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1

Dorsal locked plate fixation of distal radius fractures.  

PubMed

Distal radius fractures are common, and internal fixation for operative management of these injuries is widely accepted. Although use of the volar approach for plate fixation has become more popular, benefits of the dorsal surgical approach include the potential for direct reduction and assessment of articular alignment, evaluation and management of concomitant intrinsic intercarpal ligament injury, and initiation of early range of motion. For certain fracture patterns, dorsal plate fixation is the preferred surgical technique. Improvements in implant design, in particular the use of low-profile dorsal plates, has decreased the rate of complications seen previously with this technique. Here, we provide an overview of the evaluation of patients with distal radius fractures, as well as the surgical indications and contraindications, techniques, and complications after dorsal locked plate fixation of intra-articular distal radius fractures. PMID:23751326

Lutsky, Kevin; Boyer, Martin; Goldfarb, Charles

2013-07-01

2

Complications after volar locking plate fixation of distal radius fractures.  

PubMed

Volar locking plates are an increasingly popular treatment for distal radius fractures. We reviewed complications observed after volar locking plate fixation in a busy teaching hospital. The purpose of the study was to assess whether complication rates after volar locking plate use in general, routine trauma practice were higher than published literature from expert users. A retrospective review was carried out of patients treated with a volar locking plate between January 2009 and December 2010. The series included 206 procedures in 204 patients (77 males and 127 females) with mean age of 55 years (range 16-94). Surgery was performed by 18 different consultant surgeons and 11 registrars. A total of 22 complications were observed in 20 patients with an overall complication rate of 9.7%. Seven (3.4%) patients developed tendon problems including four (1.9%) tendon ruptures. Four (1.9%) patients required re-operation for metalwork problems; four patients developed complex regional pain syndrome (CRPS). Three fracture reduction problems were noted. A total of 16 further operations were carried out for complications. The overall complication rate was low even when surgery was done by many surgeons, suggesting that this is a safe and reproducible technique. This study provides information which can be used to counsel patients about risks, including those of tendon and metalwork problems. This allows patients to make an informed decision. Surgeons must have specific strategies to avoid these complications and remain vigilant so that these can be identified and managed early. PMID:24176679

Johnson, N A; Cutler, L; Dias, J J; Ullah, A S; Wildin, C J; Bhowal, B

2014-03-01

3

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

Microsoft Academic Search

Metallic implants are often involved in the open reduction and internal fixation of fractures. Open reduction and internal fixation is commonly used in cases of trauma when the bone cannot be healed using external methods such as casting. The locking compression plate combines the conventional screw hole, which uses non-locking screws, with a locking screw hole, which uses locking head

Danielle L. Miller; Tarun Goswami

2007-01-01

4

Biomechanical comparison of anterior cervical spine locked and unlocked plate-fixation systems  

Microsoft Academic Search

Three different anterior plate-fixation systems are available for the stabilisation of the cervical spine: (1) the cervical spine locking plate (CSLP), (2) dynamic plates allowing vertical migration of the fixation screws, and (3) various types of plates that are secured with either monocortical or bicortical unlocked screws. Unicortical screw purchase does not involve the risk of posterior cortex penetration and

Wolfgang Lehmann; Daniel Briem; Michael Blauth; Ulf Schmidt

2005-01-01

5

Bone transport with an external fixator and a locking plate for segmental tibial defects.  

PubMed

Although gradual bone transport may permit the restoration of large-diameter bones, complications are common owing to the long duration of external fixation. In order to reduce such complications, a new technique of bone transport involving the use of an external fixator and a locking plate was devised for segmental tibial bone defects. A total of ten patients (nine men, one woman) with a mean age at operation of 40.4 years (16 to 64) underwent distraction osteogenesis with a locking plate to treat previously infected post-traumatic segmental tibial defects. The locking plate was fixed percutaneously to bridge proximal and distal segments, and was followed by external fixation. After docking, percutaneous screws were fixed at the transported segment through plate holes. At the same time, bone grafting was performed at the docking site with the external fixator removed. The mean defect size was 5.9 cm (3.8 to 9.3) and mean external fixation index was 13.4 days/cm (11.8 to 19.5). In all cases, primary union of the docking site and distraction callus was achieved, with an excellent bony result. There was no recurrence of deep infection or osteomyelitis, and with the exception of one patient with a pre-existing peroneal nerve injury, all achieved an excellent or good functional result. With short external fixation times and low complication rates, bone transport with a locking plate could be recommended for patients with segmental tibial defects. PMID:24293598

Oh, C-W; Apivatthakakul, T; Oh, J-K; Kim, J-W; Lee, H-J; Kyung, H-S; Baek, S-G; Jung, G-H

2013-12-01

6

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

PubMed Central

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

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

2010-01-01

7

Locked plate fixation of the comminuted distal fibula: a biomechanical study  

PubMed Central

Background The purpose of this study was to compare the biomechanical properties of locked versus nonlocked lateral fibular bridge plating of comminuted, unstable ankle fractures in a mode of catastrophic failure. Methods We created comminuted Weber C fractures in 8 paired limbs from fresh cadavers. Fractures were plated with either standard or locked one-third tubular bridge plating techniques. Specimens were biomechanically evaluated by external rotation to failure while subjected to a compressive load approximating body weight. We measured the angle to failure, torque to failure, energy to failure and construct stiffness. Results There was no significant difference in construct stiffness or other biomechanical properties between locked and standard one-third tubular plating techniques. Conclusion We found no difference in biomechanical properties between locked and standard bridge plating of a comminuted Weber C fibular fracture in a model of catastrophic failure. It is likely that augmentation of fixation with K-wires or trans-tibial screws provides a construct superior to locked bridge plating alone. Further biomechanical and clinical analysis is required to improve understanding of the role of locked plating in ankle fractures and in osteoporotic bone.

