety culture and lock and tag safety. The method will help your fellow workers view lock and tag and as a safety tool. Lock and tag will become part of their safety foundation. However, you may need to do some foundation building regarding safety, personal standards, and worker attitude before the principles of lock and tag training can become an integral part of your safety culture.

Wells, P.A.; Bickford, J.C.

1992-04-01

307

Less is more: lag screw only fixation of lateral malleolar fractures  

PubMed Central

Displaced fractures of the lateral malleolus are typically treated with plate osteosynthesis with or without the use of lag screws, and immobilisation in a plaster cast for up to 6 weeks. Fixation through a smaller incision with less metal, such as lag screw only fixation, would theoretically lead to decreased infection rates and less irritation caused by hardware. The purpose of this study was to evaluate the benefits and success of lag screw only fixation of the lateral malleolus in non-comminuted oblique fractures of the lateral malleolus. A total of 25 patients who had non-comminuted unstable oblique fractures of their lateral malleolus that had been surgically fixed with lag screws only were retrospectively evaluated. All patients were younger than 60 years of age. Evaluation of the success of fixation, complications, resultant mobility and patient satisfaction was based on information gathered from chart reviews, X-ray findings and a standardised questionnaire based on the AOFAS Foot and Ankle Outcomes Questionnaire. These results were compared to an age-matched group of 25 consecutive patients treated with plate osteosynthesis. Of the 25 patients fixed with lag screws, nine had an unstable fracture of the lateral malleolus only, ten were bimalleolar fractures and six were trimalleolar. Eighteen patients were treated with two lag screws, and seven were treated with three lag screws. The bi- and trimalleolar fractures were treated with standard partially threaded cancellous screws. None of the lag screw-only group lost reduction. There were no documented wound infections in the lag screw group as compared to three deep infections in the plate group. Lag screw-only patients reported no palpable hardware as compared to 50% of the plate group. AOFAS scores at a mean of 12 months post-operative were similar in both groups. Lag screw only fixation of the lateral malleolus is a safe and effective method that has a number of advantages over plate osteosynthesis, in particular less soft tissue dissection, less prominent, symptomatic and palpable hardware and a reduced requirement for secondary surgical removal. PMID:16947052

O'Shea, Kieran; Burke, Tom

2006-01-01

308

Active mode-locking in semiconductor lasers  

E-print Network

ACIIVE MODE-LOCKING IN SEMICONDUCTOR LASERS A Thesis by YONG-HUN LEE Submitted to the Office of Graduate Studies of Texas ABcM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1990 Major Subject... of Department) May 1990 Active Mode-locking in Semiconductor Lasers (May 1990) Yong-Hun Lee, B. S. , Hanyang University Chair of Advisory Committee: Dr. Henry F. Taylor An actively mode-locked L3 p. m semiconductor laser system is developed...

Lee, Yong-Hun

2012-06-07

309

The locked metacarpophalangeal joint: diagnosis and treatment.  

PubMed

The locked metacarpophalangeal joint of a finger is an unusual condition frequently confused with a "trigger finger." The causes can be classified into degenerative and spontaneous groups. Ten cases are presented. The cause of locking of one patient in the degenerative group was gouty arthritis, a cause not previously reported in the literature. Although surgery is usually necessary, joint mobility was restored in 30% of the cases by distending the joint capsule with an intraarticular injection of a local anesthetic followed by gentle manipulation. In addition to routine x-ray films, arthrotomography was found to be a useful diagnostic technique in determining the cause of locking. PMID:3958458

Posner, M A; Langa, V; Green, S M

1986-03-01

310

Bicolumnar 90-90 Plating of Low-Energy Distal Humeral Fractures in the Elderly Patient  

PubMed Central

Fragility fractures of the distal humerus in elderly patients, especially the low transcondylar fracture pattern, can be difficult to optimally manage. Although the fractures are typically low energy resulting in either extra-articular or simple intra-articular patterns, gaining fixation into the distal fragments can be difficult with open reduction internal fixation (ORIF) using traditional 90-90 or parallel plating techniques. Anatomy preserving reconstruction with ORIF is preferred over total elbow arthroplasty (TEA) if possible. In this study, 15 patients were managed with a bicolumnar 90-90 plating construct as a novel method of enhancing distal fixation in these fractures. Fourteen patients went on to radiographic union at an average of 77 days after surgery with an average arc of motion of 105°. One patient was lost to follow-up. Bicolumnar 90-90 plating of distal humerus fractures in elderly patients may represent a viable alternative to traditional ORIF or TEA. PMID:25360342

Leigey, Daniel F.; Farrell, Dana J.; Siska, Peter A.

2014-01-01

311

Locking characteristics of a 40-GHz hybrid mode-locked monolithic quantum dot laser  

NASA Astrophysics Data System (ADS)

Hybrid mode-locking in monolithic quantum dot lasers is studied experimentally and theoretically. A strong asymmetry of the locking range with respect to the passive mode locking frequency is observed. The width of this range increases linearly with the modulation amplitude for all operating parameters. Maximum locking range found is 30 MHz. The results of a numerical analysis performed using a set of five delay-differential equations taking into account carrier exchange between quantum dots and wetting layer are in agreement with experiments and indicate that a spectral filtering element could improve locking characteristics. Asymptotic analysis of the dependence of the locking range on the laser parameters is performed with the help of a more simple laser model consisting of three delay differential equations.

Vladimirov, A. G.; Wolfrum, M.; Fiol, G.; Arsenijevic, D.; Bimberg, D.; Viktorov, E.; Mandel, P.; Rachinskii, D.

2010-04-01

312

49 CFR 236.759 - Lock, facing point.  

Code of Federal Regulations, 2011 CFR

...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

2011-10-01

313

49 CFR 236.759 - Lock, facing point.  

Code of Federal Regulations, 2012 CFR

...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

2012-10-01

314

49 CFR 236.759 - Lock, facing point.  

Code of Federal Regulations, 2013 CFR

...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

2013-10-01

315

49 CFR 236.759 - Lock, facing point.  

Code of Federal Regulations, 2010 CFR

...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

2010-10-01

316

Devil's staircases in loop networks with symmetry locking  

NASA Astrophysics Data System (ADS)

In this work we analyze symmetry locking phenomena in loop networks with periodically switched connections. Exploiting the spatio-temporal symmetry properties of the system, we compute the rotation numbers of locked periodic regimes for which symmetry locking occurs. As a bifurcation parameter is varied, we compute the complete Devil's staircase reporting the symmetry of the locked periodic regimes.

Russo, Lucia; Mancusi, Erasmo

2013-10-01

317

Lock inference for systems software John Regehr Alastair Reid  

E-print Network

Lock inference for systems software John Regehr Alastair Reid School of Computing, University and other errors as well as supporting lock inference: the derivation of an appropriate lock implementa- tion for each critical section in a system. Lock inference solves a number of problems in creating

Utah, University of

318

Lock Selection in Practice Abdelsalam Shanneb and John Potter  

E-print Network

Lock Selection in Practice Abdelsalam Shanneb and John Potter Programming Languages and Compilers for offering lock choices. We show all the details involved in making lock choices for programmers. We offer different approaches to lock selection; we propose top-down and bottom-up strategies, as well as, additive

New South Wales, University of

319

Biomechanical Comparison of Osteoporotic Distal Radius Fractures Fixed by Distal Locking Screws with Different Length  

PubMed Central

Objectives To evaluate the postoperative stability of osteoporotic distal radius fractures fixed with distal locking screws with different length. Methods A comminuted extra-articular dorsally unstable distal radius fracture, treated with volar locking plate system, was created. The 18 specimens were randomized into 3 groups based on distal locked screws with different length: Group A had unicortical screws with 50% length to the dorsal cortex. Group B had unicortical screws with 75% length to the dorsal cortex. Group C had bicortical screws. Axial compression and bending loads were imposed on the models before and after cycling testing as well as load to clinical and catastrophic failure. Results Minimum change in stiffness was observed before and after fatigue for all groups. The final stiffness to bending forces was statistically similar in all groups, but stiffness to axial compression was statistically significant different: Group A approached significance with respect to groups B and C (P?=?0.017, 0.009), whereas stiffness in group B and C was statistically similar (P?=?0.93). Load to clinical failure was significantly less for group A (456.54±78.59 N) compared with groups B (580.24±73.85 N) and C (591.07±38.40 N). Load to catastrophic failure was statistically similar between groups, but mean values for Group A were 18% less than means for Group C. Conclusions The volar locking plate system fixed with unicortical locking screws with at least 75% length not only produced early stability for osteoporotic distal radius fractures, but also avoided extensor tendon complications due to dorsal screw protrusion. PMID:25080094

Liu, Xiong; Wu, Wei-dong; Fang, Ya-feng; Zhang, Mei-chao; Huang, Wen-hua

2014-01-01

320

49 CFR 236.757 - Lock, electric.  

Code of Federal Regulations, 2013 CFR

...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

2013-10-01

321

49 CFR 236.757 - Lock, electric.  

Code of Federal Regulations, 2012 CFR

...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

2012-10-01

322

49 CFR 236.757 - Lock, electric.  

Code of Federal Regulations, 2011 CFR

...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

2011-10-01

323

49 CFR 236.757 - Lock, electric.  

Code of Federal Regulations, 2010 CFR

...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

2010-10-01

324

Design Fixation in the Wild: Design Environments and Their Influence on Fixation  

ERIC Educational Resources Information Center

Many studies of design fixation ask designers to work in controlled laboratory or classroom environments, but innovative design work frequently occurs in dynamic, social environments. The two studies reviewed in this paper investigated how three independent variables likely to be present in many design environments affect design fixation. The…

Youmans, Robert J.

2011-01-01

325

Fixational saccades reflect volitional action preparation.  

PubMed

Human volitional actions are preceded by preparatory processes, a critical mental process of cognitive control for future behavior. Volitional action preparation is regulated by large-scale neural circuits including the cerebral cortex and the basal ganglia. Because volitional action preparation is a covert process, the network dynamics of such neural circuits have been examined by neuroimaging and recording event-related potentials. Here, we examined whether such covert processes can be measured by the overt responses of fixational saccades (including microsaccades), the largest miniature eye movements that occur during eye fixation. We analyzed fixational saccades while adult humans maintained fixation on a central visual stimulus as they prepared to generate a volitional saccade in response to peripheral stimulus appearance. We used the antisaccade paradigm, in which subjects generate a saccade toward the opposite direction of a peripheral stimulus. Appropriate antisaccade performance requires the following two aspects of volitional control: 1) facilitation of saccades away from the stimulus and 2) suppression of inappropriate saccades toward the stimulus. We found that fixational saccades that occurred before stimulus appearance reflected the dual preparatory states of saccade facilitation and suppression and correlated with behavioral outcome (i.e., whether subjects succeeded or failed to cancel inappropriate saccades toward the stimulus). Moreover, fixational saccades explained a large proportion of individual differences in behavioral performance (poor/excellent) across subjects. These results suggest that fixational saccades predict the outcome of future volitional actions and may be used as a potential biomarker to detect people with difficulties in volitional action preparation. PMID:23636719

Watanabe, Masayuki; Matsuo, Yuka; Zha, Ling; Munoz, Douglas P; Kobayashi, Yasushi

2013-07-01

326

Self-mode-locking semiconductor disk laser.  

