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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

Mechanical comparison of cortical screw fixation versus locking plate fixation in first metatarsal base osteotomy.  

PubMed

The oblique closing base wedge osteotomy has been used for surgical treatment of moderate to severe hallux valgus deformities with an intermetatarsal angle typically greater than 15°. Several postoperative complications have been identified that relate to failure of the fixation construct used to fixate the osteotomy, especially when that construct has been subjected to a vertical load. We performed a mechanical analysis comparing 2 constructs used to fixate oblique osteotomies of the first metatarsal using composite first metatarsals. An oblique base osteotomy was uniformly performed on 40 composite first metatarsals. Of the 40 specimens, 20 were fixated with a locking plate construct and 18 with a cortical screw construct, consisting of an anchor and compression screw (2 specimens from the latter group were excluded because of hinge fracture). Each specimen was loaded in a materials testing machine to measure the maximum load at construct failure when a vertical force was applied to the plantar aspect of the metatarsal head. The mean load to failure for the locking plate construct was significantly greater than the cortical screw construct (190.0 ± 70 N versus 110.3 ± 20.3 N, p < .001). Our study results have demonstrated that the locking plate construct was able to withstand a significantly greater vertical load before failure than was the 2-cortical screw construct in oblique osteotomies performed at the base of composite first metatarsals. PMID:24954919

Smith, Kevin; Lidtke, Roy H; Oliver, Noah G; Maker, Jared M

2014-01-01

3

Relative Stability of Conventional and Locked Plating Fixation in a Model of the Osteoporotic Femoral Diaphysis  

PubMed Central

Background This study investigated the stiffness and strength of bridge plating with uni-cortical and bi-cortical locking plate constructs relative to a conventional, non-locked construct in the osteoporotic femoral diaphysis. Methods Four bridge plating configurations were applied to a validated model of the osteoporotic femoral diaphysis. A non-locked conventional configuration served as baseline. Locked configurations included bi-cortical locked plating, uni-cortical locked plating and mix-mode locked plating, which combined uni and bi-cortical locking screws. For all configurations, an 11-hole plate was applied with 4.5-mm screws placed in the 1st, 3rd, and 5th plate hole. Five specimens of each configuration were dynamically loaded until failure in torsion, axial compression, and bending to determine construct stiffness, strength and failure modes. Findings In torsion and bending, locked plating constructs provided a significantly lower stiffness and strength than the conventional construct. The uni-cortical locked construct was 69% weaker (P<0.001) in torsion than the conventional construct, but its torsional strength improved 73% (P<0.001) by adding one bi-cortical locked screw. In axial compression, construct stiffness varied by less than 10% between the four groups. However, the bi-cortical and mixed-mode locked constructs provided a significant increase in strength of 12% (P = 0.001) and 11% (P=0.002), respectively, compared to the conventional construct. Interpretations Locked plating in the osteoporotic diaphysis can improve fixation strength under axial loading, but may reduce fixation strength in bending and torsion compared to conventional plating. Adding one bi-cortical locked screw to an otherwise uni-cortical construct is recommended to improve torsional strength. PMID:19070409

Fitzpatrick, Dan C.; Doornink, Josef; Madey, Steven M.; Bottlang, Michael

2009-01-01

4

Fixation of Traumatic Sternal Fractures Using SternaLock Plating System  

PubMed Central

A 43-year-old man experienced chest trauma due to a car accident. Compound sternal fractures with severe dislocation were seen on computed tomography of the chest. Using a SternaLock plating system with manual reduction, fixation of the sternal fracture was successfully performed. There were no complications related to the operation. PMID:24003417

Park, Jong Bin; Lee, Han Pil; Yoo, Dong Gon; Kim, Jong Wook

2013-01-01

5

Percutaneous fixation with Kirschner wires versus volar locking plate fixation in adults with dorsally displaced fracture of distal radius: randomised controlled trial  

PubMed Central

Objectives To compare the clinical effectiveness of Kirschner wire fixation with locking plate fixation for patients with a dorsally displaced fracture of the distal radius. Design A multicentre two arm parallel group assessor blind randomised controlled trial with 1:1 treatment allocation. Setting 18 trauma centres in the United Kingdom. Participants 461 adults with a dorsally displaced fracture of the distal radius within 3 cm of the radiocarpal joint that required surgical fixation. Patients were excluded if the surgeon thought that the surface of the wrist joint was so badly displaced it required open reduction. Interventions Kirschner wire fixation: wires are passed through the skin over the dorsal aspect of the distal radius and into the bone to hold the fracture in the correct anatomical position. Locking plate fixation: a locking plate is applied through an incision over the volar (palm) aspect of the wrist and secured to the bone with fixed angle locking screws. Main outcome measures Primary outcome measure: validated patient rated wrist evaluation (PRWE). This rates wrist function in two (equally weighted) sections concerning the patient’s experience of pain and disability to give a score out of 100. Secondary outcomes: disabilities of arm, shoulder, and hand (DASH) score, the EuroQol (EQ-5D), and complications related to the surgery. Results The baseline characteristics of the two groups were well balanced, and over 90% of patients completed follow-up. The wrist function of both groups of patients improved by 12 months. There was no clinically relevant difference in the patient rated wrist score at three, six, or 12 months (difference in favour of the plate group was ?1.3, 95% confidence interval ?4.5 to 1.8; P=0.40). Nor was there a clinically relevant difference in health related quality of life or the number of complications in each group. Conclusions Contrary to the existing literature, and against the rapidly increasing use of locking plate fixation, this trial found no difference in functional outcome in patients with dorsally displaced fractures of the distal radius treated with Kirschner wires or volar locking plates. Kirschner wire fixation, however, is cheaper and quicker to perform. Trial registration Current Controlled Trials ISCRTN 31379280. UKCRN 8956. PMID:25096595

Achten, Juul; Parsons, Nick R; Rangan, Amar; Griffin, Damian; Tubeuf, Sandy; Lamb, Sarah E

2014-01-01

6

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

7

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

8

The search for the ideal fixation of palatal fractures: innovative experience with a mini-locking plate.  

PubMed

Fractures of the palate have defied conventional management, such that malrotation and disinclination of the palatal shelves occur in a significant number of patients after repair. The fractured palatal shelves of eight patients were first prealigned. To do so, one or more 205-mm ratchet clamps and two intermaxillary fixation (IMF) posts were used. Rigid fixation was then achieved by applying a 2.0-mm mini-locking titanium plate (across the palatal vault) and by applying an adaptation miniplate across the fracture line as it exited the anterior surface of the maxilla. Screws were passed directly through the mucoperiosteum, to engage the palatal shelves and to lock the locking plate into position. Lacerations in the mucoperiosteum were neither used to aid fixation nor used as portals for dissection; incisions and mucoperiosteal flaps in the palatal vault were avoided. Adjuncts, such as intraoral splints, have not been used in cases to date, and early mobilization was allowed. Reconstitution of the craniomaxillofacial buttresses was added in patients with more extensive maxillary injury. The palatal appliance and screws remained rigidly in position in the roof of the mouth, much like an external fixator, until their removal 8 to 12 weeks after the repair. No patient suffered erosion of the mucoperiosteum or other major morbidity, other than a transient fistula of the soft palate. The palatoalveolar segments remained in proper realignment and inclination, and pretraumatic occlusal patterns and the width and depth of the lower face appear to have been restored with one exception. The latter suffered a subtle posterolateral open bite that was corrected orthodontically. Prealignment of fractured palatal shelves with one or more large ratchet clamps and two IMF posts provides several points of forced reduction of the palatal shelves, along the dental arch. In addition, stabilization with mini-locking plate(s) in the palatal vault and an adaptation plate across the fracture line, as it exits the maxilla, appear to have merit, based on this preliminary report (n?=?8). Outcomes seen on computed tomography and clinical examination during this 3-year experience have been favorable. PMID:22110785

Pollock, Richard A

2008-11-01

9

Polymer cable/grip-plate system with locking screws for stable fixation to promote healing of trochanteric osteotomies or fractures in revision total hip arthroplasty.  

PubMed

Multiple methods have been proposed to establish stable fixation to promote healing of trochanteric osteotomies or fractures in revision total hip arthroplasty (revTHA), from wiring techniques through cable-plate systems with or without supplemental locking screws. The purpose of this study is to report the clinical results of a single cable-plate system with locked screw fixation in revTHA. Between 2009 and 2012, 27 grip-plates (Supercable® System, Kinamed Inc., Camarillo, CA) were used in 26 patients in 27 revTHA procedures. Utilization was 12 1-hole (50 mm) grip-plates, 10 2-hole (135 mm) grip-plates, four 4-hole (190 mm) grip-plates, and one 6-hole (245 mm) grip-plate. There were 14 women and 12 men. Age averaged 63.2 years and BMI averaged 29.4 kg/m2. At average 2.5 year follow-up, grip-plate fixation was considered successful in 22 hips (81%) with five failures. Three failures consisted of 50 mm/short grip-plates used in one trochanteric slide, and two intraoperative trochanteric fractures during revTHA. The two additional failures were related to pre-revision trochanteric avulsion from bony necrosis of the proximal femur. An additional three grip-plates were removed electively for soft-tissue irritation and pain but with successful fixation and bony healing. Thus 70% of hips were free of reoperation related to the grip-plate. All other hips had successful fixation and the grip-plate was not symptomatic. In this study, the cable-grip system and isoelastic Supercables provided reliable fixation for adequate healing of difficult ETO and trochanteric fractures with an 81% rate of mechanical success with radiographic and clinical healing observed. PMID:25398403

Berend, Keith R; Willen, Jacob L; Morris, Michael J; Adams, Joanne B; Lombardi, Adolph V

2014-11-01

10

Distal tibia fractures: locked or non-locked plating?  

PubMed Central

Background and purpose Although plating is considered to be the treatment of choice in distal tibia fractures, controversies abound regarding the type of plating for optimal fixation. We conducted a systematic review to evaluate and compare the outcomes of locked plating and non-locked plating in treatment of distal tibia fractures. Patients and methods A systematic review was conducted using PubMed to identify articles on the outcomes of plating in distal tibia fractures that were published up to June 2012. We included English language articles involving a minimum of 10 adult cases with acute fractures treated using single-plate, minimally invasive techniques. Study-level binomial regression on the pooled data was conducted to determine the effect of locking status on different outcomes, adjusted for age, sex, and other independent variables. Results 27 studies met the inclusion criteria and were included in the final analysis of 764 cases (499 locking, 265 non-locking). Based on descriptive analysis only, delayed union was reported in 6% of cases with locked plating and in 4% of cases with non-locked plating. Non-union was reported in 2% of cases with locked plating and 3% of cases with non-locked plating. Comparing locked and non-locked plating, the odds ratio (OR) for reoperation was 0.13 (95% CI: 0.03–0.57) and for malalignment it was 0.10 (95% CI: 0.02–0.42). Both values were statistically significant. Interpretation This study showed that locked plating reduces the odds of reoperation and malalignment after treatment for acute distal tibia fracture. Future studies should accurately assess causality and the clinical and economic impact of these findings. PMID:24758325

Khalsa, Amrit S; Toossi, Nader; Tabb, Loni P; Amin, Nirav H; Donohue, Kenneth W; Cerynik, Douglas L

2014-01-01

11

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

12

Fracture fixation with two locking screws versus three non-locking screws  

PubMed Central

Objectives We aimed to further evaluate the biomechanical characteristics of two locking screws versus three standard bicortical screws in synthetic models of normal and osteoporotic bone. Methods Synthetic tubular bone models representing normal bone density and osteoporotic bone density were used. Artificial fracture gaps of 1 cm were created in each specimen before fixation with one of two constructs: 1) two locking screws using a five-hole locking compression plate (LCP) plate; or 2) three non-locking screws with a seven-hole LCP plate across each side of the fracture gap. The stiffness, maximum displacement, mode of failure and number of cycles to failure were recorded under progressive cyclic torsional and eccentric axial loading. Results Locking plates in normal bone survived 10% fewer cycles to failure during cyclic axial loading, but there was no significant difference in maximum displacement or failure load. Locking plates in osteoporotic bone showed less displacement (p = 0.02), but no significant difference in number of cycles to failure or failure load during cyclic axial loading (p = 0.46 and p = 0.25, respectively). Locking plates in normal bone had lower stiffness and torque during torsion testing (both p = 0.03), but there was no significant difference in rotation (angular displacement) (p = 0.84). Locking plates in osteoporotic bone showed lower torque and rotation (p = 0.008), but there was no significant difference in stiffness during torsion testing (p = 0.69). Conclusions The mechanical performance of locking plate constructs, using only two screws, is comparable to three non-locking screw constructs in osteoporotic bone. Normal bone loaded with either an axial or torsional moment showed slightly better performance with the non-locking construct. PMID:23610681

Grawe, B.; Le, T.; Williamson, S.; Archdeacon, A.; Zardiackas, L.

2012-01-01

13

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

14

A retrospective comparison of four plate constructs for first metatarsophalangeal joint fusion: static plate, static plate with lag screw, locked plate, and locked plate with lag screw.  

PubMed

The primary treatment for progressive first metatarsophalangeal (MTP) joint arthritis is arthrodesis. Multiple fixation types have been used to accomplish fusion including plating. There have been no published articles reporting the outcomes of these 4 plate and/or screw constructs. We present our experience with 138 first MTP joint fusions using these constructs. A retrospective comparison and radiographic chart review of 132 patients (138 feet) was performed to compare different constructs in regards to successful union and time to fusion. All operations were performed by 4 fellowship-trained foot and ankle surgeons. The radiographs were independently read by 2 authors not involved in the index procedures. Radiographic fusion was determined by bridging cortices across the joint line. The mean time to union (in days) and rate of fusion were static plate: 59, 95%, static plate with lag screw: 56, 86%, locked plate: 66, 92%, and locked plate with lag screw: 53, 96%. There was not a statistically significant difference between the groups in regards to patient age, time to weight bearing, time to fusion, or rate of fusion. We report on the results of fusion comparing 4 different plate and/or screw constructs for first MTP joint fusion. The data reveal no significant difference in time to fusion or rate of fusion between static and locked plates, with or without a lag screw. PMID:22459423

Hyer, Christopher F; Scott, Ryan T; Swiatek, Michael

2012-01-01

15

The strength of polyaxial locking interfaces of distal radius plates  

Microsoft Academic Search

BackgroundCurrently available polyaxial locking plates represent the consequent enhancement of fixed-angle, first-generation locking plates. In contrast to fixed-angle locking plates which are sufficiently investigated, the strength of the new polyaxial locking options has not yet been evaluated biomechanically. This study investigates the mechanical strength of single polyaxial interfaces of different volar radius plates.

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

2009-01-01

16

Flexor Tendon Problems after Volar Plate Fixation of Distal Radius Fractures  

Microsoft Academic Search

Four cases of flexor tendon problems which developed after volar plate fixation of distal radius fractures are presented.\\u000a All cases were associated with close contact of the screws or distal edge of the plate with the flexor tendons. Poor bone\\u000a stock or multiple bone fragments allowing loosening of the plate or non-locking screws cause the hardware to irritate the\\u000a flexor

Mehdi N. Adham; Margaret Porembski; Christine Adham

2009-01-01

17

Outcome comparison of Lisfranc injuries treated through dorsal plate fixation versus screw fixation  

PubMed Central

OBJECTIVE: The objective of this prospective study was to test whether the treatment of Lisfranc injuries with open reduction and dorsal plate fixation would have the same or better functional outcomes as treatment with standard trans-articular screw fixation. METHODS: Sixty patients with primarily isolated Lisfranc joint injury were treated by open reduction and dorsal plate fixation or standard screw fixation. The patients were followed on average for 31 months. Evaluation was performed with patients' chief complaint, clinical examination, radiography, and AOFAS Midfoot Scale. RESULTS: Thirty two patients were treated with open reduction and dorsal plate fixation, and twenty eight patients were treated with open reduction and screw fixation. After two years follow-up, the mean AOFAS Midfoot score was 83.1 points in the dorsal plate fixation group and 78.5 points in the screw fixation group (p<0.01). Of the dorsal plate fixation group, radiographic analysis revealed anatomic reduction in twenty-nine patients (90.6%, 29/32) and nonanatomic reduction in three patients. Of the screw fixation group, radiographic analysis revealed anatomic reduction in twenty-three patients and nonanatomic reduction in five patients (82.1%, 23/28). CONCLUSIONS: Open reduction and dorsal plate fixation for a dislocated Lisfranc injury do have better short and median term outcome and a lower reoperation rate than standard screw ORIF. In our experience, we recommend using dorsal plate in ORIF on dislocated Lisfranc injuries. Level of Evidence II, Prospective Comparative Study.

Hu, Sun-jun; Chang, Shi-min; Li, Xiao-hua; Yu, Guang-rong

2014-01-01

18

Minimally invasive metatarsal fracture repair with locking plates in a guanaco (Lama guanicoe).  

PubMed

An open grade I transverse diaphyseal fracture of the metatarsal bone in a 5-yr-old female guanaco (Lama guanicoe) was successfully stabilized with a locking plate system, which is a minimally invasive approach. A conical coupling screw-plate locking system with 3.0-mm-thick plates and 3.5-mm locking head screws was applied, after closed and indirect reduction of the bone segments, with an orthogonal configuration of the plates. The implants were protected postoperatively with a splinted bandage. The fracture healed without complications, the limb function was successfully recovered, and no major complications were observed at the 2-yr follow-up. The surgical procedure was carried out with biologic internal fixation supports and an adequate functional union within a time period similar to that reported for this species following other fracture fixation methods. This case highlights the potential benefit of combining minimally invasive plate osteosynthesis and plate-locking systems for fracture repair in camelids. PMID:25632682

Bertuglia, Andrea; Piga, Sara; Bullone, Michela; Piras, Lisa; von Degerfeld, Mitzy Mauthe

2014-12-01

19

Plate on Plate Technique of Minimally Invasive Percutaneous Plate Osteosynthesis in Distal Tibial Fractures, an Easy and Inexpensive Method of Fracture Fixation  

PubMed Central

Background: Plate on plate technique can lessen operative time and patient morbidity. Objectives: This study aimed to evaluate the outcomes of minimally invasive percutaneous plate osteosynthesis (MIPPO) using plate on plate technique of locking plate fixation for closed fractures of distal tibia in a prospective study. Patients and Methods: Twenty-five patients with distal tibial fractures were treated by MIPPO using locking plate by plate on plate technique. Preoperative variables including age of patient, mode of trauma, type of fracture and soft tissue status were recorded for each patient. Perioperative variables included surgical time and radiation exposure. Postoperative variables included wound status, time to union, return to activity and the American orthopaedic foot and ankle score (AOFAS). Results: All the fractures had united at one year. The average time to union was 16.8 weeks. There were two cases of superficial infection and two cases of deep infection, which required removal of hardware after the fracture was united. The average AO foot and ankle score was 83.6 in our study population. Conclusions: MIPPO using locking plate by plate on plate technique was a safe, effective, inexpensive and easily reproducible method for the treatment of distal tibial fractures in properly selected patients, which minimized operative time and soft tissue morbidity. PMID:25599064

Muzaffar, Nasir; Bhat, Rafiq; Yasin, Mohammad

2014-01-01

20

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

21

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

22

Construction and Biomechanical Properties of PolyAxial Self-Locking Anatomical Plate Based on the Geometry of Distal Tibia  

PubMed Central

In order to provide scientific and empirical evidence for the clinical application of the polyaxial self-locking anatomical plate, 80 human tibias from healthy adults were scanned by spiral CT and their three-dimensional images were reconstructed using the surface shaded display (SSD) method. Firstly, based on the geometric data of distal tibia, a polyaxial self-locking anatomical plate for distal tibia was designed and constructed. Biomechanical tests were then performed by applying axial loading, 4-point bending, and axial torsion loading on the fracture fixation models of fresh cadaver tibias. Our results showed that variation in twisting angles of lateral tibia surface was found in various segments of the distal tibia. The polyaxial self-locking anatomical plate was constructed based on the geometry of the distal tibia. Compared to the conventional anatomical locking plate, the polyaxial self-locking anatomical plate of the distal tibia provides a better fit to the geometry of the distal tibia of the domestic population, and the insertion angle of locking screws can be regulated up to 30°. Collectively, this study assesses the geometry of the distal tibia and provides variable locking screw trajectory to improve screw-plate stability through the design of a polyaxial self-locking anatomical plate. PMID:25025051

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

2014-01-01

23

Development of site-specific locking plates for acetabular fractures.  

PubMed

Site-specific locking plates have gained popularity for the treatment of fractures. However, the clinical use of a site-specific locking plate for acetabular fractures remains untested due to production limits. To design a universal site-specific locking plate for acetabular fractures, the 3-dimensional (3D) photographic records of 171 pelvises were retrospectively studied to generate a universal posterior innominate bone surface. Using 3D photographical processing software, the 3D coordinate system was reset according to bony landmarks and was scaled based on the acetabular diameter to allow a direct comparison between surfaces. The measured surface was separated into measurement units. At each measurement unit, the authors calculated the average z-axis values in all samples and obtained the 3D coordinate values of the point cloud that could be reconstructed into the universal surface. A plate was subsequently designed in 3D photographical processing software, and the orientation and distribution of locking screws was included. To manufacture a plate, the data were entered into Unigraphics NX version 6.0 software (Siemens PLM Software, Co, Ltd, Plano, Texas) and a CNC digital milling machine (FANUC Co, Ltd, Yamanashi, Japan). The resulting locking plate fit excellently with the reduced bone surface intraoperatively. Plate contouring was avoided intraoperatively. Universal 3.5-mm locking screws locked successfully into the plate, and their orientations were consistent with the design. No screw yielded to acetabular penetration. This method of designing a site-specific acetabular locking plate is practical, and the plates are suitable for clinical use. These site-specific locking plates may be an option for the treatment of acetabular fractures, particularly in elderly patients. PMID:23672911

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

2013-05-01

24

Results of titanium locking plate and stainless steel cerclage wire combination in femoral fractures  

PubMed Central

Background: Some in vitro studies warn combining different metals in orthopedic surgery. The aim of this study is to determine the impact of combining titanium and stainless steel on bone healing and the clinical course of patients undergoing internal fixation of femoral fractures. Materials and Methods: 69 patients with femoral fractures had polyaxial locking plate osteosynthesis. The locking plate was made of a titanium alloy. Two different cohorts were defined: (a) sole plating and (b) additional stainless steel cerclage wiring. Postoperative radiographs and clinical followup were performed at 6 weeks, 3 months and 12 months. Results: Cohorts A and B had 36 and 33 patients, respectively. Patient demographics and comorbidities were similar in both groups. In two cases in cohort A, surgical revision was necessary. No complication could be attributed to the combination of titanium and stainless steel. Conclusion: The combination of stainless steel cerclage wires and titanium plates does not compromise fracture healing or the postoperative clinical course. PMID:24133304

El-Zayat, Bilal Farouk; Ruchholtz, Steffen; Efe, Turgay; Paletta, Jürgen; Kreslo, Dimitri; Zettl, Ralph

2013-01-01

25

Reasons why dynamic compression plates are inferior to locking plates in osteoporotic bone: a finite element explanation.  

PubMed

While locking plate fixation is becoming increasingly popular for complex and osteoporotic fractures, for many indications compression plating remains the standard choice. This study compares the mechanical behaviour of the more recent locking compression plate (LCP) device, with the traditional dynamic compression plates (DCPs) in bone of varying quality using finite element modelling. The bone properties considered include orthotropy, inhomogeneity, cortical thinning and periosteal apposition associated with osteoporosis. The effect of preloads induced by compression plating was included in the models. Two different fracture scenarios were modelled: one with complete reduction and one with a fracture gap. The results show that the preload arising in DCPs results in large principal strains in the bone all around the perimeter of the screw hole, whereas for LCPs large principal strains occur primarily on the side of the screw proximal to the load. The strains within the bone produced by the two screw types are similar in healthy bone with a reduced fracture gap; however, the DCP produces much larger strains in osteoporotic bone. In the presence of a fracture gap, the DCP results in a considerably larger region with high tensile strains and a slightly smaller region with high compressive strains. These findings provide a biomechanical basis for the reported improved performance of locking plates in poorer bone quality. PMID:25473732

MacLeod, Alisdair R; Simpson, A Hamish R W; Pankaj, Pankaj

2015-12-01

26

Failure analysis of stainless steel femur fixation plate.  

PubMed

Failure analysis was performed to investigate the failure of the femur fixation plate which was previously fixed on the femur of a girl. Radiography, metallography, fractography and mechanical testing were conducted in this study. The results show that the failure was due to the formation of notches on the femur plate. These notches act as stress raisers from where the cracks start to propagate. Finally fracture occurred on the femur plate and subsequently, the plate failed. PMID:15468877

Hussain, P B; Mohammad, M

2004-05-01

27

Additive fiber-cerclages in proximal humeral fractures stabilized by locking plates  

PubMed Central

Background and purpose The effect of additive fiber-cerclages in proximal humeral fractures stabilized by locking plates on fracture stabilization and rotator cuff function is unclear. Here it was assessed in a human cadaver study. Methods 24 paired human shoulder specimens were harvested from median 77-year-old (range 66–85) female donors. An unstable 3-part fracture model with an intact rotator cuff was developed. 1 specimen of each pair received an additive fiber-cerclage of the rotator cuff after plate fixation, and the other one received a plate fixation without an additive fiber-cerclage. Force-controlled hydraulic cylinders were used to simulate physiological rotator cuff tension, while a robot-assisted shoulder simulator performed 4 relevant cases of load: (1) axial loading at 0°, (2) glenohumeral abduction at 60°, (3) internal rotation at 0° abduction, and (4) external rotation at 0° abduction, and imitated hanging arm weight during loading without affecting joint kinematics. A 3-dimensional real-time interfragmentary motion analysis was done in fracture gaps between the greater tuberosity and the head, as well as subcapital. The capacity of the rotator cuff to strain was analyzed with an optical system. Results Interfragmentary motion was similar between the groups with and without fiber-cerclages, in both fracture gaps and in any of the cases of load. Cerclages did not impair the capacity of the rotator cuff to strain. Interpretation Provided that unstable 3-part fractures are reduced and stabilized anatomically by a locking plate, additive fiber-cerclages do not reduce interfragmentary motion. Additive fiber-cerclages may be necessary in locking plate osteosyntheses of multiple-fractured greater tuberosities or lesser tuberosity fractures that cannot be fixed sufficiently by the plate. PMID:19562564

Hurschler, Christof; Rech, Louise; Vosshenrich, Rolf; Lill, Helmut

2009-01-01

28

Plate fixation or intramedullary fixation of humeral shaft fractures  

PubMed Central

Background The optimal approach to operative treatment of humeral shaft fractures remains debatable. Previously published trials have been limited in size and have been inconclusive regarding important patient outcome variables following treatment with either intramedullary nails or plates. We conducted a meta-analysis of available trials comparing treatment of humeral shaft fractures. Methods We performed a literature search from 1967 to November 2007 in the main medical search engines and selected 4 randomized trials that compared nails and plates in patients with humeral shaft fractures and that reported on complications due to surgery. We statistically pooled patient data using standard meta-analytic approaches. Our primary outcome was the total complication rate, comprised of all complications listed in the articles included. Secondary outcomes included non-union, infection, nerve palsy, and reoperation rate. Methodology was assessed using the CLEAR NPT. Results When pooling the data of the 4 trials (n = 203 patients), we did not find a statistically significant difference between implants in the rate of total complications, non-union, infection, nerve-palsy, or the need for reoperation. The studies included were small and had methodological limitations. Conclusions Our meta-analysis suggests stastistically insignificant differences between plates and nails in the treatment of humeral shaft fractures. Small sample sizes, study heterogeneity, and methodological limitations argue strongly for a definitive, large trial. We recommend that this trial should be a randomized controlled trial with appropriate allocation of patients and blinding of patients and care providers and outcome assessors, and that it should include patient-important outcomes. PMID:20170424

Poolman, Rudolf W; Nork, Sean E; Ponsen, Kees-Jan; Bhandari, Mohit

2010-01-01

29

TRACE METAL ANALYSIS FOLLOWING LOCKED VOLAR PLATING FOR UNSTABLE FRACTURES OF THE DISTAL RADIUS  

PubMed Central

An increase in the utilization of metallic devices for orthopaedic interventions from joint replacement to fracture fixation has raised concern over local metal ion release and possible systemic sequelae due to dissemination of these ions. Our purpose was to determine whether serum titanium concentrations were elevated in patients who had previously received a locked volar distal radius plate. Our hypothesis was that the simple presence of titanium alone in a relatively fixed implant was not enough to raise serum titanium levels. Twenty-two potential subjects who had received a volar locked distal radius plate were identified through review of a single surgeon's operative logs. Eleven met inclusion criteria. Serum titanium levels were measured in these subjects and compared to both current and historical control groups. We found no difference between controls and our study group with the exception of one control subject who is employed as a welder. This is in contrast to previous studies from our institution which found increases in titanium levels in hip and spine implants. We conclude that a locking titanium volar distal radius plate does not raise serum titanium levels in this population. PMID:21045978

Rylander, Lucas S; Milbrandt, Joseph C; Armington, Evan; Wilson, Marty; Olysav, David J

2010-01-01

30

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

31

Clinical outcomes of locked plating of distal femoral fractures in a retrospective cohort  

PubMed Central

Purpose Locked plating (LP) of distal femoral fractures has become very popular. Despite technique suggestions from anecdotal and some early reports, knowledge about risk factors for failure, nonunion (NU), and revision is limited. The purpose of this study was to analyze the complications and clinical outcomes of LP treatment for distal femoral fractures. Materials and methods From two trauma centers, 243 consecutive surgically treated distal femoral fractures (AO/OTA 33) were retrospectively identified. Of these, 111 fractures in 106 patients (53.8% female) underwent locked plate fixation. They had an average age of 54 years (range 18 to 95 years): 34.2% were obese, 18.9% were smokers, and 18.9% were diabetic. Open fractures were present in 40.5% with 79.5% Gustilo type III. Fixation constructs for plate length, working length, and screw concentration were delineated. Nonunion and/or infection, and implant failure were used as outcome complication variables. Outcome was based on surgical method and addressed according to Pritchett for reduction, range of motion, and pain. Results Eighty-three (74.8%) of the fractures healed after the index procedure. Twenty (18.0%) of the patients developed a NU. Four of 20 (20%) resulted in a recalcitrant NU. Length of comminution did not correlate to NU (p?=?0.180). Closed injuries had a higher tendency to heal after the index procedure than open injuries (p?=?0.057). Closed and minimally open (Gustilo/Anderson types I and II) fractures healed at a significantly higher rate after the index procedure compared to type III open fractures (80.0% versus 61.3%, p?=?0.041). Eleven fractures (9.9%) developed hardware failure. Fewer nonunions were found in the submuscular group (10.7%) compared to open reduction (32.0%) (p?=?0.023). Fractures above total knee arthroplasties had a significantly greater rate of failed hardware (p?=?0.040) and worse clinical outcome according to Pritchett (p?=?0.040). Loss of fixation was related to pain (F?=?3.19, p?=?0.046) and a tendency to worse outcome (F?=?2.43, p?=?0.071). No relationship was found between nonunion and working length. Conclusion Despite modern fixation techniques, distal femoral fractures often result in persistent disability and worse clinical outcomes. Soft tissue management seems to be important. Submuscular plate insertion reduced the nonunion rate. Preexisting total knee arthroplasty increased the risk of hardware failure. Further studies determining factors that improve outcome are warranted. PMID:24279475

2013-01-01

32

The effect of the combination of locking screws and non-locking screws on the torsional properties of a locking-plate construct.  

PubMed

Little is known about the torsional properties of bone-plate constructs when a combination of locking and non-locking screws have been used. Sixty cadaveric canine femurs were divided into three groups. In the first group, the plate was affixed using three non-locking screws. In the second group, only locking screws were used while a combination of one locking and two non-locking screws were used in the third group. All constructs were subjected to torsion until failure. Torque, angle of torsion, and work were all calculated at the maximum failure point, as well as at five degrees of plastic deformation, which was thought to be more representative of clinical failure. At the maximum failure point, the locking group had significantly higher torque, angle, and work values than the non-locking group. The combination group was intermediate to the two other groups, and significantly differed from the non-locking group in torque, and from the locking group in work. At five degrees of plastic deformation, the locking group required significantly higher torque and work than the non-locking group. The combination group required a significantly higher torque than the non-locking group. This study suggests that a construct composed of all locking screws will fail at a greater torque value, and sustain greater work to failure in torsion compared to a construct composed of all non-locking screws. The addition of a single locking screw to an otherwise non-locking construct will increase the torque at the offset failure point and may be of clinical value in constructs subjected to high torsional loads. PMID:19997676

Gordon, S; Moens, N M M; Runciman, J; Monteith, G

2010-01-01

33

Use of a locking reconstruction bone plate\\/screw system for mandibular surgery  

Microsoft Academic Search

Purpose: This study examined the use of a locking reconstruction bone plate\\/screw system for use in mandibular surgery.Patients and Methods: All patients treated with a locking reconstruction bone plate\\/screw system for fractures of the mandible or continuity defects in an 18-month period were prospectively studied. Ease of use of the locking plate\\/screw system, characteristics of the fractures\\/defects, and complications were

Alan S Herford; Edward Ellis

1998-01-01

34

Surgical treatment of comminuted mandibular fractures using a low-profile locking mandibular reconstruction plate system  

PubMed Central

Objective: The treatment of comminuted mandibular fractures is challenging due to the severity of associated injuries and the need for a careful diagnosis with adequate treatment planning. Recently, open reduction and stable internal fixation (OR-IF) with a load-bearing reconstruction plate have been advocated for reliable clinical outcomes with minimal complications. This clinical prospective study evaluated OR-IF in the surgical management of comminuted mandibular fractures with a new low-profile, thin, mandibular locking reconstruction plate. Materials and Methods: We prospectively assessed OR-IF of comminuted mandibular fractures with a low-profile locking mandibular reconstruction plate in 12 patients (nine men, three women; mean age 32.2 [range 16-71] years) between April 2010 and December 2011. The clinical characteristics and associated clinical parameters of patients were evaluated over a minimum follow-up period of 12 months. Results: Traffic accidents caused 50% of the fractures, followed by falls (25%). Four patients (33.3%) had associated midfacial maxillofacial fractures, while five patients had other mandibular fractures. Seven patients (58.3%) needed emergency surgery, mostly for airway management. Anatomical reduction of the comminuted segments re-established the mandibular skeleton in stable occlusion with rigid IF via extraoral (33.3%), intraoral (50%), or combined (16.7%) approaches. Immediate functional recovery was achieved. Sound bone healing was confirmed in all patients, with no complications such as malocclusion, surgical site infection, or malunion with a mean follow-up of 16.3 (range 12-24) months. Conclusions: OR-IF using a low-profile reconstruction plate system is a reliable treatment for comminuted mandibular fractures, enabling immediate functional recovery with good clinical results.