White, Neil J.; Corr, David T.; Wagg, James P.; Lorincz, Caeley; Buckley, Richard E.

2013-01-01

8

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

PubMed

Background?Fractures of the distal radius are among the most common injuries treated by orthopedic surgeons worldwide. Failure to restore distal radius alignment can lead to fracture malunion and poor clinical outcomes, including distal radioulnar joint (DRUJ) instability and limitation of motion. Case Description?We present a unique case of DRUJ dysfunction following volar plate fixation of bilateral distal radius fractures and analyze the biomechanical causes of this complication. As a result of a relatively excessive tilt of the precontoured locking plate (in comparison to the patient's particular anatomy), the fracture on one side was "over-reduced," disrupting the biomechanics of the DRUJ, causing a supination block. Clinical Relevance?Volar locking plates are not a panacea to all distal radius fractures. Plate selection and fixation technique must include consideration of patient anatomy. Robust plates offer the advantage of providing rigid fixation but can be difficult to contour when reconstructing normal anatomy. Restoration of patient-specific anatomy is crucial to the management of distal radius fractures. PMID:24533245

Jones, Christopher W; Lawson, Richard D

2014-02-01

9

Locking compression plate fixation of radial and tibial fractures in a young dog.  

PubMed

A six-month-old, male Bernese Mountain Dog in which radius-ulna and tibia-fibula concomitant fractures were treated each with a 3.5 mm Locking Compression Plate (LCP) is presented. Both fractures were approached and plated medially. The tibial fracture had to be revised with a 4.5 mm intramedullary nail and a new 3.5 mm LCP at the second post-operative day because of fixation breakdown. The follow-up radiographs taken at days 14 and 53 revealed uneventful healing of both fractures. Implants were removed 53 days after surgery. PMID:16594453

Schwandt, C S; Montavon, P M

2005-01-01

10

Biomechanical comparison of a unique locking plate versus a standard plate for internal fixation of proximal humerus fractures in a cadaveric model  

Microsoft Academic Search

BackgroundNewer internal fixation devices with a locking mechanism between the plate and the screw have recently been released. The efficacy of these plates in the proximal humerus has yet to be fully described. There is a need to compare the biomechanical properties of efficacy of plate fixation with or without locking screws for surgery of two-part proximal humerus fractures. Multiple-plane

Stephen Walsh; Rudy Reindl; Edward Harvey; Gregory Berry; Lorne Beckman; Thomas Steffen

2006-01-01

11

Internal fixation of displaced middle third fractures of clavicle with precontoured locking plate  

PubMed Central

Background The traditional method of treating displaced mid clavicular fractures with conservative methods gives poor results. When there is displacement more than 2 cm and shortening, internal fixation of the clavicle, when performed properly, gives better results. Methods We reviewed the results of 20 cases of middle third clavicle fractures (Edinburg type 2B) with displacement more than 2 cm which were treated with open reduction and internal fixation with precontoured locking plate and screws. Results In all the fractures radiological union was evident by 10–16 weeks. None of the patients had complications like malunion, nonunion, deep infections, and implant failure and neurovascular damage. There was no problem with hardware and implant removal was not done. The average constant score was 95.45. All the patients were satisfied with the cosmetic appearance of surgical scar. Conclusions Precontoured locking plate fixation gives excellent results, facilitates early return to function, results in better cosmesis and avoids complications of conservative methods like nonunion, malunion and also implant removal is not necessary.

Hundekar, Babu B.

2013-01-01

12

Locking plate fixation in distal metaphyseal tibial fractures: series of 79 patients.  

PubMed

Open reduction and internal fixation in distal tibial fractures jeopardises fracture fragment vascularity and often results in soft tissue complications. Minimally invasive osteosynthesis, if possible, offers the best possible option as it permits adequate fixation in a biological manner. Seventy-nine consecutive adult patients with distal tibial fractures, including one patient with a bilateral fracture of the distal tibia, treated with locking plates, were retrospectively reviewed. The 4.5-mm limited-contact locking compression plate (LC-LCP) was used in 33 fractures, the metaphyseal LCP in 27 fractures and the distal medial tibial LCP in the remaining 20 fractures. Fibula fixation was performed in the majority of comminuted fractures (n?=?41) to maintain the second column of the ankle so as to achieve indirect reduction and to prevent collapse of the fracture. There were two cases of delayed wound breakdown in fractures fixed with the 4.5-mm LC-LCP. Five patients required primary bone grafting and three patients required secondary bone grafting. All cases of delayed union (n?=?7) and nonunion (n?=?3) were observed in cases where plates were used in bridge mode. Minimally invasive plate osteosynthesis (MIPO) with LCP was observed to be a reliable method of stabilisation for these fractures. Peri-operative docking of fracture ends may be a good option in severely impacted fractures with gap. The precontoured distal medial tibial LCP was observed to be a better tolerated implant in comparison to the 4.5-mm LC-LCP or metaphyseal LCP with respect to complications of soft tissues, bone healing and functional outcome, though its contour needs to be modified. PMID:19820935

Gupta, Rakesh K; Rohilla, Rajesh Kumar; Sangwan, Kapil; Singh, Vijendra; Walia, Saurav