PubMed

The development of mode-locked semiconductor disk lasers received striking attention in the last 14 years and there is still a vast potential of such pulsed lasers to be explored and exploited. While for more than one decade pulsed operation was strongly linked to the employment of a saturable absorber, self-mode-locking emerged recently as an effective and novel technique in this field - giving prospect to a reduced complexity and improved cost-efficiency of such lasers. In this work, we highlight recent achievements regarding self-mode-locked semiconductor devices. It is worth to note, that although nonlinear effects in the active medium are expected to give rise to self-mode-locking, this has to be investigated with care in future experiments. However, there is a controversy whether results presented with respect to self-mode-locking truly show mode-locking. Such concerns are addressed in this work and we provide a clear evidence of mode-locking in a saturable-absorber-free device. By using a BBO crystal outside the cavity, green light originating from second-harmonic generation using the out-coupled laser beam is demonstrated. In addition, long-time-span pulse trains as well as radiofrequency-spectra measurements are presented for our sub-ps pulses at 500 MHz repetition rate which indicate the stable pulse operation of our device. Furthermore, a long-time-span autocorrelation trace is introduced which clearly shows absence of a pedestal or double pulses. Eventually, a beam-profile measurement reveals the excellent beam quality of our device with an M-square factor of less than 1.1 for both axes, showing that self-mode-locking can be achieved for the fundamental transverse mode. PMID:25402081

Gaafar, Mahmoud; Richter, Philipp; Keskin, Hakan; Möller, Christoph; Wichmann, Matthias; Stolz, Wolfgang; Rahimi-Iman, Arash; Koch, Martin

2014-11-17

327

Free fructose is conformationally locked.  

PubMed

Fructose has been examined under isolation conditions using a combination of UV ultrafast laser vaporization and Fourier-transform microwave (FT-MW) spectroscopy. The rotational spectra for the parent, all (six) monosubstituted (13)C species, and two single D species reveal unambiguously that the free hexoketose is conformationally locked in a single dominant ?-pyranose structure. This six-membered-chair skeleton adopts a (2)C(5) configuration (equivalent to (1)C(4) in aldoses). The free-molecule structure sharply contrasts with the furanose form observed in biochemically relevant polysaccharides, like sucrose. The structure of free fructose has been determined experimentally using substitution and effective structures. The enhanced stability of the observed conformation is primarily attributed to a cooperative network of five intramolecular O-H···O hydrogen bonds and stabilization of both endo and exo anomeric effects. Breaking a single intramolecular hydrogen bond destabilizes the free molecule by more than 10 kJ mol(-1). The structural results are compared to ribose, recently examined with rotational resolution, where six different conformations coexist with similar conformational energies. In addition, several DFT and ab initio methods and basis sets are benchmarked with the experimental data. PMID:23346993

Cocinero, Emilio J; Lesarri, Alberto; Écija, Patricia; Cimas, Álvaro; Davis, Benjamin G; Basterretxea, Francisco J; Fernández, José A; Castaño, Fernando

2013-02-20

328

[The effect of an angle-stable plate-screw connection and various screw diameters on the stability of plate osteosynthesis. An FE model study].  

PubMed

In a finite element model of a human femur with an attached stainless steel six-hole plate exposed to a load equivalent to that set up by standing on one leg, pressures on the face of the screw holes, bending stresses in the screws, and axial bone stresses in the mid-plate transverse section were determined. The calculations were performed for minor thread diameters of 3 mm, 5 mm and 8 mm. Further calculations were done assuming a fixator-like rigid screw-plate connection. As a model of a fracture a medial bone defect was chosen. The results show a definitive influence of the screw diameter and the screw-plate connection on the load distribution in the system. Increasing screw diameter makes for lower bone stresses combined with increased bending stability, a larger part of the load being carried by the plate. The rigid screw-plate connection (plate fixator) causes less bone stresses, but high bending stresses are set up the points of screw-plate fixation. Maximal stresses for screw and bone are found at the end of the plate, caused by the large difference in the E-module between the steel plate and the bone. End-plate bone and screws are loaded in excess of their material limits when 3 mm core diameters are used, and sometimes when 5 mm core diameters are used, under the assumed conditions. When a medial bone defect reducing the bone cross-sectional area by 44% is present, the loads on the inner screws increase by a factor of 3 and the loads of the distant screws, by a factor of only 1.3. The maximal pressure in the bone cross section increases 4-fold. PMID:2281325

Seide, K; Zierold, W; Wolter, D; Kortmann, H R

1990-12-01

329

Systematic review of complications after intramedullary fixation for displaced midshaft clavicle fractures  

PubMed Central

Background The number of displaced midshaft clavicle fractures treated surgically is increasing, and open reduction and intramedullary fixation is an emerging surgical treatment option. The study quality and scientific levels of published evidence in which possible complications of this treatment are presented vary greatly. Methods We performed systematic computer-based searches of EMBASE and PubMed/MEDLINE. Studies included for review reported complications after intramedullary fixation alone or in comparison to either treatment with plate fixation and/or nonoperative treatment. The Level of Evidence rating and Quality Assessment Tool were used to assess the methodological quality of the studies. Included studies were ranked according to their levels of evidence. Results Six articles were eligible for inclusion and final quality assessment; 3 studies were graded the highest level of evidence. Major complications like bone-healing problems and deep infections requiring implant removal were reported at a rate no higher than 7%. Reported rates for minor complications, such as wound infection and implant irritation that could be resolved without further surgery, were as high as 31%. Conclusion The noted rates for major complications requiring additional surgery were low, but implant-related problems that require additional surgery might present with high prevalence. Owing to routine implant removal, treatment with intramedullary fixation often requires an additional surgical procedure. PMID:23351556

Wijdicks, Frans-Jasper G.; Houwert, R. Marijn; Millett, Peter J.; Verleisdonk, Egbert J.J.M.; Van der Meijden, Olivier A.J.

2013-01-01

330

Posterolateral lumbar and lumbosacral fusion with and without pedicle screw internal fixation.  

PubMed

Forty-seven patients who had lumbar or lumbosacral fusion with or without pedicle screw internal fixation by one surgeon for treatment of degenerative lumbar disease with clinical instability were retrospectively reviewed by an independent observer. Eighteen of the 21 patients whose fusions were internally fixed with the Variable Spinal Plating (VSP) system were available for review. A control group consisted of 27 patients who had fusion without internal fixation. The rate of pseudarthrosis did not significantly differ between the two groups (VSP group, 22%; versus control group, 26%). Twelve (67%) of the 18 patients treated with fusion and VSP instrumentation were considered to have had a good or excellent outcome, whereas 19 (70%) of the 27 patients treated by fusion without internal fixation had good or excellent results. Two VSP-instrumented patients had postoperative leg dysesthesias, whereas this complication was not observed in the control group. Bilateral posterolateral lumbar or lumbosacral fusion without internal fixation is as effective as and safer than fusion with pedicle screw instrumentation. PMID:1395279

Bernhardt, M; Swartz, D E; Clothiaux, P L; Crowell, R R; White, A A

1992-11-01

331

Interrami intraoral fixation technique for severe mandibular rifle fragmented bullet injury management.  

PubMed

Interrami intraoral Kirschner wire fixation technique is presented for the reduction, stabilization, and immobilization of a pulverized and avulsed lower jaw caused by rifle fragmented bullet injuries. This indirect mandibular war injury fixation technique was tolerated by the patients and tissue more than any indirect external fixation. In addition, it is easier than open reduction using large bone plates for disrupted ballistics mandibular injury defects. An interrami intraoral fixation is appropriate for severely disrupted mandibular hard and soft tissues, and has been adapted in cases of mass casualties and limited resources. Benefits of use include limited hospital beds and fewer follow-up visits. Rifle fragmented bullet injuries need more attention for several reasons: not only because of the higher mortality and devastating nature of the injuries, but also because these injuries are responsible for an unreported type of bullet biomechanism wounding in the craniofacial region. In turn, this necessitates specialized victim management. The survival rates depend on immediate proper execution of airway, breathing, and circulation, which become more complicated as it relates to airway compromise and oropharyngeal hemorrhage resuscitation. Survival is predicated on the implementation of feasible, sensible, life-saving techniques that are applied at the appropriate time. PMID:23851763

Shuker, Sabri T

2013-07-01

332

Mechanical analysis of femoral neck fracture fixation with dynamic condylar screw in synthetic bone  

PubMed Central

Objective: To analyze statistically results in biomechanical testing of fixation of femoral neck Pauwels type III fractures, on synthetic bone, with dynamic condylar screw (DCS) and control group. Methods: Ten synthetic bones of a national brand were used. Test Group: fixation was performed after osteotomy at 70o tilt using DCS plate with four holes. We analyzed the resistance of this fixation with 5 mm displacement and rotational deviation (Step 1) and with10 mm (Step 2). Control group: the models were tested in their integrity until the femoral neck fracture occurred. Results: The values of the test group in Step 1 showed a mean of 974N and SD = 114N. In Stage 2, we obtained on average 1335N and SD = 98N. The values in the control group were: 1544N, 1110N, 1359N, 1194N, 1437N, respectively. Statistical analysis using the Mann-Whitney test for comparison of the maximum force (N) between the test group and the control, in Step 2, demonstrated that there is no significant difference between the DCS and control plates (p = 0.91). Conclusion: There is no significant difference between the DCS boards and the control group exposed to full resistance. Level of Evidence III, Case Control.

Freitas, Anderson; Maciel, Rafael Almeida; Lima, Renato De Almeida; Souto, Diogo Ranier De Macedo; Ferrer, Marcelo De Almeida

2014-01-01

333

Numerical investigation of mechanical effects caused by various fixation positions on a new radius intramedullary nail.  