Kanno, Takahiro; Sukegawa, Shintaro; Nariai, Yoshiki; Tatsumi, Hiroto; Ishibashi, Hiroaki; Furuki, Yoshihiko; Sekine, Joji

2014-01-01

35

Technical tips: dualplate fixation technique for comminuted proximal humerus fractures.  

PubMed

The authors report dualplate fixation technique for providing stable fixation in comminuted proximal humerus fractures. This technique has been used for proximal humerus fractures with metaphyseal comminution and provides excellent anatomical reduction and neck shaft angle (NSA). The recently locking plate is clinically more widely used due to its small size, low rigidity, high elasticity, and biomechanical properties such as fixed initial angle and rotational stability. However, in severely comminuted complex type proximal metaphyseal humerus fractures, the use of locking plate alone does not provide stable fixation, leading to complications such as varus collapse, anterior-posterior angulation, screw cutout, nonunion, malunion, and metal failure. Therefore, a more robust and enhanced fixation method, the dual plating technique using the locking compression plate (Proximal Humeral Internal Locking System and Variable Angle Locking Compression Plate) was developed. PMID:24813097

Choi, Sungwook; Kang, Hyunseong; Bang, Hyeongsig

2014-08-01

36

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.

37

A Gustilo type IIIB open forearm fracture treated by negative pressure wound therapy and locking compression plates: a case report.  

PubMed

A 91-year-old female sustained injuries to her left forearm while walking across a crosswalk. X-rays showed left radial shaft and ulna shaft fractures, and the injury was a type IIIB open fracture. On the day of admission, irrigation and debridement of the open wound, and temporary fixation of the radius and ulna using an external fixator and a Kirschner wire were peformed. Six days after the surgery, we used negative pressure wound therapy (NPWT) using the V.A.C.ATS system for the open wound. Thirteen days after the first surgery, definitive fixation was performed by using locking compression plates, and full thickness skin grafting was undertaken for the open wound. NPWT is a treatment that accelerates the wound healing process through the delivery of continuous subatmospheric pressure within a closed environment. In our case, we could reduce the healing period of the soft tissue and could convert to the definitive fixation in a timely fashion. NPWT is thought to be a useful adjunct in the management of the soft tissues of open fractures. PMID:22171501

Takeuchi, Naohide; Mae, Takao; Hotokezaka, Shunsuke; Sasaki, Kosuke; Matsushita, Akinobu; Miake, Go; Kuchiishi, Rintaro; Noguchi, Yasuo

2011-10-01

38

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

E-print Network

, and maintain anatomical alignment. This facilitates the healing process, allowing the union of bone segments. The continuing search for improved internal fixation of fractures has led to a new technique that employs a bone plate with an intramedullary rod...

Keiser, Michael

2012-06-07

39

Finite element analysis (FEA) for the Point contact fixator screw drive, plate design, overcuts  

Microsoft Academic Search

Finite Element (FE) analysis was performed to ensure that the newly designed plate for internal fixation, the Point Contact Fixator (PC-Fix), was at least as strong as existing implants used for the same clinical indications. The smaller holes of the PC-Fix allow for some reduction of the cross-sectional dimensions in comparison to a comparable Dynamic Compression Plate. The cross section

S. J. Bresina; S. Tepic

1995-01-01

40

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

41

Rate of Improvement following Volar Plate Open Reduction and Internal Fixation of Distal Radius Fractures.  

PubMed

Purpose. To determine recovery timeline of unstable distal radius fractures treated by open reduction and internal fixation with a locking volar plate. Methods. Data was collected prospectively on a consecutive series of twenty-seven patients during routine post-operative visits at 2 and 6 weeks, and 3, 6, 12 and 24 months. Range of motion measures and grip strength for both wrists were recorded. Results. Greatest gains were made within the first 3 months after surgery. Supination and pronation returned more quickly than flexion or extension, with supination and pronation both at 92% of the uninjured wrist at 3 months. Only flexion improved significantly between 3 and 6 months. All wrist motions showed some improvement until 1 year. Grip strength returned to 94% of the uninjured wrist by 12 months. Conclusions. Range of motion improvement will be greatest between 2 weeks and 3 months, with improvement continuing until 12 months. Grip strength should return to near normal by one year. Function and pain will improve, but not return to normal by the end of 12 months. Clinical Relevance. These results provide the surgeon with information that can be shared with patients on the anticipated timeline for normal recovery of function and strength. PMID:21991417

Dillingham, Chris; Horodyski, Marybeth; Struk, Aimee M; Wright, Thomas

2011-01-01

42

Rate of Improvement following Volar Plate Open Reduction and Internal Fixation of Distal Radius Fractures  

PubMed Central

Purpose. To determine recovery timeline of unstable distal radius fractures treated by open reduction and internal fixation with a locking volar plate. Methods. Data was collected prospectively on a consecutive series of twenty-seven patients during routine post-operative visits at 2 and 6 weeks, and 3, 6, 12 and 24 months. Range of motion measures and grip strength for both wrists were recorded. Results. Greatest gains were made within the first 3 months after surgery. Supination and pronation returned more quickly than flexion or extension, with supination and pronation both at 92% of the uninjured wrist at 3 months. Only flexion improved significantly between 3 and 6 months. All wrist motions showed some improvement until 1 year. Grip strength returned to 94% of the uninjured wrist by 12 months. Conclusions. Range of motion improvement will be greatest between 2 weeks and 3 months, with improvement continuing until 12 months. Grip strength should return to near normal by one year. Function and pain will improve, but not return to normal by the end of 12 months. Clinical Relevance. These results provide the surgeon with information that can be shared with patients on the anticipated timeline for normal recovery of function and strength. PMID:21991417

Dillingham, Chris; Horodyski, MaryBeth; Struk, Aimee M.; Wright, Thomas

2011-01-01

43

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

44

Effect of cortical thickness and cancellous bone density on the holding strength of internal fixator screws  

Microsoft Academic Search

Internal fixators are a new class of implants designed to preserve the periosteal blood supply of the bone. In contrast to conventional plate fixation in which the screws have spherical heads and are loaded mainly by axial pullout forces, screws in internal fixators are “locked” within the plate and therefore subjected to axial as well as bending loads. In this

J. Seebeck; J. Goldhahn; H. Städele; P. Messmer; M. M. Morlock; E. Schneider

2004-01-01

45

Nonunion of the clavicle treated with plate fixation: a review of forty-seven consecutive cases.  

PubMed

Forty-seven consecutive patients underwent superior plating for clavicular nonunion between 1995 and 2005. This retrospective analysis was performed to assess the efficacy of plate fixation and the need for iliac crest bone grafting. Forty-three patients were treated with pelvic reconstruction plates and four with straight dynamic compression plates. Of the patients, 30 were treated with local bone graft only, 14 with demineralized bone matrix, and 3 with distant autogenous bone graft. Of the fractures, 93% united after a single operation. Of the patients, 69% returned the Disabilities of the Arm, Shoulder and Hand questionnaire. The mean Disabilities of the Arm, Shoulder and Hand score was 14.6 (range, 0-53). Plate prominence or sensitivity resulted in removal in 20% of cases. We believe that superiorly applied plate fixation is effective for the treatment of clavicular nonunion. Distant autogenous bone graft is not necessary in most cases to obtain union. PMID:18805024

Endrizzi, Donald P; White, Raymond R; Babikian, George M; Old, Andrew B

2008-01-01

46

Surgical Treatment of Calcaneal Fractures of Sanders Type II and III by a Minimally Invasive Technique Using a Locking Plate.  

PubMed

The aim of the present study was to investigate the outcomes of surgical treatment of calcaneal fractures of Sanders type II and III using a minimally invasive technique and a locking plate. We reviewed 33 feet in 33 consecutive patients with Sanders type II and III calcaneal fractures who had undergone a minimally invasive technique using percutaneous reduction and locking plates. All operations were performed by the same surgeons. The postoperative evaluation included radiographs, determination of restoration of Böhler's angle and Gissane's angle, and administration of the American Orthopaedic Foot and Ankle Society ankle-hind foot scale, Maryland Foot Score, and visual analog scale of pain. The mean visual analog scale score was 1.6 ± 1.4 when radiographic fracture healing was observed. The median functional score of the 33 patients (33 feet) reached 82 (interquartile range 80 to 99) at the last follow-up evaluation according to the American Orthopaedic Foot and Ankle Society ankle-hind foot scale and 89 (interquartile range 80 to 99) according to Maryland Foot Score. All cases achieved restoration of a normal Böhler's angle and Gissane's angle. Postoperative superficial infections occurred in 2 patients, subtalar arthritis developed in 2, and no soft tissue necrosis was observed. For Sanders type II and III fractures of the calcaneus bone, treatment with a minimally invasive technique combining percutaneous reduction and locking plate fixation provided satisfactory clinical results, with a lower incidence of complications. However, longer term studies with a larger sample size and more randomized controlled trials are required to define the superiority of our minimally invasive technique compared with conventional surgical treatment of calcaneal fractures. PMID:25441282

Cao, Liehu; Weng, Weizong; Song, Shaojun; Mao, Ningfang; Li, Haihang; Cai, Yuanqi; Zhou, Qirong; Su, Jiacan

2015-01-01

47

A comparative review of 266 mandibular fractures with internal fixation using rigid (AO/ASIF) plates or mini-plates.  

PubMed

This study compares the internal fixation of mandibular fractures using either rigid 2.7 mm AO/ASIF plates or mini-plates. In the rigid plate group, 88 fractures were fixed with 88 plates. In the mini-plate group, 116 fractures were fixed with 170 plates. All the cases were consecutive and were treated in two South Wales hospitals during a 3-year period from 1988 to 1991. The aetiology of injury, timing of surgery, site of fracture, antibiotic policy and demographic features were evenly distributed between the two groups but there was a higher incidence of females in the mini-plate group. Both plating systems were successful in restoring functional occlusion. Rigid plates avoided the use of postoperative elastics better than mini-plates but the difference was not significant. There was a significantly higher incidence (P = 0.013) of infection in the mini-plate (12.9%) compared with the rigid plate (2.3%) group but 7.9% of the rigid group developed facial nerve weakness. A significantly higher proportion of mini-plates needed to be removed (P = 0.00019). A better treatment outcome for angle and comminuted fractures was noted with rigid plates. PMID:8866068

Kuriakose, M A; Fardy, M; Sirikumara, M; Patton, D W; Sugar, A W

1996-08-01

48

Surgical repair of a severely comminuted maxillary fracture in a dog with a titanium locking plate system.  

PubMed

A four-year old male Labrador Retriever was admitted with head trauma after being hit by a car. The dog had sustained multiple nasal, maxillary, and frontal bone fractures that resulted in separation of the maxilla from the base of the skull. A severely comminuted left zygomatic arch fracture was also present. These fractures were all repaired using a point contact, locking titanium plate system, in a single procedure that resulted in excellent postoperative occlusion and immediate function. Healing was uneventful. Full function and excellent cosmetic appearance were evident 13 months after surgery. This case illustrates the ease of repair and the success of treatment of severely comminuted maxillofacial fractures by conforming to basic biomechanical principles taken directly from the human experience and successfully applied to the dog; these included multiple plate application along the buttresses and trusses of the facial skeleton. The plate fixation was applied to bridge the multiple fractures along the most appropriate lines of stress. The small size of the plates, and the ability to easily contour them to adapt to the bone surface in three-dimensions, allowed their placement in the most appropriate positions to achieve sufficient rigidity and lead to uncomplicated healing without any postoperative complications. PMID:25088587

Illukka, E; Boudrieau, R J

2014-01-01

49

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

50

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.

51

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

52

Fixin internal fixator: concept and technique.  

PubMed

This report describes the Fixin internal fixator system(a), a fracture fixation device characterised by a locking conical coupling between screw heads and titanium alloy inserts that are screwed into a stainless steel plate construct. The mechanical principles, implants, instruments and surgical technique are discussed. PMID:20585717

Petazzoni, M; Urizzi, A; Verdonck, B; Jaeger, G

2010-01-01

53

Osteosynthesis of distal radial fractures with a volar locking screw plate system  

Microsoft Academic Search

We developed a locking screw plate system for the stabilisation of distal radial fractures, which can be inserted through a standard volar approach and in which the locking mechanism allows early post-operative mobilisation. Forty-nine patients with 50 fractures underwent surgical treatment; 66% were type C fractures. The mean follow-up was 26 months. According to the scores of Gartland and Werley

H. Drobetz; E. Kutscha-Lissberg

2003-01-01

54

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

55

Biomechanical effects of plate area and locking screw on medial open tibial osteotomy.  

PubMed

Medial open high tibial osteotomy (HTO) has been used to treat osteoarthritis of the medial compartment of the knee. However, weaker plate strength, unstable plate/screw junction and improper surgery technique are highly related to the HTO outcomes. Two ?-shape plates were designed and eight variations (two supporting area ×  four locking stiffness) were compared by finite-element method. The computed tomography-based tibia was reconstructed and both wedge micromotion and implant stresses were chosen as the comparison indices. The construct was subjected to surgical and physiological loads. The medial-posterior region is the most loaded region and the load through the posterior leg is about four times that through the anterior leg. This indicates that the two-leg design can form a force-couple mechanism to effectively reduce the implant stresses. The use of locking screws significantly decrease the screw and hole stresses. However, the extending plate reduces the stresses of screws and holes above the wedge but makes the distal screws and holes much stressed. Wedge micromotion is affected by extending plate rather than locking screw. Three factors contribute to effective stabilisation of unstable HTO wedge: (1) intimate tibia-plate contact at medial-posterior regions, (2) sufficient rigidity at plate-screw junctions and (3) effective moment-balancing design at distal tibia-plate interfaces. PMID:24617553

Luo, Chu-An; Lin, Shang-Chih; Hwa, Su-Yang; Chen, Chun-Ming; Tseng, Ching-Shiow

2015-09-01

56

Biomechanical Properties of a New Anatomical Locking Metal Block Plate for Opening Wedge High Tibial Osteotomy: Uniplane Osteotomy  

PubMed Central

Purpose The purpose of this study was to evaluate the biomechanical properties of a new anatomical locking metal block plate by comparing the initial biomechanical stability of three different fixation constructs for open wedge high tibial osteotomy (HTO). Materials and Methods Sawbones composite tibiae were used to make a 10-mm opening osteotomy model with uniplane technique. The osteotomy was secured with three different types of plates: Group I, new osteotomy plate without a metal block (n=5); Group II, new osteotomy plate with a 10-mm metal block (n=5); and Group III, two short metal block plates (n=5). Single load to failure test and staircase load-controlled cyclical failure test were performed. In the single load to failure test, the yield load, maximum failure load, and the displacement of the osteotomy gap were measured. In the staircase cyclical load to failure test, the total number of cycles to failure was recorded. Failure modes were observed during both single and cyclic load tests. Results Group II showed the highest yield and ultimate loads (1829±319 N, 3493±1250 N) compared to Group I (1512±157 N, 2422±769 N) and Group III (1369±378 N, 2157±210 N, p<0.05). The displacement of the opening gap in Group II (0.34±0.35 mm) was significantly lesser than the other groups (p<0.05). In the staircase cyclical load to failure test, the total number of cycles to failure was 12,860 at 950 N in Group III, 20,280 at 1,140 N in Group I, and 42,816 at 1,330 N in Group II (p<0.05). All the specimens showed complete fracture of the intact lateral sawbones area and slight displacement of the distal fragment of the specimens in the single load to test. None of the specimens showed deformed or broken screws and plates during the single load to test. During the fatigue test with staircase cyclic loading, no fracture of the lateral sawbones area was observed. Conclusions This study demonstrated that the new anatomical locking metal block plate could provide sufficient primary stability for open wedge HTO. The addition of a metal block to this new plate can increase the stability of the osteotomy compared to the one without a metal block. PMID:25229045

Han, Seung-Beom; Bae, Ji-Hoon; Lee, Sung-Jae; Jung, Tae-Gon; Kim, Kang-Hee; Kwon, Jae Ho

2014-01-01

57

Comparative biomechanical study of the Ligament Plate® and other fixation devices in ACL reconstruction  

PubMed Central

The objective of this study was to evaluate and compare the biomechanical properties of the Ligament Plate® with other femoral fixation devices. The Ligament Plate® and three different femoral fixation devices were used in fixation of 60 porcine femora and harvested porcine tendons. For each fixation device, a porcine graft-tendon complex was used for the simple load-to-failure test and the load-to-failure test after a cyclic loading test, and the maximal failure load was measured. The amount of graft elongation and failure pattern after the cyclic loading test and load-to-failure test were evaluated. In the BioScrew® group, the mean maximal failure load in the load-to-failure test and load-to-failure test after a cyclic loading test was significantly lower and significant graft elongation was noted. There were no significant differences between the other groups. The Ligament Plate® provided adequate initial fixation power suitable for early rehabilitation. PMID:18923833

Sim, Jae Ang; Kwak, Ji Hoon; Yang, Sang Hoon

2008-01-01

58

Distal Femoral Osteotomy in Genovalgum: Internal Fixation with Blade Plate Versus Casting  

PubMed Central

Background: To compare the results of two different ways of distal femoral osteotomy stabilization in patients suffering from genuvalgum: internal fixation with plate, and casting. Methods: In a non-randomized prospective study, after distal femoral osteotomy with the zigzag method, patients were divided into two groups: long leg casting, and internal fixation with blade plate. For all patients, questionnaires were filled to obtain data. Information such as range of motion, tibiofemoral anatomical angle and complications were recorded. Results: 38 knees with valgus deformity underwent distal femoral supracondylar osteotomy. (8 with plaster cast and 30 with internal fixation using a blade plate). Preoperative range of motion was 129±6° and six months later it was 120±14°. The preoperative tibiofemoral angle was 32±6°; postoperative tibiofemoral angles were 3±3°, 6±2°, and 7±3° just after operation, six months, and two years later, respectively. Although this angle was greater among the group stabilized with a cast, this difference was not statistically significant. In postoperative complications, over-correction was found in five, recorvatom deformity in one, knee stiffness in three and superficial wound infection was recorded in three knees. Conclusions: There is no prominent difference in final range of motion and alignment whether fixation is done with casting or internal fixation. However, the complication rate seems higher in the casting method.

Makhmalbaf, Hadi; Moradi, Ali; Ganji, Saeid

2014-01-01

59

Lamina replacement with titanium plate fixation improves spinal stability after total lumbar laminectomy.  

PubMed

Biomechanical experiments and strain analyses were performed to investigate the effects of lamina replacement surgery for intraspinal lesions on postoperative spinal stability. Eight specimens of thoracic and lumbar vertebrae (T12-L4) were collected from adult cadavers. Stepwise lumbar total laminectomy, and laminoplasty with lamina reduction and replacement was undertaken in combination with titanium-plate fixation to simulate the surgical setting. The effects of thoracic and lumbar vertebral strain, displacement, and rigidity on spinal stability were measured following both single and multiple segment laminectomy. Significant differences in mechanical indices of stability were seen between stepwise laminectomy of lumbar vertebrae and normal specimens (p < 0.05), between lamina replacement in combination with titanium-plate fixation and laminectomy (p < 0.05), and between single- and multiple-segment laminectomy (p < 0.05). Differences between laminoplasty with lamina replacement in combination with titanium-plate fixation and normal specimens need to be examined for further study. Lumbar laminectomy followed by reduction and replacement, in combination with titanium-plate fixation, was shown to be beneficial in terms of preserving spinal stability and maintaining biomechanical function and spinal loading capability. PMID:25169703

Nong, Luming; Zhou, Dong; Xu, Nanwei; Du, Rui; Jiang, Xijia

2015-12-01

60

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

61

Biomechanics of bone-fracture fixation by stiffness-graded plates in comparison with stainless-steel plates  

PubMed Central

Background In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress-shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress-shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress-shielding of the layer of the bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. Method In order to address this problem, we propose to use stiffness-graded plates. Accordingly, we have computed (by finite-element analysis) the stress distribution in the fractured bone fixed by composite plates, whose stiffness is graded both longitudinally and transversely. Results It can be seen that the stiffness-graded composite-plates cause less stress-shielding (as an example: at 50% of the healing stage, stress at the fracture interface is compressive in nature i.e. 0.002 GPa for stainless steel plate whereas stiffness graded plates provides tensile stress of 0.002 GPa. This means that stiffness graded plate is allowing the 50% healed bone to participate in loadings). Stiffness-graded plates are more flexible, and hence permit more bending of the fractured bone. This results in higher compressive stresses induced at the fractured faces accelerate bone-healing. On the other hand, away from the fracture interface the reduced stiffness and elastic modulus of the plate causes the neutral axis of the composite structure to be lowered into the bone resulting in the higher tensile stress in the bone-layer underneath the plate, wherein is conducive to the bone preserving its tensile strength. Conclusion Stiffness graded plates (with in-built variable stiffness) are deemed to offer less stress-shielding to the bone, providing higher compressive stress at the fractured interface (to induce accelerated healing) as well as higher tensile stress in the intact portion of the bone (to prevent bone remodeling and osteoporosis). PMID:16045807

Ganesh, VK; Ramakrishna, K; Ghista, Dhanjoo N

2005-01-01

62

Fixation of Vancouver B1 peri-prosthetic fractures by broad metal plates without the application of strut allografts.  

PubMed

The use of allograft struts and cerclage wire, possibly augmented by plate fixation, for the treatment of Vancouver type-B1 peri-prosthetic fractures around a total hip replacement has been strongly advocated. We examined our results using plate fixation without allograft struts and compared them with the results of the use of struts alone or when combined with plate fixation. Of 20 consecutive patients with type-B1 fractures treated by open reduction and plate fixation, 19 were available for follow-up. The fractures healed in 18 patients with a mean time to weight-bearing of ten weeks (4 to 19). There were no cases of infection or malunion. Nonunion occurred in one patient and required a second plate fixation to achieve union. Safe, cost-effective treatment of Vancouver type-B1 fractures can be performed by plate fixation without the addition of cortical struts. This procedure may allow earlier weight-bearing than allograft strut fixation alone. PMID:17075084

Old, A B; McGrory, B J; White, R R; Babikian, G M

2006-11-01

63

Further development of titanium miniplate fixation for mandibular fractures. Experience gained and questions raised from a prospective clinical pilot study with 2.0 mm fixation plates.  

PubMed

Miniplate systems are often used instead of more rigid systems for the treatment of mandibular fractures. While the most stable fixation method for all mandibular fractures is the 2.7 mm plate, most fracture sites and types are eminently suitable for miniplate fixation via an intraoral approach. However, the relatively low stability of the miniplate systems compared with rigid plate systems limits the indications for their use in mandibular fracture treatment, especially when immediate postoperative function is desired. A more rigid miniplate which provides increased stability was studied. The results of a preliminary study and a clinical trial of a 2.0 mm titanium miniplate system are presented in this paper. The therapeutic consequences of the lesser stability afforded by small plate systems are discussed. Indications for miniplate fixation without additional immobilization are reviewed. PMID:1401098

Schmelzeisen, R; McIff, T; Rahn, B

1992-01-01

64

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

65

Posterior acetabular column and quadrilateral plate fractures: fixation with tension band principles.  

PubMed

Acetabular fractures can be classified into 5 simple and 5 associated fracture patterns. A significant amount of variation and complexity exists in these fractures patterns. Fractures of the posterior wall are the most common acetabular fractures. Comminution of the quadrilateral plate adds to fracture instability, and more rigid and stable internal fixation is mandatory. The goal of this study was to assess the results of reconstruction of comminuted posterior wall fractures of the acetabulum associated with quadrilateral plate fractures using the tension band technique. Twelve patients (9 men and 3 women) were included in the study. Mean patient age was 38.6 years (range, 24-47 years). Minimum follow-up was more than 2 years postoperatively. Reconstruction of the fracture included anatomic reduction of the fracture and fixation with a buttress plate for the posterior column and a prebent one-third tubular plate for the quadrilateral plate fracture. Clinical results were excellent in 58% of patients and good in 17% of patients. Radiologic results were excellent in 50% of patients and good in 17% of patients. Radiologically, based on the fracture gap postoperatively, 8 (66%) patients showed anatomic reduction, 2 (17%) showed good reduction, and 2 (17%) showed poor reduction. The study confirms that this method of reconstruction facilitates accurate and firm reduction of displaced posterior wall fractures of the acetabulum. PMID:23823039

Aly, Tarek A; Hamed, Hany

2013-07-01

66

An analysis of tendon injuries accompanying distal radius fractures using volar locking plates.  

PubMed

We examined 6 cases of tendon injuries that accompanied distal radius fractures using volar locking plate between April 2006 and March 2012. Male: one case, female: five cases, average age 57.0 (33~70) years old. The fracture type was A2 in one case, A3 in four cases, and C2 in one case by AO classification. The average period for operation waiting was 2.7 days. We analyzed the time of occurrence of tendon rupture (extensor pollicis longus (EPL)?flexor pollicis longus (FPL)), the existence or not of screw prominence and dorsal roof fragment, and the positioning of the plate setting. The tendon ruptures were EPL in four cases, and FPL in two cases. The average period of rupture occurrence was 86.8 (1~182) days. In four EPL tendon ruptures we recognized one marked screw prominence (16.7%), and two dorsal roof fragments (50%), both showing widespread displacement. Moreover, we recognized the malposition of the plate setting in the two cases of FPL tendon rupture (100%). The incidence of tendon ruptures accompanying distal radius fractures using volar locking plates was not low at all, therefore we should more pay attention to the prevention of this occurrence. PMID:25501757

Zenke, Yukichi; Oshige, Toshihisa; Menuki, Kunitaka; Yamanaka, Yoshiaki; Murai, Teppei; Furukawa, Kayoko; Sakai, Akinori

2014-12-01

67

Analysis of a Lane-plate internal fixation device after 64 years in vivo.  

PubMed

A patient presented for an above-knee amputation 64 years after successful internal fixation of a femoral fracture with a Lane plate. Chemical analyses of the plate and corrosion products were done using atomic absorption spectrophotometry, x-ray energy spectroscopy and x-ray diffraction. Mechanical properties of the fixation devices were measured using Rockwell-type instruments and metallographic analyses were also performed. In addition, pathologic and radiologic investigations of the underlying bone were carried out. Results disclosed that extensive corrosion had weakened the plate by 50%. The metallosis of the surrounding soft tissues and abnormal morphologic features of underlying bone were analysed. No appreciable cellular inflammatory or dysplastic reaction of adjacent tissues was identified. The underlying bone showed a persistent lack of mature compact bone and no evidence of remodelling. The products of corrosion were mainly ferrous carbonate and some ferrous chloride. The mechanism of the corrosion was the formation of a galvanic cell between the iron carbide and surrounding iron, with dissolution of the iron and formation of the corrosion products. PMID:3664408

McAuley, J P; Gow, K V; Covert, A; McDermott, A G; Yabsley, R H

1987-11-01

68

Internal fixation of nonunions.  

PubMed

We review the two major types of internal fixation of nonunions (plating and intramedullary nailing), and analyze nonunions in different locations (upper and lower extremities). Depending on the type and the location of the nonunion, plating or intramedullary nailing may be selected. Both have advantages and disadvantages: plating requires opening the nonunion site, which entails some damage to the soft tissues, and carries with it a risk of secondary infection. With plating, it often is impossible to do a real decortication because the periosteum may be thin and poorly adherent to bone, and the quality of bone may prove insufficient to achieve good fixation with most of the screws. However, plating still is used in metaphyseal nonunions, and angular deformities may be corrected by applying a plate under tension on the convex side of the bone. Nailing can be done percutaneously in numerous cases; it has a smaller risk of infection but, should an infection be present, there is a risk that it may spread over the entire length of the medullary cavity. Nailing stimulates bone formation, but noninterlocking nails may cause shortening and rotational instability of the nonunion site. Plate fixation was popular approximately 20 years ago, but now has been largely superseded by intramedullary nailing except for proximal or distal nonunions. Dynamic locking nails are preferable. Successful treatment of nonunions often requires several consecutive surgical actions and a global strategy must be established from the beginning, taking care not to interfere with the successive steps. PMID:15021126

Rodriguez-Merchan, E Carlos; Gomez-Castresana, Fernando

2004-02-01

69

Medial Calcar Support and Radiographic Outcomes of Plate Fixation for Proximal Humeral Fractures  

PubMed Central

Plate fixation remains one of the most popular surgical procedures for treating proximal humeral fractures (PHFx); however, substantial rates of complications have been reported in the literature. The objectives of the study were to examine how medial calcar support (MCS) affects the radiographic outcomes and to determine the prognostic factors predicting treatment failure. We performed a retrospective cohort study of 89 adult patients who had PHFx and were treated with plate fixation at our institution in 2007–2011. The enrolled patients were separated into two groups according to disruption of medial calcar. Our results revealed an increased rate of poor radiographic outcomes in patients with disrupted medial calcar. Osteonecrosis of the humeral head and redisplacement were the two radiographic outcomes which had a positive causality with disruption of medial calcar (P = 0.008 and 0.050, resp.). Deficient medial calcar, inadequate reduction, diabetes mellitus, chronic kidney disease, and chronic liver disease were all significant predictors for the development of osteonecrosis in patients after PHFx surgery. Inadequate reduction was also a predictor for redisplacement. We confirmed that the restoration of medial calcar as well as comorbid conditions plays key roles in treatment of patients having PHFx with disrupted medial calcar.

Lin, Shih-Jie; Tsai, Yao-Hung; Yang, Tien-Yu; Shen, Shih-Hsun; Huang, Kuo-Chin; Lee, Mel S.

2015-01-01

70

Distal ulna hook plate fixation for unstable distal ulna fracture associated with distal radius fracture.  

PubMed

The significance of distal ulna fractures is often undermined, which can result in inadequate treatment compared with fractures of the radius, the ulna's larger counterpart. However, little guidance exists in the current literature on how to manage distal ulna head or neck fractures and intra-articular ulna head fractures. Therefore, the purpose of this retrospective study was to evaluate the outcomes of distal ulna hook plate fixation for the treatment of an unstable distal ulna fracture associated with a distal radius fracture. Twenty-five patients with unstable distal ulna fractures who underwent stable fixation for an associated distal radius fracture were included in the study. All patients achieved satisfactory reduction and bony union. Average final motion was as follows: wrist flexion, 72° (range, 60°-85°); extension, 69° (range, 65°-80°); pronation, 77° (range, 55°-95°); supination, 82° (range, 65°-90°); ulnar deviation, 35° (range, 15°-50°); and radial deviation, 24° (range, 10°-40°). Average postoperative grip strength was 28 kg (range, 22-30 kg) and was 91% (range, 71%-100%) in the cases in which the dominant hand was injured and 80% (range, 65%-100%) in the cases in which the nondominant hand was injured. Average postoperative modified Mayo wrist score and Disabilities of the Arm, Shoulder and Hand score was 87 points (range, 65-100 points) and 14 points (range, 0-54 points), respectively. Chronic instability of the distal radioulnar joint was not encountered in any patient. Thus, the study demonstrated that distal ulna hook plate fixation for the treatment of unstable distal ulna fractures can achieve healing with good alignment, satisfactory function, and minimal transient morbidity. PMID:22955402

Lee, Sang Ki; Kim, Kap Jung; Park, Ju Sang; Choy, Won Sik

2012-09-01

71

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

72

The Use of 2.4-mm Locking Plate System in Treating Comminuted Mandibular Fracture by Firearm  

PubMed Central

Maxillofacial trauma caused by firearms has considerably increased, in which the mandibular body is the site of highest incidence of firearm projectiles. In these cases, the use of titanium plates and screws allows the early restoration of form and function of the mandible with stable and predictable results. Recently, conventional plates have been extensively used to treat comminuted mandibular fractures. Nevertheless, the conventional system presents several limitations such as screw compression against the bone interface and the necessity of precise fit of plate to the bone. To overcome such drawbacks, the locking plates have emerged. The present clinical case reported the operative treatment of mandibular fracture caused by firearm projectiles with the use of locking plate. The indications, advantages, and disadvantages of this system are presented. PMID:23730424

Pereira, Cassiano Costa Silva; Letícia dos Santos, Pâmela; Jardim, Ellen Cristina Gaetti; Júnior, Idelmo Rangel Garcia; Shinohara, Elio Hitoshi; Araujo, Marcelo Marotta

2012-01-01

73

Thermal diffusivity measurements of thin plates and filaments using lock-in thermography  

NASA Astrophysics Data System (ADS)

Photothermal radiometry has been widely used to measure the thermal diffusivity of bulk materials. In the case of thin plates and filaments, a one-dimensional heat propagation model including heat losses has been developed, predicting that the thermal diffusivity can be obtained by recording both the surface temperature amplitude and phase profile slopes ("slope method"). However, this method has given highly overestimated values of the thermal diffusivity of poor-conducting films and filaments. In this paper we analyze the effect of the experimental factors affecting the thermal diffusivity measurements of thin plates and filaments using infrared thermography, in order to establish the experimental conditions needed to obtain accurate and reliable values of the diffusivity of any kind of material using the slope method. We present the calculations of the surface temperature of thin isotropic and anisotropic plates heated by a modulated and tightly focused laser beam, showing that the slope method is also valid for this kind of pointlike heating. Special attention is paid to the effect of surface heat losses (convective and radiative) on the diffusivity measurements of small-dimension and poor-conducting materials. Lock-in thermography measurements performed in the best experimental conditions on a wide set of samples of different thermal properties (thin isotropic and anisotropic plates and filaments) confirm the validity of the slope method to measure accurately the thermal diffusivity of samples of these shapes.