2010-12-01

13

PALMAR PLATE FIXATION OF AO TYPE C2 FRACTURE OF DISTAL RADIUS USING A LOCKING COMPRESSION PLATE – A BIOMECHANICAL STUDY IN A CADAVERIC MODEL  

Microsoft Academic Search

The stability of palmar plate fixation using a locking compression T-plate was compared with that of a conventional palmar T-plate and a dorsal T-plate in a cadaveric model of an AO type C2 fracture of distal radius. The wrist axial load transmission through the radius was tested for each fixation. The results show that, under 100N axial load, the palmar

F. LEUNG; L. ZHU; H. HO; W. W. LU; S. P. CHOW

2003-01-01

14

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

PubMed Central

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

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

2014-01-01

15

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

PubMed

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

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

2014-01-01

16

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

PubMed

Objective: Debate continues regarding the management of calcaneal fractures, between open reduction and internal fixation and closed treatment. Hence we aim at evaluating the radiological and functional outcomes of open reduction and internal fixation in displaced joint depression type of calcaneal fractures fixed with locking calcaneal plate. Methods: In this series, 28 patients (26 unilateral and 2 bilateral) with joint depression type of calcaneal fractures as per Essex-Lopresti classification system were operated on with locking calcaneal plate within 3 weeks of injury. Patients were evaluated in terms of associated injuries and X-rays of anteroposterior, lateral and axial views of the calcaneum. CT scan was done to assess the amount of comminution and articular depression. Patients were followed up clinically and radiologically at least for 1 year. Radiological assessment was done by Bohler's angle and Gissane's angle along with measurement of calcaneal height and width. Functional outcome was assessed using the American Orthopaedics Foot and Ankle Society (AOFAS) scale. Results: At average follow-up of 14.5 months, average AOFAS score was 86.3 (range 66 to 97), with 86% having excellent to good results and 2 (7.7%) and 1 (3.7%) having fair and poor results respectively. All patients had stable ankle joint with all having dorsiflexion and plantar flexion more than 30 degrees. Average subtalar range of motion was 17 degrees The mean Bohler's angle, mean Gissane's angle, calcaneal height and width were 25.47 degrees 121.3 degrees 4.32 cm and 3.81 cm respectively at final follow-up. Three patients had flap necrosis at incision site and one had superficial and deep infection. Subtalar arthritis was seen in 5 patients, whereas sural nerve hypoaesthesia in 1 patient. None of the patients had compartment syndrome, heel pad problems, peroneal tendinitis, reflex sympathetic dystropy or implant failure. Conclusion: Open reduction and internal fixation with locking calcaneal plate gives sound functional outcome, i.e. restoring anatomically reconstruction of height, width, Bohler's and Gissiane's angles of the calcaneum, and allowing early mobilization. PMID:24295583

Jain, Saurabh; Jain, Anil Kumar; Kumar, Ish

2013-12-01

17

Functional outcome in patients with unstable distal radius fractures, volar locking plate versus external fixation: a meta-analysis.  

PubMed

The aim of this study was to compare bridging external fixation with volar locked plating in patients with unstable distal radial fractures regarding functional outcome. A systematic search was performed in the Cochrane Central Register of Controlled Trials, Medline and EMBASE. All randomized controlled trials that compared bridging external fixation directly with volar locked plating in patients with distal radial fractures were considered. Three reviewers extracted data independently from eligible studies using a data collection form. Studies in which the primary endpoint was measured on the disabilities of the arm shoulder and hand (DASH) score at 3, 6 and 12 months were included in the analysis. To this end, mean scores and standard deviations were extracted. The software package Revman 5 provided by the Cochrane Collaboration was used for data analysis. Three studies involving 174 patients were analyzed. Ninety patients were treated with an (augmented) bridging external fixator and 84 with a volar locking plate. Data were analyzed with the random effects model. The robustness of the results was explored using a sensitivity analysis. Patients treated with a volar locking plate showed significantly lower DASH scores at all times. A difference of 16 (p = 0.006), six (p = 0.008) and eight points (p = 0.06) was found at 3, 6 and 12 months follow-up, respectively. Patients treated with a volar locking plate showed significantly better functional outcome throughout the entire follow-up. However, this difference was only clinically relevant during the early postoperative period (3 months). PMID:23892535

Walenkamp, Monique M J; Bentohami, Abdelali; Beerekamp, M Suzan H; Peters, Rolf W; van der Heiden, Remy; Goslings, J Carel; Schep, Niels W L

2013-08-01

18

Evaluation of a new approach for modelling the screw-bone interface in a locking plate fixation: a corroboration study.  

PubMed

Computational modelling of the screw-bone interface in fracture fixation constructs is challenging. While incorporating screw threads would be a more realistic representation of the physics, this approach can be computationally expensive. Several studies have instead suppressed the threads and modelled the screw shaft with fixed conditions assumed at the screw-bone interface. This study assessed the sensitivity of the computational results to modelling approaches at the screw-bone interface. A new approach for modelling this interface was proposed, and it was tested on two locking screw designs in a diaphyseal bridge plating configuration. Computational models of locked plating and far cortical locking constructs were generated and compared to in vitro models described in prior literature to corroborate the outcomes. The new approach led to closer agreement between the computational and the experimental stiffness data, while the fixed approach led to overestimation of the stiffness predictions. Using the new approach, the pattern of load distribution and the magnitude of the axial forces, experienced by each screw, were compared between the locked plating and far cortical locking constructs. The computational models suggested that under more severe loading conditions, far cortical locking screws might be under higher risk of screw pull-out than the locking screws. The proposed approach for modelling the screw-bone interface can be applied to any fixation involved application of screws. PMID:23636756