PubMed

Fracture of the radius diaphysis is an unusual injury in adults. Open reduction and plate osteosynthesis has been recommended by most of the authors. However, this trend has started to change with the recent introduction of newly designed interlocking intramedullary (IM) nails. New generation of IM nails are developed in order to utilise the advantages of IM nails against plates. Because of its anatomical structure, the radius bone has a complex geometry. Therefore, the callus structure, which forms during the healing period, should not be affected from external effects, such as excessive loads or motion. In this study, effects of radial styloid process (RSP), dorsal side and ulnar notch edge fixations of a new design radius IM nail on the healing period were numerically investigated. A three-dimensional solid model of radius was obtained from computed tomography images of a volunteer and callus structure model, was placed accordingly and different fixations of implants were performed. The models were analysed under axial loads transferring from the wrist to the radius bone using finite element method. As a result of the analysis, fixation of IM nail from RSP was found to be beneficial on healing period in terms of both callus motion and emerging stresses. PMID:23682815

Celik, A; Kovac?, H; Saka, G; Kaymaz, I

2015-02-01

334

Nitrogen fixation and nitrogen fertilization of soybeans.  

PubMed

Abstract In pot experiments with (15)N labelled soil and mineral (15)N, the influence of Bradyrhizobium (Rhizobium japonicum) inoculation and N fertilization on the symbiotic N(2) fixation and yield of soybeans [Glycine max (L.) Merill., cv. 'Fiskeby V'] was investigated. Symbiotic N(2) fixation only occured after inoculation with Bradyrhizobium. Considerable differences in efficiency of the bacterial preparations were observed. Shortly after flowering, the symbiotic nitrogen fixation was finished and, subsequently, soybeans took up considerable N amounts from the soil. N fertilization at seeding suppressed N(2) fixation of soybeans. In this case, the dry matter and nitrogen yield increased, because the loss of fixed nitrogen was overcompensated by the mineral N uptake. During flowering of soybeans, the N(2) fixation was not affected by N supply, because this process was already terminated. The mineral N was additionally available to the plants and led to increased N amounts in plants. It was absorbed to a considerable degree by soybeans. The mineral N was translocated (partly, after intermediate storage in the vegetative organs) into the seeds thus increasing their yields. PMID:22088108

Merbach, W; Jacob, H J

1996-08-01

335

Transoral Miniplate Fixation of Mandibular Angle Fracture with and without 2 Weeks of Maxillomandibular Fixation: A Clinical Trial Study.  

PubMed

Background and Objectives The ideal line of osteosynthesis in mandibular angle fractures indicates that a plate might be placed either along or just below the external oblique ridge. Some authors believe that using one miniplate at this line at the mandibular angle region provides sufficient strength to stabilize the fracture but others imply a second plate is required. Such controversies exist in the use of maxillomandibular fixation (MMF). The intention of the present study was to compare efficiency and complications of using one miniplate with and without MMF in mandibular angle fractures. Methods and Materials Forty patients with facial trauma with mandibular angle fractures including displaced and unfavorable fractures were categorized into two groups of 20 persons. In all patients, one miniplate was placed on the external oblique ridge. In the first group, patients had light maxillomandibular elastic bands just after surgery but no rigid MMF. In the second group, patients had rigid MMF for 2 weeks after surgery. Patients were followed to evaluate complications and treatment efficiency. Conclusions Our study showed that use of a single miniplate in the external oblique ridge is a functionally stable treatment for all types of angle fractures (including displaced and unfavorable fractures) except comminuted and long oblique fractures, which were not included in our study. Use of postoperative MMF did not improve the results. PMID:24436745

Khiabani, Kazem S; Mehmandoost, Meghdad Khanian

2013-06-01

336

Transoral Miniplate Fixation of Mandibular Angle Fracture with and without 2 Weeks of Maxillomandibular Fixation: A Clinical Trial Study  

PubMed Central

Background and Objectives The ideal line of osteosynthesis in mandibular angle fractures indicates that a plate might be placed either along or just below the external oblique ridge. Some authors believe that using one miniplate at this line at the mandibular angle region provides sufficient strength to stabilize the fracture but others imply a second plate is required. Such controversies exist in the use of maxillomandibular fixation (MMF). The intention of the present study was to compare efficiency and complications of using one miniplate with and without MMF in mandibular angle fractures. Methods and Materials Forty patients with facial trauma with mandibular angle fractures including displaced and unfavorable fractures were categorized into two groups of 20 persons. In all patients, one miniplate was placed on the external oblique ridge. In the first group, patients had light maxillomandibular elastic bands just after surgery but no rigid MMF. In the second group, patients had rigid MMF for 2 weeks after surgery. Patients were followed to evaluate complications and treatment efficiency. Conclusions Our study showed that use of a single miniplate in the external oblique ridge is a functionally stable treatment for all types of angle fractures (including displaced and unfavorable fractures) except comminuted and long oblique fractures, which were not included in our study. Use of postoperative MMF did not improve the results. PMID:24436745

Khiabani, Kazem S.; Mehmandoost, Meghdad Khanian

2013-01-01

337

Plate Tectonics Animation  

NSDL National Science Digital Library

Plate tectonics describes the behavior of Earth's outer shell, with pieces (plates) bumping and grinding and jostling each other about. Explore these maps and animations to get a jump start on understanding plate tectonic processes, history, and how motion of the plates affects our planet today.

2002-01-01

338

MICROBIOLOGY: A Fifth Pathway of Carbon Fixation  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Genome sequence analyses and enzymatic studies reveal a novel CO2 fixation cycle in some autotrophic archaea. Autotrophs are organisms that can grow using carbon dioxide (CO2) as their sole source of carbon. Four mechanisms are known by which autotrophic organisms fix carbon. Berg et al. describe a fifth autotrophic CO2 fixation pathway in archaea that may have been used by some of the earliest organisms on Earth.

Rudolf K. Thauer (Max Planck Institute for Terrestrial Microbiology;)

2007-12-14

339

Evolution of mesh fixation for hernia repair.  

PubMed

Hernia repair remains one of the most common surgical procedures performed around the world. Over the past several decades, in response to various mesh-related complications and coinciding with the influx of laparoscopy into the field of general surgery, numerous advancements have been made in regards to the technology of mesh products being used in hernia repair today. Along these same lines, devices used for mesh fixation have evolved at a similar pace. The goal of this chapter is to review the various materials and methods of mesh fixation being utilized in both ventral and inguinal hernia repair today. PMID:25398127

Webb, David; Stoikes, Nathaniel; Voeller, Guy

2014-11-01

340

[Iris-fixated intraocular lenses: reinforced monitoring].  

PubMed

In 1986, the concept of the claw lens was applied to correct myopia in phakic patients. Since then, progress has made iris-fixated phakic intraocular lenses (IOL) relatively safe, predictable, and effective for the correction of myopia, hyperopia, and astigmatism. All these models have undergone a series of design improvements to prevent complications. Despite having excellent refractive results, the principal risk is a potential progressive endothelial cell loss. Many authors have presented encouraging results. Phakic iris-fixated IOL surgery is a potentially reversible procedure, but the surgeon cannot rule out the possibility of complications. Therefore, long-term follow-up is mandatory. PMID:19520458

Fournié, P; Malecaze, F

2009-11-01

341

Cooling arrangement for the locking device in pressure gasification reactors  

SciTech Connect

A cooling arrangement particularly for cooling a locking device arranged in a fuel feed opening of pressure gasification generators comprises a lock seat connected to the generator and a lock cone adapted for moving into and out of engagement with the lock seat and provided with a supply line to provide a cooling medium to the lock cone and a discharge line through which the used medium is drained off the lock cone. The lock cone is formed as a hollow body with a cooling chamber in its interior and is provided with guide means extending towards the lowermost area of the lock cone to direct the cooling medium into contact with the mostly overheated lowermost area of the lock cone positioned in a close relationship with the pressure gasification generator.

Jaschke, P.; Monch, E.; Weber, R.

1981-06-02

342

49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.  

Code of Federal Regulations, 2013 CFR

...false Electromechanical interlocking machine; locking between electrical and mechanical...340 Electromechanical interlocking machine; locking between electrical and mechanical... In electro-mechanical interlocking machine, locking between electric and...

2013-10-01

343

Mapping Plate Tectonic Boundaries  

NSDL National Science Digital Library

To prepare for this activity, students do background reading on Plate Tectonics from the course textbook. Students also participate in a lecture on the discovery and formulation of the unifying theory of plate tectonics, and the relationship between plate boundaries and geologic features such as volcanoes. Lastly, in lecture, students are introduced to a series of geologic hazards caused by certain plate tectonic interactions. The activity gives students practices at identifying plate boundaries and allows them to explore lesser known tectonically active regions.

Kerwin, Michael

344

Simultaneous glutaraldehyde-osmium tetroxide fixation with postosmication  

Microsoft Academic Search

A fixation procedure for electron microscopy is described which includes a simultaneous glutaraldehyde-OsO4 fixation followed by postosmication. This procedure was found to have considerable advantages in preserving structures of plant and animal cells.

Werner W. Franke; Sigrid Krien; R. Malcolm Brown

1969-01-01

345

Temporizing external fixation of the lower extremity: a survey of the orthopaedic trauma association membership.  

PubMed

This study examined the opinions of practicing traumatologists to aid in the initial treatment of complicated lower extremity fractures in accordance with current staged protocols. A 40-question online survey of the Orthopaedic Trauma Association (OTA) membership was administered from November 2008 to February 2009. The survey investigated surgeons' preferences regarding general principles and routine management of joint-spanning lower extremity external fixators, as well as favored knee- and ankle-spanning constructs and conditions of definitive surgical reconstruction. Data were collected using a 5-point Likert scale ranging from strongly agree (5) to strongly disagree (1). Responses were given numerical weight in descending order (scoring 5-1) and were reported as straight percentages and with a weighted mean called the rating average.Responses were received from half of the OTA membership. Among the strongest preferences (rating average >4) were for obtaining a computed tomography (CT) scan as part of prereconstruction planning (4.8) and obtaining that CT scan after joint-spanning external fixation was applied (4.6). Restoration of length as the most important part of limb realignment at the time of temporizing external fixator application (4.3), the use of soft tissue protection during pin application (4.4), and avoiding overlap of pin sites with a plate at the time of reconstruction (4.3) were highly favored. Survey respondents treated a sizable volume of periarticular lower extremity injuries with temporizing external fixation and staged reconstruction. This consolidation of trends and preferences for constructing and using temporizing external fixation for complex lower extremity injuries hopefully will aid in the treatment of these difficult fractures. PMID:20415303

Collinge, Cory; Kennedy, Jason; Schmidt, Andrew

2010-04-01

346

Stability with unilateral external fixation in the tibia  

Microsoft Academic Search

\\u000a Abstract\\u000a   Unilateral external fixation can be used in the provisional or definitive treatment of tibial fractures. A properly applied\\u000a fixator allows bony and soft tissue stability, whereas an improperly applied fixator achieves neither and can be a hindrance.\\u000a The principles for the successful application of monolateral external fixation, including the rationale for choosing this\\u000a type of device, the assembly of

N. Giotakis; B. Narayan

2007-01-01

347

Suture Bridge Fixation of a Femoral Condyle Traumatic Osteochondral Defect  

Microsoft Academic Search

Internal fixation of a traumatic osteochondral defect presents a challenge in terms of obtaining anatomic reduction, fixation,\\u000a and adequate compression for healing. Fixation with countersunk intraarticular screws, Herbert screws, bioabsorbable screws\\u000a and pins, mini-cancellous screws, and glue tissue adhesive have been reported with varying results. We present an alternative\\u000a fixation method used in two patients for femoral condylar defects that

Andrea L. Bowers; G. Russell Huffman

2008-01-01

348

Surgical strategies to improve fixation in the osteoporotic spine: the effects of tapping, cement augmentation, and screw trajectory.  