Mendioroz, Arantza; Fuente-Dacal, Raquel; Apiñaniz, Estibaliz; Salazar, Agustín

2009-07-01

74

Thermal diffusivity measurements of thin plates and filaments using lock-in thermography.  

PubMed

Photothermal radiometry has been widely used to measure the thermal diffusivity of bulk materials. In the case of thin plates and filaments, a one-dimensional heat propagation model including heat losses has been developed, predicting that the thermal diffusivity can be obtained by recording both the surface temperature amplitude and phase profile slopes ("slope method"). However, this method has given highly overestimated values of the thermal diffusivity of poor-conducting films and filaments. In this paper we analyze the effect of the experimental factors affecting the thermal diffusivity measurements of thin plates and filaments using infrared thermography, in order to establish the experimental conditions needed to obtain accurate and reliable values of the diffusivity of any kind of material using the slope method. We present the calculations of the surface temperature of thin isotropic and anisotropic plates heated by a modulated and tightly focused laser beam, showing that the slope method is also valid for this kind of pointlike heating. Special attention is paid to the effect of surface heat losses (convective and radiative) on the diffusivity measurements of small-dimension and poor-conducting materials. Lock-in thermography measurements performed in the best experimental conditions on a wide set of samples of different thermal properties (thin isotropic and anisotropic plates and filaments) confirm the validity of the slope method to measure accurately the thermal diffusivity of samples of these shapes. PMID:19655974

Mendioroz, Arantza; Fuente-Dacal, Raquel; Apiñaniz, Estibaliz; Salazar, Agustín

2009-07-01

75

Long-term results after non-plate head-preserving fixation of proximal humeral fractures  

PubMed Central

A retrospective study was conducted to evaluate displaced proximal humeral fractures treated with a non-plate head-preserving fixation and to detect factors predicting functional outcome. After a median follow-up period of 79.7 months, 105 patients with nine A-fractures, 36 B-fractures and 60 C-fractures (nine two-part-fractures, 41 three-part fractures and 55 four-part fractures) were assessed. Functional outcome was measured based on the Constant and UCLA scores. Of all patients, 70–75% had excellent or good Constant and UCLA scores. In 74% a good or satisfactory quality of initial reduction fracture was achieved. About one-fifth (21%) of the fractures showed a secondary displacement. Twenty-seven percent of the patients had signs of humeral head necrosis and 22% had implant related problems. There were significant correlations between a high final score and young age, low AO fracture severity, good quality of fracture reduction and residual osseous deformity, absence of secondary fracture displacement, implant-related complications, shoulder arthrosis and humeral head necrosis at the time of follow-up. In conclusion, the non-plate head-preserving fixation of proximal humeral fractures is an alternative treatment for displaced proximal humeral fractures. Especially in severely displaced C-fractures in older patients, non-anatomical reduction leads to a high rate of secondary displacement, residual osseous deformity and only a fair shoulder function. For these cases alternative methods such as prosthetic replacement should be chosen. PMID:19705115

Bahrs, Christian; Rolauffs, Bernd; Weise, Kuno; Zipplies, Sebastian; Dietz, Klaus; Eingartner, Christoph

2009-01-01

76

Long-term results after non-plate head-preserving fixation of proximal humeral fractures.  

PubMed

A retrospective study was conducted to evaluate displaced proximal humeral fractures treated with a non-plate head-preserving fixation and to detect factors predicting functional outcome. After a median follow-up period of 79.7 months, 105 patients with nine A-fractures, 36 B-fractures and 60 C-fractures (nine two-part-fractures, 41 three-part fractures and 55 four-part fractures) were assessed. Functional outcome was measured based on the Constant and UCLA scores. Of all patients, 70-75% had excellent or good Constant and UCLA scores. In 74% a good or satisfactory quality of initial reduction fracture was achieved. About one-fifth (21%) of the fractures showed a secondary displacement. Twenty-seven percent of the patients had signs of humeral head necrosis and 22% had implant related problems. There were significant correlations between a high final score and young age, low AO fracture severity, good quality of fracture reduction and residual osseous deformity, absence of secondary fracture displacement, implant-related complications, shoulder arthrosis and humeral head necrosis at the time of follow-up. In conclusion, the non-plate head-preserving fixation of proximal humeral fractures is an alternative treatment for displaced proximal humeral fractures. Especially in severely displaced C-fractures in older patients, non-anatomical reduction leads to a high rate of secondary displacement, residual osseous deformity and only a fair shoulder function. For these cases alternative methods such as prosthetic replacement should be chosen. PMID:19705115

Bahrs, Christian; Badke, Andreas; Rolauffs, Bernd; Weise, Kuno; Zipplies, Sebastian; Dietz, Klaus; Eingartner, Christoph

2010-08-01

77

a Lock-Free Material Finite Element for Non-Linear Oscillations of Laminated Plates  

NASA Astrophysics Data System (ADS)

The objective of the present paper is to propose an efficient, accurate and robust four-node shear flexible composite plate element with six degrees of freedom per node to investigate the non-linear oscillatory behavior of unsymmetrical laminated plates. The degrees of freedom considered are three displacement (u, v, w) along x-, y- and z -axis, two rotations (?x, ?y) abouty - and x -axis and twist ?xy. The elementc employs coupled displacement field, which is derived using moment-shear equilibrium and in-plane equilibrium of composite strips along the x - andy -axis. The displacement field so derived not only depend on the element co-ordinates but are a function of extensional, bending-extensional, bending and transverse shear stiffness coefficients as well. A bi-cubic polynomial distribution with 16 generalized undetermined coefficients for the transverse displacement is assumed. The element stiffness and mass matrices are computed numerically by employing 3×3 Gauss Legendre product rules. The element is found to be free of shear locking and does not exhibit any spurious modes. The element is found to be free of shear locking and does not exhibit any spurious modes. In order to compute the non-linear frequencies, linear mode shape corresponding to fundamental frequency is assumed as the spatial distribution and non-linear finite element equations are reduced to a single non-linear second order ordinary differential equation. This equation is solved by employing direct numerical integration method. A series of numerical examples is solved to demonstrate the efficacy of the proposed material finite element.

SINGH, GAJBIR; VENKATESWARA RAO, G.

2000-02-01

78

Locking Compression Plates for the Treatment of Periprosthetic Femoral Fractures Around Well-Fixed Total Hip and Knee Implants  

Microsoft Academic Search

There are currently few published studies examining the use of locking compression plates for the treatment of periprosthetic femoral fractures. Fifteen total hip or knee arthroplasty patients with 16 Vancouver type B1 and C fractures with an average age of 76 years were fixed and followed clinically and radiographically for 2 years. Fourteen patients achieved radiographic union by 6 months,

Gavin C. A. Wood; Doug R. Naudie; James McAuley; Richard W. McCalden

2011-01-01

79

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

80

Rapid prototyping to design a customized locking plate for pancarpal arthrodesis in a giant breed dog.  

PubMed

This report describes the treatment of traumatic carpal hyperextension in a giant breed dog by pancarpal arthrodesis using a custom-made Fixin locking plate, created with the aid of a three-dimensional plastic model of the bones of the antebrachium produced by rapid prototyping technology. A three-year-old 104 kg male Mastiff dog was admitted for treatment of carpal hyperextension injury. After diagnosis of carpal instability, surgery was recommended. Computed tomography images were used to create a life-size three-dimensional plastic model of the forelimb. The model was used as the basis for constructing a customized 12-hole Fixin locking plate. The plate was used to attain successful pancarpal arthrodesis in the animal. Radiographic examination after 74 and 140 days revealed signs of osseous union of the arthrodesis. Further clinical and radiographic follow-up examination three years later did not reveal any changes in implant position or complications. PMID:24317796

Petazzoni, M; Nicetto, T

2014-01-01

81

A new total wrist fusion locking plate for patients with small hands or with failed partial wrist fusion: preliminary experience.  

PubMed

The author has designed a custom-made titanium plate for total wrist fusion for small-handed persons or patients with failed partial wrist fusions. From May 2011 to April 2013, this plate was used on 13 wrists, 5 of them with a minimum follow-up of 1 year. This implant is downsized compared with the standard wrist fusion plate: lower in profile, shorter in length, and narrower than the standard one. It is fixed to the radius by means of 2.7-mm screws and to the capitate and third metacarpal with 2.4-mm screws. In the curved plate all the screws are locked to the plate with a predetermined coaxial angle. The plate has a curvature to fit the dorsum of the carpus; it is 10° dorsally extended and has undercuts on the contact areas at the radius and third metacarpal dorsal surface. The indication for this implant is a short-statured patient for whom the standard plate is too large and bulky; a failed partial wrist fusion or proximal row carpectomy, for which a shorter plate is needed because only one articulation should be fused (midcarpal or radiocapitate joint); or both. The five wrists (two primary fusions and three failed radioscapholunate [RSL] fusions) healed between 11 and 14 weeks. No plate loosening was observed, and none of the patients felt painful prominence to the distal end of the plate on the dorsum of the hand. PMID:24872923

del Pino, Juan González

2014-05-01

82

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

83

Open Reduction and Plate Fixation of Dorsally Displaced Fractures of the Distal Radius: Surgical Technique, Clinical and Radiological Outcome  

Microsoft Academic Search

Thirty-five unstable dorsally displaced fractures of the distal radius in 34 patients (mean age 39) were studied; 28 fractures were intra-articular. All fractures had open reduction and fixation, through a dorsal approach, with mini-fragment plates placed between the first and second dorsal tendon compartments and deep to the fourth compartment. A congruous reduction of the articular surface was obtained in

T. E. J. Hems; B. Rooney

2010-01-01

84

Biomechanical Study in Polyurethane Mandibles of Different Metal Plates and Internal Fixation Techniques, Employed in Mandibular Angle Fractures.  

PubMed

The aim of this study was to perform a physicochemical and morphological characterization and compare the mechanical behavior of an experimental Ti-Mo alloy to the analogous metallic Ti-based fixation system, for mandibular angle fractures. Twenty-eight polyurethane mandibles were uniformly sectioned on the left angle. These were divided into 4 groups: group Eng 1P, one 2.0-mm plate and 4 screws 6 mm long; group Eng 2P, two 2.0-mm plates, the first fixed with 4 screws 6 mm long and the second with 4 screws 12 mm long. The same groups were created for the Ti-15Mo alloy. Each group was subjected to linear vertical loading at the first molar on the plated side in a mechanical testing unit. Means and standard deviations were compared with respect to statistical significance using ANOVA. The chemical composition of the Ti-15Mo alloy was close to the nominal value. The mapping of Mo and Ti showed a homogeneous distribution. SEM of the screw revealed machining debris. For the plates, only the cpTi plate undergoes a surface treatment. The metallographic analysis reveals granular microstructure, from the thermomechanical trials. A statistically significant difference was found (P < 0.05) when the comparison between both internal fixation techniques was performed. The 2P technique showed better mechanical behavior than 1P. PMID:25340696

Guastaldi, Fernando Pozzi Semeghini; Hochuli-Vieira, Eduardo; Guastaldi, Antonio Carlos

2014-10-21

85

A novel murine model of established Staphylococcal bone infection in the presence of a fracture fixation plate to study therapies utilizing antibiotic-laden spacers after revision surgery.  

PubMed

Mice are the small animal model of choice in biomedical research due to the low cost and availability of genetically engineered lines. However, the devices utilized in current mouse models of implant-associated bone infection have been limited to intramedullary or trans-cortical pins, which are not amenable to treatments involving extensive debridement of a full-thickness bone loss and placement of a segmental antibiotic spacer. To overcome these limitations, we developed a clinically faithful model that utilizes a locking fracture fixation plate to enable debridement of an infected segmental bone defect (full-thickness osteotomy) during a revision surgery, and investigated the therapeutic effects of placing an antibiotic-laden spacer in the segmental bone defect. To first determine the ideal time point for revision following infection, a 0.7mm osteotomy in the femoral mid-shaft was stabilized with a radiolucent PEEK fixation plate. The defect was inoculated with bioluminescent Staphylococcus aureus, and the infection was monitored over 14days by bioluminescent imaging (BLI). Osteolysis and reactive bone formation were assessed by X-ray and micro-computed tomography (micro-CT). The active bacterial infection peaked by 5days post-inoculation, however the stability of the implant fixation became compromised by 10-14days post-inoculation due to osteolysis around the screws. Thus, day 7 was defined as the ideal time point to perform the revision surgery. During the revision surgery, the infected tissue was debrided and the osteotomy was widened to 3mm to place a poly-methyl methacrylate spacer, with or without vancomycin. Half of the groups also received systemic vancomycin for the remaining 21days of the study. The viable bacteria remaining at the end of the study were measured using colony forming unit assays. Volumetric bone changes (osteolysis and reactive bone formation) were directly measured using micro-CT image analysis. Mice that were treated with local or systemic vancomycin did not display gross pathology at the end of the study. While localized vancomycin delivery alone tended to decrease the bacterial burden and osteolysis, these effects were only significant when combined with systemic antibiotic therapy. This novel mouse model replicates key features of implant-associated osteomyelitis that make treatment extremely difficult, such as biofilm formation and osteolysis, and imitates the clinical practice of placing an antibiotic-laden spacer after infected tissue debridement. In addition, the model demonstrates the limitations of current PMMA spacers and could be an invaluable tool for evaluating alternative antimicrobial treatments for implant-associated bone infection. PMID:25459073

Inzana, Jason A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

2015-03-01

86

The biomechanical analysis of three plating fixation systems for periprosthetic femoral fracture near the tip of a total hip arthroplasty  

PubMed Central

Background A variety of techniques are available for fixation of femoral shaft fractures following total hip arthroplasty. The optimal surgical repair method still remains a point of controversy in the literature. However, few studies have quantified the performance of such repair constructs. This study biomechanically examined 3 different screw-plate and cable-plate systems for fixation of periprosthetic femoral fractures near the tip of a total hip arthroplasty. Methods Twelve pairs of human cadaveric femurs were utilized. Each left femur was prepared for the cemented insertion of the femoral component of a total hip implant. Femoral fractures were created in the femurs and subsequently repaired with Construct A (Zimmer Cable Ready System), Construct B (AO Cable-Plate System), or Construct C (Dall-Miles Cable Grip System). Right femora served as matched intact controls. Axial, torsional, and four-point bending tests were performed to obtain stiffness values. Results All repair systems showed 3.08 to 5.33 times greater axial stiffness over intact control specimens. Four-point normalized bending (0.69 to 0.85) and normalized torsional (0.55 to 0.69) stiffnesses were lower than intact controls for most comparisons. Screw-plates provided either greater or equal stiffness compared to cable-plates in almost all cases. There were no statistical differences between plating systems A, B, or C when compared to each other (p > 0.05). Conclusions Screw-plate systems provide more optimal mechanical stability than cable-plate systems for periprosthetic femur fractures near the tip of a total hip arthroplasty. PMID:20653962

2010-01-01

87

Do fluids control locking and seismic slip on the subduction fault? - evidence from the Chilean plate boundary  

NASA Astrophysics Data System (ADS)

A number of recent studies have suggested that the interseismic locking degree inverted from geodetic data at convergent plate boundaries may be closely related to slip distribution of subsequent megathrust earthquakes as found recently for the Maule 2010 and Tohoku 2011 earthquakes. The physical nature of locking, however, remains a matter of debate. We explore seismic, seismological and geodetic data collected from the southern part of the Maule 2010 earthquake rupture zone - overlapping with the northern termination of the Valdivia 1960 earthquake - in the decade before the event to identify the spatial variability of pore fluid pressure and effective stress along the plate interface zone. The reflection seismic and the seismological data exhibit well defined changes of reflectivity and Vp/Vs ratio along the plate interface that can be correlated with different parts of the coupling zone as well as with changes during the seismic cycle. High Vp/Vs domains, interpreted as zones of elevated pore fluid pressure, spatially correlate with lower locking degree, and exhibit higher background seismicity as expected for partly creeping domains. In turn, unstable slip associated to a higher degree of locking is promoted in lower pore fluid pressure domains. This relationship is particularly well expressed in the upper two thirds of the seismic coupling zone down to a depth of some 25 km at an estimated 250°C. In the gradient zone towards deeper domains locking gradually decreases to very low values, and the elevated Vp/Vs-ratio returns to standard values. At the same time seismic reflectivity remains high to some 35 km and then disappears with only minor S-wave reflectivity persisting down to the zone of intermediate depth seismicity at some 60 km depth that is again highlighted by bright reflections. This transition zone, at temperatures > 250°C is also largely coincident with aftershock clusters and a concentration of geodetically recorded afterslip following the Maule earthquake. From their spatial interrelationship, we suggest similar, but less strongly expressed activity of an overpressured fluid. We demonstrate that variations of pore pressure at the plate interface control locking degree variations and therefore coseismic slip distribution of large earthquakes. Lateral variations of pore fluid pressure may be related to the subduction of a transform zone (Maule fracture zone) responsible for part of the fluid input. Finally, we speculate that pore pressure increase during the terminal stage of a seismic cycle to close to lithostatic pressure with an equivalent reduction of effective strength may be as relevant for earthquake triggering as stress loading from long-term plate convergence.

Oncken, Onno; Moreno, Marcos; Haberland, Christian; Rietbrock, Andreas; Angiboust, Samuel; Bedford, Jon

2014-05-01

88

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

89

Plate fixation of premaxillomaxillary suture and compensatory midfacial growth changes in the rabbit.  

PubMed

It has been suggested that rigid fixation of the developing craniofacial skeleton may lead to altered craniofacial growth. However, recent experimental studies have shown that microplate fixation of slow-growing calvarial sutures resulted in regional growth disturbances but had little effect on overall craniofacial growth. The present study was designed to assess the effects of microplate fixation of the more rapidly growing facial sutures on compensatory midfacial growth in the rabbit. Twenty-two 1.5-week-old rabbits were randomly divided into 2 groups: sham controls (n = 11) and animals with bilateral premaxillomaxillary suture fixation (n = 11). Fixation was accomplished using an intraoral approach, a 6-mm straight Luhr microplate, and two 2-mm long self-tapping screws across each suture. Serial lateral head radiographs were collected at 1.5, 3.5, 6, 12, and 18 weeks of age. Results revealed that by 3.5 weeks, animals with rigid fixation showed significantly shortened premaxillary lengths (p < 0.05), class III occlusal relationships, decreased midfacial heights, and abnormal palatocranial base angles compared with sham control animals. By 12 weeks of age, "catch-up" growth was evident in most dimensions in animals with fixation compared with shams. Gross examination of the cleaned and dried skulls revealed bony bridging across the premaxillomaxillary suture and osseous fracture lines extending superiorly from the site of screw fixation. Results demonstrated that rigid fixation of a rapidly growing facial suture did not impair long-term midfacial growth in the rabbit model and suggest that compensatory changes may have occurred at fracture lines from the self-tapping screws in these animals. PMID:1298421

Mooney, M P; Losken, H W; Siegel, M I; Tsachakaloff, A; Losken, A; Janosky, J

1992-12-01

90

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

E-print Network

. These internal fixation devices act as mechanical fasteners which transfer the physiological loads acting on the bone from one end of the fracture to the other, while maintaining the bone fragments in varying degrees of anatomical Juxtaposition. The ultimate aim...

Nori, Meera

2012-06-07

91

Comparison of resorbable plates and titanium plates for fixation stability of combined mandibular symphysis and angle fractures  

PubMed Central

Objectives We compared resorbable plates with titanium plates for treatment of combined mandibular angle and symphyseal fractures. Materials and Methods Patients with mandibular angle and symphysis fractures were divided into two groups. The control (T) group received titanium plates while the experimental (R) group received resorbable plates. All procedures were carried out under general anesthesia using standard surgical techniques. We compared the frequency of wound dehiscence, development of infection, malocclusion, malunion, screw breakage, and any other technical difficulties between the two groups. Results Thirteen patients were included in the R group, where 39 resorbable plates were applied. The T group consisted of 16 patients who received 48 titanium plates. The mean age in the R and T groups was 28.29 and 24.23 years, respectively. Primary healing of the fractured mandible was obtained in all patients in both groups. Postoperative complications were minor and transient. Moreover, there were no significant differences in the rates of various complications between the two groups. Breakage of 3 screws during the perioperative period was seen in the R group, while no screws or plates were broken in the T group. Conclusion Resorbable plates can be used to stabilize combined mandibular angle and symphysis fractures. PMID:25551093

Lim, Ho-Yong; Jung, Chang-Hwa; Kim, Seong-Yong; Cho, Jin-Yong; Ryu, Jae-Young

2014-01-01

92

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

93

A Biomechanical Comparison of Three 1.5-mm Plate and Screw Configurations and a Single 2.0-mm Plate for Internal Fixation of a Mandibular Condylar Fracture.  

PubMed

The most stable pattern of internal fixation for mandibular condyle fractures is an area of ongoing discussion. This study investigates the stability of three patterns of plate fixation using readily available, commercially pure titanium implants. Finite element models of a simulated mandibular condyle fracture were constructed. The completed models were heterogeneous in bone material properties, contained approximately 1.2 million elements and incorporated simulated jaw adducting musculature. Models were run assuming linear elasticity and isotropic material properties for bone. No human subjects were involved in this investigation. The stability of the simulated condylar fracture reduced with the different implant configurations, and the von Mises stresses of a 1.5-mm X-shaped plate, a 1.5-mm rectangular plate, and a 1.5-mm square plate (all Synthes (Synthes GmbH, Zuchwil, Switzerland) were compared. The 1.5-mm X plate was the most stable of the three 1.5-mm profile plate configurations examined and had comparable mechanical performance to a single 2.0-mm straight four-hole plate. This study does not support the use of rectangular or square plate patterns in the open reduction and internal fixation of mandibular condyle fractures. It does provide some support for the use of a 1.5-mm X plate to reduce condylar fractures in selected clinical cases. PMID:25136411

Aquilina, Peter; Parr, William C H; Chamoli, Uphar; Wroe, Stephen; Clausen, Philip

2014-09-01

94

Poly( l-lactide) bone plates and screws for internal fixation of mandibular swing osteotomies  

Microsoft Academic Search

This study evaluated bone healing after mandibular swing osteotomies fixed with biodegradable poly(l-lactide) (PLLA) bone plates in four patients. A step osteotomy treated with two PLLA bone plates (n=3), and a straight osteotomy treated with one PLLA bone plate (n=1) were performed. Bone healing was uneventful in all patients; only in the patient with the straight osteotomy was callus observed.

J. Tams; F. R. rozema; R. R. M. Bos; J. L. N. Roodenburg; P. G. J. Nikkels; A. Vermey

1996-01-01

95

Choosing a proper working length can improve the lifespan of locked plates  

Microsoft Academic Search

BackgroundIt is hypothesized that the working length influences the implants fatigue behavior. However, few studies addressing this issue came to contrary results. Therefore, we tested systematically the influence of working length and implant material on the plate's endurance.

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

2011-01-01

96

Open reduction and plate fixation of dorsally displaced fractures of the distal radius: surgical technique, clinical and radiological outcome.  

PubMed

Thirty-five unstable dorsally displaced fractures of the distal radius in 34 patients (mean age 39) were studied; 28 fractures were intra-articular. All fractures had open reduction and fixation, through a dorsal approach, with mini-fragment plates placed between the first and second dorsal tendon compartments and deep to the fourth compartment. A congruous reduction of the articular surface was obtained in all cases. Twenty-four patients were available for follow-up (median 38 months). The Modified Mayo wrist score was excellent in 12 cases, good in four, and fair in eight. The median Patient Evaluation Measure score was 23.5. There were no cases of extensor tendon rupture. Radiographic assessment at follow-up showed a mean palmar angle of 6 degrees. There was evidence of osteoarthritis in six patients who had had intra-articular fractures. Open reduction and plating gives satisfactory medium term results for treatment of displaced intra-articular fractures of the distal radius in young patients. PMID:19687079

Hems, T E J; Rooney, B

2010-01-01

97

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

98

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

PubMed Central

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.

2014-01-01

99

Mini-plate versus Kirschner wire internal fixation for treatment of metacarpal and phalangeal fractures in Chinese Han population: a meta-analysis  

PubMed Central

Objectives This meta-analysis aimed to compare the therapeutic effect of mini-plate versus Kirschner wire (K-wire) internal fixation on the treatment of metacarpal and phalangeal fractures among Chinese Han population. Methods Databases of China National Knowledge Infrastructure (CNKI), Wanfang, Chinese VIP, PubMed, and Embase were retrieved for studies on mini-plate (case group) versus K-wire (control group) internal fixation for the treatment of metacarpal and phalangeal fractures among Chinese Han population. The odds ratio (OR) and standardized mean difference (SMD) at 95% confidence interval (CI) were used for estimating the effects of dichotomous data and continuous data, respectively. All statistical analyses were performed by Review Manager 5.2 software. Results A total of 18 studies involving 1,375 metacarpal or phalangeal fracture patients (709 cases and 666 controls) were included in the meta-analysis. There were significant differences in fracture healing time (SMD?=??1.28; 95% CI: ?1.81, ?0.76), postoperative infection rate (OR?=?0.25; 95% CI: 0.16, 0.39), complication incidence (OR?=?0.24; 95% CI: 0.15, 0.38), and surgery time (SMD?=?1.57; 95% CI: 0.76, 2.37) between the case and the control group, while no significant difference was found in hospital stays between these two groups (SMD?=?0.43; 95% CI: ?0.34, 1.20; P?=?0.27). Conclusions For the treatment of metacarpal or phalangeal fracture among Chinese Han population, mini-plate has advantages of shorter healing time and lower infection rate and complication incidence compared with K-wire internal fixation, while a longer surgery time than K-wire. In conclusion, mini-plate is prior than K-wire internal fixation for the treatment of metacarpal or phalangeal fracture among Chinese Han population. PMID:24721182

2014-01-01

100

The Clinical Usefulness of Ultrasound-Aided Fixation Using an Absorbable Plate System in Patients with Zygomatico-Maxillary Fracture  

PubMed Central

Background Ultrasound-aided fixation is a recently developed alternative method of treatment of zygomatico-maxillary (ZM) fracture, and it can resolve the problems of excessive torsion force and subsequent fractures of screws. We conducted this study to evaluate the clinical usefulness of ultrasound-aided fixation as compared with the conventional fixation method using a drill and an expander in patients with ZM fracture. Methods We conducted a retrospective study in 35 patients with ZM fracture who had been treated at our hospital during a period ranging from March of 2008 to December of 2010. We divided them into two groups: an ultrasound-aided fixation group, comprising 13 patients who underwent ultrasound-aided fixation (SonicWeld Rx, KLS Martin), and a conventional group, comprising 22 patients who underwent conventional fixation (Biosorb FX, Linvatec Biomaterials Ltd.). We compared such variables as sex, direction, age at operation, follow-up period, operation duration, number of fixed holes, and time to discharge between the two groups. Results The ultrasound-aided fixation reduced the operation duration by about 30 minutes as compared with that of conventional fixation. There was no significant difference in follow-up period, number of fixed holes, or time to discharge between the two groups. Furthermore, there were no complications in either group. Conclusions The ultrasound-aided fixation of fractured ZM bone using an absorbable implant system is safe and effective in promptly reducing the bone fracture and providing satisfactory cosmetic outcomes over time. PMID:23898427

Park, Jun Hyung

2013-01-01

101

Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).  

PubMed

Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2014. PMID:24964903

Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

2014-06-26

102

Guided bone regeneration technique in the esthetic zone: a novel approach using resorbable PLLA-PGA plates and screw fixation. A case report.  

PubMed

The use of biodegradable fixation materials or devices during maxillofacial, craniofacial, and orthopedic reconstructive surgical procedures reduces or eliminates the need to perform a second surgical procedure, which would otherwise be required to remove a nonbiodegradable device. This article presents a novel approach to augment a horizontally deficient alveolar ridge using both a resorbable plate/screw fixation system composed of a polylactic acid-polyglycolic acid (PLLA-PGA) copolymer to provide a rigid scaffolding for the bone chips and a resorbable collagen barrier (Bio-Gide, Osteohealth) to secure the graft material. For periodontal reconstructive procedures, such as guided bone regeneration, the clinical application of this technique may be advantageous and also provide a more esthetic result by minimizing the need for an additional surgical procedure. (Int J Periodontics Restorative Dent 2009;29:543-547.). PMID:19888498

Fabbri, Giacomo; Brennan, Myra; Manfredi, Massimiliano; Ban, Georgio

2009-10-01

103

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

104

Clinical and Radiological Results of Fixation of Acromioclavicular Joint Dislocation by Hook Plates Retained for More Than Five Months  

PubMed Central

Background: Hook plates are used to treat acromioclavicular joint dislocations. Our study took into consideration the patients’ outcome following treatment with clavicular hook plates retained for more than five months. Objectives: Our aim was to assess the response to treatment of acromioclavicular joint dislocation by clavicular hook plate when retained for more than five months. Patients and Methods: We treated 24 patients who had acromioclavicular joint dislocation with a clavicular hook plate between 2008 and 2012 at our hospital. We did not repair the coracoclavicular ligament. In all patients, the plate remained more than five months because they did not come back at the recommended time for removal of their plates. The follow-up period ranged from five to thirty three months with a mean of nineteen months. Results: The main complication was osteolysis that was seen in two patients. The mean constant score was 94.5 ± 8.77 out of 100 with a range between 70 and 100. Conclusions: Our study showed that the use of clavicular hook plates was a good treatment option for acromioclavicular joint dislocation. However, scores were lower in case of prolonged presence of plates. PMID:25032147

Jafary, Dawood; Keihan Shokouh, Hassan; Najd Mazhar, Farid; Shariat Zadeh, Human; Mochtary, Tahmineh

2014-01-01

105

Investigation of a HA/PDLGA/Carbon Foam Material System for Orthopedic Fixation Plates Based on Time-Dependent Properties  

E-print Network

experiments are conducted to elicit the time-dependent properties of the material system at the material scale. These properties are then incorporated into computational models of an internal plate attached to a fractured human femur to design and predict...

Rodriguez, Douglas E.

2010-01-14

106

Immuno-inflammatory tissue reaction to stainless-steel and titanium plates used for internal fixation of long bones  

Microsoft Academic Search

The immuno-inflammatory responses to stainless-steel (21 implants in 20 patients) and titanium plates (22 implants in 20 patients) used in the treatment of long bone fractures were studied immunohistochemically. All fractures healed without complications. In the soft tissue adjacent to the surface of the implants a dark discolouration of the tissue was visible in 18\\/21 stainless-steel and 20\\/22 titanium plates.

Gregor Voggenreiter; Stefan Leiting; Holger Brauer; Peter Leiting; Matthias Majetschak; Mark Bardenheuer; Udo Obertacke

2003-01-01

107

Influence of the volume of bone defect, bone grafting methods, and hook fixation on stress on the Kerboull-type plate and screw in total hip arthroplasty: three-dimensional finite element analysis.  

PubMed

For total hip arthroplasty or revision surgery using acetabular reinforcement cross-plates, choosing between bulk and morselized bone grafts for filling acetabular defects is challenging. We used finite element model (FEM) analysis to clarify various stresses on the cross-plate based on bone defect size, bone graft type, and presence or absence of hook fixation to the bone. We constructed 12-pattern FEMs and calculated the maximum stress generated on the Kerboull-type (KT) plate and screw. Bone defects were classified into four patterns according to the volume. Regarding the bone graft type, bulk bone grafts were considered as cortical bone, and morselized bone grafts were considered to consist of cancellous bone. Models were compared based on whether hook fixation was used and whether a gap was present behind the plate. The upper surface of the host bone was fixed, and a 1,000-N load was imposed on the horizontal axis at 71°. Larger bone defects increased the stress on the KT plate and screws. This stress increased when no bone was grafted; it was lower when bulk cortical bone grafts were used for filling than when morselized cancellous bone grafts were used. For cortical bone grafts, the increased stress on the KT plate and screws was lowered with hook removal. Attaching the hook to the bone and filling the gap behind the KT plate with an adequate bone graft reduced the stress on the KT plate and screws, particularly for large bone defects filled by bulk bone grafting. PMID:24964969

Kaku, Nobuhiro; Hara, Katsutoshi; Tabata, Tomonori; Tsumura, Hiroshi

2015-02-01

108

Does osteoporosis have a negative effect on the functional outcome of an osteoporotic distal radial fracture treated with a volar locking plate?  