Moazen, Mehran; Mak, Jonathan H; Jones, Alison C; Jin, Zhongmin; Wilcox, Ruth K; Tsiridis, Eleftherios

2013-07-01

19

Comparison of Locked Volar Plating Versus Pinning and External Fixation in the Treatment of Unstable Intraarticular Distal Radius Fractures  

Microsoft Academic Search

Introduction  We retrospectively compared the outcomes of open reduction and internal fixation (ORIF) with volar locking plate versus standard\\u000a external fixation and percutaneous pinning in treating similar unstable distal radius fractures with a minimum 2-year follow-up.\\u000a \\u000a \\u000a \\u000a Methods  The ORIF group included 41 patients with an average follow-up of 29 months. The external fixation group comprised 14 patients\\u000a with an average follow-up of 33 months.

Marco Rizzo; Brian A. Katt; Joshua T. Carothers

2008-01-01

20

Comparison of tension band wiring and precontoured locking compression plate fixation in Mayo type IIA olecranon fractures.  

PubMed

Aim of the present study was to compare the clinical and radiographic outcome of tension band wiring and precontoured locking compression plate fixation in patients treated surgically for an isolated olecranon fractures type IIA according to the Mayo classification. Of 26 patients presenting with an isolated Mayo type IIA olecranon fracture, 13 underwent fixation with a precontoured locking compression plate (group A), 13 patients were treated with tension band wiring (group B). At a mean follow-up of 43 months, patients were clinically and radiographically re-examined using the DASH score, the Mayo Elbow Performance score (MEPS) and anteroposterior and lateral radiographs. The mean DASH score was 14 points in group A and 12.5 points in group B. Regarding the MEPS, 92% of the patients in group A achieved a good to excellent results in comparison to 77% in group B. No significant differences between the two groups could be detected regarding the clinical and radiographic outcome. Implant-related irritations requiring hardware removal occurred more frequently in group B (12 vs. 7). Procedure and implant related costs were significantly higher in group A. Tension band wiring is still a preferable surgical method to treat simple isolated olecranon fractures. The patient must be informed that in all likelihood implant removal will be required once the fracture has healed. Fixation with precontoured locking compression plates does not provide better functional and radiographic outcome but is more expensive than tension band wiring. PMID:24873093

Schliemann, Benedikt; Raschke, Michael J; Groene, Philipp; Weimann, André; Wähnert, Dirk; Lenschow, Simon; Kösters, Clemens

2014-03-01

21

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.

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

2012-01-01

22

Locking screw-plate fixation of cervical spine fractures with and without ancillary posterior plating  

Microsoft Academic Search

Forty consecutive patients with 19 fractures and 21 fracture-dislocations in the lower cervical spine were treated prospectively with open reduction and interbody fusion, using the AO titanium locking screwplate system. There were 30 men and 10 women with a mean age of 36 years (range 16–90 years). Eight were admitted tetraplegic, 12 tetraparetic, and 6 had nerve root injuries. Eleven

H. Jónsson; K. Cesarini; M. Petrén-Mallmin; W. Rauschning

1991-01-01

23

Comparison between cast immobilization versus volar locking plate fixation of distal radius fractures in active elderly patients, the Asian perspective.  

PubMed

Displaced distal radius fractures in active elderly patients with high functional demand present a clinical dilemma because current evidence is equivocal in the recommendation of treatment. Internal fixation is an increasingly popular option with proposed superior results. Our study aims to evaluate the results among a population of active elderly patients with displaced fractures managed with either cast immobilization or internal fixation with volar locking plate. Seventy-five patients (35 cast immobilization and 40 internal fixation) with mean age of 74 ± 7.5 years with minimum of 12 months follow-up were studied. The radiological and clinical parameters were assessed at three, six, and 12 months. Functional outcomes (DASH, Green-O'Brien) were assessed at 12 months. Patients who underwent surgery regain wrist motion and grip strength earlier, but this was not statistically significant after six months. PMID:24641736

Chan, Ying-Ho; Foo, Tun-Lin; Yeo, Chong-Jin; Chew, Winston Yoon-Chong

2014-01-01

24

Retrospective comparison of external fixation versus volar locking plate in the treatment of unstable intra-articular distal radius fractures.  

PubMed

The aim of this study is to compare the radiological and functional outcomes of open reduction and volar locking plates versus external fixation (EF) in the treatment of unstable intra-articular distal radius fractures. In this retrospective comparative study, 69 of 80 patients who underwent an operation for AO/ASIF C1, C2 and C3 distal radius fractures were assessed. Functional evaluation was performed using the Gartland-Werley scoring system and the PRWE scale, and wrist range of motion and grip strength was also measured. For the radiological assessment, radial inclination, volar tilt, radial length, ulnar variance, and articular step-off were compared. The range of movement was better for all parameters in the volar plate group, but only wrist flexion and pronation range differed significantly between the groups (p = 0.037 and p = 0.014, respectively). With the exception of better subjective functional results in the volar plate group, the differences were not significant. With respect to radiological evaluation, all parameters were better in the volar plate group, but only radial inclination and articular step-off were significantly better (p = 0.018 and p = 0.029, respectively). In the volar plate group, two patients had carpal tunnel syndrome and one patient had regional pain syndrome. In the external fixator group, six patients had superficial pin tract infection, two patients had sensory branch injury, and four patients had regional pain syndrome. Volar locking plate fixation appeared as a dependable method for the treatment of intra-articular distal radius, with lower complication rates. On the other hand, EF remains a suitable surgical alternative for these fractures, with easy application and acceptable results. PMID:23417090