PubMed

Study Design?Biomechanical study of pedicle screw fixation in osteoporotic bone. Objective?To investigate whether it is better to tap or not tap osteoporotic bone prior to placing a cement-augmented pedicle screw. Methods?Initially, we evaluated load to failure of screws placed in cancellous bone blocks with or without prior tapping as well as after varying the depths of tapping prior to screw insertion. Then we evaluated load to failure of screws placed in bone block models with a straight-ahead screw trajectory as well as with screws having a 23-degree cephalad trajectory (toward the end plate). These techniques were tested with nonaugmented (NA) screws as well as with bioactive cement (BioC) augmentation prior to screw insertion. Results?In the NA group, pretapping decreased fixation strength in a dose-dependent fashion. In the BioC group, the tapped screws had significantly greater loads to failure (p?fixation is often inadequate in the osteoporotic spine, but this study suggests tapping prior to cement augmentation will substantially improve fixation when compared with not tapping. Angulating screws more cephalad also seems to enhance aging spine fixation. PMID:24494181

Kuhns, Craig A; Reiter, Michael; Pfeiffer, Ferris; Choma, Theodore J

2014-02-01

349

Postmortem inflation and fixation of human lungs  

PubMed Central

Wright, B. M., Slavin, G., Kreel, L., Callan, K., and Sandin, Brenda (1974).Thorax, 29, 189-194. Postmortem inflation and fixation of human lungs. A method of fixing lungs by inflating them with heated formalin vapour is described. This method facilitates postmortem correlations between radiographic and histological appearances. Images PMID:4598582

Wright, B. M.; Slavin, G.; Kreel, L.; Callan, K.; Sandin, Brenda

1974-01-01

350

Constraining Potential Locking Area on the Creeping Segment of the San Andreas Fault  

NASA Astrophysics Data System (ADS)

The San Andreas Fault has historically been known for producing large earthquakes, especially in the Los Angeles and San Francisco areas. However, it is currently unclear whether the region between these two areas, a 150-km long section of the fault extending from Parkfield north, could also produce large earthquakes. This section of the fault is known to be creeping at the surface, and in some areas may move at nearly the deep slip rate. Our current research utilizes GPS and InSAR data to constrain the bounds on locking of the fault at depth to estimate potential for producing large earthquakes, using a block model to compute slip rates on the fault segment between Parkfield and San Juan Bautista. The degree of locking along the fault trace can then be estimated and potential accumulation of strain across the plate boundary estimated. The results will be an improved understanding of potential earthquake hazards in this region.

Maurer, J.; Johnson, K. M.

2012-12-01

351

Locked pubic symphysis into the obturator foramen: a rare case presentation and literature review.  

PubMed

Locked pubic symphysis is a rare form of pelvic injury. It occasionally occurs after a lateral compression injury of the pelvis. We described an overlapping pubic symphysis dislocation that was locked into the contralateral obturator foramen. To the best of our knowledge, there are about seventeen similar cases reported in the literature. The pubic symphysis was finally reduced by means of a superior pubic ramus osteotomy to unlock the incarcerated pubic body out of the contralateral obturator foramen. As the reduction was unstable, the pubic symphysis was fixed with a reconstruction plate. The patient recovered completely and returned to normal activities within 4months. At 1year's follow-up she reported no discomfort in the pubic symphysis region and was able to void urine normally. PMID:23270720

Li, K H; Sun, B H; Zhu, Y; Long, H T

2013-02-01

352

Locked overlapping dislocation of the pubic symphysis into the obturator foramen: a case report.  

PubMed

A 20-year-old man sustained an overlapping dislocation of the pubic symphysis following a low velocity side-to-side compression injury. Such injuries are rare in the literature. This case, where the pubis was locked into the obturator foramen, may be the first of its kind to be reported. The pubic symphysis was successfully reduced by levering, with difficulty, the locked pubic body out of the left obturator foramen. As the reduction was unstable, the pubic symphysis was fixed with 2 reconstruction plates. The patient was able to mobilise fully after 3 months and returned to work. At 18 months' follow-up he was able to void urine normally after urethral repair. PMID:16914789

Sreesobh, K V; Sageer, A M; Raffic, M

2006-08-01

353

SWITCHED REFERENCE PHASE LOCK LOOP (SRPLL).  

SciTech Connect

The Brookhaven National Laboratory Relativistic Heavy Ion Collider (RHIC) has two beam synchronous event links (BSL), one for each ring, which use the 28 MHz ring low level rf to distribute event codes synchronously with a precise phase relationship to the beam. During a cogging reset just before injection, the low level rf sine wave is interrupted which causes the BSL receivers to lose lock. Lock loss in turn causes false triggers and other undesirable-effects on the beam position monitors (BPM), ionization profile monitors (IPM), the tune meter and various experiments which use the BSLs. To rectify these problems, a SRPLL has been inserted between the beam synchronous master and the low level rf source. The SRPLL inserts a frequency and phase continuous splice over the dead-band gap in the rf source created during a cogging reset. The splice removes the gap and prevents the distributed BSL receivers from losing lock.

KERNER,T.

2001-06-18

354

Using river locks to teach hydrodynamic concepts  

NASA Astrophysics Data System (ADS)

In this work, the use of a river lock as a non-formal setting for teaching hydrodynamical concepts is proposed. In particular, we describe the operation of a river lock situated at the Sobradinho dam, on the São Francisco River (Brazil). A model to represent and to analyse the dynamics of river lock operation is presented and we derive the dynamical equations for the rising of the water column as an example to understand the Euler equation. Furthermore, with this activity, we enable the integration of content initially introduced in the classroom with practical applications, thereby allowing the association of physical themes to content relevant in disciplines such as history and geography. In addition, experiences of this kind enable teachers to talk about the environmental and social impacts caused by the construction of a dam and, consequently, a crossover of concepts has been made possible, leading to more meaningful learning for the students.

Carvalho-Santos, Vagson L.; Mendes, Thales C.; Silva, Enisvaldo C.; Rios, Márcio L.; Silva, Anderson A. P.

2013-11-01

355

Three-dimensional load measurements in an external fixator  

Microsoft Academic Search

On the basis of a six-degree-of-freedom adjustable fracture reduction hexapod external fixator, a system which can be used for measuring axial and shear forces as well as torsion and bending moments in the fixator in vivo was developed. In a pilot study on 9 patients (7 fresh fractures and 2 osteotomies of the tibia), the load in the fixator during

K Seide; N Weinrich; M. E Wenzl; D Wolter; C Jürgens

2004-01-01

356

Sliding performance of unilateral external fixators for tibia  

Microsoft Academic Search

Some unilateral external fixators have a sliding mechanism to achieve dynamic axial fixation. However, it has been reported that binding of this mechanism occurs during routine ambulation. The Hifixator, a unilateral external fixator, has been developed which has a new type of sliding mechanism. The mechanism of the Hifixator was tested by connecting it to a fractured bone model with

Takashi Matsushita; Kozo Nakamura; Isao Ohnishi; Takahide Kurokawa

1998-01-01

357

Nonunion after primary treatment of tibia fractures with external fixation  

Microsoft Academic Search

The authors retrospectively reviewed 207 fractures of tibial diaphysis, treated primarily with external fixation without bone grafting. Forty-two fractures (20.3%) resulted in nonunion and required reoperation. Parameters analyzed for their significance for nonunion included, soft tissue damage, energy of injury, method of fracture reduction, type of external fixation frame, supplemental interfragmentary screw fixation, dynamization at the fracture site, and postoperative

N. Papaioannou; D. Mastrokalos; P. J. Papagelopoulos; M. Tyllianakis; J. Athanassopoulos; P. A. Nikiforidis

2001-01-01

358

Unfixing Design Fixation: From Cause to Computer Simulation  

ERIC Educational Resources Information Center

This paper argues that design fixation, in part, entails fixation at the level of meta-representation, the representation of the relation between a representation and its reference. In this paper, we present a mathematical model that mimics the idea of how fixation can occur at the meta-representation level. In this model, new abstract concepts…

Dong, Andy; Sarkar, Somwrita

2011-01-01

359

The Two Phases of the Coalescent and Fixation Processes Introduction  

E-print Network

the stasis phase. Because the expected fixation and coalescent times are equal, and those processes share the transition phase, the expected lengths of the stasis phase are the same for the coalescent and fixation shall denote as T and t, contain the stasis phases for coalescence and fixation, respectively. Hence I

Campbell, Russell Bruce

360

Systematic comparison of tissue fixation with alternative fixatives to conventional tissue fixation with buffered formalin in a xenograft-based model.  