PubMed

We performed a retrospective study to determine the effect of osteoporosis on the functional outcome of osteoporotic distal radial fractures treated with a volar locking plate. Between 2009 and 2012 a total of 90 postmenopausal women with an unstable fracture of the distal radius treated with a volar locking plate were studied. Changes in the radiological parameters of 51 patients with osteoporosis (group 1, mean age 66.9, mean T-score -3.16 (sd 0.56)) were not significantly different from those in 39 patients without osteoporosis (group 2, mean age 61.1, mean T-score -1.72 (sd 0.57)). The mean Disabilities of the Arm, Shoulder and Hand (DASH) score at final follow-up was 11.5 (sd 12.2) in group 1 and 10.5 (sd 13.25) in group 2. The mean modified Mayo wrist score at final follow-up was 79.0 (sd 14.04) in group 1 and 82.6 (sd 13.1) in group 2. However, this difference was not statistically significant (p = 0.35 for DASH score, p = 0.2 for modified Mayo wrist score). Univariable and multivariable logistic regression analysis showed that only the step-off of the radiocarpal joint was related to both a poor DASH and modified Mayo wrist score. Pearson's correlation coefficient showed a weak negative relationship only between the T-score and the change in volar tilt (intraclass coefficient -0.26, p = 0.02). We found that osteoporosis does not have a negative effect on the functional outcome and additional analysis did not show a correlation between T-score and outcome. Cite this article: Bone Joint J 2015;97-B:229-34. PMID:25628287

Choi, W-S; Lee, H J; Kim, D-Y; Lee, C-H; Lee, B G; Kim, J-H; Lee, K-H

2015-02-01

109

Plate on Plate Osteosynthesis for the Treatment of Nonhealed Periplate Fractures  

PubMed Central

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

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

2014-01-01

110

Locked up in America  

NSDL National Science Digital Library

FRONTLINE explores "America's fixation on incarceration" with this two-film report, Locked Up In America. Through the episodes "Solitary Nation" and "Prison State," viewers are offered a dramatic and intimate look at this pressing issue. First-time visitors can look at some short clips, including "Who's Locked Up in America" and "How Much Time U.S. Prisoners Spend in Solitary." Moving on, the site also includes a range of other materials, including teachers guidebooks and discussion questions, along with three separate podcasts. Visitors are also encouraged to leave their own comments and meditations.

111

Mid-term functional outcome after the internal fixation of distal radius fractures  

PubMed Central

Background Distal radius fracture is a common injury with a variety of operative and non-operative management options. There remains debate as to the optimal treatment for a given patient and fracture. Despite the popularity of volar locking plate fixation, there are few large cohort or long term follow up studies to justify this modality. Our aim was to report the functional outcome of a large number of patients at a significant follow up time after fixation of their distal radius with a volar locking plate. Methods 180 patients with 183 fractures and a mean age of 62.4 years were followed up retrospectively at a mean of 30 months (Standard deviation = 10.4). Functional assessment was performed using the Disabilities of the Arm, Shoulder and Hand (DASH) and modified MAYO wrist scores. Statistical analysis was performed to identify possible variables affecting outcome and radiographs were assessed to determine time to fracture union. Results The median DASH score was 2.3 and median MAYO score was 90 for the whole group. Overall, 133 patients (74%) had a good or excellent DASH and MAYO score. Statistical analysis showed that no specific variable including gender, age, fracture type, post-operative immobilisation or surgeon grade significantly affected outcome. Complications occurred in 27 patients (15%) and in 11 patients were major (6%). Conclusion This single centre large population series demonstrates good to excellent results in the majority of patients after volar locking plate fixation of the distal radius, with complication rates comparable to other non-operative and operative treatment modalities. On this basis we recommend this mode of fixation for distal radius fractures requiting operative intervention. PMID:22280557

2012-01-01

112

Comparison of internal and external fixation of distal radius fractures  

PubMed Central

Background and purpose There is no consensus on the difference in effects of internal fixation (IF) and external fixation (EF) on outcomes for the treatment of distal radius fractures. We performed a meta-analysis of randomized clinical studies. Methods We searched the literature and included studies that compared the effects of IF and EF on the treatment of distal radius fractures. Statistically, we pooled patient data using standard meta-analytic methods. For the continuous variables, the weighted mean difference (WMD) was used. For dichotomous data, the relative risk (RR) was calculated. Results 10 studies were eligible for data extraction. The pooled data showed that compared with EF, IF led to statistically significantly better Disabilities of the Arm, Shoulder, and Hand (DASH) scores at 12 months postoperatively, recovery of forearm supination at 3 months, and restoration of volar tilt and radial inclination. IF using volar locking plates resulted in better DASH scores than EF at 3 and 6 months, but the trend diminished over time; at 12 months postoperatively, the scores were not statistically significant. Compared with EF, IF led to fewer minor surgical complications. Interpretation For surgical treatment of distal radius fractures, IF yields better functional outcomes, forearm supination, restoration of anatomic volar tilt and radial inclination, and fewer minor complications. The patients who received IF using volar locking plates for the treatment of distal radius recovered more quickly than did patients who received EF. PMID:23594247

2013-01-01

113

Intramedullary Nail versus Dynamic Compression Plate Fixation in Treating Humeral Shaft Fractures: Grading the Evidence through a Meta-Analysis  

PubMed Central

There is a debate regarding the choice of operative intervention in humeral shaft fractures that require surgical intervention. The choices for operative interventions include intramedullary nailing (IMN) and dynamic compression plate (DCP). This meta-analysis was performed to compare fracture union, functional outcomes, and complication rates in patients treated with IMN or DCP for humeral shaft fractures and to develop GRADE (Grading of Recommendations, Assessment, Development, and Evaluation)-based recommendations for using the procedures to treat humeral shaft fractures. A systematic search of all the studies published through December 2012 was conducted using the Medline, Embase, Sciencedirect, OVID and Cochrane Central databases. The randomized controlled trials (RCTs) and quasi-RCTs that compared IMN with DCP in treating adult patients with humeral shaft fractures and provided data regarding the safety and clinical effects were identified. The demographic characteristics, adverse events and clinical outcomes were manually extracted from all of the selected studies. Ten studies that included a total of 448 patients met the inclusion criteria. The results of a meta-analysis indicated that both IMN and DCP can achieve similar fracture union with a similar incidence of radial nerve injury and infection. IMN was associated with an increased risk of shoulder impingement, more restriction of shoulder movement, an increased risk of intraoperative fracture comminution, a higher incidence of implant failure, and an increased risk of re-operation. The overall GRADE system evidence quality was very low, which reduces our confidence in the recommendations of this system. DCP may be superior to IMN in the treatment of humeral shaft fractures. Because of the low quality evidence currently available, high-quality RCTs are required. PMID:24358141

Ma, XinLong; Gao, Feng; Wei, Qiang; Jia, HaoBo; Feng, Rui; Yu, JingTao; Wang, Jie

2013-01-01

114

Evaluation of proximal femoral locking plate in unstable extracapsular proximal femoral fractures: Surgical technique & mid term follow up results?  

PubMed Central

Background Stable trochanteric femur fractures can be treated successfully with conventional implants such as sliding hip screw, cephalomedullary nails, angular blade plates. However comminuted and unstable inter or subtrochanteric fractures with or without osteoporosis are challenging & prone to complications. The PF-LCP is a new implant that allows angular stability by creating fixed angle block for treatment of complex, comminuted proximal femoral fractures. Method We reviewed 30 patients with unstable inter or subtrochanteric fractures, which were stabilized with PF-LCP. Mean age of patient was 65 years, and average operative time was 80 min. Patients were followed up for a period of 3 years (June 2010–June 2013). Patients were examined regularly at 3 weekly interval for signs of union (radiological & clinical), varus collapse (neck-shaft angle), limb shortening, and hardware failure. Result All patients showed signs of union at an average of 9 weeks (8–10 weeks), with minimum varus collapse (<10°), & no limb shortening and hardware failure. Results were analysed using IOWA (Larson) hip scoring. Average IOWA hip score was 77.5. Conclusion PF-LCP represents a feasible alternative for treatment of unstable inter- or subtrochanteric fractures.

Kumar, Nishikant; Kataria, Himanshu; Yadav, Chandrashekhar; Gadagoli, Bharath S.; Raj, Rishi

2014-01-01

115

Positive effect of removal of subchondral bone plate for cemented acetabular component fixation in total hip arthroplasty: a randomised RSA study with ten-year follow-up.  

PubMed

We hypothesised that the removal of the subchondral bone plate (SCBP) for cemented acetabular component fixation in total hip arthroplasty (THA) offers advantages over retention by improving the cement-bone interface, without jeopardising implant stability. We have previously published two-year follow-up data of a randomised controlled trial (RCT), in which 50 patients with primary osteoarthritis were randomised to either retention or removal of the SCBP. The mean age of the retention group (n = 25, 13 males) was 70.0 years (sd 6.8). The mean age in the removal group (n = 25, 16 males) was 70.3 years (sd 7.9). Now we have followed up the patients at six (retention group, n = 21; removal group, n = 20) and ten years (retention group: n = 17, removal group: n = 18), administering clinical outcome questionnaires and radiostereometric analysis (RSA), and determining the presence of radiolucent lines (RLLs) on conventional radiographs. RSA demonstrated similar translation and rotation patterns up to six years. Between six and ten years, proximal acetabular component migration and changes of inclination were larger in the retention group, although the mean differences did not reach statistical significance. Differences in migration were driven by two patients in the SCBP retention group with extensive migration versus none in the SCBP removal group. The significant difference (p < 0.001) in the development of radiolucent lines in the retention group, previously observed at two years, increased even further during the course of follow-up (p < 0.001). While recognising SCBP removal is a more demanding technique, we conclude that, wherever possible, the SCBP should be removed to improve the cement-bone interface in order to maximise acetabular component stability and longevity. Cite this article: Bone Joint J 2015;97-B:35-44. PMID:25568411

Flivik, G; Kristiansson, I; Ryd, L

2015-01-01

116

Intraoral epimucosal fixation for reducible maxillary fractures of the jaws; surgical considerations in comparison to current techniques.  

PubMed

Fractures of the jaw are often treated with rigid and stable internal fixation using plates or miniplates. Early surgery for jaw fractures is the optimal treatment; however, if a late treatment is begun, often the adoption of other protocols is needed. When the jaw fracture has one free bone fragment with 2 full-thickness lesions of mucoperiosteal soft tissues both on the buccal and palatal sides, the risk of resorption or necrosis is very high after elevating a mucoperiosteal flap for rigid fixation. For this reason, we developed an intraoral epimucosal fixation technique using self-locking screws and plates. Substantial advantages of this new technique, in comparison with other commonly used fixation techniques, consisted in the prevention of bone resorption or necrosis by safe and simple screw insertion procedure after manipulation of the fracture for reduction in closed surgery. Major indications for epimucosal fixation in closed surgery are the presence of jaw fractures without dislocation or reducible jaw fractures by manipulation particularly in edentulous patients. PMID:25318439

Cortese, Antonio; Savastano, Germano; Amato, Massimo; Pantaleo, Giuseppe; Claudio, Pier Paolo

2014-11-01

117

44. LOCK AND DAM NO. 26 (REPLACEMENT). LOCK LOCK ...  

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

44. LOCK AND DAM NO. 26 (REPLACEMENT). LOCK -- LOCK GUIDEWALLS -DOWNSTREAM GUIDEWALL, PARTIAL ISOMETRIC VIEW. M-L 26(R) 26/40 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

118

Locking mechanism  

DOEpatents

The invention is a motorized linkage for operating a door strike. A six volt power source, controlled by a security code, rotates a small electric motor when a proper security code is given. The motor rotates a shaft which engages a coil spring. This moves a locking cam. When a catch on the locking cam separates from the locking lever catch, the latch bolt keeper may be manipulated by a user.

Williams, Gary L. (428 E. Third Avenue, Kennewick, WA 99336); Goin, Jr., Jesse L. (480 Kau Trail, Pasco, WA 99301); Kirby, Patrick G. (1010 W. Fifteenth Pl., Kennewick, WA 99337); McKenna, John P. (Rt. 3, Box 1818, Benton City, WA 99320)

1997-01-01

119

Rigid fixation of mandibular condyle fractures.  

PubMed

This article reviews the anatomy and surgical approaches for treating fractures of the mandibular condyle with plate and screw fixation. Advantages and disadvantages of the preauricular, submandibular, intraoral, retromandibular, and rhytidectomy approaches are presented. PMID:8351124

Ellis, E; Dean, J

1993-07-01

120

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

121

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

122

42. LOCK AND DAM NO. 26 (REPLACEMENT). LOCK LOCK ...  

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

42. LOCK AND DAM NO. 26 (REPLACEMENT). LOCK -- LOCK GATES -- LIFT GATE, DOWNSTREAM LEAF, D.S. ELEVATION & GIRDERS. M-L 26(R) 21/29 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

123

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

124

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

125

Is a single anterolateral screw-plate fixation sufficient for the treatment of spinal fractures in the thoracolumbar junction? A Biomechanical in vitro Investigation  

Microsoft Academic Search

Controversy exists about the indications, advantages and disadvantages of various surgical techniques used for anterior interbody fusion of spinal fractures in the thoracolumbar junction. The purpose of this study was to evaluate the stabilizing effect of an anterolateral and thoracoscopically implantable screw-plate system. Six human bisegmental spinal units (T12–L2) were used for the biomechanical in vitro testing procedure. Each specimen

Ulrich Schreiber; Tibor Bence; Thomas Grupp; Erwin Steinhauser; Thomas Mückley; Wolfram Mittelmeier; Rudolf Beisse

2005-01-01

126

Tectonic Plates and Plate Boundaries  

NSDL National Science Digital Library

Continents were once thought to be static, locked tight in their positions in Earth's crust. Similarities between distant coastlines, such as those on opposite sides of the Atlantic, were thought to be the work of a scientist's overactive imagination, or, if real, the result of erosion on a massive scale. This interactive feature shows 11 tectonic plates and their names, the continents that occupy them, and the types of boundaries between them.

127

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

128

Biomechanical analyses of static and dynamic fixation techniques of retrograde interlocking femoral nailing using nonlinear finite element methods.  

PubMed

Femoral shaft fractures can be treated using retrograde interlocking nailing systems; however, fracture nonunion still occurs. Dynamic fixation techniques, which remove either the proximal or distal locking screws, have been used to solve the problem of nonunion. In addition, a surgical rule for dynamic fixation techniques has been defined based on past clinical reports. However, the biomechanical performance of the retrograde interlocking nailing systems with either the traditional static fixation technique or the dynamic fixation techniques has not been investigated by using nonlinear numerical modeling. Three-dimensional nonlinear finite element models were developed, and the implant strength, fixation stability, and contact area of the fracture surfaces were evaluated. Three types of femoral shaft fractures (a proximal femoral shaft fracture, a middle femoral shaft fracture, and a distal femoral shaft fracture) fixed by three fixation techniques (insertion of all the locking screws, removal of the proximal locking screws, or removal of the distal locking screws) were analyzed. The results showed that the static fixation technique resulted in sufficient fixation stability and that the dynamic fixation techniques decreased the failure risk of the implant and produced a larger contact area of the fracture surfaces. The outcomes of the current study could assist orthopedic surgeons in comprehending the biomechanical performances of both static and dynamic fixation techniques. In addition, the surgeons could also select a fixation technique based on the specific patient situation using the numerical outcomes of this study. PMID:24280626

Shih, Kao-Shang; Hsu, Ching-Chi; Hsu, Tzu-Pin; Hou, Sheng-Mou; Liaw, Chen-Kun

2014-02-01

129

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

130

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

131

Does the Lateral Plate need to Overlap the Stem to Mitigate Stress Concentration When Treating Vancouver C Periprosthetic Supracondylar Femur Fracture?  

PubMed

The effect of construct length on cortical strain and load to failure between locked compression plating and cemented femoral stem in a fall model was analyzed. Eight Sawbone femurs with cemented stems were instrumented with increasing fixation lengths starting 8cm distal to stem tip and progressing proximally to overlapping constructs. Uniaxial strain gauges measured cortical strain. Load to failure was performed with 8cm gap between implants, 2cm gap, and proximally overlapping configurations. Strain was significantly reduced as the 8cm gap transitioned to an overlapped construct with most comparisons. Load to failure in the overlapped construct was 273% greater compared to 2cm gap construct. Overlapping the stem with a locking compression plate resulted in reduced strain and increased load to failure. PMID:25443562

Kubiak, Erik N; Haller, Justin M; Kemper, Dan D; Presson, Angela P; Higgins, Thomas F; Horwitz, Daniel S

2015-01-01

132

Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques: A CONSORT-compliant article.  

PubMed

Reliable osteosynthesis of intraarticular fractures depends on lasting interfragmentary compression. Its amount differs in the applied fixation method. The interfragmentary compression of cancellous and cortical lag screws and angle stable locking plates was quantified in an osteoporotic and non-osteoporotic synthetic human bone model.A split fracture of the lateral tibia plateau (AO/OTA type 41-B1.1) was mimicked by an osteotomy in right adult synthetic human tibiae with hard or soft cancellous bone. Specimens were fixed with either two 6.5?mm cancellous, four 3.5?mm cortical lag screws, or 3.5?mm LCP proximal lateral tibia plate preliminary compresed by a reduction clamp (n?=?5 per group). A pressure sensor film was used to register the interfragmentary compression. One-way analysis of variance (ANOVA) with Bonferroni post hoc correction was performed for statistical analysis (p?locking plate itself maintained the compression in non-osteoporotic (0.53?±?0.11?MPa) and osteoporotic bone (0.50?±?0.14?MPa). Four 3.5?mm cortical lag screws provided a compression of 1.69?±?0.65?MPa in non-osteoporotic bone, being not significantly different to the osteoporotic bone group (1.43?±?0.47?MPa, P?=?1.0). Two 6.5?mm cancellous lag screws showed a significantly higher compression in non-osteoporotic (2.1?±?0.59?MPa) compared to osteoporotic (0.77?±?0.21?MPa, P?locking plates maintained the compression preliminarily applied by a reduction clamp. Two 6.5?mm cancellous lag screws are especially suited for non-osteoporotic bone, whereas four 3.5?mm cortical screws exhibited comparable compression in both bone qualities. PMID:25569643

Kojima, K; Gueorguiev, B; Seva, G; Stoffel, K; de Oliveira, R Garcia; Eberli, U; Nicolino, T; Lenz, M

2015-01-01

133

Controlled dynamic stability as the next step in “biologic plate osteosynthesis” - a pilot prospective observational cohort study in 34 patients with distal tibia fractures  

PubMed Central

Introduction Delayed bone healing is an eminent problem in the operative treatment of distal tibia fractures. To address this problem from a biomechanical perspective, the DLS 3.7 (Dynamic Locking Screw 3.7 mm) as a new generation of locking screws has been developed. This screw enables the surgeon to control the rigidity of the plate osteosynthesis and thereby to expand clinical options in cases where the bridge plating is chosen for fracture treatment. Purpose The purpose of the present prospective study was to evaluate the safety use of the DLS 3.7 in distal tibia fractures where bridge plating osteosynthesis is recommended. Methods In a prospective non-controlled cohort study, 34 patients with acute distal tibia fractures (AO 43 A-C) were treated with an angular stable plate fixation using DLS 3.7 or LHS 3.5. Follow-up examinations were performed three, six, twelve, and twenty-four weeks postoperatively and all registered complications were carefully collected. Results A total of 34 patients were prospectively enrolled in this study with a minimum follow-up of 6 months or obvious osseous consolidation at an earlier stage. No complications directly related to the DLS 3.7 were recorded and no infections were observed. Conclusions This observational study could show that the DLS 3.7 in combination with locking compression plates provides a secure and easy application. According to the recent literature inter-fragmentary micro-motion is one evident goal to increase the reliability in fracture healing. The new DLS 3.7 with a maximum micro-motion of 0.2 mm combines the advantage of micro-motion with the well-known advantages of angular stable plate fixation. PMID:24447901

2014-01-01

134

Internal fracture fixation in patients with osteoporosis.  

PubMed

Because of the decreased holding power of plate-and-screw fixation in osteoporotic bone fractures, internal fixation can have a high failure rate, ranging from 10% to 25%. Screws placed into cortical bone have better resistance to pullout than do those placed into adjacent trabecular bone. Plates should not be used to bridge unstable regions of bony comminution in osteoporotic patients. Fixation stability is optimized by securing stable bone contact across the fracture site and by placing screws both as close to and as far from the fracture as possible. Intentional shortening can improve stability and load sharing of the fracture construct. Structural bone graft or other types of fillers can be used to fill voids when comminution prevents stable contact. Load-sharing fixation devices such as the sliding hip screw, intramedullary nail, antiglide plate, and tension band constructs are better alternatives for osteoporotic metaphyseal locations. Proper planning is essential for improved fracture fixation in this high-risk patient group. PMID:12670137

Cornell, Charles N

2003-01-01

135

Biomechanical evaluation of maxillary Lefort ? fracture with bioabsorbable osteosynthesis internal fixation.  

PubMed

The aim of this study was to apply biomechanical analysis model to evaluate the effects of bioabsorbable internal fixation devices on maxillary Lefort ? fracture. CT scan technology and the finite element software (ansys) were used to establish three-dimensional finite element models of five resorbable internal fixation devices in maxillary Lefort ? fractures. We used the model to calculate the stress of the upper jaw and internal fixation. We further analyzed the stability of fixation under four occlusions. The fixation using two bioabsorbable plates was not stable. The zygomaticomaxillary pillars fixation is more stable than other fixations. The stability of fracture fixation was influenced with the molar occlusion. The current study developed a functional three-dimensional finite element model of bioabsorbable internal fixation and compared the stability of five fixation methods for maxillary Lefort ? fractures. The results would facilitate the application of bioabsorbable materials in dental clinic. PMID:25146129

Wu, Wei; Zhou, Jiang; Xu, Chong-Tao; Zhang, Jie; Jin, Yan-Jiao; Sun, Geng-Lin

2014-12-01

136

Plate mouse  

PubMed Central

Fracture shaft humerus when surgically fixed is known to go into non-union and one of the main reasons of this is implant failure. The causes of implant failure may lie in the fracture personality, faulty implant material or choice, dubious surgical technique & faulty mechanics of fixation. Implants may break and cut-through but a unique type of implant migration from one surgical compartment to the other or one anatomical part of body to the other has not been hitherto reported. A 45-year-old male, farmer by occupation, was operated for fracture shaft of humerus 15 years back. He presented to us because of pain due to subcutaneous presence of plate in forearm. X-ray of the elbow with forearm showed that the plate used for fixation of humerus had migrated from one body part to another that is from arm to forearm. The patient on deliberation regarding the pros and cons of surgical treatment options, chose not to get his humerus non-union resolved surgically. This was because he could do his activities related to farming reasonably well.

Lal, Hitesh; Sharma, Deepak Kumar; Mittal, Deepak

2012-01-01

137

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

138

Minimal locked trees  

E-print Network

Locked tree linkages have been known to exist in the plane since 1998, but it is still open whether they have a polynomial-time characterization. This paper examines the properties needed for planar trees to lock, with a ...

Ballinger, Brad

139

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

140

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

141

Screw-locking wrench  

NASA Technical Reports Server (NTRS)

A tool comprises a first handle and a second handle, each handle extending from a gripping end portion to a working end portion, the first handle having first screw threads disposed circumferentially about an inner portion of a first through-hole at the working end portion thereof, the second handle having second screw threads disposed circumferentially about an inner portion of a second through-hole at the working end portion thereof, the first and second respective through-holes being disposed concentrically about a common axis of the working end portions. First and second screw locks preferably are disposed concentrically with the first and second respective through-holes, the first screw lock having a plurality of locking/unlocking screw threads for engaging the first screw threads of the first handle, the second screw lock having a plurality of locking/unlocking screw threads for engaging the second screw threads of the second handle. A locking clutch drive, disposed concentrically with the first and second respective through-holes, engages the first screw lock and the second screw lock. The first handle and the second handle are selectively operable at their gripping end portions by a user using a single hand to activate the first and second screw locks to lock the locking clutch drive for either clockwise rotation about the common axis, or counter-clockwise rotation about the common axis, or to release the locking clutch drive so that the handles can be rotated together about the common axis either the clockwise or counter-clockwise direction without rotation of the locking clutch drive.

Vranish, John M. (Inventor)

2007-01-01

142

Fixation: A Bibliography.  

ERIC Educational Resources Information Center

Fixation and regression were considered complementary by Freud. You tend to regress to a point of fixation. They are both opposed to progression. In the general area, Anna Freud has written (The Ego and the Mechanisms of Defence. London: Hogarth and the Psycho-Analytic Institute, 1937), Sears has evaluated (Survey of Objective Studies of…

Pedrini, D. T.; Pedrini, Bonnie C.

143

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.

144

Anterior subcutaneous internal fixation for treatment of unstable pelvic fractures  

PubMed Central

Background Fractures of the pelvic ring including disruption of the posterior elements in high-energy trauma have both high morbidity and mortality rates. For some injury pattern part of the initial resuscitation includes either external fixation or plate fixation to close the pelvic ring and decrease blood loss. In certain situations – especially when associated with abdominal trauma and the need to perform laparotomies – both techniques may put the patient at risk of either pintract or deep plate infections. We describe an operative approach to percutaneously close and stabilize the pelvic ring using spinal implants as an internal fixator and report the results in a small series of patients treated with this technique during the resuscitation phase. Findings Four patients were treated by subcutaneous placement of an internal fixator. Screw fixation was carried out by minimally invasive placement of two supra-acetabular iliac screws. Afterwards, a subcutaneous transfixation rod was inserted and attached to the screws after reduction of the pelvic ring. All patients were allowed to fully weight-bear. No losses of reduction or deep infections occurred. Fracture healing was uneventful in all cases. Conclusion Minimally invasive fixation is an alternative technique to stabilize the pelvic ring. The clinical results illustrate that this technique is able to achieve good results in terms of maintenance of reduction the pelvic ring. Also, abdominal surgeries no longer put the patient at risk of infected pins or plates. PMID:24606833

2014-01-01

145

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

146

EXTERIOR VIEW OF LOWER LOCK GATES CLOSED. FROM LOCK WALL, ...  

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

EXTERIOR VIEW OF LOWER LOCK GATES CLOSED. FROM LOCK WALL, LOOKING NORTH NORTHWEST. - Illinois Waterway, La Grange Lock and Dam, 3/4 mile south of Country 795N at Illinois River, Versailles, Brown County, IL

147

75 FR 5071 - Lock + TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [Project No. 13649-000] Lock + \\TM\\ Hydro Friends Fund XXXI, LLC; Notice of...22, 2010. On January 8, 2010, Lock + \\TM\\ Hydro Friends Fund XXXI, LLC (Lock + Hydro...1-29-10; 8:45 am] BILLING CODE...

2010-02-01

148

75 FR 5068 - Lock + TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [Project No. 13651-000] Lock + \\TM\\ Hydro Friends Fund XXXIII, LLC; Notice...22, 2010. On January 8, 2010, Lock + \\TM\\ Hydro Friends Fund XXXIII, LLC (Lock...1-29-10; 8:45 am] BILLING CODE...

2010-02-01

149

``Old'' locked inflation  

Microsoft Academic Search

In this paper, we revisit the idea of locked inflation, which does not require a potential satisfying the normal slow-roll condition, but suffers from the problems associated with ``saddle inflation''. We propose a scenario based on locked inflation, however, with an alternative evolution mechanism of the ``waterfall field'' phi. Instead of rolling down along the potential, the phi field will

Yang Liu; Yun-Song Piao; Zong-Guo Si

2009-01-01

150

Rotatable stem and lock  

DOEpatents

A valve stem and lock is disclosed which includes a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

Deveney, J.E.; Sanderson, S.N.

1981-10-27

151

Rotatable stem and lock  

DOEpatents

A valve stem and lock include a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

Deveney, Joseph E. (Albuquerque, NM); Sanderson, Stephen N. (Albuquerque, NM)

1984-01-01

152

Plate Tectonics: Plate Interactions  

NSDL National Science Digital Library

This Science Object is the fourth of five Science Objects in the Plate Tectonic SciPack. It identifies the events that may occur and landscapes that form as a result of different plate interactions. The areas along plate margins are active. Plates pushing against one another can cause earthquakes, volcanoes, mountain formation, and very deep ocean trenches. Plates pulling apart from one another can cause smaller earthquakes, magma rising to the surface, volcanoes, and oceanic valleys and mountains from sea-floor spreading. Plates sliding past one another can cause earthquakes and rock deformation. Learning Outcomes:? 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.

National Science Teachers Association (NSTA)

2006-11-01

153

Measuring electrical resistivity to interpret tectonic plate coupling  

NASA Astrophysics Data System (ADS)

The coupling of tectonic plates—the degree to which the plates are locked together or free to move—is controlled by factors ranging from temperature and pressure to the shear stress between the plates as well as the shape of the interface between the plates. At subduction margins, GPS observations can be used to identify places where the subducting plates are locked or unlocked. At the Hikurangi margin, a subduction zone that runs north to south off New Zealand's eastern coast, a strong longitudinal gradient in plate coupling is present that is unexplained by any of the familiar factors.

Schultz, Colin

2013-12-01

154

35. INTERIOR VIEW OF THE GUARD LOCKS LOCK HOUSE: CLOSED ...  

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

35. INTERIOR VIEW OF THE GUARD LOCKS LOCK HOUSE: CLOSED LOCK GATES AND TWO SETS OF MACHINERY TO ASSIST IN OPERATING THEM. VIEW FROM THE FAST END OF THE BUILDING LOOKING WEST 1976 - Pawtucket Canal, Guard Locks, Lowell, Middlesex County, MA

155

Electronic door locking mechanism  

DOEpatents

The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch.

Williams, Gary Lin (428 E. Third Ave., Kennewick, WA 99336); Kirby, Patrick Gerald (1010 W. Fifteenth Pl., Kennewick, WA 99337)

1997-01-01

156

Rotary Ball Locking Mechanism  

NASA Technical Reports Server (NTRS)

Ball locking mechanism links input drive shaft to output shaft and disengages two shafts from each other when it locks output shaft at either of two fixed angular positions. Part of drive system turning microwave antenna 143.5 degrees between stowage and employment orientations and holds it at either orientation without back-loading drive motor and gears. Angular interval and dimensions modified for use in robotic or other actuators in which desirable to "rest" drive trains while locking actuators at fixed positions.

Holman, Earl V.

1990-01-01

157

Electronic door locking mechanism  

DOEpatents

The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch. 6 figs.

Williams, G.L.; Kirby, P.G.

1997-10-21

158

Comparison of Internal Fixations for Distal Clavicular Fractures Based on Loading Tests and Finite Element Analyses  

PubMed Central

It is difficult to apply strong and stable internal fixation to a fracture of the distal end of the clavicle because it is unstable, the distal clavicle fragment is small, and the fractured region is near the acromioclavicular joint. In this study, to identify a superior internal fixation method for unstable distal clavicular fracture, we compared three types of internal fixation (tension band wiring, scorpion, and LCP clavicle hook plate). Firstly, loading tests were performed, in which fixations were evaluated using bending stiffness and torsional stiffness as indices, followed by finite element analysis to evaluate fixability using the stress and strain as indices. The bending and torsional stiffness were significantly higher in the artificial clavicles fixed with the two types of plate than in that fixed by tension band wiring (P < 0.05). No marked stress concentration on the clavicle was noted in the scorpion because the arm plate did not interfere with the acromioclavicular joint, suggesting that favorable shoulder joint function can be achieved. The stability of fixation with the LCP clavicle hook plate and the scorpion was similar, and plate fixations were stronger than fixation by tension band wiring. PMID:25136691

Sakai, Rina; Matsuura, Terumasa; Tanaka, Kensei; Nakao, Masaki

2014-01-01

159

Retrospective Comparison of Percutaneous Fixation and Volar Internal Fixation of Distal Radius Fractures  

Microsoft Academic Search

A change in the practice of a single surgeon provided an opportunity for retrospective comparison of comparable cohorts treated\\u000a with percutaneous fixation (17 patients) or a volar plate and screws (23 patients) an average of 30 months after surgery.\\u000a The final evaluation was performed according to the Gartland and Werley and Mayo rating systems and the DASH questionnaire.\\u000a There were no

Santiago A. Lozano-Calderón; Job N. Doornberg; David Ring

2008-01-01

160

Locked-In Syndrome  

MedlinePLUS

... Funding Information Research Programs Training & Career Awards Enhancing Diversity Find People About NINDS NINDS Locked-In Syndrome ... News From NINDS | Find People | Training | Research | Enhancing Diversity Careers@NINDS | FOIA | Accessibility Policy | Contact Us | Privacy ...

161

''Old'' locked inflation  

SciTech Connect

In this paper, we revisit the idea of locked inflation, which does not require a potential satisfying the normal slow-roll condition, but suffers from the problems associated with ''saddle inflation''. We propose a scenario based on locked inflation, however, with an alternative evolution mechanism of the ''waterfall field'' {phi}. Instead of rolling down along the potential, the {phi} field will tunnel to end the inflation stage like in old inflation, by which the saddle inflation could be avoided. Further, we study a cascade of old locked inflation, which can be motivated by the string landscape. Our model is based on the consideration of making locked inflation feasible so as to give a working model without slow roll; It also can be seen as an effort to embed the old inflation in string landscape.

Liu, Yang; Piao, Yun-Song [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China)] [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Si, Zong-Guo, E-mail: liuyangbyf@mail.sdu.edu.cn, E-mail: yspiao@gucas.ac.cn, E-mail: zgsi@sdu.edu.cn [Department of Physics, Shandong University, Jinan 250100 (China)] [Department of Physics, Shandong University, Jinan 250100 (China)

2009-05-15

162

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.

163

Contributions of retinal input and phenomenal representation of a fixation object to the saccadic gap effect.  