Kumbaraci, Mert; Kucuk, Levent; Karapinar, Levent; Kurt, Cengizhan; Coskunol, Erhan

2014-02-01

25

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

26

Mandibular Osteosynthesis: A Comparative Evaluation of Two Different Fixation Systems Using 2.0 mm Titanium Miniplates & 3-D Locking Plates  

Microsoft Academic Search

Purpose  To compare & evaluate postoperative complications & treatment outcome in mandibular fracture fixation using 2.0 mm titanium\\u000a miniplates & 3-D locking plates.\\u000a \\u000a \\u000a \\u000a \\u000a Method  30 patients were divided randomly into two groups of 15 each (including comminuted & malunited fractures). GROUP A was treated\\u000a with Open Reduction Internal Fixation (ORIF) using 2.0 mm miniplates & GROUP B with 3-D locking plates.\\u000a \\u000a \\u000a \\u000a \\u000a Results  A total of

Manoj Goyal; Karan Marya; Sonia Chawla; Richa Pandey

27

Fixation of lapidus arthrodesis with a plantar interfragmentary screw and medial locking plate: a report of 88 cases.  

PubMed

Lapidus arthrodesis is a powerful procedure that can be used to correct pathologic features within the forefoot or midfoot. Many different methods of fixation for this procedure have been reported. The use of plating constructs has been shown to provide increased stability compared with screw-only constructs. The technique we have described consists of a plantar to dorsal retrograde lag screw across the arthrodesis site, coupled with a low-profile medial locking plate. A total of 88 consecutive patients were treated with this modification of the Lapidus procedure by 2 surgeons and were retrospectively evaluated. All patients followed an early postoperative weightbearing protocol. Patient age, gender, follow-up duration, interval to weightbearing and radiographic fusion, preoperative and postoperative intermetatarsal angle, hardware removal, preoperative and postoperative American Orthopaedic Foot and Ankle Society midfoot scores, and adjunct procedures were analyzed. The mean follow-up period was 16.76 ± 5.9 (range 12 to 36) months, and all healed fusions demonstrated radiographic union at a mean of 51 ± 19.1 (range 40 to 89) days. The patients were treated with weightbearing starting a mean of 10.90 ± 4.1 (range 5 to 28) days postoperatively. Complications included 15 patients (17%) requiring hardware removal, 2 cases (2%) of hallux varus, 6 cases (7%) of radiographic recurrent hallux valgus, and 2 patients (2%) with first metatarsocuneiform nonunion. The results of the present study have demonstrated that plantar lag screw fixation with medial locking plate augmentation for Lapidus arthrodesis allows for early weightbearing with satisfactory outcomes, improved clinical and radiographic alignment, and improved American Orthopaedic Foot and Ankle Society scores. PMID:23540755

Cottom, James M; Vora, Anand M

2013-01-01

28

Is Loss of Fixation Following Locked Plating of Proximal Humeral Fractures Related to the Number of Screws and Their Positions in the Humeral Head?  

PubMed Central

The aim of the study was to examine the correlation between the chosen position of screws and the complications observed in patients who underwent locked plating of proximal humeral fractures. We evaluated radiographs of 367 patients treated by locked-plating for proximal humeral fractures. Radiographs were taken at one day, 6 weeks, 3 months and 6 months after surgery, and were analyzed for secondary fracture displacement, loss of fixation, cutting out of screws and necrosis of the humeral head. Secondary loss of fixation occurred in 58 cases (15.8%) and among those cutting out of screws was observed in 25 cases (6.8%). In cases of secondary loss of fixation a mean of 6.7 screws were used to fix the fracture (vs 6.6, P=0.425). There was neither significant correlation between position of screws and the occurrence of postoperative loss of fixation in Spearman correlation nor relationship from backward logistic regression analysis. Loss of fixation following locked plating of proximal humeral fractures does not relate to the number of screws and their positions in the humeral head. In consequence, anatomic fracture reduction and restoration of the humeral head-shaft angle are still important factors and should not be disregarded.

Maddah, Mohammad; Prall, Wolf C.; Geyer, Lucas; Wirth, Stefan; Mutschler, Wolf; Ockert, Ben

2014-01-01

29

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

PubMed

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

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

2011-02-01

30

Characteristics of two different locking compression plates in the volar fixation of complex articular distal radius fractures  

PubMed Central

Objectives To investigate the differences of open reduction and internal fixation (ORIF) of complex AO Type C distal radius fractures between two different models of a single implant type. Methods A total of 136 patients who received either a 2.4 mm (n = 61) or 3.5 mm (n = 75) distal radius locking compression plate (LCP DR) using a volar approach were followed over two years. The main outcome measurements included motion, grip strength, pain, and the scores of Gartland and Werley, the Short-Form 36 (SF-36) and the Disabilities of the Arm, Shoulder, and Hand (DASH). Differences between the treatment groups were evaluated using regression analysis and the likelihood ratio test with significance based on the Bonferroni corrected p-value of < 0.003. Results The groups were similar with respect to baseline and injury characteristics as well as general surgical details. The risk of experiencing a complication after ORIF with a LCP DR 2.4 mm was 18% (n = 11) compared with 11% (n = 8) after receiving a LCP DR 3.5 mm (p = 0.45). Wrist function was also similar between the cohorts based on the mean ranges of movement (all p > 0.052) and grip strength measurements relative to the contralateral healthy side (p = 0.583). In addition, DASH and SF-36 component scores as well as pain were not significantly different between the treatment groups throughout the two-year period (all p ? 0.005). No patient from either treatment group had a step-off > 2 mm. Conclusions Differences in plate design do not influence the overall final outcome of fracture fixation using LCP.

von Recum, J.; Matschke, S.; Jupiter, J. B.; Ring, D.; Souer, J-S.; Huber, M.; Audige, L.