PubMed

In our study we systematically compared the alternative fixatives acidified formal alcohol (AFA), PAXgene®, HOPE®, and combinations of AFA or formalin with ultrasound treatment to standard (buffered) formalin fixation. We examined general morphology and detectability of protein structures by immunohistochemistry of the membrane receptors epidermal growth factor receptor (EGFR), insulin-like growth factor 1 receptor (IGF-1R), and phosphorylated human epidermal growth factor receptor 2 (phospho-HER2). In order to allow for stringent comparability of different fixation techniques, we used matched mouse xenograft tumor samples from three different human cancer cell lines (colon, ovarian, and non-small cell lung cancer), either fixed conventionally with formalin or an alternative fixative. Tissue morphology after fixation with AFA and PAXgene® was comparable to formalin-fixed paraffin-embedded tissue (FFPET) morphology. Ultrasound fixations resulted in slightly inferior morphology and HOPE® fixation preserved morphology only poorly compared to FFPET in this system. None of the tested alternative fixatives enabled immunohistochemical detectability of all three targets in the same manner as FFPET. Pronounced staining was possible for EGFR and IGF-1R with all alternative fixatives but HOPE®, and phospho-HER2 staining was only noteworthy with formalin-ultrasound-fixed tissue. Therefore, the use of alternative fixatives comes with the need for careful validation of obtained IHC results individually for each target. PMID:22814649

Nietner, Thorben; Jarutat, Tiantom; Mertens, Alfred

2012-09-01

361

Adult tibial eminence fracture fixation: arthroscopic procedure using K-wire folded fixation  

Microsoft Academic Search

The purpose of this article is to describe a new and simple technique for arthroscopic fixation of tibial intercondylar eminence\\u000a avulsion fractures using folded surgical pin. This technique allows reduction and fixation of the bone fragment without using\\u000a special equipment. After standard arthroscopic procedure to explore the knee and to remove fracture debris and blood clot,\\u000a the bone block is

Nicolas Bonin; Laurent Jeunet; Laurent Obert; David Dejour

2007-01-01

362

Lock-in by molecular multiplication  

NASA Astrophysics Data System (ADS)

A lock-in amplifier is physically realized at the level of fluorescent dye molecules. It is based on the general property that the emission of a fluorescent dye is the product of quantum efficiency and illumination intensity. For each pixel of a microscopic image, we measure in amplitude and phase an environment property of the dye, such as conformation, membrane voltage, or temperature. This lock-in implementation is highly parallel and reaches the ultimate photon shot noise limit. Using fast temperature oscillations, we apply it to measure the opening/closing kinetics of a molecular beacon (DNA hairpin) at 5 ?s resolution.

Braun, Dieter; Libchaber, Albert

2003-12-01

363

Spacer grid assembly and locking mechanism  

DOEpatents

A spacer grid assembly is disclosed for retaining a plurality of fuel rods in substantially parallel spaced relation, the spacer grids being formed with rhombic openings defining contact means for engaging from one to four fuel rods arranged in each opening, the spacer grids being of symmetric configuration with their rhombic openings being asymmetrically offset to permit inversion and relative rotation of the similar spacer grids for improved support of the fuel rods. An improved locking mechanism includes tie bars having chordal surfaces to facilitate their installation in slotted circular openings of the spacer grids, the tie rods being rotatable into locking engagement with the slotted openings.

Snyder, Jr., Harold J. (Rancho Santa Fe, CA); Veca, Anthony R. (San Diego, CA); Donck, Harry A. (San Diego, CA)

1982-01-01

364

Frequency spectrum analyzer with phase-lock  

DOEpatents

A frequency-spectrum analyzer with phase-lock for analyzing the frequency and amplitude of an input signal is comprised of a voltage controlled oscillator (VCO) which is driven by a ramp generator, and a phase error detector circuit. The phase error detector circuit measures the difference in phase between the VCO and the input signal, and drives the VCO locking it in phase momentarily with the input signal. The input signal and the output of the VCO are fed into a correlator which transfers the input signal to a frequency domain, while providing an accurate absolute amplitude measurement of each frequency component of the input signal.

Boland, Thomas J. (Idaho Falls, ID)

1984-01-01

365

Hydrodynamic phase-locking of swimming microorganisms  

E-print Network

Some microorganisms, such as spermatozoa, synchronize their flagella when swimming in close proximity. Using a simplified model (two infinite, parallel, two-dimensional waving sheets), we show that phase-locking arises from hydrodynamics forces alone, and has its origin in the front-back asymmetry of the geometry of their flagellar waveform. The time-evolution of the phase difference between co-swimming cells depends only on the nature of this geometrical asymmetry, and microorganisms can phase-lock into conformations which minimize or maximize energy dissipation.

Elfring, Gwynn J

2009-01-01

366

Hydrodynamic phase-locking of swimming microorganisms  

E-print Network

Some microorganisms, such as spermatozoa, synchronize their flagella when swimming in close proximity. Using a simplified model (two infinite, parallel, two-dimensional waving sheets), we show that phase-locking arises from hydrodynamics forces alone, and has its origin in the front-back asymmetry of the geometry of their flagellar waveform. The time-evolution of the phase difference between co-swimming cells depends only on the nature of this geometrical asymmetry, and microorganisms can phase-lock into conformations which minimize or maximize energy dissipation.

Gwynn J. Elfring; Eric Lauga

2009-07-06

367

Integrated injection-locked semiconductor diode laser  

DOEpatents

A continuous wave integrated injection-locked high-power diode laser array is provided with an on-chip independently-controlled master laser. The integrated injection locked high-power diode laser array is capable of continuous wave lasing in a single near-diffraction limited output beam at single-facet power levels up to 125 mW (250 mW total). Electronic steering of the array emission over an angle of 0.5 degrees is obtained by varying current to the master laser. The master laser injects a laser beam into the slave array by reflection of a rear facet.

Hadley, G. Ronald (Albuquerque, NM); Hohimer, John P. (Albuquerque, NM); Owyoung, Adelbert (Albuquerque, NM)

1991-01-01

368

Flexibly controllable multi-pulse mode-locked MOPA Yb-doped fiber laser in all normal dispersion regime  

NASA Astrophysics Data System (ADS)

A Controllable, high energy, all normal dispersion (ANDi), passively mode-locked Yb-doped fiber laser is demonstrated with a Master Oscillator Power-Amplifier (MOPA) structure. The mode-locking is achieved by nonlinear polarization evolution (NPE). different types of laser pulse are achieved from fundamental mode-locked (FML) single pulse to twin pulse and then to harmonically mode-locked (HML) pulses (the maximum order is 7 times) by adjusting quarter-wave plates (QWPS) and a half-wave plate (HWP) in our system. Using a cascaded long-period fiber grating as the spectral filter, the center wavelength of our laser is fixed at 1034nm.The repetition frequency rate of the FML pulse is 1.53MHz with a pulse width of 817ps. The maximum average energy is 450 mW and the maximum pulse energy of FML single pulse is 294 nJ. Besides, the 517nm green laser output is also achieved by using a LiB3O5 (LBO) crystal as the frequency doubling crystal. The maximum average of the green pulse is 4.71mW.

Bu, Chenxi; Wang, Chinhua

2013-09-01

369

Creeping and locked segments along the Main Marmara Fault  

NASA Astrophysics Data System (ADS)

It is known since the last 1999 Izmit earthquake that the North Anatolian Fault is hosting a final important seismic gap along a 150 km region that corresponds to the Main Marmara Fault (MMF) below the Sea of Marmara. The gap is owing to a major locking zone where slip along the fault is blocked despite a significant remote plate boundary loading (23 mm/yr). After about 250 years of quiescence the fault is now very close to failure. Unfortunately any attempt of prediction which relies on a very fine monitoring of the fault behavior, is strongly limited by the sea coverage. Direct observations in particular from geodetic measurements are indeed very difficult. However, local seismicity along the MMF provides crucial indirect evidences. The present work is based on this approach and includes precise geographical and depth locations from a large compilation of seismic stations around the Sea of Marmara. We aim at interpreting micro-earthquake spatial distribution in terms of regional geodynamical information and compare it to other approaches like geodesy. From the geographical and depth distribution of micro-seismicity between 2007 and 2012, three domains can be defined along the Main Marmara Fault (MMF) : the West Marama (WM) zone which includes the Tekidag and Central Basins where seismicity is abundant and well distributed in depth (from surface to 17 km) including several vertically extended clusters, the Kumburgaz basin (KB) in the center zone of the Marmara Sea where seismicity is very spare, and the Cinarcik basin (CB) where seismicity is uniformly distributed along the MMF but mostly at depth along a narrow zone (except at both ends of this basin where vertically extended swarms also exist). We evidence three different behaviors. The western Marmara segment is mostly creeping on the contrary to the central Kumburgaz Basin fault zone which is entirely locked as well as possible upper sub-regions of the Princess Island fault and/or the Tekirdag basin. Implications for regional seismic hazard are discussed.

Schmittbuhl, Jean; Karabulut, Hayrullah; Lengliné, Olivier; Bouchon, Michel

2014-05-01

370

Viscoelastic deformation near active plate boundaries  

NASA Technical Reports Server (NTRS)

Model deformations near the active plate boundaries of Western North America using space-based geodetic measurements as constraints are discussed. The first six months of this project were spent gaining familarity with space-based measurements, accessing the Crustal Dynamics Data Information Computer, and building time independent deformation models. The initial goal was to see how well the simplest elastic models can reproduce very long base interferometry (VLBI) baseline data. From the Crustal Dynamics Data Information Service, a total of 18 VLBI baselines are available which have been surveyed on four or more occasions. These data were fed into weighted and unweighted inversions to obtain baseline closure rates. Four of the better quality lines are illustrated. The deformation model assumes that the observed baseline rates result from a combination of rigid plate tectonic motions plus a component resulting from elastic strain build up due to a failure of the plate boundary to slip at the full plate tectonic rate. The elastic deformation resulting from the locked plate boundary is meant to portray interseismic strain accumulation. During and shortly after a large interplate earthquake, these strains are largely released, and points near the fault which were previously retarded suddenly catch up to the positions predicted by rigid plate models. Researchers judge the quality of fit by the sum squares of weighted residuals, termed total variance. The observed baseline closures have a total variance of 99 (cm/y)squared. When the RM2 velocities are assumed to model the data, the total variance increases to 154 (cm/y)squared.

Ward, S. N.

1986-01-01

371

Arthroscopic double-locked stitch: a new technique for suturing rotator cuff tears.  

PubMed

There are a number of reasons for failed rotator cuff tear repair. In such cases the suture-tendon interface seems to be the most vulnerable area, especially when tendon degeneration is present. We describe a new technique, the arthroscopic double-locked suture, that increases the tendon fixation and has the added benefit of being placed parallel to the blood vessels, therefore avoiding damage to the tendon vascularization. The suture may be achieved by use of knots or knotless anchors and suture passers, without the need for any additional instrumentation. The new technique is especially helpful in cases in which the tendon is retracted and degeneration is present, impeding the use of the double-row technique or its transosseous equivalents. PMID:24904764

Miyazaki, Alberto N; Zanella, Luiz A Z; La Salvia, João C; Fregoneze, Marcelo; Santos, Pedro D; da Silva, Luciana A; Sella, Guilherme do Vall; Checchia, Sergio L

2014-04-01

372

Lock-free dynamic hash tables with open addressing  

Microsoft Academic Search

We present an efficient lock-free algorithm for parallel accessible hash tables with open addressing, which promises more robust performance and reliability than conventional lock-based implementations. \\

Hui Gao; Jan Friso Groote; Wim H. Hesselink

2005-01-01

373

49 CFR 236.339 - Mechanical locking, maintenance requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Mechanical locking, maintenance requirements...Rules and Instructions § 236.339 Mechanical locking, maintenance requirements...following will be prevented: (a) Mechanical machine —(1) Latch-operated...