PubMed

The saccadic "gap effect" refers to a phenomenon whereby saccadic reaction times (SRTs) are shortened by the removal of a visual fixation stimulus prior to target presentation. In the current study, we investigated whether the gap effect was influenced by retinal input of a fixation stimulus, as well as phenomenal permanence and/or expectation of the re-emergence of a fixation stimulus. In Experiment 1, we used an occluded fixation stimulus that was gradually hidden by a moving plate prior to the target presentation, which produced the impression that the fixation stimulus still remained and would reappear from behind the plate. We found that the gap effect was significantly weakened with the occluded fixation stimulus. However, the SRT with the occluded fixation stimulus was still shorter in comparison to when the fixation stimulus physically remained on the screen. In Experiment 2, we investigated whether this effect was due to phenomenal maintenance or expectation of the reappearance of the fixation stimulus; this was achieved by using occluding plates that were an identical color to the background screen, giving the impression of reappearance of the fixation stimulus but not of its maintenance. The result showed that the gap effect was still weakened by the same degree even without phenomenal maintenance of the fixation stimulus. These results suggest that the saccadic gap effect is modulated by both retinal input and subjective expectation of re-emergence of the fixation stimulus. In addition to oculomotor mechanisms, other components, such as attentional mechanisms, likely contribute to facilitation of the subsequent action. PMID:23438584

Ueda, Hiroshi; Takahashi, Kohske; Watanabe, Katsumi

2013-04-19

164

Stephen Crews Lab February 21, 2009 Embryo Fixation  

E-print Network

Stephen Crews Lab February 21, 2009 1 Embryo Fixation 1) Collect embryos on grape juice/agar plates 2) Rinse embryos with water (a squirt bottle works well) into a collection vial. We use collection. 3) Rinse the embryos well with water making sure to rid them of all yeast and other debris. 4

Crews, Stephen

165

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

166

Tacks: a new technique for craniofacial fixation.  

PubMed

Biodegradable fixation in craniofacial surgery provides secure fixation while eliminating much of the concern over intracranial migration of metallic plates and screws. One limitation of present biodegradable systems, however, is the need for tapping the drill hole before screw insertion. Herein, a new method of rigid, biodegradable fixation with tacks (Macrapore, Inc., San Diego, CA) is described. The tacks are made of a 70:30 ratio of the L and DL form of polylactic acid (L,DL-PLA). Degradation times range from 18 to 36 months. Newer prototypes are nearly developed for more rapid dissolution times. From April 1999 to February 2000, tack fixation has been applied in 100 patients (51 males, 49 females aged 3 months to 61 years). Indications for operation were craniosynostosis (n = 33); craniofacial trauma or post-traumatic deformities (n = 11); cleft lip and palate (n = 13); craniofacial syndromes (n = 18); other diagnoses (n = 11). Patients underwent fronto-orbital advancement with cranial reshaping; monobloc osteotomy, open reduction-internal fixation of fractures; hypertelorbitism repair; cranioplasty; stabilization of grafts; major cranial reconstruction; zygomatic advancement; alveolar cleft repair; and iliac bone graft donor site protection. Tacks were also used for temporalis muscle and lateral canthal suspension. Follow-up ranged from 16 to 28 months. Complications occurred in 7 patients, 4 of whom had infections and during debridement had biodegradable implants removed. None of the complications appeared to be related to the use of tacks. The tacks are carried in a specially designed holder and may be placed by hand or with the light tap of a mallet on the tack driver. An automatic driver has been developed. Overall, the performance of the tacks has been excellent. They are easily handled by the nursing personnel and rapidly inserted by the surgeon. Stability appears to be excellent. At this time, it is probably preferable to employ tap and screws for orthognathic surgery or other osteotomies with substantial load bearing. PMID:11711829

Cohen, S R; Holmes, R E; Amis, P; Fitchner, H; Shusterman, E M

2001-11-01

167

Plate TectonicsPlate Tectonics Plate TectonicsPlate Tectonics  

E-print Network

Plate TectonicsPlate Tectonics #12;Plate TectonicsPlate Tectonics · Lithosphere ­ strong, rigid, transform boundaries ­ travel 1 to 11 cm/yr relative to one another #12;14 tectonic plates today #12;Mid asthenosphere that flows · 8 large lithospheric plates and 6 smaller ones ­ separated by divergent, convergent

Siebel, Wolfgang

168

The Fixation of Nitrogen.  

ERIC Educational Resources Information Center

Discusses the fixation of atmospheric nitrogen in the form of ammonia as one of the foundations of modern chemical industry. The article describes ammonia production and synthesis, purifying the hydrogen-nitrogen mix, nitric acid production, and its commericial plant. (HM)

Andrew, S. P. S.

1978-01-01

169

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

170

External fixation of tibial fractures.  

PubMed

External fixation for definitive or initial management of tibial fractures has a long history, with pin-to-bar external fixation being the standard of care for definitive management of tibial fractures. However, the use of this method lessened because of the increased popularity of intramedullary nailing and drawbacks associated with external fixation. This method is still commonly in use in the military environment and can be used for temporary stabilization of tibial fractures, especially in the setting of periarticular injuries. These fixators also may be useful for salvage of open and/or infected fractures that are unsuitable for internal fixation. PMID:25613987

Tejwani, Nirmal; Polonet, David; Wolinsky, Philip R

2015-02-01

171

Cement-Lock for Decontaminating  

E-print Network

Cement-Lock® Technology for Decontaminating Dredged Estuarine Sediments Topical Report N O L O G Y I N S T I T U T E Cement-Lock Demo Plant Prepared by: Michael C. Mensinger GAS conducted as part of the overall program "Cement-Lock®1 Technology for Decontaminating Dredged Estuarine

Brookhaven National Laboratory

172

A supramolecular keypad lock.  

PubMed

The reversible photoswitching between an anthracene derivative and its [4+4] dimer, using the template effect of the CB8 macrocycle, was demonstrated. This example of supramolecular chemistry in water was harnessed to demonstrate the operation of a keypad lock device that is driven by means of light and chemicals as inputs. PMID:25574596

Carvalho, Cátia Parente; Domínguez, Zoe; Da Silva, José Paulo; Pischel, Uwe

2015-01-29

173

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

174

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

175

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

1985-06-19

176

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

177

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

178

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

179

Biomechanical comparison of gourd-shaped LCP versus LCP for fixation of comminuted tibial shaft fracture.  

PubMed

The purpose of this study was to compare monotonic biomechanical properties of gourd-shaped LCP fixation with LCP fixation of human tibial shaft in gap fracture mode. Twenty paired fresh cadaveric human tibias were randomly divided into 4 groups (5 pairs each): (1) axial loading single cycle to failure testing, (2) torsion single cycle to failure testing, (3) 4-point bending single cycle to failure testing, and (4) dynamic 4-point bending testing. A 7-hole 4.5 mm gourd-shaped LCP was secured on the anteromedial surface of 1 randomly selected bone from each pair, respectively, using 6 locking screws in the 1st, 2nd, 3rd, 5th, 6th and 7th hole with the middle hole unfilled and just located at the mid-diaphysis of the tibia. A 7-hole 4.5 mm LCP was secured on the other bone with the same method. Standard AO/ASIF techniques were used. After fixation finished, a 10 mm gap in the mid-diaphysis of tibia was created, centrally located at the unfilled hole. The axial, torsional, and bending stiffness and failure strengths were calculated from the collected data in static testings and statistically compared using paired Student's t-test. The 4-point bending fatigue lives of the two constructs were calculated from the dynamic testing data and also statistically compared using paired Student's t-test. Failure modes were recorded and visually analyzed. P<0.05 was considered significant. Results showed that the axial, torsional and bending stiffness of gourd-shaped LCP construct was greater (4%, 19%, 12%, respectively, P<0.05) than that of the LCP construct, and the axial, torsional and bending failure strengths of gourd-shaped LCP construct were stronger (10%, 46%, 29%, respectively, P<0.05) than those of the LCP construct. Both constructs failed as a result of plate plastic torsional deformation. After axial loading and 4-point bending testings, LCP failed in term of an obvious deformation of bent apex just at the unfilled plate hole, while the gourd-shaped LCP failed in term of a deformation of bent arc between the 3rd and 5th holes, which indicated a more consistent stress distribution on gourd-shaped LCP. Fatigue life of gourd-shaped LCP construct was significantly greater than LCP construct (153 836±2 228 vs. 132 471±6 460 cycles, P<0.01). All constructs failed as a result of fracture of the plate through the compression hole of the unfilled combination screw hole. The biomechanical testing showed that gourd-shaped LCP can provide greater stiffness and strength, and longer fatigue life than LCP. The gourd-shaped LCP may be more advantageous mechanically and may reduce the plate breakage rate clinically. PMID:23592139

Xu, Guo-hui; Liu, Bo; Zhang, Qi; Wang, Juan; Chen, Wei; Liu, Yue-ju; Peng, A-qin; Zhang, Ying-ze

2013-04-01

180

Arthroscopic Suture Bridge Fixation of Tibial Intercondylar Eminence Fractures  

PubMed Central

Tibial intercondylar eminence fractures that are displaced and non-reducible require open or arthroscopically assisted repair. Ideally, fracture reduction and fixation would be performed with a technique that has low morbidity, allows easy visualization and reduction, provides firm fixation, does not violate the proximal tibial physis, avoids metal hardware, and does not require a second procedure for implant removal. The suture bridge technique, used in the shoulder for rotator cuff tears and greater tuberosity fracture repair, has the ability to produce high contact pressures with rigid fixation. We describe an all-inside and all-epiphyseal arthroscopic suture bridge technique for tibial intercondylar eminence fracture repair performed with PushLock anchors (Arthrex, Naples, FL). One or 2 anchors preloaded with No. 2 FiberWire (Arthrex) are placed in the posterior fracture bed, followed by fracture reduction. The suture limbs are shuttled through and around the anterior cruciate ligament and over the fracture fragment in crossing fashion and are secured by use of additional anchors placed at the anteromedial and anterolateral fracture margin. The anchors are placed obliquely to avoid the proximal tibial physis in the pediatric population. Anatomic reduction and secure fixation allow more aggressive rehabilitation and faster restoration of joint function. PMID:24400173

Sawyer, Gregory A.; Hulstyn, Michael J.; Anderson, Brett C.; Schiller, Jonathan

2013-01-01

181

Absorbable Biologically Based Internal Fixation.  

PubMed

Absorbable fixation devices have developed since first being introduced. Current products are manufactured for greater strength and stiffness and slower break down. Absorbable devices for internal fixation should not be used when fracture fragments exclusively depend on screws for bearing direct load; rather, they are preferred for maintaining adequate compression and preventing displacement when some intrinsic stability exists between bones. The main advantage of absorbable internal fixation devices is their flexibility of use. A newer generation synthesized from silk has emerged and may help to overcome current limitations and address a broader range of fixation needs. PMID:25440418

Ibrahim, Ahmed M S; Koolen, Pieter G L; Kim, Kuylhee; Perrone, Gabe S; Kaplan, David L; Lin, Samuel J

2015-01-01

182

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

183

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

184

Comparison of a New Braid Fixation System to an Interlocking Intramedullary Nail for Tibial Osteotomy Repair in an Ovine Model  

E-print Network

by placing 1or 2 lock- ing screws at either end of the nail. These screws engage the bone cortices, HIROHITO KOBAYASHI, MS, and MARK D. MARKEL, DVM, PhD, Diplomate ACVS Objectives--To compare bone healing) and polymethylmethacrylate bone cement with an interlocking intramedullary (IM) nail fixation in an ovine model. Study Design

Scharer, John E.

185

Plate motion  

SciTech Connect

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

Gordon, R.G. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

186

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

187

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

188

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

189

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

190

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

191

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

192

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

193

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

194

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

195

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

196

Biomechanical investigation of different internal fixations in medial opening-wedge high tibial osteotomy  

Microsoft Academic Search

Background. The medial opening-wedge osteotomy for treatment of varus gonarthritis has become very popular in recent years. Different implants for internal fixation after the osteotomy have been created. It is still unclear, which principle of internal fixation (angle stable or non-angle-stable plate with or without spacer) has the best biomechanical properties.The aim of this study was to determine the biomechanical

Gunter Spahn; Thomas Mückley; Enrico Kahl; Gunther O. Hofmann

2006-01-01

197

Bone-screw mandible fixation: An intraoperative alternative to arch bars  

Microsoft Academic Search

Objectives: Bone-screw mandible fixation (BSMF) is evaluated as an alternative to intraoperative arch-bar maxillomandibular fixation before plating of mandibular fractures. BSMF is achieved by wire ligation of opposing bone-screws placed in the maxilla and mandible. Methods: A retrospective evaluation of 23 patients with 40 mandibular fractures who underwent mandibular fracture repairs. BSMF was used instead of arch bars to ensure

A. John Vartanian; Aijaz Alvi

2000-01-01

198

Investigation of metallic and carbon fibre PEEK fracture fixation devices for three-part proximal humeral fractures.  

PubMed

A computational investigation of proximal humeral fracture fixation has been conducted. Four devices were selected for the study; a locking plate, intramedullary nail (IM Nail), K-wires and a Bilboquet device. A 3D model of a humerus was created using a process of thresholding based on the grayscale values of a CT scan of an intact humerus. An idealised three part fracture was created in addition to removing a standard volume from the humeral head as a representation of bone voids that occur as a result of the injury. All finite element simulations conducted represent 90° arm abduction. Simulations were conducted to investigate the effect of filling this bone void with calcium phosphate cement for each device. The effect of constructing devices from carbon fibre polyetheretherketone (CFPEEK) was investigated. Simulations of cement reinforced devices predict greater stability for each device. The average unreinforced fracture line opening (FLO) is reduced by 48.5% for metallic devices with a lesser effect on composite devices with FLO reduced by 23.6%. Relative sliding (shear displacement) is also reduced between fracture fragments by an average of 58.34%. CFPEEK device simulations predict reduced stresses at the device-bone interface. PMID:22989528

Feerick, Emer M; Kennedy, Jim; Mullett, Hannan; FitzPatrick, David; McGarry, Patrick

2013-06-01

199

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

200

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

201

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

202

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

203

Locking gas equalizer assembly  

SciTech Connect

This patent describes a method for pumping a fluid with a high gas content with a standing check valve in a standing cage and a traveling check valve in a traveling cage. It comprises: the steps of mechanically unseating the traveling check valve when the traveling cage is at a position nearest the standing cage; mechanically unseating the traveling check valve momentarily as the traveling cage reverses direction at a location furthest from the standing cage; actuating a piston disposed between the traveling cage and the standing valve to axially reciprocate an unseating rod for engaging the traveling check valve; and locking the piston against rotation relative to the traveling cage.

Hebert, D.W.; Harris, E.

1990-03-13

204

Plate Boundaries  

NSDL National Science Digital Library

This site provides information on plate boundaries, which are found at the edge of the lithospheric plates and are of three types: convergent, divergent and conservative. Wide zones of deformation are usually characteristic of plate boundaries because of the interaction between two plates. The three boundaries are characterized by their distinct motions which are described in the text and depicted with block diagram illustrations, all of which are animated. There are also two maps that show the direction of motion of the plates. Active links lead to more information on plate tectonics.

205

49 CFR 236.761 - Locking, electric.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Locking, electric. 236.761 Section 236.761...Definitions § 236.761 Locking, electric. The combination of one or more electric locks and controlling circuits by means of which levers of an...

2013-10-01

206

49 CFR 236.761 - Locking, electric.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 false Locking, electric. 236.761 Section 236.761...Definitions § 236.761 Locking, electric. The combination of one or more electric locks and controlling circuits by means of which levers of an...

2010-10-01

207

49 CFR 236.761 - Locking, electric.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Locking, electric. 236.761 Section 236.761...Definitions § 236.761 Locking, electric. The combination of one or more electric locks and controlling circuits by means of which levers of an...

2011-10-01

208

49 CFR 236.761 - Locking, electric.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Locking, electric. 236.761 Section 236.761...Definitions § 236.761 Locking, electric. The combination of one or more electric locks and controlling circuits by means of which levers of an...

2012-10-01

209

75 FR 78234 - Lock+TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...13764-000; Project No. 13786-000] Lock+ TM Hydro Friends Fund XXXIV; FFP Missouri 5...Emsworth Lock and Dam Projects: Lock+ TM Hydro Friends Fund XXXIV's proposed project...12-14-10; 8:45 am] BILLING CODE...

2010-12-15

210

Antifungal Lock Therapy  

PubMed Central

The widespread use of intravascular devices, such as central venous and hemodialysis catheters, in the past 2 decades has paralleled the increasing incidence of catheter-related bloodstream infections (CR-BSIs). Candida albicans is the fourth leading cause of hospital-associated BSIs. The propensity of C. albicans to form biofilms on these catheters has made these infections difficult to treat due to multiple factors, including increased resistance to antifungal agents. Thus, curing CR-BSIs caused by Candida species usually requires catheter removal in addition to systemic antifungal therapy. Alternatively, antimicrobial lock therapy has received significant interest and shown promise as a strategy to treat CR-BSIs due to Candida species. The existing in vitro, animal, and patient data for treatment of Candida-related CR-BSIs are reviewed. The most promising antifungal lock therapy (AfLT) strategies include use of amphotericin, ethanol, or echinocandins. Clinical trials are needed to further define the safety and efficacy of AfLT. PMID:23070153

Walraven, Carla J.

2013-01-01

211

Reconstitutable nuclear fuel assembly having locking tubes with dimples  

Microsoft Academic Search

In reconstitutable nuclear reactor fuel assembly, a top-nozzle-to-control-rod-guide-thimble attachment system is described comprising: (a) a top nozzle with an adaptor plate having a control rod passageway with a smaller diameter upper portion, (b) a control rod guide thimble having a top portion with a longitudinal, open-ended slots defining fingers therebetween, (c) a locking tube including a flexible, annular cylinder coaxially

J. M. Shallenberger; S. J. Ferlan

1988-01-01

212

Meshfree Particle Methods for Thin Plates , Christopher Davis  

E-print Network

examples in civil engineering structures are floor and foundation slabs, lock-gates, thin retaining walls Introduction A large number of structural components in engineering can be classified as plates. Typical. In this paper, we are concerned with the classical plate model. Numerous papers and books have been published

Oh, Hae-Soo

213

Locke e a Adulação 1  

Microsoft Academic Search

This article verifies the relevance of a specific political vice, namely, flattery, in John Locke's political thought. It is shown that for Locke flattery originates in learned agents whom incite aspirants to political power, appealing to the pride that typically characterizes them. This political vice, therefore, endangers the survival of political regimes of limited and decentralized powers since it incites,

Tomás Chuaqui

2010-01-01

214

Treatment of Mandibular Fractures by Two Perpendicular Mini-Plates  

PubMed Central

Introduction: In open reduction and internal fixation for the treatment of mandibular fracture, the fixation technique used is very important in reducing post-operative complications and promoting the healing process. This study assessed the results of fixation of the mandible using two mini-plates perpendicular to each other in the lower border of the mandible for fracture treatment. Materials and Methods: Access to the fractures was via an extraoral approach (through existing scars or incisions). After reductions of mandibular fractures, the fracture line fixation was accomplished using two mini-plates perpendicular to each other. One-week intermaxillary fixation (IMF) was applied and 3 weeks of soft diet was recommended in the post-operative period. All patients were followed up for at least 1 year regarding infection and malocclusion. Results: Twenty-five patients (28 fracture lines) underwent this technique. Most (81.8%) patients were male and the mean age was 41.3±7.59 years (range, 17–73 years). Symphyseal fracture (frequency, 52%) was the most prevalent followed by angle (32%) and body (16%) fractures. Among the patients who underwent surgery, only one malocclusion and no cases of infection were observed. No cases of facial nerve weakness or damage were observed in this study. Conclusion: This method can be used in specific cases to replace treatment with one mini-plate, which necessitates a more intensive fixation or reconstruction plate therapy. PMID:24505572

Rahpeyma, Amin; Khajehahmadi, Saeedeh; Barkhori Mehni, Sadegh

2014-01-01

215

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.

216

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

217

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

218

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

219

Tectonic Plates and Plate Boundaries  

NSDL National Science Digital Library

This interactive activity adapted from NASA features world maps that identify different sections of the Earth's crust called tectonic plates. The locations of different types of plate boundaries are also identified, including convergent, divergent, and transform boundaries.

2005-12-17

220

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

221

Internal fixation of osteoporotic fractures.  

PubMed

Osteoporosis leads to bone fragility and increased risk of fracture. Despite advances in diagnosis and treatment, the prevalence continues to rise. Osteoporotic fracture treatment has a unique set of difficulties related to poor bone quality and traditional approaches, and implants may not perform well. Fixation failure and repeat surgery are poorly tolerated and highly undesirable in this patient population. This review illustrates the most recent updates in internal fixation, implant design, and surgical theory regarding treatment of patients with osteoporotic fractures. PMID:25424965

Rothberg, David L; Lee, Mark A

2015-02-01

222

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

223

[Locked posterior shoulder dislocation].  

PubMed

Posterior shoulder dislocations are diagnosed rarely in every-day practice. Although the methods of radiological imaging have been developing and becoming commonly available, the cases of late diagnosis are still happening. Proper clinical examination and properly conducted and interpretated radiographs allow for identification and implementation of appropriate medical procedures. In spite of fact that such cases are identified expectionally rarely, a few types of procedural have been analised and numerous therapeutic methods have been described. The choice of an appropriate treatment is complicated and requires in-depth theoretical knowledge as well as the knowledge of specific conditions within the shoulder surgery. Based on an algorithm, proposed by Griggs, between 2000-2006 seven patients with locked posterior instability were treated, for all of them defect of the proximal humerus did not exceed 30%. In all these cases the goals of improving stability and range of motion were obtained. PMID:18853661

Gadek, Artur; Slusarski, Jakub; Kasprzyk, Marcin; Ciszek, Elzbieta

2008-01-01

224

Color-flavor locked strangelets.  

PubMed

Finite lumps of color-flavor locked strange-quark matter (CFL strangelets) are significantly more stable than strangelets without color-flavor locking for wide ranges of parameters, increasing the likelihood of strangelet metastability, or even absolute stability beyond some minimum baryon number A(min). Whereas bulk CFL strange-quark matter is electrically neutral, CFL strangelets are positively charged, with Z approximately 0.3A(2/3). This is quite different from "ordinary" strangelets and may provide a possible test of color-flavor locking if strangelets are detected in upcoming cosmic-ray space experiments. PMID:11690265

Madsen, J

2001-10-22

225

Perspectives on Marine Nitrogen Fixation  

NASA Astrophysics Data System (ADS)

The importance of nitrogen fixation in ocean biogeochemistry has only recently come to be fully appreciated. As biological nitrogen fixation was being uncovered in terrestrial ecosystems (late 1800s), some ocean surveys were mapping the large-scale distribution of important planktonic diazotrophs, such as the cyanobacterium Trichodesmium, unaware of their functional significance. Early marine N biogeochemists speculated that nitrogen fixation was largely confined to the terrestrial realm, with combined nitrogen being transferred to the ocean from land, there to be taken up by phytoplankton or denitrified. Later, A. Redfield invoked nitrogen fixation as a mechanism to prevent N limitation in the sea. Systematic studies of nitrogen fixation started rolling in the 1960s with the introduction of enriched 15N tracer methodology by R. Dugdale and his associates and, subsequently, with the introduction of a simple field assay for this activity. While results from field studies in the 1980s, largely limited to mid-latitudes and marginal tropical and subtropical seas, also indicated a relatively limited role for nitrogen fixation, several lines of geochemical evidence emerged in the late 1990s which suggested otherwise. This prompted a resurgence in field efforts examining this process which in turn provided direct evidence to support the biogeochemical significance of nitrogen fixation in the oligotrophic ocean. Research in this area continues to move rapidly. The infusion of molecular biological methods also provided new tools to explore and appreciate the real diversity of marine diazotrophs. Many current biogeochemical models incorporate nitrogen fixation as an explicit function providing input of new reactive nitrogen into marine ecosystems. However, there are still major puzzles to be solved. Two current and related conundrums are whether denitrification and nitrogen fixation are near balance in the current ocean, and how closely they are coupled. Recent experimental and modeling results suggests diazotrophs, which are not limited by nitrogen availability, may be limited by other macro and micronutrient factors in different ocean basins. Finally, atmospheric N deposition to the ocean is rapidly accelerating and will soon exceed current estimates of oceanic nitrogen fixation.

Capone, D. G.

2008-05-01

226

[Implant materials for the internal fixation of midfacial fractures].  

PubMed

The material used for osteosynthesis plays a crucial role in the management of facial fractures. Plates need to be flexible enough to be bent and should not be palpable through the skin, while ensuring stable fixation und adequate biocompatibility. Although stainless steel was initially the material of choice, titanium has become the standard material due to its superior biocompatibility. While the explantation of titanium plates and screws appears unnecessary in general, it should be considered in cases of dislocation, cosmetic concerns, pain and infection. Due to their limited initial stability and a potential increase in local complications, resorbable materials based on polymeric lactose are used with caution in midfacial fractures in adults. Our own retrospective study comparing the postoperative complications after fixation of lateral midfacial fractures with titanium and resorbable systems demonstrated a low complication rate for both systems (7-8%) and no statistically significant difference between the two. The appropriate material for fixation should be selected based on the localization and severity of the fracture, the experience of the surgeon as well as on the age and overall condition of the patient. PMID:22012485

Stuck, B A; Heller, T

2011-11-01

227

Comparison of Routine Fixation of Tissues with Rapid Tissue Fixation  

PubMed Central

Introduction: Conventional formalin-fixed, paraffin-embedded tissue provides superior cellular morphology and long-term storage. Problems with formalin fixation comprise delay of fixation and variations in the duration of fixation. Microwave assisted tissue fixation removes the use of noxious and potentially toxic formalin that decreases the turnaround time and creates a personnel friendly workflow. Material and Methods: The present study was conducted over a period of two years. One hundred and forty paired tissue sections were taken including both neoplastic and non-neoplastic tissues. One of the paired tissues was fixed in formalin and the other was fixed by using microwave irradiation in phosphate buffered saline. Both were then processed by conventional method. Each slide was examined and rated for the adequacy of fixation by two pathologists in a blinded fashion using 7 parameters: Cellular outline, cytoplasmic detail, nuclear detail, erythrocyte integrity, lymphocyte appearance, overall morphology and overall staining. Results: Statistical analysis showed that sections obtained from microwave fixed tissues were comparable to that of routinely fixed tissue. The p-values of all parameters were not significant except for the overall morphology for which p-value was significant owing to loss of tissue in some cases. Conclusion: Microwave irradiation substantially shortened the time from specimen reception to diagnosis (turnaround time) and allowed same-day tissue processing and diagnosis of specimens without compromising the overall quality of the histologic section. PMID:24551633

Tripathi, Meenakshi; Bansal, Rani; Gupta, Mamta; Bharat, Vinay

2013-01-01

228

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

229

Hock Locks and Other Accoutrements  

MedlinePLUS

... Administrative Forms Standard Forms Skip Navigation Z7_0Q0619C0JGR010IFST1G5B10H1 Web Content Viewer (JSR 286) Actions ${title} Loading... / Topics / ... Locks / Hock Locks and Other Accoutrements Z7_0Q0619C0JGR010IFST1G5B10H3 Web Content Viewer (JSR 286) Actions ${title} Loading... Z7_ ...

230

Commentary: Incorporating new technology into spine care: the case of resorbable cervical plates.  

PubMed

Commentary on: Lebl DR, Bono CM, Metkar US, et al. Bioabsorbable anterior cervical plate fixation for single-level degenerative disorders: early clinical and radiographic experience. Spine J 2011;11:1002-8 (in this issue). PMID:22122833

Truumees, Eeric

2011-11-01

231

Avascular necrosis in proximal humeral fractures in patients treated with operative fixation: a meta-analysis  

PubMed Central

Background Proximal humeral fractures are common lesions of the elderly, but there are no established treatment guidelines. A surgical treatment for comminuted and displaced fractures of the proximal humerus was developed and is still evolving. The aim of this study was to perform a quantitative review to evaluate the risk of avascular necrosis (AVN) in patients with proximal humeral fractures who were treated by operative fixation compared with conservative treatment. Methods We searched the PubMed, MEDLINE, Springer, Elsevier Science Direct, Cochrane Library, Google Scholar, China National Knowledge Infrastructure (in Chinese), and Wanfang database (in Chinese) up to December 2013 to identify studies related to operative fixation and AVN in patients with proximal humeral fractures. Results Seven studies with a total of 291 patients (142 operative fixation cases and 149 conservative treatment cases) with proximal humeral fractures were considered in the meta-analysis. The overall meta-analysis showed no significant difference in the incidence of AVN between the two groups [odds ratio (OR) 1.42, 95% confidence interval (CI) 0.33–6.11, p?=?0.64]. The subgroup meta-analysis by study design (retrospective/prospective), sample size (?40/>40), and ethnicity (European/Asian) demonstrated similar results. However, the subgroup analysis by specific operative approach (plate fixation/tension band wiring fixation/others) indicated that plate fixation was associated with a higher rate of AVN than conservative treatment (OR 0.20, 95% CI 0.05–0.76, p?=?0.019). Conclusions Plate fixation was associated with a higher risk of AVN development than conservative treatment in patients with proximal humeral fractures. PMID:24767176

2014-01-01

232

Clinical and radiographic evaluation of biodegradable bone plates in the treatment of mandibular body fractures  

PubMed Central

Background: Many different systems are available for the treatment of fractures ranging from the heavy compression plates for mandibular reconstruction to low profile plates for mid-facial fixation, and are made either from stainless steel, titanium or vitallium. Recently, biodegradable, self-reinforced polylactide plates and screws have been used for the internal fixation of fractures of the mandible with good results. Aim of this study: This study evaluated clinically the biodegradable bone plates for treatment of mandibular body fracture and to evaluate bone healing during the follow-up period using digital radiography. Materials and Methods: Eight patients had been suffered from mandibular body fractures were treated using Inion CPSTM bioresorbable fixation system and the healing process were followed up using digitised panoramic radiography at first week and after 1, 3 and 6 months. Results: Clinical examination of fractured segments revealed stable fixation across the fracture sites while visual and quantitative assessment of radiograph showed healing process was comparable with results previously reported by titanium bone plates. Conclusion: Open reduction and internal fixation of mandibular fractures using bioresorbable fixation system with a brief period of inter-maxillary fixation have evolved to the point where the physical properties are sufficient to withstand the post-operative loads required for fracture repair of mandibular body fractures. The foreign body reaction is a major material-related problem which requires further studies. PMID:25657494

Elhalawany, Sherin Kamal; Tarakji, Bassel; Azzeghaiby, SN; Alzoghaibi, Ibrahim; Baroudi, Kusai; Nassani, Mohammad Zakaria

2015-01-01

233

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

234

[A rapid intermaxillary fixation technic].  

PubMed

The authors describe a new intermaxillary fixation (IMF) technique. This technique is particularly easy and quick. It needs usual 4/10 or 5/10 steel wire with a small pearl fixed at one extremity. Four wires are used, passed from lingual side to vestibular side, between premolars. Wires are then linked and intermaxillary fixation is performed. Osteosynthesis is realised by intraoral approach. This technique does not allow to maintain IMF during a long postoperative period. Therefore, it should be reserved for cases where miniplate osteosynthesis will be sufficient. It seems interesting to use this technique for monofocal mandibular fractures, in association with rigid miniplate osteosynthesis. PMID:8685623

Paoli, J R; Lauwers, F; Boutault, F

1996-01-01

235

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

236

Mandibular osteotomies for tumor extirpation: the advantages of rigid fixation.  

PubMed

Adequate exposure of intraoral tumors occupying the posterior oral cavity, base of tongue, tonsil, and superior hypopharynx for wide-field primary surgical resection is critical to precise tumor ablation. The exposure resulting from a mandibular osteotomy has greatly assisted the tumor ablation of these areas. This procedure has also been beneficial in providing exposure to the anterior skull base, pterygomaxillary, and infratemporal space, clivus, and nasopharynx. In evaluating various osteotomy sites and methods of fixation, we reviewed 26 patients treated for benign or malignant neoplasia of the head and neck requiring mandibulotomy. The osteotomy complication rate was 2 (29%) of 7 for wire osteosynthesis and 1 (5.3%) of 19 for plate osteosynthesis. All patients with osteotomy complications had received preoperative radiation therapy. The one complication in the plated group was associated with a lateral stairstep osteotomy and two screws on either side of the osteotomy. This study suggests advantages of absolute rigid internal fixation of mandibular osteotomies used for tumor ablation. It is also concluded that a midline osteotomy reapproximated with rigid internal fixation has the benefits of 1. primary bone healing by means of plating counteracting the balanced forces acting on the symphysis; 2. improved reapproximation with minimal bony loss, improving occlusion; 3. decreased incidence of osteoradionecrosis as the symphysis lies outside the usual radiation ports; 4. preservation of the neurovascular bundle; and 5. maintenance of osteotomy-site immobility in an infected field. This review helped identify surgical techniques that decrease the complications that are commonly associated with mandibular osteotomies for precise tumor ablation. PMID:1731161

Sullivan, P K; Fabian, R; Driscoll, D

1992-01-01

237

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

238

Humeral shaft fracture management, a prospective study; nailing or plating  

PubMed Central

Introduction In this fast moving & advancing era no body want to remain handicapped in immobilization by cast with limited movement. As our knowledge is growing, orthopedic implants and appliances also advancing, and creating a very potential options to manage fracture shaft of humerus by internal fixation either by plate osteosynthesis or interlocking nailing. We are here to evaluate the options of internal fixation; nailing and plating. Material and method We prospectively evaluated the results of 30 patients having humeral Shaft fracture. Who were internally fixed by antegrade interlocking nailing (15) and DCP plate (15). Patients are followed up on average of 16–19 months and results were evaluated with standard protocol. Results All fractures united uneventfully with usual complication. However we need 2 reoperation in nailing and 1 case of plating for bone grafting. Conclusion Internal fixation have immense use in providing better results in form of less deformity, early mobilization and good union. Plating is better option for fixation in terms of less union time, better joint function and lesser reoperation However Nailing is good alternative as minimal invasive approach, less infection, less nerve injury, less chance of implant failure.

Kumar, Rupesh; Singh, Pankaj; Chaudhary, Lal Jee; Singh, Shailendra

2012-01-01

239

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

240

Peen plating  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

241

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

242

Circuit breaker lock out assembly  

DOEpatents

A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly S shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

Gordy, W.T.