2012-01-01

31

Mandibular Osteosynthesis: A Comparative Evaluation of Two Different Fixation Systems Using 2.0 mm Titanium Miniplates and 3-D Locking Plates  

Microsoft Academic Search

Purpose  To compare and evaluate postoperative complications and treatment outcome in mandibular fracture fixation using 2.0 mm titanium\\u000a miniplates and 3-D locking plates.\\u000a \\u000a \\u000a \\u000a \\u000a Method  Thirty patients were divided randomly into two groups of 15 each (including comminuted and malunited fractures). Group A was\\u000a treated with open reduction internal fixation using 2.0 mm miniplates and group B with 3-D locking plates.\\u000a \\u000a \\u000a \\u000a \\u000a Results  A total of five

Manoj Goyal; Karan Marya; Sonia Chawla; Richa Pandey

2011-01-01

32

Simulation-based particle swarm optimization and mechanical validation of screw position and number for the fixation stability of a femoral locking compression plate.  

PubMed

Locking compression plates (LCPs) have been used to fix femoral shaft fractures. Previous studies have attempted to identify the best LCP screw positions and numbers to achieve the fixation stability. However, the determined screw positions and numbers were mainly based on the surgeons' experiences. The aim of this study was to discover the best number and positions of LCP screws to achieve acceptable fixation stability. Three-dimensional numerical models of a fractured femur with the LCP were first developed. Then, the best screw position and number of LCPs were determined by using a simulation-based particle swarm optimization algorithm. Finally, the results of the numerical study were validated by conducting biomechanical tests. The results showed that the LCP with six locking screws resulted in the necessary fixation stability, and the best combination of positions of locking screws inserted into the LCP was 1-5-6-7-8-12 (three locking screws on either side of the bone fragment with two locking screws as close as practicable to the fracture site). In addition, the numerical models and algorithms developed in this study were validated by the biomechanical tests. Both the numerical and experimental results can provide clinical suggestions to surgeons and help them to understand the biomechanics of LCP systems. PMID:24090880

Lee, Chian-Her; Shih, Kao-Shang; Hsu, Ching-Chi; Cho, Tomas

2014-01-01

33

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.

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

2014-01-01

34

Distal tibia fractures: locked or non-locked plating?  

PubMed

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

2014-06-01

35

Locked vs. unlocked plate osteosynthesis of the proximal humerus – A biomechanical study  

Microsoft Academic Search

BackgroundLocked plates (internal fixators) have been found to be an optimal method for the fixation in proximal humeral fractures. In a biomechanical cadaver study the difference between locked and non-locked osteosyntheses was investigated.

K. Seide; J. Triebe; M. Faschingbauer; A. P. Schulz; K. Püschel; G. Mehrtens; Ch. Jürgens

2007-01-01

36

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

PubMed Central

Background The use of minimally invasive plate osteosynthesis (MIPO) via anterolateral deltoid splitting has good outcomes in the management of proximal humerus fractures. While using this approach has several advantages, including minimal soft tissue disruption, preservation of natural biology and minimal blood loss, there is an increased risk for axillary nerve damage. This study compared the advantages and clinical and radiological outcomes of MIPO or open reduction and internal fixation (ORIF) in patients with proximal humerus fractures. Methods A matched-pair analysis was performed, and patient groups were matched according to age (±3 years), sex and fracture type. Forty-three pairs of patients (average age: MIPO, 63 and ORIF, 61) with a minimum follow-up of 12 months were enrolled in the study group. The patients were investigated radiographically and clinically using the Constant score. Results The MIPO technique required less surgery time and caused less blood loss compared to ORIF (p?Fixation) fracture classification, did not significantly influence the functional results. The complication rate was comparable between both groups. Conclusion The use of MIPO with a locking compression plate in the management of proximal humerus fractures is a safe and superior option compared to ORIF.

2014-01-01

37

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

2014-01-01

38

Internal fixation of intracapsular fractures of the hip using a dynamic locking plate: Two-year follow-up of 320 patients.  

PubMed

A consecutive series of 320 patients with an intracapsular fracture of the hip treated with a dynamic locking plate (Targon Femoral Neck (TFN)) were reviewed. All surviving patients were followed for a minimum of two years. During the follow-up period 109 patients died. There were 112 undisplaced fractures, of which three (2.7%) developed nonunion or re-displacement and five (4.5%) developed avascular necrosis of the femoral head. Revision to an arthroplasty was required for five patients (4.5%). A further six patients (5.4%) had elective removal of the plate and screws. There were 208 displaced fractures, of which 32 (15.4%) developed nonunion or re-displacement and 23 (11.1%) developed avascular necrosis. A further four patients (1.9%) developed a secondary fracture around the TFN. Revision to a hip replacement was required for 43 patients (20.7%) patients and a further seven (3.3%) had elective removal of the plate and screws. It is suggested that the stronger distal fixation combined with rotational stability may lead to a reduced incidence of complications related to the healing of the fracture when compared with other contemporary fixation devices but this needs to be confirmed in further studies. PMID:24078540

Parker, M; Cawley, S; Palial, V

2013-10-01

39

Early Healing With Locked Condylar Plating of Periprosthetic Fractures Around the Knee  

Microsoft Academic Search

Management of periprosthetic fractures around the knee is often difficult because of poor bone quality, comminution, and constraints imposed by the existing prosthesis. Locked condylar plates may provide more reliable fixation for these fractures than traditional methods of fixation. Eleven patients with periprosthetic fractures around the knee were treated with open reduction and internal fixation using a locked condylar plate.