2013-10-01

374

49 CFR 236.339 - Mechanical locking, maintenance requirements.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Mechanical locking, maintenance requirements...Rules and Instructions § 236.339 Mechanical locking, maintenance requirements...following will be prevented: (a) Mechanical machine —(1) Latch-operated...

2010-10-01

375

49 CFR 236.339 - Mechanical locking, maintenance requirements.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Mechanical locking, maintenance requirements...Rules and Instructions § 236.339 Mechanical locking, maintenance requirements...following will be prevented: (a) Mechanical machine —(1) Latch-operated...

2011-10-01

376

49 CFR 236.339 - Mechanical locking, maintenance requirements.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Mechanical locking, maintenance requirements...Rules and Instructions § 236.339 Mechanical locking, maintenance requirements...following will be prevented: (a) Mechanical machine —(1) Latch-operated...

2012-10-01

377

31. DETAILED INTERIOR VIEW OF AUXILIARY LOCK, SHOWING RECESSES FOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. DETAILED INTERIOR VIEW OF AUXILIARY LOCK, SHOWING RECESSES FOR MITER GATE OPERATING MACHINERY IN LEFT FOREGROUND. LOOKING NORTHEAST (UPSTREAM) - Upper Mississippi River Nine-Foot Channel Project, Lock & Dam No. 25, Cap au Gris, Lincoln County, MO

378

"Thoughts Concerning Education": John Locke On Teaching Speech  

ERIC Educational Resources Information Center

Locke's suggestions for more effective speech instruction have gone largely unnoticed. Consequently, it is the purpose of this article to consider John Locke's criticisms, theory and specific methods of speech education. (Author)

Baird, John E.

1971-01-01

379

49 CFR 236.775 - Movement, switch-and-lock.  

Code of Federal Regulations, 2012 CFR

...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

2012-10-01

380

49 CFR 236.775 - Movement, switch-and-lock.  

Code of Federal Regulations, 2011 CFR

...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

2011-10-01

381

49 CFR 236.775 - Movement, switch-and-lock.  

Code of Federal Regulations, 2010 CFR

...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

2010-10-01

382

49 CFR 236.775 - Movement, switch-and-lock.  

Code of Federal Regulations, 2013 CFR

...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

2013-10-01

383

31. INTERIOR VIEW OF MAIN LOCK, WITH CENTRAL CONTROL STATION ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. INTERIOR VIEW OF MAIN LOCK, WITH CENTRAL CONTROL STATION IN RIGHT BACKGROUND, LOOKING SOUTHEAST, DOWNSTREAM - Upper Mississippi River 9-Foot Channel Project, Lock & Dam No. 5, Minneiska, Winona County, MN

384

14 CFR 27.679 - Control system locks.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Control system locks. 27.679 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 27.679 Control system locks. If there is a...

2011-01-01

385

14 CFR 23.679 - Control system locks.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Control system locks. 23.679 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 23.679 Control system locks. If there is a...

2011-01-01

386

14 CFR 23.679 - Control system locks.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Control system locks. 23.679 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 23.679 Control system locks. If there is a...

2010-01-01

387

14 CFR 29.679 - Control system locks.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Control system locks. 29.679 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 29.679 Control system locks. If there is a...

2010-01-01

388

14 CFR 29.679 - Control system locks.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Control system locks. 29.679 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 29.679 Control system locks. If there is a...

2011-01-01

389

14 CFR 25.679 - Control system gust locks.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Control system gust locks. 25.679...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 25.679 Control system gust locks. (a)...

2010-01-01

390

14 CFR 25.679 - Control system gust locks.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Control system gust locks. 25.679...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 25.679 Control system gust locks. (a)...

2011-01-01

391

14 CFR 27.679 - Control system locks.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Control system locks. 27.679 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...Design and Construction Control Systems § 27.679 Control system locks. If there is a...

2010-01-01

392

DOG HOUSE AT UPSTREAM LOCK GATE. ALSO SEEN AT LEFT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DOG HOUSE AT UPSTREAM LOCK GATE. ALSO SEEN AT LEFT IN PHOTO NO. IL-164-A-23. - Illinois Waterway, La Grange Lock and Dam, 3/4 mile south of Country 795N at Illinois River, Versailles, Brown County, IL

393

21 CFR 872.4600 - Intraoral ligature and wire lock.  

Code of Federal Regulations, 2013 CFR

...wire lock is a metal device intended to constrict fractured bone segments in the oral cavity. The bone segments are stabilized by wrapping the ligature (wire) around the fractured bone segments and locking the ends together. (b)...

2013-04-01

394

21 CFR 872.4600 - Intraoral ligature and wire lock.  

Code of Federal Regulations, 2010 CFR

...wire lock is a metal device intended to constrict fractured bone segments in the oral cavity. The bone segments are stabilized by wrapping the ligature (wire) around the fractured bone segments and locking the ends together. (b)...

2010-04-01

395

21 CFR 872.4600 - Intraoral ligature and wire lock.  

Code of Federal Regulations, 2012 CFR

...wire lock is a metal device intended to constrict fractured bone segments in the oral cavity. The bone segments are stabilized by wrapping the ligature (wire) around the fractured bone segments and locking the ends together. (b)...

2012-04-01

396

21 CFR 872.4600 - Intraoral ligature and wire lock.  

Code of Federal Regulations, 2011 CFR

...wire lock is a metal device intended to constrict fractured bone segments in the oral cavity. The bone segments are stabilized by wrapping the ligature (wire) around the fractured bone segments and locking the ends together. (b)...

2011-04-01

397

21 CFR 872.4600 - Intraoral ligature and wire lock.  

...wire lock is a metal device intended to constrict fractured bone segments in the oral cavity. The bone segments are stabilized by wrapping the ligature (wire) around the fractured bone segments and locking the ends together. (b)...

2014-04-01

398

27 CFR 19.282 - Breaking Government locks.  

Code of Federal Regulations, 2010 CFR

...TREASURY LIQUORS DISTILLED SPIRITS PLANTS Construction, Equipment and Security § 19.282 Breaking Government locks...locks may be removed, by the proprietor, or by police or firefighters. When such action is taken, the proprietor shall...

2010-04-01

399

49. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

49. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- DAM CONCRETE -- TYPICAL PIER ISOMETRIC. M-L 26(R) 40/1 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

400

50. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

50. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- DAM CONCRETE -- GENERAL ARRANGEMENT -- SECTION AND ELEVATIONS. M-L 26(R) 40/3 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

401

3. Down river view of lock and dam to southwest ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Down river view of lock and dam to southwest - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

402

Escaping lock-in: The case of the electric vehicle  

Microsoft Academic Search

The study addresses the issue of technological “lock-in” and the possibilities of escape from it. Earlier literature on technological lock-in has tended to focus on intraindustry sources of positive feedbacks that are at the core of the technological lock-in phenomena. This study draws attention to the importance of interindustry sources in contributing to technological lock-in. Several possible avenues of escape

Robin Cowan; Staffan Hultén

1996-01-01

403

Plate versus titanium elastic nail in treatment of displaced midshaft clavicle fractures  

PubMed Central

Background: With changing trends in treatment of displaced midshaft clavicle fractures (DMCF), plating remains the standard procedure for fixation. An attracting alternative method of fixation is the titanium elastic nailing (TEN). However, prospective randomized studies comparing the two methods of fixation are lacking. We assessed the effectiveness of minimally invasive antegrade TEN and plating technique for the treatment of DMCF. Materials and Methods: 80 unilateral displaced midclavicular fractures operated between October 2010 and May 2013 were included in study. This prospective comparative study was approved by the local ethical committee. Followups were at 2nd and 6th weeks and subsequently at 3, 6, 12, 18 and 24 months postoperatively. Primary outcome was measured by the Constant score, union rate and difference in clavicular length after fracture union. Secondary outcome was measured by operative time, intraoperative blood loss, wound size, cosmetic results and complications. Results: During analysis, we had 37 patients in the plate group and 34 patients in the TEN group. There was no significant difference in Constant scores between the two groups. However, faster fracture union, lesser operative time, lesser blood loss, easier implant removal and fewer complications were noted in the TEN group. Conclusion: The use of minimally invasive antegrade TEN for fixation of displaced midshaft clavicle fractures is recommended in view of faster fracture union, lesser morbidity, better cosmetic results, easier implant removal and fewer complications; although for comminuted fractures plating remains the procedure of choice.

Saha, Partha; Datta, Prasenjit; Ayan, Saankritya; Garg, Anant Kumar; Bandyopadhyay, Utpal; Kundu, Srikanta

2014-01-01

404

External Resource: Plate Tectonics  

NSDL National Science Digital Library

This Windows to the Universe interactive webpage connects students to the study and understanding of plate tectonics, the main force that shapes our planets surface. Topics: plate tectonics, lithosphere, subduction zones, faults, ridges.

1900-01-01

405

Plate Tectonics: Further Evidence  

NSDL National Science Digital Library

The representation depicts the spreading of the sea floor along the mid-ocean ridges. The resource generally describes the theory of plate tectonics, including the movement of plates with regard to one another.

406

The PLATES Project  

NSDL National Science Digital Library

This is the web page for PLATES, a program of research into plate tectonic and geologic reconstructions at the University of Texas at Austin Institute for Geophysics. The page contains links to a brief overview of plate tectonics and plate reconstructions using the PLATES Project's global plate reconstruction model, in addition to movies in the format of powerpoint animations which can be downloaded for later use. Models are shown on the evolution of the earth's oceans and the movement of the earth's tectonic plates from the Late Precambrian through the present day, reconstructing (i.e. "predicting") geological environments through geologic history. Maps of the following can be accessed: late Neo-Proterozoic, Silurian, early Jurassic, early Cretaceous, Cretaceous-Tertiary Boundary, and Oligocene. Movies are available on the following subjects: global plate motion, Jurassic to present day, opening of the Indian Ocean, and tectonic evolution of the Arctic region.

407

Technical note: How to spare the pronator quadratus during MIPO of distal radius fractures by using a mini-volar plate.  