1983-05-18

243

Locking mechanism for orthopedic braces  

NASA Technical Reports Server (NTRS)

An orthopedic brace locking mechanism is described which under standing or walking conditions cannot be unlocked, however under sitting conditions the mechanism can be simply unlocked so as to permit bending of the patient's knee. Other features of the device include: (1) the mechanism is rendered operable, and inoperable, dependent upon the relative inclination of the brace with respect to the ground; (2) the mechanism is automatically locked under standing or walking conditions and is manually unlocked under sitting conditions; and (3) the mechanism is light in weight and is relatively small in size.

Chao, J. I.; Epps, C. H., Jr.

1981-01-01

244

Phase-locked laser array  

NASA Technical Reports Server (NTRS)

A phase-locked laser array comprises a body of semiconductor material having means for defining a plurality of substantially parallel lasing zones which are spaced an effective distance apart so that the modes of the adjacent lasing zones are phase-locked to one another. One of the array electrodes comprises a plurality of electrical contacts to the body between the lasing zones. These contacts provide an enhanced current density profile and thus an increase in the gain in the regions between the lasing zones so that zero degree phase-shift operation between adjacent lasing zones is achievable.

Botez, Dan (Inventor)

1987-01-01

245

Circuit breaker lock out assembly  

DOEpatents

A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly "S" shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

Gordy, Wade T. (Jackson, SC)

1984-01-01

246

Stabilization of mobile mandibular segments in mandibular reconstruction: use of spanning reconstruction plate.  

PubMed

The fibular free flap is the gold standard for mandibular reconstruction. Accurate 3-dimensional contouring and precise alignment of the fibula is critical for reestablishing native occlusion and facial symmetry. Following segmental mandibulectomy, the remaining mandibular fragments become freely mobile. Various stabilization methods including external fixation, intermaxillary fixation, and preplating with reconstruction plate have been used. We describe a modification to the preplating technique. After wide resection of buccal squamous cell carcinoma, our patient had an 11-cm mandibular defect from the angle of the left mandible to the right midparasymphyseal region. A single 2.0-mm Unilock® (Synthes, Singapore) plate was used to span the defect. This was placed on the vestibular aspect of the superior border of the mandibular remnants before resection. Segmental mandibulectomy was then performed with the plate removed. The spanning plate was then reattached to provide rigid fixation. The fibular bone was contoured with a single osteotomy and reattached. The conventional technique involves molding of the plate at the inferior border of the mandible. This is time-consuming and not possible in patients with distorted mandibular contour. It is also difficult to fit the osteotomized fibula to the contoured plate. In comparison, the superiorly positioned spanning plate achieve rigid fixation of the mandible while leaving the defect completely free and unhampered by hardware, allowing space for planning osteotomies and easier fixation of the neomandible. Using this modified technique, we are able to recreate the original mandibular profile with ease. PMID:23997856

Yap, Yan Lin; Lim, Jane; Ong, Wei Chen; Yeo, Matthew; Lee, Hanjing; Lim, Thiam Chye

2012-09-01

247

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

248

49 CFR 236.769 - Locking, traffic.  

Code of Federal Regulations, 2012 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...

2012-10-01

249

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

250

Obituary: Martha Locke Hazen, 1931-2006  

NASA Astrophysics Data System (ADS)

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, where she lived for most of her life. Her father coined the term "servo-mechanism" while serving as an engineering professor and dean for graduate students at the Massachusetts Institute of Technology. Her mother majored in chemistry at Mount Holyoke College. After receiving an A.B. in astronomy from Mount Holyoke College in 1953, Martha earned a Ph.D. in astronomy in 1958 from the University of Michigan, defending a dissertation on the distribution of intensity in elliptical galaxies in the Virgo cluster. Martha's marriage to William Liller in 1959, and the births of two children, inevitably slowed down her progress in observational astronomy. As a research fellow of the Harvard College Observatory, Martha continued to observe two to three weeks a year in Chile, and to reduce those observations and publish the results for sixteen years. Martha's first publication, at least as far as Astrophysics Data System includes the literature, was with Alice Farnsworth on the 1952 occultations of stars by the Moon, published in the Astronomical Journal (1953). In 1958 she joined L. R. Doherty and D. H. Menzel on a short note about the calculation of line profiles in a stratified atmosphere, her only theory paper. Martha's most cited paper is "The Distribution of Intensity in Elliptical Galaxies of the Virgo Cluster," (ApJ, 132, p.306, 1960). There she acknowledges Allan Sandage for suggesting the problem and providing some of the data. Her second most cited paper is "Photometric histories of QSOs - Two QSOs with large light amplitude," (Liller, M. H. & Liller, W., ApJ (Letters), 199, p. L133-L135, 1975). Progressing to smaller objects, other frequently cited papers are on eta Carinae and spectroscopic binaries in the globular cluster M3. All of these, and most of her other papers, involve photographic photometry, mostly using archival data. In 1969, Harvard appointed Martha Curator of Astronomical Photographs, placing her in responsible charge of the world renowned Harvard Plate Archives. Under attack during the mid-1950s because it occupied too much physical space, the collection had been neglected for over a decade when Martha assumed this additional responsibility. Though she continued to observe for a few years thereafter, her stewardship of the invaluable plate archives gradually demanded her full attention, which it held until her retirement in 2002. In her thirty-three years as curator of the plate stacks, as the archive is popularly known, Martha made numerous friends in both the professional and amateur communities. Astronomical researchers on a wide variety of topics relied on her detailed knowledge of the collection to guide them to important discoveries or discovery confirmations on the old plates, and to historical understanding of results in which some detail of origin needed clarification. Martha researched and documented the characteristics of nearly a hundred separate telescopic cameras used to take the plates archived in the collection. Much of this information was ephemeral, having been passed orally from observer to observer and was in danger of passing from human memory. This was, in itself, an enormous and valuable undertaking as it ensures the utility of the plates for future research. More importantly, Martha conserved and catalogued the all important logbooks that record the date, time, and other exposure circumstances for each of the plates in the collection. The full measure of Martha's long-term contribution in this regard undoubtedly will be realized as the digitization of the entire collection of plates is completed. The Digital Access to a Sky Century from Harvard (DASCH) project will ow

Williams, Thomas R.; Willson, Lee Anne

2007-12-01

251

Mechanical properties of Indonesian-made narrow dynamic compression plate.  

PubMed

Osteosynthesis plates are clinically used to fixate and position a fractured bone. They should have the ability to withstand cyclic loads produced by muscle contractions and total body weight. The very high demand for osteosynthesis plates in developing countries in general and in Indonesia in particular necessitates the utilisation of local products. In this paper, we investigated the mechanical properties, i.e. proportional limit and fatigue strength of Indonesian-made Narrow Dynamic Compression Plates (Narrow DCP) as one of the most frequently used osteosynthesis plates, in comparison to the European AO standard plate, and its relationship to geometry, micro structural features and surface defects of the plates. All Indonesian-made plates appeared to be weaker than the standard Narrow DCP because they consistently failed at lower stresses. Surface defects did not play a major role in this, although the polishing of the Indonesian Narrow DCP was found to be poor. The standard plate showed indications of cold deformation from the production process in contrast to the Indonesian plates, which might be the first reason for the differences in strength. This is confirmed by hardness measurements. A second reason could be the use of an inferior version of stainless steel. The Indonesian plates showed lower mechanical behaviour compared to the AO-plates. These findings could initiate the development of improved Indonesian manufactured DCP-plates with properties comparable to commonly used plates, such as the standard European AO-plates. PMID:22842280

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

2012-09-01

252

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

253

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

254

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

255

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

256

75 FR 2129 - Lock+TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...13625-000] Lock+ TM Hydro Friends Fund XXX, LLC; Notice of Preliminary Permit Application...13, 2009, Lock+ TM Hydro Friends Fund XXX, LLC filed an application, pursuant to...Krouse, Lock+ TM Hydro Friends Fund XXX, LLC, 5090 Richmond Avenue...

2010-01-14

257

76 FR 48840 - Lock+TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...14136-000; 14139-000] Lock+\\TM\\ Hydro Friends Fund XXXV Riverbank...Applications On April 1, 2011, Lock+\\TM\\ Hydro Friends Fund XXXV (Hydro...Managing Partner, Lock+\\TM\\ Hydro Friends Fund XXXV, 5090...45 am] BILLING CODE...

2011-08-09

258

Removable splint with locking attachments for maxillary distraction osteogenesis with the RED system.  

PubMed

The external traction hooks of the intraoral splint used to control traction forces applied to the maxilla with the rigid external distraction system represent a major barrier to surgical procedures. The purpose of this article is to introduce a removable intraoral splint with locking attachments that can be placed post-surgically immediately before distraction, facilitating surgery and consequently reducing the operative time. Fifteen cleft lip and palate patients underwent maxillary distraction osteogenesis using a rigid external distraction device in combination with the proposed removable splint that was fixed onto the maxillary teeth to provide anchorage. Initial records showed severe maxillary hypoplasia and negative overjet. The removable splint was fabricated using 1.5-mm diameter stainless-steel rigid orthodontic wires soldered to the locking attachments (Y&B Products LP, Chiang Mai, Thailand), making possible its placement post-surgically. Stable splint fixation was achieved prior to the distraction procedure and the desired treatment goals were reached. No complications inserting or removing the splint post-surgically, including pain or discomfort, were observed. The use of the removable splint with locking attachments has proved to be a highly effective fixation approach to manage the severely hypoplastic maxilla, eliminating lip constraints resulting from scarring, and allowing for easier, more deliberate and careful dissection. PMID:17629458

Suzuki, E Y; Suzuki, B

2007-12-01

259

Growth Plate Injuries  

MedlinePLUS

Growth Plate Injuries May 2014 Questions and Answers about Growth Plate Injuries This publication contains general information about ... Classification of Growth Plate Injuries What Is the Growth Plate? The growth plate, also known as the ...

260

Implant fixation by bone ingrowth.  

PubMed

The term osseointegration referred originally to an intimate contact of bone tissue with the surface of a titanium implant; the term bone ingrowth refers to bone formation within an irregular (beads, wire mesh, casting voids, cut grooves) surface of an implant. The section dealing with the historical background describes the development of macroporous, microporous, and textured surfaces with an emphasis on the evolution of porous and textured metal surfaces. The principal requirements for osseointegration and bone ingrowth are systematically reviewed as follows: i) the physiology of osseointegration and bone ingrowth, including biomaterial biocompatibility with respect to cellular and matrix response at the interface; ii) the implant surface geometry characteristics; iii) implant micromotion and fixation modes; and iv) the implant-bone interface distances. Based on current methods of bone ingrowth assessment, this article comparatively reviews and discusses the results of experimental studies with the objective of determining local and systemic factors that enhance bone ingrowth fixation. PMID:10220191

Kienapfel, H; Sprey, C; Wilke, A; Griss, P

1999-04-01

261

Musical Plates  

NSDL National Science Digital Library

This on-line project is part of the Center for Improved Engineering and Science Education (CIESE) program. As they complete this series of lessons, students will use real-time data to solve a problem, study the correlation between earthquakes and tectonic plates, and determine whether or not there is a relationship between volcanoes and plate boundaries. Musical Plates has four Core Activities that will teach students how to access and interpret real-time earthquake and volcano data and to how use the information to solve a real-world problem. Each of the core activities is designed to be used in a 45-minute class period. This unit also has three enrichment lessons and a final project lesson that can also be used for assessment.

2007-12-12

262

Biological fixation of endosseous implants.  

PubMed

Primary implant stability is ensured by a mechanical fixation of implants. However, during implant healing a biological anchorage is necessary to achieve final osseointegration. Aim of this study was to investigate the histological aspects of biological fixation around titanium screws. Forty-eight titanium screws with different surfaces (smooth, plasma sprayed, sand blasted) were inserted in tibiae and femura of sheep and analyzed by light microscope and SEM 1 hour, 14 and 90 days after implantation. One hour after implantation the implant-bone gap was filled with a blood clot and host bone chips arising from burr surgical preparation or friction during implant insertion. Fourteen days after implantation new trabecular bone and enveloped bone chips were observed in the gap: no osteogenesis developed where implant threads were in contact with host bone. Ninety days after surgery all trabecular bone and most of the bone chips were substituted by a mature lamellar bone with few marrow spaces. Our results suggest that the trabecular bone and bone chips represent a three-dimensional network ensuring a biological implant fixation in all different implant surfaces 2 weeks after surgery. Host bone chips could favour the peri-implant osteogenesis. Inter-trabecular and implant-trabecular marrow spaces of both trabecular and lamellar bone may favour the peri-implant bone turnover. PMID:16233979

Franchi, M; Fini, M; Martini, D; Orsini, E; Leonardi, L; Ruggeri, A; Giavaresi, G; Ottani, V

2005-01-01

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

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

265

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

266

Overcoming fixation with repeated memory suppression.  

PubMed

Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information. PMID:24575886

Angello, Genna; Storm, Benjamin C; Smith, Steven M

2015-04-01

267

Preservation of tracheal mucus by nonaqueous fixative.  

PubMed

Two nonaqueous fixatives, composed of fluorocarbon solvents with dissolved osmium tetroxide, were used to determine the feasibility of preserving the mucous coat in bovine and rat trachea for light and electron microscopy. Aqueous fixatives, while providing excellent cytological preservation, wash away the mucous lining, precluding ultrastructural analysis. Inclusion of ruthenium red or alcian blue within aqueous fixative improved retention of mucus, but provided incomplete, patchy results. Fixation with nonaqueous fluorocarbon solvent and dissolved osmium tetroxide preserved a continuous mucous epiphase layer above a clear hypophase layer. Subcomponents of the mucus included an electron dense surface layer, interrupted patches of mucus above the surface layer and electron dense membrane-like material within the mucus. This method of fixation will preserve mucus for light, scanning and transmission electron microscopy, using either intratracheal or immersion methods of fixation. The latter would enable use of materials from large animal models, autopsy or an abattoir. PMID:1832970

Sims, D E; Westfall, J A; Kiorpes, A L; Horne, M M

1991-01-01

268

Impact response and simulation of damaged ulna with internal fixation.  

PubMed

The objectives of this work were to explore a methodology that combines static and dynamic finite element (FE) analysis, linear elastic fracture mechanics (LEFM) and experimental methods to investigate a worst-case scenario in which a previously damaged bone plate system is subjected to an impact load. Cadaver ulnas with and without midshaft dynamic compression plates are subjected to a static three-point bend test and loaded such that subcritical crack growth occurs as predicted by a hybrid method that couples LEFM and static FE. The plated and unplated bones are then unloaded and subsequently subjected to a midshaft transverse impact test. A dynamic strain-based FE model is also developed to model the midshaft transverse impact test. The average value of the impact energy required for failure was observed to be 10.53% greater for the plated set. There appears to be a trade-off between impact damage and impact resistance when ulnas are supported by fixation devices. Predictions from the dynamic FE model are shown to corroborate inferences from the experimental approach. PMID:22084055

Coates, Cameron; Goeser, Priya; Coates-Clark, Camille; Jenkins, Mark

2012-07-01

269

Biomet reunite absorbable fixation in lesser metatarsal chevron shortening osteotomy: A new fixation technique  

Microsoft Academic Search

A procedure to fixate lesser metatarsal osteotomies with absorbable internal fixation is presented. This method may help prevent metatarsal head and toe elevatus. (The Journal of Foot & Ankle Surgery 42(2):105-107, 2003)

Louis D. Centrella; Robert L. van Brederode

2003-01-01

270

Interplate strain, wide plate margin deformation, intraplate strain: The GPS analysis spectrum  

Microsoft Academic Search

Global Positioning System (GPS) data from southern Central America and northwestern South America collected during 1991, 1994, 1996, and 1998 reveal wide plate boundary deformation and escape tectonics occurring along an 1400 km length of the North Andes; locking of the subducting Nazca plate, strain accumulation in the Ecuador-Colombia forearc; ongoing collision of the Panama arc and Colombia; and convergence

Robert Anthony Trenkamp

2003-01-01

271

What matters in neuronal locking?  

PubMed

Exploiting local stability, we show what neuronal characteristics are essential to ensure that coherent oscillations are asymptotically stable in a spatially homogeneous network of spiking neurons. Under standard conditions, a necessary and, in the limit of a large number of interacting neighbors, also sufficient condition is that the postsynaptic potential is increasing in time as the neurons fire. If the postsynaptic potential is decreasing, oscillations are bound to be unstable. This is a kind of locking theorem and boils down to a subtle interplay of axonal delays, postsynaptic potentials, and refractory behavior. The theorem also allows for mixtures of excitatory and inhibitory interactions. On the basis of the locking theorem, we present a simple geometric method to verify the existence and local stability of a coherent oscillation. PMID:8888612

Gerstner, W; van Hemmen, J L; Cowan, J D

1996-11-15

272

Locking mechanism for indexing device  

DOEpatents

Disclosed is a locking mechanism for an indexing spindle. A conventional r gear having outwardly extending teeth is affixed to the spindle. Also included is a rotatably mounted camshaft whose axis is arranged in skewed relationship with the axis of the spindle. A disk-like wedge having opposing camming surfaces is eccentrically mounted on the camshaft. As the camshaft is rotated, the camming surfaces of the disc-like member are interposed between adjacent gear teeth with a wiping action that wedges the disc-like member between the gear teeth. A zero backlash engagement between disc-like member and gear results, with the engagement having a high mechanical advantage so as to effectively lock the spindle against bidirectional rotation.

Lindemeyer, Carl W. (Aurora, IL)

1984-01-01

273

Digital phase-lock loop  

NASA Technical Reports Server (NTRS)

An improved digital phase lock loop incorporates several distinctive features that attain better performance at high loop gain and better phase accuracy. These features include: phase feedback to a number-controlled oscillator in addition to phase rate; analytical tracking of phase (both integer and fractional cycles); an amplitude-insensitive phase extractor; a more accurate method for extracting measured phase; a method for changing loop gain during a track without loss of lock; and a method for avoiding loss of sampled data during computation delay, while maintaining excellent tracking performance. The advantages of using phase and phase-rate feedback are demonstrated by comparing performance with that of rate-only feedback. Extraction of phase by the method of modeling provides accurate phase measurements even when the number-controlled oscillator phase is discontinuously updated.

Thomas, Jr., Jess B. (Inventor)

1991-01-01

274

Methanotrophy induces nitrogen fixation during peatland development.  

PubMed

Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation. PMID:24379382

Larmola, Tuula; Leppänen, Sanna M; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

2014-01-14

275

Methanotrophy induces nitrogen fixation during peatland development  

PubMed Central

Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation. PMID:24379382

Larmola, Tuula; Leppänen, Sanna M.; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

2014-01-01

276

Initial Fixation Strength of Modified Patellar Tendon Grafts for Anatomic Fixation in Anterior Cruciate Ligament Reconstruction  

Microsoft Academic Search

Summary: Recently it has been shown that anatomic tibial graft fixation in anterior cruciate ligament (ACL) reconstruction is preferable in order to increase isometry and knee stability. To facilitate anatomic patellar tendon graft fixation, customized graft length shortening is necessary. The purpose of this study was to compare the initial fixation strength of four different shortened patellar tendon grafts including

Reinhard F. G. Hoffmann; Ricarda Peine; Hermann J. Bail; Norbert P. Südkamp; Andreas Weiler

1999-01-01

277

Information locking in black holes  

E-print Network

The black hole information loss paradox has plagued physicists since Hawking's discovery that black holes evaporate thermally in contradiction to the unitarity expected by quantum mechanics. Here we show that one of the central presumptions of the debate is incorrect. Ensuring that information not escape during the semi-classical evaporation process does not require that all the information remain in the black hole until the final stages of evaporation. Using recent results in quantum information theory, we find that the amount of information that must remain in the black hole until the final stages of evaporation can be very small, even though the amount already radiated away is negligible. Quantum effects mean that information need not be additive: a small number of quanta can lock a large amount of information, making it inaccessible. When this small number of locking quanta are finally emitted, the full information (and unitarity) is restored. Only if the number of initial states is restricted will the locking mechanism leak out information early.

John Smolin; Jonathan Oppenheim

2005-07-28

278

Osteotomy at the distal third of tibial tuberosity with LCP L-buttress plate for correction of tibia vara  

PubMed Central

Background Many osteotomy methods and fixation types have been used to correct the misalignment observed in tibia vara and to achieve a more uniform distribution of weight across the knee joint. Purpose The aim of this study is to test the efficacy and safety of a modified closing wedge high tibial osteotomy (CWHTO) procedure for tibia vara. Methods In this prospective study, young adults with tibia vara and mild medial arthritic changes were included. A CWHTO was performed at the distal third of the tibial tuberosity, instead of the conventional proximal site. An L-shaped locking compression plate was used for internal fixation. Before/after evaluation of femoro-tibial angle (FTA), pain relief, patellar height, and posterior tibial slope were evaluated. Adverse events were monitored. Results Seventy-five knees from 46 patients aged 27.2?±?5.8 years (range, 14–43 years) underwent the modified CWHTO procedure. After a follow-up of 26.3?±?7.4 months (range, 15–46 months), FTA correction was 12.4°?±?4.7° (range, 7°–31°), and pain was relieved. Reduction in the posterior tibial slope was 3.0°?±?2.3° (p?

2014-01-01

279

Nitrogen fixation method and apparatus  

DOEpatents

A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O[sub 2]/cm promotes the formation of vibrationally excited N[sub 2]. Atomic oxygen interacts with vibrationally excited N[sub 2] at a much quicker rate than unexcited N[sub 2], greatly improving the rate at which NO is formed. 1 fig.

Chen, H.L.

1983-08-16

280

Thoracolumbar spinal fractures: radiological results of transpedicular fixation combined with transpedicular cancellous bone graft and posterior fusion in 183 patients  

Microsoft Academic Search

In internal posterior fixation of thoracolumbar fractures combined with transpedicular cancellous bone graft and posterior fusion of the intervertebral facet joints at the level of the destroyed end plate it is still uncertain as to whether significant vertebral body collapse and loss of correction of the regional angle (RA) and the intervertebral angle (IVA) occur (after removal of the implants).

V. Leferink; K. Zimmerman; E. Veldhuis; E. ten Vergert; H. ten Duis

2001-01-01

281

[Use of electron scanning microscopy and technical mechanics methods for determination of prolonged usefulness of Polfix plates after clinical use].  

PubMed

The paper deals with mechanical properties and structural changes within POLFIX external fixator plates used for tibial fracture treatment. The results indicate strengthening of the ALSI 316 L steel in the course of using of the plate. Structural comparison between the new and used implant showed insignificant increase of fatigue features within the plate. Overall results allow for multiple use of POLFIX plates. PMID:9684501

Toborek, J; Laskawiec, J; Balin, A; Laskawiec, J; Mo?ko, K; Soza?ska, M

1998-01-01

282

21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.  

Code of Federal Regulations, 2014 CFR

...false Spinal intervertebral body fixation orthosis. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...3060 Spinal intervertebral body fixation orthosis. (a... A spinal intervertebral body fixation orthosis is a...

2014-04-01

283

21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.  

Code of Federal Regulations, 2013 CFR

...false Spinal intervertebral body fixation orthosis. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...3060 Spinal intervertebral body fixation orthosis. (a... A spinal intervertebral body fixation orthosis is a...

2013-04-01

284

21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.  

Code of Federal Regulations, 2012 CFR

...false Spinal intervertebral body fixation orthosis. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...3060 Spinal intervertebral body fixation orthosis. (a... A spinal intervertebral body fixation orthosis is a...

2012-04-01

285

21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.  

Code of Federal Regulations, 2011 CFR

...false Spinal intervertebral body fixation orthosis. 888...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...3060 Spinal intervertebral body fixation orthosis. (a... A spinal intervertebral body fixation orthosis is a...

2011-04-01

286

21 CFR 872.4880 - Intraosseous fixation screw or wire.  

Code of Federal Regulations, 2011 CFR

...false Intraosseous fixation screw or wire. 872.4880 Section...4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended...be inserted into fractured jaw bone segments to prevent their...

2011-04-01

287

21 CFR 872.4880 - Intraosseous fixation screw or wire.  

Code of Federal Regulations, 2013 CFR

...false Intraosseous fixation screw or wire. 872.4880 Section...4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended...be inserted into fractured jaw bone segments to prevent their...

2013-04-01

288

21 CFR 872.4880 - Intraosseous fixation screw or wire.  

Code of Federal Regulations, 2014 CFR

...false Intraosseous fixation screw or wire. 872.4880 Section...4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended...be inserted into fractured jaw bone segments to prevent their...

2014-04-01

289

21 CFR 872.4880 - Intraosseous fixation screw or wire.  

Code of Federal Regulations, 2010 CFR

...false Intraosseous fixation screw or wire. 872.4880 Section...4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended...be inserted into fractured jaw bone segments to prevent their...

2010-04-01

290

21 CFR 872.4880 - Intraosseous fixation screw or wire.  

Code of Federal Regulations, 2012 CFR

...false Intraosseous fixation screw or wire. 872.4880 Section...4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended...be inserted into fractured jaw bone segments to prevent their...

2012-04-01

291

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

292

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

293

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

294

3, 779801, 2006 Nitrogen fixation and  

E-print Network

BGD 3, 779­801, 2006 Nitrogen fixation and temperature E. Breitbarth et al. Title Page Abstract #12;BGD 3, 779­801, 2006 Nitrogen fixation and temperature E. Breitbarth et al. Title Page Abstract nitrogen cycle due to its significant input of atmospheric nitrogen into the ocean. Incorporating Tri

Boyer, Edmond

295

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

296

Chemical fixation of arsenic in contaminated soils  

Microsoft Academic Search

Arsenic-contaminated soils have been successfully treated using fixation methods whereby chemicals are added to prevent As mobilization. However, the chemistry of the fixation process used in the field is poorly understood. We have examined one process which succeeded in immobilizing 0. I to 0.2 weight % As in soil at a 69 a old dump site through the addition of

Remy J.-C. Hennet; S. L. Brantley

1996-01-01

297

Foveated analysis of image features at fixations  

Microsoft Academic Search

Analysis of the statistics of image features at observers' gaze can provide insights into the mechanisms of fixation selection in humans. Using a foveated analysis framework, in which image patches were analyzed at the resolution corresponding to their eccentricity from the prior fixation, we studied the statistics of four low-level local image features: luminance, RMS contrast, and bandpass outputs of

Umesh Rajashekar; Ian van der Linde; Alan C. Bovik; Lawrence K. Cormack

2007-01-01

298

HERBERT SCREW FIXATION OF SCAPHOID FRACTURES  

Microsoft Academic Search

er eviewed the records of 431 patients who had open reduction and internal fixation of the scaphoid performed by one surgeon (TJH) over a 13-year period. The Herbert bone screw provided adequate internal fixation without the use of plaster immobilisation, promoting a rapid functional recovery. On average, patients returned to work 4.7 weeks after surgery and wrist function was significantly

S. L. FILAN; T. J. HERBERT

299

Concurrent Kernels and Multiple GPUs 1 Page Locked Host Memory  

E-print Network

Concurrent Kernels and Multiple GPUs 1 Page Locked Host Memory host memory that is page locked and Multiple GPUs 1 Page Locked Host Memory host memory that is page locked or pinned executing a zero copy 2) Concurrent Kernels & Multiple GPUs L-39 21 April 2014 2 / 30 #12;page locked or pinned memory In contrast

Verschelde, Jan

300

Outcome after open reduction and angular stable internal fixation for supra-intercondylar fractures of the distal humerus: preliminary results with the LCP distal humerus system  

Microsoft Academic Search

Introduction  Fractures of the distal humerus are complex injuries that can be effectively treated with open reduction and internal fixation\\u000a (ORIF). The new LCP distal humerus system allows angular stable fixation of these complex fractures with anatomically preshaped\\u000a plates. The aim of the study was to evaluate operative reposition, fracture healing, and pain, function and patient satisfaction\\u000a after open reduction with

S. Greiner; N. P. Haas; H. J. Bail

2008-01-01

301

Microcontroller-based locking in optics experiments  

E-print Network

Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

K. Huang; H. Le Jeannic; J. Ruaudel; O. Morin; J. Laurat

2015-01-09

302

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

303

Microcontroller-based locking in optics experiments  

NASA Astrophysics Data System (ADS)

Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

Huang, K.; Le Jeannic, H.; Ruaudel, J.; Morin, O.; Laurat, J.

2014-12-01

304

Rapid eye-fixation training without eyetracking.  

PubMed

Maintenance of stable central eye fixation is crucial for a variety of behavioral, electrophysiological, and neuroimaging experiments. Naive observers in these experiments are not typically accustomed to fixating, either requiring the use of cumbersome and costly eyetracking or producing confounds in results. We devised a flicker display that produced an easily detectable visual phenomenon whenever the eyes moved. A few minutes of training using this display dramatically improved the accuracy of eye fixation while observers performed a demanding spatial attention cuing task. The same amount of training using control displays did not produce significant fixation improvements, and some observers consistently made eye movements to the peripheral attention cue, contaminating the cuing effect. Our results indicate that (1) eye fixation can be rapidly improved in naive observers by providing real-time feedback about eye movements, and (2) our simple flicker technique provides an easy and effective method for providing this feedback. PMID:19451374

Guzman-Martinez, Emmanuel; Leung, Parkson; Franconeri, Steve; Grabowecky, Marcia; Suzuki, Satoru

2009-06-01

305

Plate motions: fundamentals  

E-print Network

lithospheric plates" · Plate tectonics = a kinematic theory ­ Rigid plates (no intraplate deformation") · Convergent = subductions ("trenches") · Strike-slip = transform faults · Plate tectonics describesPlate motions: fundamentals · Assume a pie-shaped wedge plate B, rotating around E (=rotation pole

Déverchère, Jacques

306

Plate Tectonics  

NSDL National Science Digital Library

In this activity, presented by the Lane Community College MAPS GIS Program, students will learn the concept of a digital data viewer, and how this resource can help them learn more about plate tectonics. Students will learn terminology associated with both geology and computer aided GIS. The activity is presented as a PDF, and helps the student learn by presenting a series of easy to follow questions. This allows students to learn at their own pace, as it tests their knowledge every step of the way. Visitors will find links to the instructor and student versions of the lesson and links to the web-based GIS utility used in the activity.

2008-12-11

307

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

308

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

309

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

310

30 CFR 56.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Locking transformer enclosures. 56.12068 Section 56.12068...MINES Electricity § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2013-07-01

311

30 CFR 56.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Locking transformer enclosures. 56.12068 Section 56.12068...MINES Electricity § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2012-07-01

312

30 CFR 57.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Locking transformer enclosures. 57.12068 Section 57.12068...Electricity Surface Only § 57.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2010-07-01

313

30 CFR 57.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Locking transformer enclosures. 57.12068 Section 57.12068...Electricity Surface Only § 57.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2014-07-01

314

30 CFR 56.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Locking transformer enclosures. 56.12068 Section 56.12068...MINES Electricity § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2011-07-01

315

30 CFR 57.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Locking transformer enclosures. 57.12068 Section 57.12068...Electricity Surface Only § 57.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2012-07-01

316

30 CFR 57.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Locking transformer enclosures. 57.12068 Section 57.12068...Electricity Surface Only § 57.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2013-07-01

317

30 CFR 57.12068 - Locking transformer enclosures.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Locking transformer enclosures. 57.12068 Section 57.12068...Electricity Surface Only § 57.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

2011-07-01

318

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

319

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

320

170. VIEW OF UNIDENTIFIED LOCK SHOWING DOORS PARTIALLY OPEN. IRON ...  

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

170. VIEW OF UNIDENTIFIED LOCK SHOWING DOORS PARTIALLY OPEN. IRON RODS STICKING UP FROM GATES OPERATE PADDLES THAT ALLOWS WATER IN LOCK TO EQUALIZE WITH WATER IN CANAL DURING THE LOCKING PROCEDURE. - Morris Canal, Phillipsburg, Warren County, NJ

321

15. GUARD LOCKS VIEWED FROM THE NORTHWEST BANK: SHOWS UPSTREAM ...  

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

15. GUARD LOCKS VIEWED FROM THE NORTHWEST BANK: SHOWS UPSTREAM SIDE. GATEHOUSE ON THE LEFT, ISLAND IN THE CENTER, AND LOCK HOUSE ON THE RIGHT 1976 - Pawtucket Canal, Guard Locks, Lowell, Middlesex County, MA

322

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

323

Self-Injection Locking Of Diode Lasers  

NASA Technical Reports Server (NTRS)

Simple optical coupling scheme locks array of gain-guided diode lasers into oscillation in single mode and with single-lobed output beam. Selective feedback from thin etalon self-injection-locks array into desired mode. One application of new scheme for pumping of neodymium: yttrium aluminum garnet lasers with diode-laser arrays.

Hemmati, H.

1991-01-01

324

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

325

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

326

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

327

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

328

77 FR 71590 - Lock+TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [Project No. 13500-002] Lock+ TM Hydro Friends Fund XI, LLC; Notice of Preliminary...Competing Applications On October 1, 2012, Lock+ TM Hydro Friends Fund XI, LLC filed an application...11-30-12; 8:45 am] BILLING CODE...

2012-12-03

329

75 FR 78233 - Lock+TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...13761-000; Project No. 13770-000] Lock+\\TM\\ Hydro Friends Fund XXXVII; FFP Missouri...Emsworth Back Channel Dam Projects: Lock+ TM Hydro Friends Fund XXXVII's proposed project...12-14-10; 8:45 am] BILLING CODE...

2010-12-15

330

78 FR 26349 - Lock+TM  

Federal Register 2010, 2011, 2012, 2013, 2014

...Nos. 13424-002; 14516-000] Lock+\\TM\\ Hydro Friends Fund VI, LLC, FFP Iowa 2...Applications On January 2, 2013, Lock+\\TM\\ Hydro Friends Fund VI, LLC (Hydro Friends...5-3-13; 8:45 am] BILLING CODE...

2013-05-06

331

Past, Present, Future Erosion at Locke Island  

SciTech Connect

This report describes and documents the erosion that has occurred along the northeast side of Locke Island over the last 10 to 20 years. The principal cause of this erosion is the massive Locke Island landslide complex opposite the Columbia River along the White Bluffs, which constricts the flow of the river and deflects the river's thalweg southward against the island.