Gregory E. Raab; Charles M. Davis

2005-01-01

40

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

2014-01-01

41

Biomechanical Evaluation of Volar Locking Plates for Distal Radius Fractures  

Microsoft Academic Search

Purpose  Fixed-angle devices have been a major advancement in orthopedic fracture care and have become an attractive option for fixation\\u000a of distal radius fractures. Several volar locking plates exist, but there is insufficient literature comparing the strengths\\u000a of these plates. This study compares the biomechanical strength of two popular volar locking plate systems (Synthes LCP and\\u000a Hand Innovations DVR-A) along with

Scott M. Levin; Cory O. Nelson; Jonathan D. Botts; Glenn A. Teplitz; Yong Kwon; Fred Serra-Hsu

2008-01-01

42

Volar locking plates versus Kirschner wires for distal radial fractures—A cost analysis study  

Microsoft Academic Search

BackgroundThere is an increasing trend for managing dorsally angulated distal radial fractures with locked volar plate fixation in fractures that may have previously been managed with percutaneous Kirschner wire (K-wire) fixation. There has been no prospective randomised trial comparing locked volar plate fixation with percutaneous K-wire fixation. In the absence of data guiding management with regard to clinical effectiveness, we

Gunaratnam Shyamalan; Chris Theokli; Yemi Pearse; Duncan Tennent

2009-01-01

43

PWR integral tie plate and locking mechanism  

SciTech Connect

A locking mechanism for securing an upper tie plate to the tie rods of a nuclear fuel bundle is described. The mechanism includes an upper tie plate assembly and locking sleeves fixed to the ends of the tie rods. The tie plate is part of the upper tie plate assembly and is secured to the fuel bundle by securing the entire upper tie plate assembly to the locking sleeves fixed to the tie rods. The assembly includes, in addition to the tie plate, locking nuts for engaging the locking sleeves, retaining sleeves to operably connect the locking nuts to the assembly, a spring biased reaction plate to restrain the locking nuts in the locked position and a means to facilitate the removal of the entire assembly as a unit from the fuel bundle.

Flora, B.S.; Osborne, J.L.

1980-08-26

44

Topical review: locking plate technology in foot and ankle surgery.  

PubMed

The use of locking plate technology in foot and ankle surgery has increased over the last decade. Reported applications include fracture repair, deformity correction, and arthrodesis. There is limited evidence, however, to guide clinicians with regard to the appropriate and optimal use of this technology. This work aims to examine the current biomechanical and clinical evidence comparing locking construct technology to other forms of fixation in the field of foot and ankle surgery. PMID:24492280

Jastifer, James R

2014-05-01

45

Far Cortical Locking Can Reduce Stiffness of Locked Plating Constructs While Retaining Construct Strength  

PubMed Central

Background: Several strategies to reduce construct stiffness have been proposed to promote secondary bone healing following fracture fixation with locked bridge plating constructs. However, stiffness reduction is typically gained at the cost of construct strength. In the present study, we tested whether a novel strategy for stiffness reduction, termed far cortical locking, can significantly reduce the stiffness of a locked plating construct while retaining its strength. Methods: Locked plating constructs and far cortical locking constructs were tested in a diaphyseal bridge plating model of the non-osteoporotic femoral diaphysis to determine construct stiffness in axial compression, torsion, and bending. Subsequently, constructs were dynamically loaded until failure in each loading mode to determine construct strength and failure modes. Finally, failure tests were repeated in a validated model of the osteoporotic femoral diaphysis to determine construct strength and failure modes in a worst-case scenario of bridge plating in osteoporotic bone. Results: Compared with the locked plating constructs, the initial stiffness of far cortical locking constructs was 88% lower in axial compression (p < 0.001), 58% lower in torsion (p < 0.001), and 29% lower in bending (p < 0.001). Compared with the locked plating constructs, the strength of far cortical locking constructs was 7% lower (p = 0.005) and 16% lower (p < 0.001) under axial compression in the non-osteoporotic and osteoporotic diaphysis, respectively. However, far cortical locking constructs were 54% stronger (p < 0.001) and 9% stronger (p = 0.04) under torsion and 21% stronger (p < 0.001) and 20% stronger (p = 0.02) under bending than locked plating constructs in the non-osteoporotic and osteoporotic diaphysis, respectively. Within the initial stiffness range, far cortical locking constructs generated nearly parallel interfragmentary motion. Locked plating constructs generated significantly less motion at the near cortex adjacent to the plate than at the far cortex (p < 0.01). Conclusions: Far cortical locking significantly reduces the axial stiffness of a locked plating construct. This gain in flexibility causes only a modest reduction in axial strength and increased torsional and bending strength. Clinical Relevance: Far cortical locking may provide a novel bridge plating strategy to enhance interfragmentary motion for the promotion of secondary bone healing while retaining sufficient construct strength.