PubMed

Few surgical approaches have been described that spare the pronator quadratus (PQ) during the treatment of distal radius fractures. The PQ supplies blood to the distal radial epiphysis, helps stabilize the distal radio-ulnar joint, and contributes 21% of pronation strength. Sparing the PQ should result in faster bone union and shorter recovery time. To achieve these goals, we currently use a minimally-invasive volar procedure using a specially-designed short plate (APTUS Wrist 2.5 XS, Medartis(©)). A 20mm incision is made over the fracture line as described by Henry. The PQ is dissected and then detached from the volar side of the radius. Forceps are used to slide the plate under the muscle. The screws are locked after carefully elevating the distal edge of the PQ. A preliminary study of distal radius fracture fixation by this technique was performed in 31 patients. The scar was 26mm in length and the duration of surgery was 34minutes on average. Patients wore a removable brace for 15 days, and passive wrist motion without loading was allowed during the first week. Functional recovery was faster than seen in previously published series. An average Quick DASH score of 10 was achieved by the 10th post-operative week. Although there are no contraindications to this technique, the quality of the reduction is more important than the scar size and desire to spare the PQ. Never hesitate to convert the incision to a classical Henry approach if technical difficulties arise. Our technique seems best suited to patients with high functional demands. It is currently being evaluated in a prospective series. PMID:24629441

Rey, P-B; Rochet, S; Loisel, F; Obert, L

2014-04-01

408

Uniaxial crushing of sandwich plates under air blast: Influence of mass distribution  

Microsoft Academic Search

Motivated by recent efforts to mitigate blast loading using energy-absorbing materials, this paper uses analytical and computational modeling to investigate the influence of mass distribution on the uniaxial crushing of cellular sandwich plates under air blast loading. In the analytical model, the cellular core is represented using a rigid, perfectly-plastic, locking idealization, as in previous studies, and the front and

Joseph A. Main; George A. Gazonas

2008-01-01

409

Great earthquakes and slab pull: interaction between seismic coupling and plate–slab coupling  

Microsoft Academic Search

Great earthquakes, the few largest earthquakes that account for most of the Earth’s seismic energy release, have occurred at only a few subduction zones around the world. Strong locking, or ‘seismic coupling’, of the interface between plates at certain subduction zones is often invoked to explain these great earthquakes. Although past studies have correlated strong seismic coupling with a compressional

Clinton P. Conrad; Susan Bilek; Carolina Lithgow-Bertelloni

2004-01-01

410

Functional outcome of Schatzker type V and VI tibial plateau fractures treated with dual plates  

PubMed Central

Background: Dual plate fixation in comminuted bicondylar tibial plateau fractures remains controversial. Open reduction and internal fixation, specifically through compromised soft tissues, has historically been associated with major wound complications. Alternate methods of treatment have been described, each with its own merits and demerits. We performed a retrospective study to evaluate the functional outcome of lateral and medial plate fixation of Schatzker type V and VI fractures through an anterolateral approach, and a medial minimally invasive approach or a posteromedial approach. Materials and Methods: We treated 46 tibial plateau fractures Schatzker type V and VI with lateral and medial plates through an anterolateral approach and a medial minimal invasive approach over an 8 years period. Six patients were lost to followup. Radiographs in two planes were taken in all cases. Immediate postoperative radiographs were assessed for quality of reduction and fixation. The functional outcome was evaluated according to the Oxford Knee Score criteria on followup. Results: Forty patients (33 men and 7 women) who completed the followup were included in the study. There were 20 Schatzker type V fractures and 20 Schatzker type VI fractures. The mean duration of followup was 4 years (range 1-8 years). All patients had a satisfactory articular reduction defined as ?2 mm step-off or gap as assessed on followup. All patients had a good coronal and sagittal plane alignment, and articular width as assessed on supine X-rays of the knee in the anteroposterior (AP) and lateral views. The functional outcome, as assessed by the Oxford Knee Score, was excellent in 30 patients and good in 10 patients. All patients returned to their pre-injury level of activity and employment. There were no instances of deep infection. Conclusions: Dual plate fixation of severe bicondylar tibial plateau fractures is an excellent treatment option as it provides rigid fixation and allows early knee mobilization. Careful soft tissue handling and employing minimal invasive techniques minimizes soft tissue complications. PMID:23682182

Prasad, G Thiruvengita; Kumar, T Suresh; Kumar, R Krishna; Murthy, Ganapathy K; Sundaram, Nandkumar

2013-01-01

411

Coupled Cavity Mode-locking Using Nonlinear Amplitude Modulators  

Microsoft Academic Search

A straightforward analysis of the process by which nonlinear amplitude modulators in coupled cavities can lead to enhanced mode-locking is presented. The application of the theory is demonstrated by using second-harmonic generation in an external cavity to mode-lock a Nd:YAG laser yielding 30 ps pulses in a Q-switched and mode-locked pulse train.

J. R. M. Barr; D. W. Hughes

1990-01-01

412

Transactional memory: architectural support for lock-free data structures  

Microsoft Academic Search

A shared data structure is lock-free if its operations do not require mutual exclusion. If one process is interrupted in the middle of an operation, other processes will not be prevented from operating on that object. In highly concurrent systems, lock-free data structures avoid common problems associated with conventional locking techniques, including priority inversion, convoying, and difficulty of avoiding deadlock.

Maurice Herlihy; J. Eliot B. Moss

1993-01-01

413

Locke on Education and the Rights of Parents  

ERIC Educational Resources Information Center

John Locke is often taken to be a staunch defender of parents' rights in the realm of education. In fact, Locke's pedagogical reasons for preferring home education to school education do not necessarily apply to similar choices in modern contexts. Locke's political argument for defining education as a duty of parents rather than the state does not…

Tuckness, Alex

2010-01-01

414

LOCK, DOG HOUSE, CONTROL STATION, DAM GATE, MANEUVER BOAT No. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LOCK, DOG HOUSE, CONTROL STATION, DAM GATE, MANEUVER BOAT No. 1, AND DAM. NOTE LOWER LOCK GATE IN FOREGROUND. LOOKING NORTH NORTHEAST. - Illinois Waterway, La Grange Lock and Dam, 3/4 mile south of Country 795N at Illinois River, Versailles, Brown County, IL

415

45. View along the length of the lock, from the ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

45. View along the length of the lock, from the east, looking southwest Oak shooks and carpet protected the resource from visitor traffic. A worker is 'watering down' the lock, to prevent damage from desiccation. - Wabash & Erie Canal, Lock No. 2, 8 miles east of Fort Wayne, adjacent to U.S. Route 24, New Haven, Allen County, IN

416

Locked modes and magnetic field errors in MST  

Microsoft Academic Search

In the MST reversed field pinch, magnetic oscillations become stationary (locked) in the lab frame as a result of a process involving interactions between the modes, sawteeth, and field errors. Several helical modes become phase locked to each other to form a rotating localized disturbance; the disturbance locks to an impulsive field error generated at a sawtooth crash; the error

A. F. Almagri; S. Assadi; S. C. Prager; J. S. Sarff; D. W. Kerst

1992-01-01

417

Locked Magnetic Islands in Toroidally Flow-Damped Tokamak Plasmas  

E-print Network

' & $ % Locked Magnetic Islands in Toroidally Flow-Damped Tokamak Plasmas Richard Fitzpatrick island chain forms at surface. Chain locked to resonant harmonic. Overlapping chains generate magnetic overcomes plasma flow, leading to sudden transition from helical current sheet to locked island chain

Fitzpatrick, Richard

418

Locked Magnetic Islands Chains in Toroidally Flow Damped Tokamak Plasmas  

E-print Network

Locked Magnetic Islands Chains in Toroidally Flow Damped Tokamak Plasmas R. Fitzpatrick and F USA E-mail: rfitzp@farside.ph.utexas.edu Abstract. The physics of a locked magnetic island chain flow causes a helical phase-shift to develop between the locked island chain and the resonant harmonic

Fitzpatrick, Richard

419

Planar view of interior of southeast side of lock wall, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Planar view of interior of southeast side of lock wall, upstream (westernmost) section of lock, propane tank in background, view towards southeast - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL

420

49 CFR 236.387 - Movable bridge locking.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Movable bridge locking. 236.387 Section 236.387 Transportation...Interlocking Inspection and Tests § 236.387 Movable bridge locking. Movable bridge locking shall be tested at least once a...

2012-10-01

421

49 CFR 236.387 - Movable bridge locking.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Movable bridge locking. 236.387 Section 236.387 Transportation...Interlocking Inspection and Tests § 236.387 Movable bridge locking. Movable bridge locking shall be tested at least once a...

2010-10-01

422

49 CFR 236.387 - Movable bridge locking.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Movable bridge locking. 236.387 Section 236.387 Transportation...Interlocking Inspection and Tests § 236.387 Movable bridge locking. Movable bridge locking shall be tested at least once a...

2011-10-01

423

49 CFR 236.387 - Movable bridge locking.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Movable bridge locking. 236.387 Section 236.387 Transportation...Interlocking Inspection and Tests § 236.387 Movable bridge locking. Movable bridge locking shall be tested at least once a...

2013-10-01

424

Effects of locking granularity in a database management system  

Microsoft Academic Search

Many database systems guarantee some form of integrity control upon multiple concurrent updates by some form of locking. Some “granule” of the database is chosen as the unit which is individually locked, and a lock management algorithm is used to ensure integrity. Using a simulation model, this paper explores the desired size of a granule. Under a wide variety of

Daniel R. Ries; Michael Stonebraker

1977-01-01

425

19. A photograph of the lock during preliminary archaeological work, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

19. A photograph of the lock during preliminary archaeological work, looking west along the path of the lock, showing the pool, portions of the east forebay and its sills. - Wabash & Erie Canal, Lock No. 2, 8 miles east of Fort Wayne, adjacent to U.S. Route 24, New Haven, Allen County, IN

426

Assessment of visual fixation in vegetative and minimally conscious states  

PubMed Central

Background Visual fixation plays a key role in the differentiation between vegetative state/unresponsive wakefulness (VS/UWS) syndrome and minimally conscious state (MCS). However, the use of different stimuli changes the frequency of visual fixation occured in patients, thereby possibly affecting the accuracy of the diagnosis. In order to establish a standardized assessment of visual fixation in patients in disorders of consciousness (DOC), we compared the frequency of visual fixation elicited by mirror,a ball and a light. Method Visual fixation was assessed in eighty-one post-comatose patients diagnosed with a MCS or VS/UWS. Occurrence of fixation to different stimuli was analysis used Chi-square testing. Result 40 (49%) out of the 81 patients showed fixation to visual stimuli. Among those, significantly more patients (39, 48%) had visual fixation elicited by mirror compared to a ball (23, 28%) and mirror compared to a light (20, 25%). Conclusion The use of a mirror during the assessment of visual fixation showed higher positive response rate, compared to other stimuli in eliciting a visual fixating response. Therefore, fixation elicited by a mirror can be a very sensitive and accurate test to differentiate the two disorders of consciousness. PMID:25027769

2014-01-01

427

Ultralong photon storage using an optical locking  

Microsoft Academic Search

A novel method of multi-bit quantum optical data storage is presented, where the storage time can be lengthened far beyond the spin phase-decay time in a reversible spin inhomogeneous system excited by consecutive resonant Raman optical data pulses. The ultralong storage time is obtained by an optical population locking mechanism of modified rephasing process. This gives potentials to quantum repeaters

Byoung S. Ham

2010-01-01

428

Overcoming grape growers’ pesticide lock-in  

Microsoft Academic Search

An evolutionary framework is used here to study the issue of pesticide reduction in vineyards. After analyzing grape growers’ pesticide lock-in we show that, although Integrated Pest Management (IPM) could reduce pesticide use significantly, the lack of specific implementation know-how hampers its diffusion. Consequently, once the features of technological change for IPM have been scrutinized, we adopt a case analysis

Adeline UGAGLIA; Bernard DEL’HOMME; Maryline FILIPPI

2011-01-01

429

School Choice Litigation after "Zelman" and "Locke"  

ERIC Educational Resources Information Center

In the past 2 years, the United States Supreme Court has decided two important cases that will bear directly on legislation and litigation involving school choice programs that provide financial aid to parents of children attending religious schools. Those cases are "Zelman v. Simmons-Harris" (2002) and "Locke v. Davey" (2004). The reasoning in…

Liekweg, John A.