Bjornstad, Bruce N.

2006-08-08

332

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

2014-08-29

333

Alain Locke on Race and Race Relations.  

ERIC Educational Resources Information Center

Alain Locke's thinking on race and race relations is not always clearly understood. His interest in race stemmed primarily from his attempt to combat notions of national, racial, and cultural superiority. As excerpts from his works show, Locke's position is more appropriately described as culturally pluralistic, rather than integrationist.…

Mason, Ernest D.

1979-01-01

334

The Race Consciousness of Alain Locke.  

ERIC Educational Resources Information Center

Discusses the literary and philosophical writings of Alain Locke, focusing on his views of the relations between race, ethnicity, and art. Analyzes the tension between Locke's support for Black writers and his belief that they must strive to "universalize" their work for a non-Black audience. (KH)

Ochillo, Yvonne

1986-01-01

335

Morphological character of cervical spine for anterior transpedicular screw fixation  

PubMed Central

Background: Anterior cervical interbody grafts/cages combined with a plate were frequently used in multilevel discectomies/corpectomies. In order to avoid additional posterior stabilization in patients who undergo anterior reconstructive surgery, an anterior cervical transpedicular screw fixation, which offers higher stability is desirable. We investigated in this study the anatomical (morphologic) characters for cervical anterior transpedicular screw fixation. Materials and Methods: Left pedicle parameters were measured on computed tomography (CT) images based on 36 cervical spine CT scans from healthy subjects. The parameters included outer pedicle width (Distance from lateral to medial pedicle surface in the coronal plane), outer pedicle height (OPH) (Distance from upper to lower pedicle surface in the sagittal plane), maximal pedicle axis length (MPAL), distance transverse insertion point (DIP), distance of the insertion point to the upper end plate (DIUP), pedicle sagittal transverse angle (PSTA) and pedicle transverse angle (PTA) at C3 to C7. Results: The values of outer pedicle width and MPAL in males were larger than in females from C3 to C7. The OPH in males was larger than in females at C3 to C6, but there was no difference at C7. The DIP and PTA were significantly greater in males than in females at C3, but there was no difference in the angle at C4-7. The PSTA was not statistically different between genders at C3, 4, 7, but this value in males was larger than females at C5, 6. The DIUP was significantly greater in males at C3, 4, 6, 7 but was non significant at C5. Conclusions: The placement of cervical anterior transpedicular screws should be individualized for each patient and based on a detailed preoperative planning. PMID:24379459

Zhou, Rong-Ping; Jiang, Jian; Zhan, Zi-Chun; Zhou, Yang; Liu, Zhi-Li; Yin, Qing-Shui

2013-01-01

336

Is Supplementary Fixation Necessary in Anterior Cruciate Ligament Reconstructions?  

Microsoft Academic Search

Background: There has been concern regarding the fixation of anterior cruciate ligament reconstruction, with soft tissue grafts being strong and stiff enough to allow for early accelerated postoperative rehabilitation. Therefore, some have recommended supplementary fixation for soft tissue tibia interference screw fixation with a staple, to improve the strength and stiffness of the fixation. Unfortunately, with staple supplementation, there is

John J. Lee; Karimdad Otarodifard; Bong Jae Jun; Michelle H. McGarry; George F. Hatch; Thay Q. Lee

2011-01-01

337

Fixation stability in schizophrenia, bipolar, and control subjects  

Microsoft Academic Search

A few investigators have suggested that visual fixation abnormalities may serve as an endophenotype of liability for schizophrenia. However, the data are equivocal. Conflicting reports regarding the specificity of fixation deficits to schizophrenia may be attributable to methodological differences. Thirty-four schizophrenia patients, 20 bipolar patients, and 30 non-patient controls were presented targets for central fixation. Fixation was scored in terms

Diane C. Gooding; Jeffrey A. Grabowski; Christian S. Hendershot

2000-01-01

338

Earth's Decelerating Tectonic Plates  

Microsoft Academic Search

Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown

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

2008-01-01

339

Risk factors contributing to symptomatic plate removal in maxillofacial trauma patients.  

PubMed

This study analyzed the fate of plates used to correct maxillofacial injuries and defined risk factors that eventually resulted in plate removal. The outpatient clinic files of 108 patients treated with rigid internal fixation after maxillofacial trauma were reviewed. Study variables included age, sex, trauma circumstances, diagnosis, type of fracture, approach to the facial skeleton, presence of teeth in the line of fracture, plate material, site of plates, and reasons for plate removal. Of 204 plates used for fixation, 44 plates (22 percent) were removed. When all factors were considered together, only fracture diagnosis (mandibular body and angle) and plate location (mandibular body and angle) were statistically significant. Only when each factor was considered separately, the approach to the facial skeleton (intraoral) and the type of fracture (comminuted and compound fractures) were statistically associated with plate removal. Selection of favorable plate location, the extraoral approach, and vigilant infection control may reduce plate removal in patients with maxillofacial injuries. Special attention should be given to compound and comminuted fractures of the mandibular body and angle. PMID:10697155

Chaushu, G; Manor, Y; Shoshani, Y; Taicher, S

2000-02-01

340

An examination of fixation in brainstorming  

E-print Network

In this dissertation, two areas of creativity are reviewed. “Fixation” refers to the inability to solve a problem or retrieve a memory due to prior experience or an inappropriate solution path. Brainstorming is the process of generating as many...

Kohn, Nicholas William

2009-05-15

341

Neglected locked vertical patellar dislocation.  

PubMed

Patellar dislocations occurring about the vertical and horizontal axis are rare and irreducible. The neglected patellar dislocation is still rarer. We describe the clinical presentation and management of a case of neglected vertical patellar dislocation in a 6 year-old boy who sustained an external rotational strain with a laterally directed force to his knee. Initially the diagnosis was missed and 2 months later open reduction was done. The increased tension generated by the rotation of the lateral extensor retinaculum kept the patella locked in the lateral gutter even with the knee in full extension. Traumatic patellar dislocation with rotation around a vertical axis has been described earlier, but no such neglected case has been reported to the best of our knowledge. PMID:23162154

Gupta, Rakesh Kumar; Gupta, Vinay; Sangwan, Sukhbir Singh; Kamboj, Pradeep

2012-09-01

342

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

343

Open pisiform fracture: excision or internal fixation?  

PubMed Central

A 53-year-old man presented with an open fracture of the pisiform after a fall on his left wrist. Treatment of the patient presented a dilemma between excision of the proximal fragment and internal fixation. The patient underwent internal fixation with a 2.5 cortical screw. At 6?months follow-up the fracture appeared fully consolidated with full functional recovery of the wrist. PMID:23307459

Agathangelidis, Filon; Boutsiadis, Achilleas; Ditsios, Konstantinos

2013-01-01

344

Dinitrogen fixation in the Indian Ocean  

NASA Astrophysics Data System (ADS)

Several lines of geochemical evidence suggest that biological dinitrogen (N2) fixation is a quantitatively important process in the marine nitrogen (N) cycle. However, global and basin-scale rates of N2 fixation remain poorly constrained due to spatial and temporal under-sampling; this is particularly the case in the Indian Ocean (IO). Recent and multiple lines of evidence also suggest that N2 fixation and denitrification may be more closely coupled in space than previously suggested. In the Arabian Sea's (AS) oxygen minimum zone (OMZ), isotopic evidence and N2 supersaturation suggests N2 fixation is a significant process, and new analyses using a nutrient tracer, P*, suggests substantial N2 fixation in surface waters downstream of the AS OMZ. However, despite the geochemical inferences regarding the location and magnitude of N2 fixation in the AS, and the importance of this basin in removing fixed N from the ocean, observations of diazotrophic organisms supporting these conjectures are sparse, and rate measurements are few. The limited observational data available suggest the presence of a diverse group of diazotrophs, including Trichodesmium, cyanobacterial symbionts, and coccoid cyanobacteria. Specific controls on N2 fixation likely vary across the basin in response to external forcing (e.g., seasonal monsoons and upwelling) and inputs (e.g., aeolian and riverine fluxes). To better model the N cycle under current and future (and by extension, past) oceanic conditions, we need a better understanding of where N2 fixation occurs with respect to the OMZ, at what rates, and the physiological and environmental controls on diazotrophy in the IO.

Mulholland, Margaret R.; Capone, Douglas G.

345

Internal fixation in pediatric maxillofacial fractures.  

PubMed

Pediatric facial trauma presents unique problems in diagnosis and management. The following review highlights relevant points of craniofacial growth and applied anatomy. The epidemiology of pediatric facial fractures is presented followed by pertinent features of clinical presentation and diagnosis. Management of midfacial injuries is discussed individually for each specific type of fracture with emphasis on the role of rigid fixation. Finally, the relationships between childhood fractures, rigid fixation and craniofacial growth are reviewed. PMID:10371893

Winzenburg, S M; Imola, M J

1998-01-01

346

Foveation dynamics in congenital nystagmus I: Fixation  

Microsoft Academic Search

Congenital nystagmus (CN) has been described as a ‘fixation’ nystagmus implying an inability to fixate a target. However, each cycle of CN contains a target-foveation period during which the eye velocity is at, or near, zero. Prolongation of foveation time, reduction of retinal image velocity and cycle-to-cycle foveation repeatability all contribute to increased visual acuity. We developed several methods to

L. F. Dell'osso; J. Steen; R. M. Steinman; H. Coleewijn

1992-01-01

347

Resource Optimization and Symbiotic Nitrogen Fixation  

Microsoft Academic Search

In temperate forests, symbiotic nitrogen (N) fixation is restricted to the early phases of succession despite the persistence\\u000a of N limitation on production late in succession. This paradox has yet to be explained adequately. We hypothesized that the\\u000a restriction of N fixation to early stages of succession results from the optimization of resource allocation in the vegetation.\\u000a Because of this

E. B. Rastetter; P. M. Vitousek; C. Field; G. R. Shaver; D. Herbert; G. I. gren

2001-01-01

348

Plate Tectonics: Consequences of Plate Interactions  

NSDL National Science Digital Library

This Science Object is the fourth of five Science Objects in the Plate Tectonic SciPack. It identifies the events that may occur and landscapes that form as a result of different plate interactions. The areas along plate margins are active. Plates pushing against one another can cause earthquakes, volcanoes, mountain formation, and very deep ocean trenches. Plates pulling apart from one another can cause smaller earthquakes, magma rising to the surface, volcanoes, and oceanic valleys and mountains from sea-floor spreading. Plates sliding past one another can cause earthquakes and rock deformation. Learning Outcomes:? 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.

National Science Teachers Association (NSTA)

2006-11-01

349

Maxwellian Eye Fixation during Natural Scene Perception  

PubMed Central

When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF) of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell's law for each participant and for each scene condition (normal or scrambled). The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes. PMID:23226987

Duchesne, Jean; Bouvier, Vincent; Guillemé, Julien; Coubard, Olivier A.

2012-01-01

350

[Treatment of mandibular fractures with different fixation techniques--results of a prospective fracture study].  

PubMed

In a prospective study 150 adult patients with mandible fractures were analysed. Criteria for entry into the study were fractures of the mandibular body with and without associated condylar fractures. The fractures must fit to the Spiessl-classes F1 and F2, L1 to L4, W0 to W3 and the patients must have had a sufficient dentition to judge their occlusion. Not included were patients with combinations of mandible and Le Fort fractures, comminuted and defect fractures and patients who could not communicate preoperatively in order to have a full preoperative examination. The patients were equally distributed among 3 different treatment groups. Group 1 was treated conservatively with MMF, only displaced fractures which needed open reduction were internally fixed with wire osteosynthesis. Group 2 received rigid internal fixation with AO 2.7-plates from an intraoral approach, group 3 internal fixation with miniadaption-plates also from an intraoral approach. Using a standardized treatment protocol the patients were followed in defined intervals up to a maximum of 2 years after therapy. Group 1 presented with the lowest complication rate, group 2 with the highest rate of overall complications as far as disturbances of the occlusion and sensory disturbances were concerned. Except one plate fracture in group 3 with subsequent pseudarthrosis, which required a reosteosynthesis with a rigid plate, no major complications in bone healing were observed. PMID:8755403

Ehrenfeld, M; Roser, M; Hagenmaier, C; Mast, G

1996-01-01

351

Korean Type Distal Radius Anatomical Volar Plate System: A Preliminary Report  

PubMed Central

Background Distal radius fracture is the most common fracture of the upper extremity, and approximately 60,000 distal radius fractures occur annually in Korea. Internal fixation with an anatomical volar locking plate is widely used in the treatment of unstable distal radius fractures. However, most of the currently used distal radius anatomical plate systems were designed based on the anatomical characteristics of Western populations. Recently, the Korean-type distal radius anatomical volar plate (K-DRAVP) system was designed and developed based on the anatomical characteristics of the distal radius of Koreans. The purpose of this study was to evaluate the preliminary results of the new K-DRAVP system, and to compare its radiologic and functional results with those of the other systems. Methods From March 2012 to October 2012, 46 patients with acute distal radius fractures who were treated with the K-DRAVP system at three hospitals were enrolled in this study. Standard posteroanterior and lateral radiographs were obtained to assess fracture healing, and three radiographic parameters (volar tilt, radial inclination, and radial length) were assessed to evaluate radiographic outcomes. The range of motion and grip strength, the Gartland and Werley scoring system, and the disabilities of the arm, shoulder and hand (DASH) questionnaire were used to assess clinical and functional outcomes. Results All radiologic parameters were restored to normal values, and maintained without any loosening or collapse until the time of final follow-up. Grip strength was restored to 84% of the value for the unaffected side. The mean range of motion of the wrist at final follow-up was restored to 77%-95% of the value for the unaffected side. According to the Gartland and Werley scoring system, there were 16 excellent, 26 good, and 4 fair results. The mean DASH score was 8.4 points. There were no complications after surgery. Conclusions The newly developed K-DRAVP system could be used to restore and maintain good anatomical parameters, and provide good clinical outcomes with low complication rates. This system is a promising surgical option for the treatment of distal radius fractures in the Korean population. PMID:25177449

Kim, Jeong Hwan; Kim, Jihyeung; Kim, Min Bom; Rhee, Seung Hwan; Gong, Hyun Sik; Lee, Young Ho

2014-01-01

352

Growth Plate Fractures  

MedlinePLUS

... 2013 by the American Academy of Orthopaedic Surgeons. Growth Plate Fractures Description The bones of children and ... also subject to a unique injury called a growth plate fracture. Growth plates are areas of developing ...

353

Caribbean plate tectonics  

NSDL National Science Digital Library

This illustration available at Wikimedia Commons shows the plate tectonic setting in the Caribbean. Plate boundaries are color-coded by margin type and plate motions are noted with direction and magnitude in mm/yr.

Sting; Commons, Wikimedia

354

Cost of external fixation vs external fixation then nailing in bone infection  

PubMed Central

AIM: To study the cost benefit of external fixation vs external fixation then nailing in treatment of bone infection by segment transfer. METHODS: Out of 71 patients with infected nonunion tibia treated between 2003 and 2006, 50 patients fitted the inclusion criteria (26 patients were treated by external fixation only, and 24 patients were treated by external fixation early removal after segment transfer and replacement by internal fixation). Cost of inpatient treatment, total cost of inpatient and outpatient treatment till full healing, and the weeks of absence from school or work were calculated and compared between both groups. RESULTS: The cost of hospital stay and surgery in the group of external fixation only was 22.6 ± 3.3 while the cost of hospital stay and surgery in the group of early external fixation removal and replacement by intramedullary nail was 26.0 ± 3.2. The difference was statistically significant regarding the cost of hospital stay and surgery in favor of the group of external fixation only. The total cost of medical care (surgery, hospital stay, treatment outside the hospital including medications, dressing, physical therapy, outpatient laboratory work, etc.) in group of external fixation only was 63.3 ± 15.1, and total absence from work was 38.6 ± 6.6 wk. While the group of early removal of external fixation and replacement by IM nail, total cost of medical care was 38.3 ± 6.4 and total absence from work or school was 22.7 ± 4.1. The difference was statistically significant regarding the total cost and absence from work in favor of the group of early removal and replacement by IM nail. CONCLUSION: Early removal of external fixation and replacement by intramedullary nail in treatment of infected nonunion showed more cost effectiveness. Orthopaedic society needs to show the cost effectiveness of different procedures to the community, insurance, and health authorities.

Emara, Khaled Mohamed; Diab, Ramy Ahmed; Ghafar, Khaled Abd EL

2015-01-01

355

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

356

VIEW LOOKING NORTHEAST INTO LOCK 71. NOTE THE SEDIMENT BUILD ...  

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

VIEW LOOKING NORTHEAST INTO LOCK 71. NOTE THE SEDIMENT BUILD UP. THIS IS BY DESIGN, NOT ONLY ARE THE OLDER LOCKS USED AS AN OVERFLOW SPILLWAY FOR THE CURRENT LOCKS, THEY ARE ALSO USED FOR SEDIMENT AND DEBRIS CONTROL. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

357

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

358

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

359

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

360

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

361

Open Reduction and Internal Fixation of Intraarticular Fractures of the Humerus: Evaluation of 33 Cases  

PubMed Central

Background Standard treatment of type C elbow fractures is open reduction and internal fixation using reconstruction plates and pins. Objectives The aim of this study was to evaluate the functional outcome following internal fixation of intraarticular fractures of the distal humerus (AO Type C) with a minimum follow-up of three years. A retrospective evaluation was undertaken. Patients and Methods Thirty-three patients (28 males, 5 females; mean age 34.3years) type C elbow fractures were treated and observed over a period of three years. Six fractures were open and 27 closed; causes were falls (7 cases), traffic accidents (22 cases) and altercation (4 cases). All operations were performed using a posterior approach with an olecranon osteotomy. Mean duration of follow-up was 18 months (range 6–36). Mean duration of fracture healing was 2.3 months (range 2–4). Functional outcomes were assessed by Jupiter criteria. Results Excellent results were found in 69.7% (23 cases), very good reaults and good results were found in the remaining 30.3% (10 cases). Three of 33 patients 9% (3 cases) presented postoperative complications. No patient exhibited symptoms of ulnar nerve injury following surgery. One patient had cubitusvarus deformities and one case had heterotopic ossification. One patient had malunion and one case had deep infection. Conclusions Complications were minimal and outcomes were satisfactory in patients with type C distal humerus fractures who underwent bilateral plate fixation via a posterior approach. PMID:24350136

Mardanpour, Keykhosro; Rahbar, Mahtab

2013-01-01

362

Affective processing in natural scene viewing: Valence and arousal interactions in eye-fixation-related potentials.  

PubMed

Attention is drawn to emotionally salient stimuli. The present study investigates processing of emotionally salient regions during free viewing of emotional scenes that were categorized according to the two-dimensional model comprising of valence (unpleasant, pleasant) and arousal (high, low). Recent studies have reported interactions between these dimensions, indicative of stimulus-evoked approach or withdrawal tendencies. We addressed the valence and arousal effects when emotional items were embedded in complex real-world scenes by analyzing both eye movement behavior and eye-fixation-related potentials (EFRPs) time-locked to the critical event of fixating the emotionally salient items for the first time. Both data sets showed an interaction between the valence and arousal dimensions. First, the fixation rates and gaze durations on emotionally salient regions were enhanced for unpleasant versus pleasant images in the high arousal condition. In the low arousal condition, both measures were enhanced for pleasant versus unpleasant images. Second, the EFRP results at 140-170ms [P2] over the central site showed stronger responses for high versus low arousing images in the unpleasant condition. In addition, the parietal LPP responses at 400-500ms post-fixation were enhanced for stimuli reflecting congruent stimulus dimensions, that is, stronger responses for high versus low arousing images in the unpleasant condition and stronger responses for low versus high arousing images in the pleasant condition. The present findings support the interactive two-dimensional approach, according to which the integration of valence and arousal recruits brain regions associated with action tendencies of approach or withdrawal. PMID:25463473

Simola, Jaana; Le Fevre, Kevin; Torniainen, Jari; Baccino, Thierry

2015-02-01

363

The nature of the plate interface and driving force of interseismic deformation in the New Zealand plate-boundary zone, revealed by the continuous GPS velocity field  

NASA Astrophysics Data System (ADS)

New Zealand straddles the boundary between the Australian and Pacific plates. Cenozoic relative plate motion has resulted in a complex pattern of faulting and block rotation, with displacements on individual faults up to hundreds of kilometers. However, over periods of several years, GPS measurements show a remarkably smooth pattern of velocities. We show here using a new method of back slip analysis, that almost the entire plate-boundary continuous GPS velocity field can be predicted within measurement error from a simple model of elastic distortion due to deep slip on a single plate interface (megathrust in the Hikurangi and Putsegur subduction zones or fault through continental lithosphere beneath the Southern Alps) at the relative plate motion rates. This suggests that the main driving force of plate-boundary deformation is slip on the deeper moving part of the plate interface, without buried creep in localized shear zones beneath individual surface faults. The depth at which this deep slip terminates (locking point line) determines the width of deformation. Along the Hikurangi margin, there is also clockwise rotation of ~150 km long segment of the fore arc (Wairoa domain) at 4.5° ± 1 Ma, relative to the Australian Plate, about a pole in western North Island; model residuals in the velocity field are mainly a result of incomplete averaging of the cycle of slow slip events on the plate interface, downdip of the locking point.

Lamb, Simon; Smith, Euan

2013-06-01

364

Plate osteosynthesis of 367 mandibular fractures. The unrestricted indication for the intraoral approach.  

PubMed

Experience in the management of 916 fractures of the mandible stimulated us to develop new methods and surgical techniques for functionally-stable intraoral internal plate osteosynthesis. The development of a fixation bar which is adapted to the alveolar process of the fractured mandible enables a compression of this area prior to the plate osteosynthesis. This procedure facilitates the plate application from the intraoral approach so that in 358 cases all types of fractures of the body, angle and ascending ramus can be reduced using this access, and not only the selected favourable cases. A new plate and screws of our own design have been successfully used in cases with comminuted multifragmentary and defect fractures. The rigid fixation of the head of the screws to the plate produces an optimal functional stability compared with conventional systems. The combination of the advantages of an external fixation device and those of stable internal osteosynthesis produces a long term functional stability even in cases with extensive defects where delayed consolidation is to be expected; tilting and loosening of the screws or resorption of the compact bone underneath the plate do not occur. Thus the extraoral approach and visible skin incisions can be avoided. This procedure is time sparing and less traumatic to the soft tissues compared with the extraoral approach. The extremely low complication rate in 358 fractures managed by plate osteosynthesis using the intraoral approach confirms the efficiency of this method. PMID:3479445

Raveh, J; Vuillemin, T; Lädrach, K; Roux, M; Sutter, F

1987-10-01

365

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

366

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

367

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

368

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

369

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

370

Locking and releasing system in space telescope  

NASA Astrophysics Data System (ADS)

Space telescope locking and releasing system is one of the most important part in aerospace. It can provide the part in the spacecraft from being under attack. In this letter, the developing status and primary characteristics of several locking and releasing system in recent years were summarized. The main locking and releasing system can be part with pyrotechnic device and un-pyrotechnic device. The paper introduces the system and the way that the device released by compared the pyrotechnic and the un-pyrotechnic device. In the way of comparing the different device, the letter made the point that each of these device had its advantages that should been developed, and the disadvantages that should been improved. These analyses will provide references for the design of the locking and releasing system in the future of telescope research.

Wang, Yijian; Dong, Jihong; Li, Wei; Zhao, Weiguo

2014-09-01

371

Fixation Methods for Implantable Port Chamber: Comparative Study Using Glue, Self-stabilizing Leg and Suture Fixations in Rabbits  

PubMed Central

Objective To evaluate the fixation strength and tissue reaction of the glue fixation and self-stabilizing leg fixation methods and to compare the results with those of the conventional tagging suture fixation method. Materials and Methods Twelve healthy rabbits were selected and three different methods of implanting the port chamber were employed on the back of each rabbit. A total of thirty six port chambers were implanted with these three different methods, viz. the glue fixation method using tissue adhesive, the self-stabilizing leg method using a self-expandable stabilizing leg, and the suture fixation method. The fixation strength and the gross and histopathologic changes of each fixation method were evaluated at three days, one week, two weeks and four weeks after port implantation. Results The glue fixation method showed a good fixation strength, which was similar to that of the tagging suture method (p = 0.3486). Five of the six ports (83%) implanted with the glue fixation method which were examined after two weeks showed cracks on the external surface, but this had no adverse effects on their function. A large amount of granulation tissue reaction was found at the bottom of the chamber (p = 0.0025). The fixation with the self-stabilizing leg showed relatively lower fixation strength (p = 0.0043), but no turning-over of the chamber occurred. The fixation strength improved with time after the first week, and minimal granulation tissue reaction was observed with this method. Conclusion The glue fixation method exhibited equal fixation strength compared to the suture fixation, but showed cracking and a large amount of granulation tissue, whereas the fixation with a self-stabilizing leg showed weaker fixation strength. PMID:15637477

Na, Hyoung Il; Kwak, Byung Kook; Kim, Hyeon Joo; Lee, Yong Cheol

2004-01-01

372

Osteomyelitis After TightRope(®) Fixation of the Ankle Syndesmosis: A Case Report and Review of the Literature.  

PubMed

Fixation of ankle syndesmosis injuries using the Ankle TightRope(®) has been gaining popularity. It has been shown to produce good results, facilitate early weightbearing, reduce the need for implant removal, and allow an earlier return to work and, possibly, a more anatomic syndesmotic reduction compared with screw fixation. However, its usage has been associated with complications such as soft tissue irritation, infection and wound breakdown, suture-button subsidence, and pathologic fracture from the screw tract. We describe a case of chronic osteomyelitis and suture-button migration associated with TightRope(®) fixation and a limited contact-dynamic compression plate for ankle syndesmosis disruption and lateral malleolus fracture. PMID:25451206

Hong, Choon Chiet; Lee, Wei Ting; Tan, Ken Jin

2015-01-01

373

Transverse mode-locking in microcavity lasers  

NASA Astrophysics Data System (ADS)

We experimentally demonstrate mode-locking between the transverse modes of a laser. A vertical-cavity surface-emitting laser with evenly-spaced transverse modes is shown to emit a train of 2.1±0.1 ps pulses with an 11 ps repetition rate and a timing jitter of 235±30 fs. Transverse mode-locking in microcavity lasers has potential to improve the compactness, stability, integrability, repetition rate tunability, and efficiency of ultrafast optical communication sources.

Gordon, R.; Heberle, A. P.; Cleaver, J. R. A.

2002-12-01

374

Experimental Aspects Concerning Self-locking Angle  

Microsoft Academic Search

\\u000a Self-locking is a phenomenon that occurs both in lower pairs and higher pairs, being quantified by the self-locking angle;\\u000a it occurs due to friction forces, depending directly on normal forces from mechanism pairs. The paper presents some preliminary\\u000a experimental aspects regarding the influence of different parameters (bushing geometry and material, shaft heat treating,\\u000a gap dimension and friction type, rolling\\/sliding for

S. Alaci; F. C. Ciornei; L. Irimescu; D. Amarandei

375

Bayonet plug with ramp-activated lock  

NASA Technical Reports Server (NTRS)

Matched pair of washers with broad surface ramps is locking mechanism in bayonet plug. It can be used where threaded springs and fasteners are impractical because of extreme temperatures or other environmental incompatibility. Matched pair of ramped washers is placed on plug and bayonet inserted. Inner slot of one washer matches contour of plug; this washer is stationary. Inner slot of second washer is circular. When second washer is rotated, washers push against bayonet plug, locking it in place. Retaining wire secures plug.

Wood, K. E.

1980-01-01

376

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

377

Lock-Out / Tag-Out  

NSDL National Science Digital Library

Tags and locks can be the last line of defense against machinery accidents. This MATEC module leaves your learners solidly grounded in OSHA's six-step lockout/tagout procedures for preventing unexpected start-ups of equipment. They learn how to use energy-isolating devices and how to safely remove locks and tags. They can demonstrate their facility with the OHSA standards using a machine on the manufacturing floor.

378

Primer on the Lock-in Amplifier  

NSDL National Science Digital Library

This is an experiment designed to measure the resistance of copper and gold nanowires using a lock-in amplifier. Students learn: 1. about different types of noise, 2. the principles of phase-sensitive techniques, 3. to extract signals buried in noise using a lock-in amplifier, 4. to operate optical chopper to measure weak optical signals modulated at a certain frequency. 4. to measure the minute resistance of a conducting nanowires.

Farooq, Sidra; Salman, Rabiya; Zia, Wasif; Hassan, Umer; Anwar, Muhammad S.

2012-02-10

379

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

380

The Fixation and Saccade P3  

PubMed Central

Although most instances of object recognition during natural viewing occur in the presence of saccades, the neural correlates of objection recognition have almost exclusively been examined during fixation. Recent studies have indicated that there are post-saccadic modulations of neural activity immediately following eye movement landing; however, whether post-saccadic modulations affect relatively late occurring cognitive components such as the P3 has not been explored. The P3 as conventionally measured at fixation is commonly used in brain computer interfaces, hence characterizing the post-saccadic P3 could aid in the development of improved brain computer interfaces that allow for eye movements. In this study, the P3 observed after saccadic landing was compared to the P3 measured at fixation. No significant differences in P3 start time, temporal persistence, or amplitude were found between fixation and saccade trials. Importantly, sensory neural responses canceled in the target minus distracter comparisons used to identify the P3. Our results indicate that relatively late occurring cognitive neural components such as the P3 are likely less sensitive to post saccadic modulations than sensory neural components and other neural activity occurring shortly after eye movement landing. Furthermore, due to the similarity of the fixation and saccade P3, we conclude that the P3 following saccadic landing could possibly be used as a viable signal in brain computer interfaces allowing for eye movements. PMID:23144959

Dandekar, Sangita; Ding, Jian; Privitera, Claudio; Carney, Thom; Klein, Stanley A.

2012-01-01

381

Chemical and physical basics of routine formaldehyde fixation  

PubMed Central

Formaldehyde is the widely employed fixative that has been studied for decades. The chemistry of fixation has been studied widely since the early 20th century. However, very few studies have been focused on the actual physics/chemistry aspect of process of this fixation. This article attempts to explain the chemistry of formaldehyde fixation and also to study the physical aspects involved in the fixation. The factors involved in the fixation process are discussed using well documented mathematical and physical formulae. The deeper understanding of these factors will enable pathologist to optimize the factors and use them in their favor. PMID:23248474

Thavarajah, Rooban; Mudimbaimannar, Vidya Kazhiyur; Elizabeth, Joshua; Rao, Umadevi Krishnamohan; Ranganathan, Kannan

2012-01-01

382

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

383

Antibiotic cement-coated plates for management of infected fractures.  

PubMed

Deep infection in the presence of an implant after open reduction and internal fixation is usually treated with removal of the implant, serial débridement procedures, lavage, intravenously administered antibiotics, and occasionally, placement of antibiotic-impregnated beads. If infection occurs during the early stages of bone healing, fracture stabilization might be compromised after implant removal. Osteomyelitis, unstable owing to a bone deficit or fracture, was treated with an antibiotic cement-coated (tobramycin and vancomycin) plate. The goal was successful eradication of infection with the patient remaining infection-free for 1 year. Four patients were treated with antibiotic-coated plates for osteomyelitis and all have achieved successful union, clinically free of signs of infection for more than 1 year. One patient experienced a prominent and painful plate, necessitating removal. Based on our experience, early aggressive débridement coupled with broad-spectrum antibiotic cement-coated plate insertion, provides fracture stability and helps eradicate the infection with 1 surgical procedure. PMID:25658083

Conway, Janet D; Hlad, Lee M; Bark, Samantha E

2015-02-01

384

Correction of moderate and severe hallux valgus deformity with a distal metatarsal osteotomy using an intramedullary plate.  

PubMed

More than 200 surgeries have been described for hallux valgus correction. The distal V-shape chevron-type osteotomy was described with no more than 50% translation of the distal fragment in relation to the metatarsal shaft. This concept of high, powerful correction for distal chevron osteotomy fixed by the Mini MaxLock Extreme ISO gives the surgeon the possibility of a mini-invasive rapid solution. A new technique of fixation is based on the Murawski and Beskin concept, because a powerful correction can be performed with a minimally invasive approach, but, in contrast to other studies, with stable osteotomy fixation. PMID:24878409

Palmanovich, Ezequiel; Myerson, Mark S

2014-06-01

385

Mechanical analysis of a rodent segmental bone defect model: the effects of internal fixation and implant stiffness on load transfer.  