2004-01-01

430

49 CFR 236.768 - Locking, time.  

Code of Federal Regulations, 2012 CFR

...caused to display its most restrictive aspect, the operation of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by that signal, and which prevents an aspect to proceed from being displayed for any...

2012-10-01

431

49 CFR 236.768 - Locking, time.  

Code of Federal Regulations, 2011 CFR

...caused to display its most restrictive aspect, the operation of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by that signal, and which prevents an aspect to proceed from being displayed for any...

2011-10-01

432

49 CFR 236.760 - Locking, approach.  

Code of Federal Regulations, 2010 CFR

...caused to display its most restrictive aspect, the movement of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by the signal, and which prevents an aspect to proceed from being displayed for any...

2010-10-01

433

49 CFR 236.760 - Locking, approach.  

Code of Federal Regulations, 2012 CFR

...caused to display its most restrictive aspect, the movement of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by the signal, and which prevents an aspect to proceed from being displayed for any...

2012-10-01

434

49 CFR 236.768 - Locking, time.  

Code of Federal Regulations, 2010 CFR

...caused to display its most restrictive aspect, the operation of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by that signal, and which prevents an aspect to proceed from being displayed for any...

2010-10-01

435

49 CFR 236.768 - Locking, time.  

Code of Federal Regulations, 2013 CFR

...caused to display its most restrictive aspect, the operation of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by that signal, and which prevents an aspect to proceed from being displayed for any...

2013-10-01

436

49 CFR 236.756 - Lock, bolt.  

Code of Federal Regulations, 2012 CFR

...lock so arranged that if a switch, derail or movable-point frog is not in the proper position for a train movement, the signal...will prevent a movement of the switch, derail or movable-point frog unless the signal displays its most restrictive...

2012-10-01

437

49 CFR 236.760 - Locking, approach.  

Code of Federal Regulations, 2011 CFR

...caused to display its most restrictive aspect, the movement of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by the signal, and which prevents an aspect to proceed from being displayed for any...

2011-10-01

438

49 CFR 236.756 - Lock, bolt.  

Code of Federal Regulations, 2010 CFR

...lock so arranged that if a switch, derail or movable-point frog is not in the proper position for a train movement, the signal...will prevent a movement of the switch, derail or movable-point frog unless the signal displays its most restrictive...

2010-10-01

439

49 CFR 236.756 - Lock, bolt.  

Code of Federal Regulations, 2011 CFR

...lock so arranged that if a switch, derail or movable-point frog is not in the proper position for a train movement, the signal...will prevent a movement of the switch, derail or movable-point frog unless the signal displays its most restrictive...

2011-10-01

440

49 CFR 236.756 - Lock, bolt.  

Code of Federal Regulations, 2013 CFR

...lock so arranged that if a switch, derail or movable-point frog is not in the proper position for a train movement, the signal...will prevent a movement of the switch, derail or movable-point frog unless the signal displays its most restrictive...

2013-10-01

441

49 CFR 236.760 - Locking, approach.  

Code of Federal Regulations, 2013 CFR

...caused to display its most restrictive aspect, the movement of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by the signal, and which prevents an aspect to proceed from being displayed for any...

2013-10-01

442

Obituary: Martha Locke Hazen, 1931-2006  

Microsoft Academic Search

Longtime Harvard Curator of Astronomical Photographs and AAVSO officer Martha Hazen passed away on 23 December 2006 at Hingham, Massachusetts, after a short illness due to acute myelogenous leukemia. One of four children of Harold Locke and Katherine (neé Salisbury) Hazen, Martha was born in Cambridge, Massachusetts, on 15 July 1931, and raised in the Town of Belmont, near Cambridge,

Thomas R. Williams; Lee Anne Willson

2007-01-01

443

Soliton mode locking by nonlinear Faraday rotation  

NASA Astrophysics Data System (ADS)

We propose nonlinear Faraday rotation as a mechanism for achieving stable polarization mode locking of a soliton laser. We analyze by perturbation theory and beam-propagation simulations the interplay between bandwidth-limited gain, gain dichroism, and linear and nonlinear Faraday rotation. .

Wabnitz, S.; Westin, E.; Frey, R.; Flytzanis, C.

1996-11-01

444

Error Fields and Locked Modes in NSTX  

NASA Astrophysics Data System (ADS)

The full set of six mid-plane external error field and RWM control coils has now been installed and utilized on NSTX. Locked-mode threshold experiments performed with these coils imply that a 1-2 Gauss resonant 2/1 intrinsic error field is present in NSTX. The in-vessel BR sensor array and direct measurements of PF coil shapes indicate the presence of an effective shift of the lower primary vertical field coil (PF5) relative to the nominal machine centerline. The error field magnitude predicted by this shifted PF5 model is consistent with the results from locked-mode experiments, but the toroidal phase angle differs by as much as 60 degrees. Thus far, the 2/1 resonant error field threshold for mode locking has been measured as a function of plasma density in NSTX, and locking as a function of q, BT, and elongation in LSN will be investigated in the near term. These studies will allow comparison to the threshold scaling derived from higher aspect ratio experiments. Plans for error field studies extended to higher-? plasmas will also be discussed. Simultaneously, magnetic field characteristics of external error field coils are investigated in the context of how a desired and pure (n=1, 3) compensating field can be produced. This preliminary study will continue on more efficient pre-programmed and dynamic control of error fields in NSTX.

Park, Jong-Kyu

2005-10-01

445

Filter for third order phase locked loops  

NASA Technical Reports Server (NTRS)

Filters for third-order phase-locked loops are used in receivers to acquire and track carrier signals, particularly signals subject to high doppler-rate changes in frequency. A loop filter with an open-loop transfer function and set of loop constants, setting the damping factor equal to unity are provided.

Crow, R. B.; Tausworthe, R. C. (inventors)

1973-01-01

446

Concentrated Sodium Citrate (23%) for Catheter Lock  

Microsoft Academic Search

For chronic central venous dialysis catheters, the standard method for maintaining catheter patency between treatments is to instill (lock) catheters with 5000 _ 10 000 units of heparin in each lumen. Sodium citrate (citrate) is an anticoagulant with intrinsic antibacterial activity (at 20% concentration or higher). Citrate has only transient anticoagulant effects if accidentally infused to the patient. Prior studies

Stephen R. Ash; Rita A. Mankus; James M. Sutton; Ruth E. Criswell; Carol C. Crull; Katherine A. Velasquez; Brian D. Smeltzer; Todd S. Ing

447

46 CFR 154.345 - Air locks.  

Code of Federal Regulations, 2012 CFR

...mechanically ventilated to make the pressure in the space greater than that in the air lock; and (2) Has a means...explosion-proof in the space when the pressure in the space falls to or below the pressure in the air...

2012-10-01

448

46 CFR 154.345 - Air locks.  

Code of Federal Regulations, 2010 CFR

...mechanically ventilated to make the pressure in the space greater than that in the air lock; and (2) Has a means...explosion-proof in the space when the pressure in the space falls to or below the pressure in the air...

2010-10-01

449

46 CFR 154.345 - Air locks.  

Code of Federal Regulations, 2011 CFR

...mechanically ventilated to make the pressure in the space greater than that in the air lock; and (2) Has a means...explosion-proof in the space when the pressure in the space falls to or below the pressure in the air...

2011-10-01

450

46 CFR 154.345 - Air locks.  

Code of Federal Regulations, 2013 CFR

...mechanically ventilated to make the pressure in the space greater than that in the air lock; and (2) Has a means...explosion-proof in the space when the pressure in the space falls to or below the pressure in the air...

2013-10-01

451

Magnetization of Color-Flavor Locked Matter  

E-print Network

We show that the magnetization in color-flavor locked superconductors can be so strong that homogeneous quark matter becomes metastable for a wide range of magnetic field values. This indicates that magnetic domains or other type of magnetic inhomogeneities can be present in the quark cores of magnetars.

Jorge Noronha; Igor A. Shovkovy

2007-10-12

452

Plate Tectonic Primer  

NSDL National Science Digital Library

This site gives an in-depth look at the theory of plate tectonics and how it works. The structure of the Earth is discussed, with brief rock type descriptions. The structure of the lithosphere, plate boundaries, interplate relationships, and types of plates are all covered in detail.

Fichter, Lynn

453

Optimal truss plates  

Microsoft Academic Search

Sandwich plates comprised of truss cores faced with either planar trusses or solid sheets are optimally designed for minimum weight subject to prescribed combinations of bending and transverse shear loads. Motivated by recent advances in manufacturing possibilities, attention is focussed on plates with truss elements and faces made from a single material. The optimized plates are compared with similarly optimized

Nathan Wicks; John W Hutchinson

2001-01-01

454

Angular shear plate  

Microsoft Academic Search

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

Mitchell C. Ruda; Alan W. Greynolds; Tilman W. Stuhlinger

2009-01-01

455

Earthquakes and Plate Tectonics  

NSDL National Science Digital Library

This article describes the theory of plate tectonics and its relation to earthquakes and seismic zones. Materials include an overview of plate tectonics, a description of Earth's crustal plates and their motions, and descriptions of the four types of seismic zones.

456