PubMed

Segmental bone defect animal models are often used for evaluating the bone regeneration performance of bone substituting biomaterials. Since bone regeneration is dependent on mechanical loading, it is important to determine mechanical load transfer after stabilization of the defect and to study the effects of biomaterial stiffness on the transmitted load. In this study, we assess the mechanical load transmitted over a 6mm femur defect that is stabilized with an internal PEEK fixation plate. Subsequently, three types of selective laser melted porous titanium implants with different stiffness values were used to graft the defect (five specimens per group). In one additional group, the defect was left empty. Micro strain gauges were used to measure strain values at four different locations of the fixation plate during external loading on the femoral head. The load sharing between the fixation plate and titanium implant was highly variable with standard deviations of measured strain values between 31 and 93% of the mean values. As a consequence, no significant differences were measured between the forces transmitted through the titanium implants with different elastic moduli. Only some non-significant trends were observed in the mean strain values that, consistent with the results of a previous finite element study, implied the force transmitted through the implant increases with the implant stiffness. The applied internal fixation method does not standardize mechanical loading over the defect to enable detecting small differences in bone regeneration performances of bone substituting biomaterials. In conclusion, the fixation method requires further optimization to reduce the effects of the operative procedure and make the mechanical loading more consistent and improve the overall sensitivity of this rat femur defect model. PMID:24882739

Yavari, S Amin; van der Stok, J; Ahmadi, S M; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

2014-08-22

386

Internal fixation versus hemiarthroplasty versus total hip arthroplasty for displaced subcapital fractures of femur — 13 year results of a prospective randomised study  

Microsoft Academic Search

In this prospective randomised trial we compare the mortality, morbidity and functional results of patients following each of the three principal methods of treatment for displaced subcapital fractures of the femur. Two hundred and ninety patients over the age of 65 years were included and randomly allocated to undergo closed reduction and internal fixation with a sliding compression screw plate

Kasetti J. Ravikumar; Gavin Marsh

2000-01-01

387

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

388

Biomechanical optimization of different fixation modes for a proximal femoral L-osteotomy  

PubMed Central

Background Numerous proposed surgical techniques have had minimal success in managing greater trochanter overgrowth secondary to retarded growth of the femoral capital epiphysis. For reconstruction of residual hip deformities, a novel type of proximal femur L-osteotomy was performed with satisfactory results. Although the clinical outcome was good, the biomechanical characteristics of the femur after such an osteotomy have not been clearly elucidated. Therefore, this study presents a three dimensional finite element analysis designed to understand the mechanical characteristics of the femur after the L-osteotomy. Methods A patient with left hip dysplasia was recruited as the study model for L-osteotomy. The normal right hip was used as a reference for performing the corrective surgery. Four FEA models were constructed using different numbers of fixation screws but the same osteotomy lengths together with four FEA models with the same number of fixation screws but different osteotomy lengths. The von Mises stress distributions and femoral head displacements were analyzed and compared. Results The results revealed the following: 1). The fixation devices (plate and screws) sustained most of the external loading, and the peak value of von Mises stress on the fixation screws decreased with an increasing number of screws. 2). Additional screws are more beneficial on the proximal segment than on the distal segment for improving the stability of the postoperative femur. 3). The extent of osteotomy should be limited because local stress might be concentrated in the femoral neck region with increasing length of the L-osteotomy. Conclusion Additional screw placement on the proximal segment improves stability in the postoperative femur. The cobra-type plate with additional screw holes in the proximal area might improve the effectiveness of L-osteotomies. PMID:19744345

Tai, Ching-Lung; Chen, Weng-Pin; Chen, Hsih-Hao; Lin, Chien-Yu; Lee, Mel S

2009-01-01

389

Wire-free fixation of jaw fractures.  

PubMed

Stainless steel wire is often used in the management of jaw fractures to provide intraoperative or postoperative intermaxillary fixation (IMF). Wiring of the jaws is time-consuming, a second procedure is needed to remove it, and needlestick injuries occur during placement. We report on 151 consecutive patients who had wire-free fixation of jaw fractures, and outline the value of a system of plastic anchorage points applied to individual teeth in both jaws that allows for wire-free IMF when they are linked by elastics (Rapid IMF, Synthes, PA, USA). A total of 150 successive patients had wire-free fixation of 146 mandibular and 5 maxillary fractures. Ninety-eight were hand-held in occlusion, and 52 were treated using Rapid IMF. There were few complications. PMID:19608310

Cousin, G C S

2009-10-01

390

Biometric recognition via fixation density maps  

NASA Astrophysics Data System (ADS)

This work introduces and evaluates a novel eye movement-driven biometric approach that employs eye fixation density maps for person identification. The proposed feature offers a dynamic representation of the biometric identity, storing rich information regarding the behavioral and physical eye movement characteristics of the individuals. The innate ability of fixation density maps to capture the spatial layout of the eye movements in conjunction with their probabilistic nature makes them a particularly suitable option as an eye movement biometrical trait in cases when free-viewing stimuli is presented. In order to demonstrate the effectiveness of the proposed approach, the method is evaluated on three different datasets containing a wide gamut of stimuli types, such as static images, video and text segments. The obtained results indicate a minimum EER (Equal Error Rate) of 18.3 %, revealing the perspectives on the utilization of fixation density maps as an enhancing biometrical cue during identification scenarios in dynamic visual environments.

Rigas, Ioannis; Komogortsev, Oleg V.

2014-05-01

391

Antimicrobial activity of UMFix tissue fixative  

PubMed Central

Aims: The aim of this study was to determine the antimicrobial effects of UMFix, an alcohol based tissue fixative, on various microorganisms. The UMFix solution was compared with 10% neutral buffered formalin. Methods: Standard methods to determine microorganism colony counts were performed after exposure of the microorganisms to UMFix and 10% neutral buffered formalin. Results: After a short exposure, UMFix rapidly killed vegetative bacteria, yeasts, moulds, and viruses. Bacterial spores were resistant to killing by UMFix. All organisms were killed by the 10% neutral buffered formalin preparation. Conclusions: UMFix was microbicidal for vegetative bacteria, yeasts, and aspergillus species after a short exposure, although it was not active against spore forming bacillus species. The methanol content of the fixative was responsible for the killing effect of this fixative. No killing was seen when polyethylene glycol was used alone. PMID:15623477

Cleary, T J; Morales, A R; Nadji, M; Nassiri, M; Vincek, V

2005-01-01

392

External fixation and limited internal fixation for complex fractures of the tibial plateau.  

PubMed

Twenty-one complex fractures of the tibial plateau in twenty patients were treated with closed reduction, interfragmental screw fixation of the articular fragments, and application of a unilateral half-pin external fixator. The average duration of external fixation was twelve weeks (range, three to twenty weeks). The fixator was left in situ until the fracture had united in all but two patients. All of the fractures healed. The complications with this technique were attributable primarily to the proximal half-pins of the external fixator. Seven patients needed antibiotics for an infection at a pin site, and two had septic arthritis that necessitated arthrotomy and débridement. The average duration of follow-up was thirty-eight months. The range of motion of nineteen of the twenty-one knees was at least a 115-degree arc. Laxity was evident in seven knees, but no patient complained of instability of the knee. Radiographs showed malalignment of more than 6 degrees in three knees compared with the normal, contralateral knee and evidence of post-traumatic osteoarthrosis in five knees. The Iowa knee score, determined for nineteen patients, averaged 87 points (range, 55 to 100 points). The SF-36 general health survey demonstrated that most patients had function close to that of age-matched controls. We concluded that external fixation with limited internal fixation is a satisfactory technique for the treatment of selected complex fractures of the tibial plateau. PMID:7744891

Marsh, J L; Smith, S T; Do, T T

1995-05-01

393

Complex fractures of the distal radius treated with angular stability plates  

Microsoft Academic Search

Complex fractures of the distal radius are articular lesions and comminuted at the level of the epiphysis and metaphysis.\\u000a Their treatment is difficult and in most cases surgical. Of all the different osteosynthesis methods available, internal fixation\\u000a with plate and screws is the most commonly used. In particular, angular stability plates are superior in terms of rigidity\\u000a and stability to

Marco Frattini; Giovanni Soncini; Maurizio Corradi; Bruno Panno; Silvio Tocco; Francesco Pogliacomi

2009-01-01

394

Spatially robust estimates of biological nitrogen (N) fixation imply substantial human alteration of the  

E-print Network

cluster sampling | free-living nitrogen fixation | nitrogen deposition | symbiotic nitrogen fixation OverSpatially robust estimates of biological nitrogen (N) fixation imply substantial human alteration, 2013) Biological nitrogen fixation (BNF) is the largest natural source of exogenous nitrogen (N

Cleveland, Cory

395

Fixation of tibial components of knee prostheses.  

PubMed

Twelve different tibial components were compared for fixation. The components included compartmental, anteriorly joined, posterior-cruciate retaining, and one-place with one, two, or three fixation posts; all-plastic or with a metal tray. The apparatus applied compressive load with anterior-posterior force, rotational torque, or varus-valgus moment. The relative deflections, both compressive and distractive, were measured between the component and the bone. The least deflections occurred with one-piece metal-tray components with one or two posts and with one-piece plastic components with a post on each side. Compartmental components deflected the most. PMID:7462283

Walker, P S; Greene, D; Reilly, D; Thatcher, J; Ben-Dov, M; Ewald, F C

1981-02-01

396

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

397

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

Code of Federal Regulations, 2012 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...

2012-10-01

398

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

Code of Federal Regulations, 2010 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...

2010-10-01

399

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

Code of Federal Regulations, 2011 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...

2011-10-01

400

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

401

Finite element analysis of three patterns of internal fixation of fractures of the mandibular condyle.  

PubMed

The most stable pattern of internal fixation for fractures of the mandibular condyle is a matter for ongoing discussion. In this study we investigated the stability of three commonly used patterns of plate fixation, and constructed finite element models of a simulated mandibular condylar fracture. The completed models were heterogeneous in the distribution of bony material properties, contained about 1.2 million elements, and incorporated simulated jaw-adducting musculature. Models were run assuming linear elasticity and isotropic material properties for bone. This model was considerably larger and more complex than previous finite element models that have been used to analyse the biomechanical behaviour of differing plating techniques. The use of two parallel 2.0 titanium miniplates gave a more stable configuration with lower mean element stresses and displacements over the use of a single miniplate. In addition, a parallel orientation of two miniplates resulted in lower stresses and displacements than did the use of two miniplates in an offset pattern. The use of two parallel titanium plates resulted in a superior biomechanical result as defined by mean element stresses and relative movement between the fractured fragments in these finite element models. PMID:22981343

Aquilina, Peter; Chamoli, Uphar; Parr, William C H; Clausen, Philip D; Wroe, Stephen

2013-06-01

402

The locking and unlocking characteristics of a seat belt inertial locking system due to acceleration.  

PubMed

An inertial locking mechanism of a seatbelt is designed to prevent further seatbelt extension when it exceeds an acceleration threshold. The acceleration threshold varies with the orientation of the mechanism and direction of acceleration. A setup and procedure were created to test the acceleration threshold of the inertial locking mechanism of a seatbelt in various orientations. For an example of an inertial locking mechanism a 1984 Ford Mustang seatbelt mechanism was used. During testing, the mechanism was put into an orientation that simulated accelerations that could be seen in normal collisions. The mechanism responded by locking with an average acceleration of 2.535 g. The mechanism was then tested in orientations that would simulate those seen by a vehicle in a rollover situation. In certain orientations, the mechanism was locked while at rest, but became unlocked when accelerated. PMID:15133989

Ladd, Mark; Breiding, David; Pohlman, Jon; Smith, Matthew

2004-01-01

403

Early Experience With Poly L-Lactic Acid Bioabsorbable Fixation System for Paediatric Craniosynostosis Surgery. Report of 3 Cases  

Microsoft Academic Search

Summary  ¶?Objective. The authors describe early experience in the use of bioabsorbable fixation devices for cranial reconstruction of paediatric\\u000a craniosynostosis patients.\\u000a \\u000a ?Methods. Three patients, individually respectively presenting sagittal synostosis, metopic synostosis, and clover leaf skull deformity,\\u000a underwent cranial reconstruction using poly L-lactic acid (PLLA) plates and screws. The patients ranged in age from 2 to 10\\u000a months at the time of

H. Arai; K. Sato; O. Okuda; M. Miyajima; M. Hishii; H. Nakanishi; H. Ishii

2000-01-01

404

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

405

Complex nonunion of fractures of the femoral shaft treated by wave-plated osteosynthesis  

Microsoft Academic Search

We have treated 42 consecutive complex ununited fractures of the femoral shaft by wave-plate osteosynthesis at five different medical centres. There were 13 with previous infection, 12 with segmental cortical defects, and 3 were pathological fractures. In 39 cases there had been previous internal fixation and 21 patients had had more than one earlier operation. Union was achieved in 41

David Ring; Jesse B. Jupiter; Richard A. Sanders; Jaime Quintero; Vincent M. Santoro; Reinhold Ganz; Rene K. Marti

1997-01-01

406

A biologic model for assessment of osseous strain patterns and plating systems in the human maxilla  

Microsoft Academic Search

Purpose: This study was conducted to examine a biomechanical model and to help answer fundamental questions that relate to rigid plate fixation in the maxilla. Specifically, we sought to elucidate the principal strain patterns generated in the maxilla secondary to masticatory forces as well as the amount of permanent deformational changes incurred due to these loading forces. Materials and Methods:

L. Russell Alberts; Kenneth O. Phillips; Harold K. Tu; Warren W. Stinson; Andrew Friedman

2003-01-01

407

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. PMID:25404771

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

2014-01-01

408

New surgical technique to secure the bone strut during anterior cervical corpectomy and fusion: kusabi fixation technique--technical note.  

PubMed

Fixation using an anterior cervical plate is frequently used in anterior cervical discectomy or corpectomy and fusion procedures because of the higher fusion rate than without instrumentation. The surgical outcomes with the anterior plate technique are acceptable, but various hardware-related complications have been reported. The authors describe a new surgical technique, called the kusabi fixation technique, for securing the bone strut during anterior cervical corpectomy using cylindrical cages. Following corpectomy, the trimmed bone strut was placed into the space drilled-out. Two small holes of 5-6-mm diameter and 5-mm depth were drilled out at the interface of two bones at the top and bottom of the bone strut in a diagonal orientation. Two cylindrical cages filled with autologous bone tips were tapped into the interface. Eight patients with myelopathy were treated by this method. All procedures were uneventfully performed as a single level surgery (two vertebral bodies and one disk level). Solid bone union was obtained in all patients at 6 months after the operation. Apparent alignment change in the cervical spine was observed in only one patient, who developed asymptomatic kyphosis. No instrumentation failure or significant complications related to the surgery occurred. Precise biomechanical aspects and long-term radiographic analysis compared with the plate fixation technique should be established, but this new method provides another way to secure the bone strut in anterior cervical corpectomy and fusion. PMID:20098036

Tani, Satoshi; Homma, Takao; Uchikado, Hisaaki; Nagashima, Hiroyasu; Isoshima, Akira; Ohhashi, Hiroki; Tochigi, Satoru; Abe, Toshiaki

2010-01-01

409

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

410

Original article Nitrogen fixation by Trifolium repens and Lotus  

E-print Network

Original article Nitrogen fixation by Trifolium repens and Lotus tenuis-based pastures. (© Inra/ Elsevier, Paris.) N2fixation / Lotus tenuis / Trifolium repens / Festuca arundinacea / continuous grazing Résumé - Fixation d'azote par des prairies à base de Trifolium repens ou Lotus tenuis de

Paris-Sud XI, Université de

411

Functional Ecology of Free-Living Nitrogen Fixation  

E-print Network

Functional Ecology of Free-Living Nitrogen Fixation: A Contemporary Perspective Sasha C. Reed,1;1. INTRODUCTION Nitrogen (N) is essential to all life, and a single process--biological N2 fixation--is thought fixation that does not consist of a demarcated symbiotic relationship between plants and microorganisms

Cleveland, Cory

412

Modelling nitrogen fixation of pea (Pisum sativumL.)  

Microsoft Academic Search

Nitrogen fixation was simulated for a leafless variety (Delta) of pea (Pisum sativum L.) in central Sweden. It is assumed that N2 fixation is basically proportional to root biomass, but limited by high root N or low substrate carbon concentrations. Input data on root carbon and nitrogen were estimated from observations of above-ground biomass and nitrogen. The simulated N2 fixation

Henrik Eckersten; Linda AF Geijersstam; Bengt Torssell

2006-01-01

413

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

414

Regional alterations in long bone /sup 85/Sr clearance produced by internal fixation devices. Part II. Histomorphometry  

SciTech Connect

The effects of each of the surgical stages involved in compression plating on the development of cortical thinning and porosity were assessed in the intact midshaft, stress-shielded femoral segments of adult mongrel dogs 6 months postoperatively. The data were evaluated in terms of a postsurgical tetracycline-based measure of remodeling and terminal /sup 85/Sr clearance (SrC) values for the plated segments of bone. Drilling had no effect on any parameter. Screw application was associated with minimal cortical thinning (p less than 0.05), while plate fixation clearly promoted thinning (p less than 0.01) and porosity (p less than 0.05). The percentage of labeled osteons, a measure of remodeling activity, increased only after plate fixation (p less than 0.05), and the labeling patterns suggested that most osteons had formed during the first 4 postsurgical months. That none of these changes were correlated with the 6-month SrC values suggests that the development of plate-induced osteopenia involves disparate histomorphometric time constants, rather than lack of any association.

Simmons, D.J.; Daum, W.J.; Calhoun, J.H.

1988-01-01

415

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

416

Probability of fixation and evolution of cooperation  

E-print Network

of cooperation Sabin Lessard Universit´e de Montr´eal 1. Examples of cooperation 2. Prisoner's Dilemma 3. Evolutionary dynamics in an infinite population 4. Probability of fixation in a finite population 5. Generalized one-third law 6. Projected average allelic effect 7. Effect of population structure 8. Variants

Lessard, Sabin

417

Titanium alloys for fracture fixation implants  

Microsoft Academic Search

This paper is intended to provide an overview of the composition, mechanical properties, biocompatibility, and clinical applications for titanium alloys that are used for fracture fixation implants. A new class of titanium implant alloys has emerged in recent years that exhibits a ? microstructure and a unique combination of mechanical properties. Important information regarding notch sensitivity testing and clinical significance

J. A. Disegi

2000-01-01

418

Foveated analysis of image features at fixations.  

PubMed

Analysis of the statistics of image features at observers' gaze can provide insights into the mechanisms of fixation selection in humans. Using a foveated analysis framework, in which image patches were analyzed at the resolution corresponding to their eccentricity from the prior fixation, we studied the statistics of four low-level local image features: luminance, RMS contrast, and bandpass outputs of both luminance and contrast, and discovered that the image patches around human fixations had, on average, higher values of each of these features at all eccentricities than the image patches selected at random. Bandpass contrast showed the greatest difference between human and random fixations, followed by bandpass luminance, RMS contrast, and luminance. An eccentricity-based analysis showed that shorter saccades were more likely to land on patches with higher values of these features. Compared to a full-resolution analysis, foveation produced an increased difference between human and random patch ensembles for contrast and its higher-order statistics. PMID:17889221

Rajashekar, Umesh; van der Linde, Ian; Bovik, Alan C; Cormack, Lawrence K

2007-11-01

419

Biomechanical evaluation of rotator cuff fixation methods  

Microsoft Academic Search

Initial fixation strength and failure mode for various rotator cuff reattachment techniques (variations of the McLaughlin technique) were evaluated. Repair methods included standard suture (control), reinforced suture [expanded polytetrafluoroethylene (PTFE) patch and polydioxanone (PDS) tape augmentation] and stapling (nonarthroscopic and arthroscopic soft-tissue staples). The average strength of intact rotator cuff tissue (su praspinatus tendon) was also determined. The different rotator

E. Paul France; Lonnie E. Paulos; Chris D. Harner; Chris B. Straight

1989-01-01

420

Methods for enhancing symbiotic nitrogen fixation  

Microsoft Academic Search

Biological nitrogen fixation of leguminous crops is becoming increasingly important in attempts to develop sustainable agricultural production. However, these crops are quite variable in their effectiveness in fixing nitrogen. By the use of the 15N isotope dilution method some species have been found to fix large proportions of their nitrogen, while others like common bean have been considered rather inefficient.

Gudni Hardarson

1993-01-01

421

Cloned nodulin genes for symbiotic nitrogen fixation  

Microsoft Academic Search

plant genes encoding nodule-specific proteins (nodulins) are expressed only after the infection of the legume plant with Rhizobium and their expression occurs prior to and independent of the commencement of nitrogen fixation in nodules. Nodulins appear to play three major roles: they participate in the morphogenesis of the nodule including the formation of the endosymbiotic compartment; they are involved in

Ashton J. Delauney; Desh Pal S. Verma

1988-01-01

422

Molybdenum and Sulphur in Symbiotic Nitrogen Fixation  

Microsoft Academic Search

NITRATE accumulation due to ineffective nitrate utilization may occur in plants in cases of deficiencies of either molybdenum1-3 or of sulphur4, 5. Though high in nitrogen, such affected plants show symptoms of nitrogen deficiency. It has also been suggested that the effect of molybdenum on legumes is due to its influence in the actual process of symbiotic nitrogen fixation rather

A. J. Anderson; D. Spencer

1949-01-01

423

Genomics insights into symbiotic nitrogen fixation  

Microsoft Academic Search

Following an interaction with rhizobial soil bacteria, legume plants are able to form a novel organ, termed the root nodule. This organ houses the rhizobial microsymbionts, which perform the biological nitrogen fixation process resulting in the incorporation of ammonia into plant organic molecules. Recent advances in genomics have opened exciting new perspectives in this field by providing the complete gene

Stefan Weidner; Alfred Pühler; Helge Küster

2003-01-01

424

Antimicrobial activity of UMFix tissue fixative  

Microsoft Academic Search

Aims: The aim of this study was to determine the antimicrobial effects of UMFix, an alcohol based tissue fixative, on various microorganisms. The UMFix solution was compared with 10% neutral buffered formalin.Methods: Standard methods to determine microorganism colony counts were performed after exposure of the microorganisms to UMFix and 10% neutral buffered formalin.Results: After a short exposure, UMFix rapidly killed

T J Cleary; A R Morales; M Nadji; M Nassiri; V Vincek

2005-01-01

425

Photoelastic stress analysis of internal fixation techniques for femur shaft crack  

NASA Astrophysics Data System (ADS)

In this paper, a photoelastic stress analysis is carried out for a cracked femur bone with compression plate fixation. A loading rig has been designed and manufactured to apply forces in the physical directions on the 2D modal of the femur bone based on a single-leg-stance. Three femur models made of photoelastic materials had been fabricated with three configurations and loaded. A recently developed three- load to phase shifting method is adopted to extract the full-field quantitative information from the fringe patterns of the loaded models. A comparison shows that the configuration where the screws point away from each other had the best effectiveness.

Liu, Tong; Chai, Gin B.; Asundi, Anand K.; Murugiah, Arumaaran

2001-06-01

426

Analysis of initial fixation strength of press-fit fixation technique in anterior cruciate ligament reconstruction  

Microsoft Academic Search

We performed a controlled laboratory study to evaluate the initial fixation strength of press-fit technique. Forty porcine lower limbs were used and divided into four groups according to the method of fixation; group 1 (press-fit+1.4 mm), in which the diameter difference between the bone plug and the femoral tunnel was 1.4 mm; group 2 (press-fit+1.4 mm, 30°), in which the

Myung Chul Lee; Hyunchul Jo; Tae-Soo Bae; Jin Dae Jang; Sang Cheol Seong

2003-01-01

427

Prefrontal phase locking to hippocampal theta oscillations.  

PubMed

The interactions between cortical and hippocampal circuits are critical for memory formation, yet their basic organization at the neuronal network level is not well understood. Here, we demonstrate that a significant portion of neurons in the medial prefrontal cortex of freely behaving rats are phase locked to the hippocampal theta rhythm. In addition, we show that prefrontal neurons phase lock best to theta oscillations delayed by approximately 50 ms and confirm this hippocampo-prefrontal directionality and timing at the level of correlations between single cells. Finally, we find that phase locking of prefrontal cells is predicted by the presence of significant correlations with hippocampal cells at positive delays up to 150 ms. The theta-entrained activity across cortico-hippocampal circuits described here may be important for gating information flow and guiding the plastic changes that are believed to underlie the storage of information across these networks. PMID:15820700

Siapas, Athanassios G; Lubenov, Evgueniy V; Wilson, Matthew A

2005-04-01

428

Self-locking mechanical center joint  

NASA Technical Reports Server (NTRS)

A device for connecting, rotating and locking together a pair of structural half columns is described. The device is composed of an identical pair of cylindrical hub assemblies connected at their inner faces by a spring loaded hinge; each hub assembly having a structural half column attached to its outer end. Each hub assembly has a spring loading locking ring member movably attached adjacent to its inner face and includes a latch member for holding the locking ring in a rotated position subject to the force of its spring. Each hub assembly also has a hammer member for releasing the latch on the opposing hub assembly when the hub assemblies are rotated together. The spring loaded hinge connecting the hub assemblies rotates the hub assemblies and attached structural half columns together bringing the inner faces of the opposing hub assemblies into contact with one another.

Bush, H. G.; Wallsom, R. E. (inventors)

1985-01-01

429

Entropy driven key-lock assembly.  

PubMed

The effective interaction between a sphere with an open cavity (lock) and a spherical macroparticle (key), both immersed in a hard sphere fluid, is studied by means of Monte Carlo simulations. As a result, a two-dimensional map of the key-lock effective interaction potential is constructed, which leads to the proposal of a self-assembling mechanism: There exists trajectories through which the key-lock pair could assemble avoiding trespassing potential barriers. Hence, solely the entropic contribution can induce their self-assembling even in the absence of attractive forces. This study points out the solvent contribution within the underlying mechanisms of substrate-protein assemblydisassembly processes, which are important steps of the enzyme catalysis and protein mediated transport. PMID:19044943

Odriozola, G; Jiménez-Angeles, F; Lozada-Cassou, M

2008-09-21

430

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

431

Finite element methods for Timoshenko beam, circular arch and Reissner-Mindlin plate problems  

Microsoft Academic Search

In this paper some finite element methods for Timoshenko beam, circular arch and Reissner-Mindlin plate problems are discussed. To avoid locking phenomenon, the reduced integration technique is used and a bubble function space is added to increase the solution accuracy. The method for Timoshenko beam is aligned with the Petrov-Galerkin formulation derived in Loula et al. (1987) and can be

Xiao-liang Cheng; Weimin Han; Hong-ci Huang

1997-01-01

432

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

433

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.

434

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

435

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.

436

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

437

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

438

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. 18 figures.

Hadley, G.R.; Hohimer, J.P.; Owyoung, A.

1991-02-19

439

Mode-locked silicon evanescent lasers.  

PubMed

We demonstrate electrically pumped lasers on silicon that produce pulses at repetition rates up to 40 GHz. The mode locked lasers generate 4 ps pulses with low jitter and extinction ratios above 18 dB, making them suitable for data and telecommunication transmitters and for clock generation and distribution. Results of both passive and hybrid mode locking are discussed. This type of device could enable new silicon based integrated technologies, such as optical time division multiplexing (OTDM), wavelength division multiplexing (WDM), and optical code division multiple access (OCDMA). PMID:19547478

Koch, Brian R; Fang, Alexander W; Cohen, Oded; Bowers, John E

2007-09-01

440

SESAM mode-locked red praseodymium laser.  

PubMed

We present the first semiconductor saturable absorber mirror (SESAM) mode-locked praseodymium solid-state laser. The laser is based on a Pr3+:LiYF4 crystal as gain medium and a GaInP-quantum well-based SESAM. Self-starting continuous-wave mode-locked laser operation with an average output power of 16 mW is achieved at a center wavelength of 639.5 nm. The laser operates at a repetition rate of ?85.55??MHz and emits pulses with a duration of ?18??ps. PMID:25503035

Gaponenko, Maxim; Metz, Philip Werner; Härkönen, Antti; Heuer, Alexander; Leinonen, Tomi; Guina, Mircea; Südmeyer, Thomas; Huber, Günter; Kränkel, Christian

2014-12-15

441

Hydrodynamic Phase Locking in Mouse Node Cilia  

NASA Astrophysics Data System (ADS)

Rotational movement of mouse node cilia generates leftward fluid flow in the node cavity, playing an important role in left-right determination in the embryo. Although rotation of numerous cilia was believed necessary to trigger the determination, recent reports indicate the action of two cilia to be sufficient. We examine cooperative cilia movement via hydrodynamic interaction. Results show cilia to be cooperative, having phases locked in a certain relation; a system with a pair of nonidentical cilia can achieve phase-locked states more easily than one with a pair of identical cilia.

Takamatsu, Atsuko; Shinohara, Kyosuke; Ishikawa, Takuji; Hamada, Hiroshi

2013-06-01

442

Hydrodynamic Phase Locking of Swimming Microorganisms  

NASA Astrophysics Data System (ADS)

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 coswimming 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.; Lauga, Eric

2009-08-01

443

Lock-in transition in layered superconductors  

NASA Astrophysics Data System (ADS)

We have studied the equilibrium vortex state of various layered superconductors by torque magnetometry. From the angle dependence of the torque the anisotropy of the magnetic penetration depth ?= ??/ ?| is determined. In Tl 2Ca 2Ba 2Cu 3O 10 and Bi 2Sr 2CaCu 2O 8 we find extreme values up to ?=900. At field orientations close to parallel to the layers a double peak of the torque appears as a fingerprint of the vortex lock-in transition. In the locked state we observe ideal screening of the field component perpendicular to the planes.

Steinmeyer, F.; Kleiner, R.; Müller, P.; Winzer, K.

1994-02-01

444

Dark Carbon Fixation: An Important Process in Lake Sediments  

PubMed Central

Close to redox boundaries, dark carbon fixation by chemoautotrophic bacteria may be a large contributor to overall carbon fixation. Still, little is known about the relative importance of this process in lake systems, in spite the potentially high chemoautotrophic potential of lake sediments. We compared rates of dark carbon fixation, bacterial production and oxygen consumption in sediments from four Swedish boreal and seven tropical Brazilian lakes. Rates were highly variable and dark carbon fixation amounted up to 80% of the total heterotrophic bacterial production. The results indicate that non-photosynthetic carbon fixation can represent a substantial contribution to bacterial biomass production, especially in sediments with low organic matter content. PMID:23776549

Santoro, Ana Lúcia; Bastviken, David; Gudasz, Cristian; Tranvik, Lars; Enrich-Prast, Alex

2013-01-01

445

Dark carbon fixation: an important process in lake sediments.  

PubMed

Close to redox boundaries, dark carbon fixation by chemoautotrophic bacteria may be a large contributor to overall carbon fixation. Still, little is known about the relative importance of this process in lake systems, in spite the potentially high chemoautotrophic potential of lake sediments. We compared rates of dark carbon fixation, bacterial production and oxygen consumption in sediments from four Swedish boreal and seven tropical Brazilian lakes. Rates were highly variable and dark carbon fixation amounted up to 80% of the total heterotrophic bacterial production. The results indicate that non-photosynthetic carbon fixation can represent a substantial contribution to bacterial biomass production, especially in sediments with low organic matter content. PMID:23776549

Santoro, Ana Lúcia; Bastviken, David; Gudasz, Cristian; Tranvik, Lars; Enrich-Prast, Alex

2013-01-01

446

ORV Arthroscopic Reduction and Internal Fixation of Tibial Eminence Fractures.  

PubMed

Tibial eminence fractures are an uncommon but well-described avulsion of the anterior cruciate ligament. Treatment principles are based on the amount and pattern of fracture displacement. Management has evolved from closed reduction and immobilization to arthroscopic reduction and internal fixation followed by early rehabilitation. Various fixation methods have evolved, ranging from arthroscopic reduction and percutaneous screw fixation to arthroscopic suture repair. We present a technique for arthroscopic reduction and internal fixation using a cannulated drill bit and high-strength suture. This technique facilitates anatomic reduction with uncomplicated tunnel placement and suture passing in an effort to allow strong fixation and early rehabilitation. PMID:24400179

Myer, Daniel M; Purnell, Gregory J; Caldwell, Paul E; Pearson, Sara E

2013-01-01

447

ORV Arthroscopic Reduction and Internal Fixation of Tibial Eminence Fractures  

PubMed Central

Tibial eminence fractures are an uncommon but well-described avulsion of the anterior cruciate ligament. Treatment principles are based on the amount and pattern of fracture displacement. Management has evolved from closed reduction and immobilization to arthroscopic reduction and internal fixation followed by early rehabilitation. Various fixation methods have evolved, ranging from arthroscopic reduction and percutaneous screw fixation to arthroscopic suture repair. We present a technique for arthroscopic reduction and internal fixation using a cannulated drill bit and high-strength suture. This technique facilitates anatomic reduction with uncomplicated tunnel placement and suture passing in an effort to allow strong fixation and early rehabilitation. PMID:24400179

Myer, Daniel M.; Purnell, Gregory J.; Caldwell, Paul E.; Pearson, Sara E.

2013-01-01

448

44. LOCK, ELECTRICAL SYSTEM, HAULAGE ENGINES, ELECTRICAL DETAILS AND LOCATION. ...  

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

44. LOCK, ELECTRICAL SYSTEM, HAULAGE ENGINES, ELECTRICAL DETAILS AND LOCATION. February 1938 - Mississippi River 9-Foot Channel Project, Lock & Dam No. 17, Upper Mississippi River, New Boston, Mercer County, IL

449

14 CFR 25.679 - Control system gust locks.  

Code of Federal Regulations, 2014 CFR

... 2014-01-01 2014-01-01 false Control system gust locks. 25.679 Section 25.679...CATEGORY AIRPLANES Design and Construction Control Systems § 25.679 Control system gust locks. (a) There must be a...

2014-01-01

450

14 CFR 25.679 - Control system gust locks.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 2013-01-01 false Control system gust locks. 25.679 Section 25.679...CATEGORY AIRPLANES Design and Construction Control Systems § 25.679 Control system gust locks. (a) There must be a...

2013-01-01

451

Lock No. 1 St. Lucie Canal. Upper gate structure, masonry ...  

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

Lock No. 1- St. Lucie Canal. Upper gate structure, masonry plan- masonry elevations. - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL

452

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

453

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

454

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

455

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

456

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

457

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

458

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

459

49 CFR 236.339 - Mechanical locking, maintenance requirements.  

Code of Federal Regulations, 2010 CFR

...shall be maintained so that, when a lever or latch is mechanically locked the following will be prevented: (a) Mechanical machine —(1) Latch-operated locking. Raising lever latch block so that bottom thereof is within...

2010-10-01

460

49 CFR 236.339 - Mechanical locking, maintenance requirements.  

Code of Federal Regulations, 2011 CFR

...shall be maintained so that, when a lever or latch is mechanically locked the following will be prevented: (a) Mechanical machine —(1) Latch-operated locking. Raising lever latch block so that bottom thereof is within...

2011-10-01