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

2009-01-01

46

Efficacy of 2-mm locking miniplates in the management of mandibular fractures without maxillomandibular fixation  

PubMed Central

Background: The management of trauma has evolved greatly over the past many years. Various bone plating systems have been developed to provide stable fixation of mandibular fractures. The introduction of the locking plate/screw system has offered certain advantages over the conventional plating systems. This system does not require intimate adaptation of the miniplates to the underlying bone and has greater stability. This study evaluates the efficacy of locking miniplate/screw system in the treatment of mandibular fractures without maxillomandibular fixation. Materials and Methods: This was a prospective study analyzing 20 patients with undisplaced or minimally displaced mandibular fractures, who reported to Department of Oral and Maxillofacial Surgery, Government Dental College and Research Institute, Bangalore. The selected cases were treated by open reduction and internal fixation using the 2.0 mm locking plate/screw system. Results: Open reduction and internal fixation with the 2.0 mm locking plate/screw system were achieved in all the 20 cases with satisfactory stability of the fracture fragments. The system was found to be reliable and effective intraoperatively. Only two complications were noted in the study. Conclusion: The locking miniplate system was found to be reliable and effective in management of mandibular fractures without postoperative intermaxillary fixation, however further studies with more sample size is required.

Prabhakar, Chandan; Shetty, Jayaprasad N.; Hemavathy, O. R.; Guruprasad, Yadavalli

2011-01-01

47

Biomechanical Analysis of the Efficacy of Locking Plates during Cyclic Loading in Metacarpal Fractures  

PubMed Central

Purpose. To analyse the biomechanical characteristics of locking plates under cyclic loading compared to a nonlocking plate in a diaphyseal metacarpal fracture. Methods. Oblique diaphyseal shaft fractures in porcine metacarpal bones were created in a biomechanical fracture model. An anatomical reduction and stabilization with a nonlocking and a comparable locking plate in mono- or bicortical screw fixation followed. Under cyclic loading, the displacement, and in subsequent load-to-failure tests, the maximum load and stiffness were measured. Results. For the monocortical screw fixation of the locking plate, a similar displacement, maximum load, and stiffness could be demonstrated compared to the bicortical screw fixation of the nonlocking plate. Conclusions. Locking plates in monocortical configuration may function as a useful alternative to the currently common treatment with bicortical fixations. Thereby, irritation of the flexor tendons would be avoided without compromising the stability, thus enabling the necessary early functional rehabilitation.

Meffert, Rainer H.; Raschke, Michael J.; Blunk, Torsten; Ochman, Sabine

2014-01-01

48

Biomechanical analysis of anterior cervical spine plate fixation systems with unicortical and bicortical screw purchase  

Microsoft Academic Search

Anterior plate fixation with unicortical screw purchase does not involve the risk of posterior cortex penetration and possible injuries of the spinal cord. However, there are very few biomechanical data about the immediate stability of non-locking plate fixation with unicortical or bicortical screw placement. The aim of the present study was to evaluate the immediate biomechanical properties in terms of

Wolfgang Lehmann; Michael Blauth; Daniel Briem; Ulf Schmidt

2004-01-01

49

Displaced proximal humeral fractures: an Indian experience with locking plates  

PubMed Central

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

2010-01-01

50

A comparison of conventional versus locking plates in intraarticular calcaneus fractures: A biomechanical study in human cadavers  

Microsoft Academic Search

BackgroundInternal fixation of displaced intraarticular calcaneal fractures in patients older than 50 years remains controversial. This is, in many cases, due to fear of loss of fixation and the risk of implant failure in osteoporotic bone. It is the objective of this study to compare the fixation strength obtained using calcaneal plates with and without locking screws, in the fixation

Karl Stoffel; Grant Booth; Stephan M. Rohrl; Markus Kuster

2007-01-01

51

New innovations in craniomaxillofacial fixation: the 2.0 lock system.  

PubMed

Rigid internal fixation with plates and screws is now standard for the treatment of fractures, osteotomies and reconstruction of the craniomaxillofacial skeleton. The latest innovations are self-drilling, self-tapping screws and locking miniplates. These screws offer the prospect of less instrumentation and faster application. Preclinical testing has shown them to be substantially more retentive in cancellous bone, a significant advance in cancellous block bone grafting. Locking 2.0 miniplates utilize double threaded screws which both lock to the bone and the plate creating a mini-internal fixator. This results in a more rigid construct with less distortion of the fracture or osteotomy, screws which do not loosen and less interference with bone circulation since the plate is not pressed tightly against the bone. Locking miniplates are designed for midface application in the repair of fractures, osteotomies and defects. Three configurations in a variety of shapes and lengths are available for mandibular surgery. The thinner and medium varieties are useful in transoral plating of fractures utilizing the Champy technique. The heavier, longer variety are used in unilateral edentulous fractures in the symphysis and parasymphysis as well as an aid to tumor resection and reconstruction with both free and vascularized grafts. They are not designed to replace the heavier 2.4 locking reconstruction plates designed for complex fractures or extensive reconstructions. PMID:12862364

Alpert, Brian; Gutwald, Rolf; Schmelzeisen, Rainer

2003-06-01

52

Does Locked Plating of Periprosthetic Supracondylar Femur Fractures Promote Bone Healing by Callus Formation? Two Cases with Opposite Outcomes  

PubMed Central

Contemporary locking plates promote biological fixation through indirect reduction techniques and by elevating the plate from the bone. They have improved fixation strength in osteoporotic bone. Periarticular locking plates are rapidly being adopted for bridge plating of periprosthetic femur fractures. When these plates are used for indirect reduction and bridge plating osteosynthesis, fracture union occurs by secondary bone healing with callus formation which is stimulated by interfragmentary motion. In two patients with similar periprosthetic femur fractures treated with periarticular locking plates one fracture healed by ample callus formation while the other resulted in a non-union and had no callus formation six months post-operatively. The case, which progressed to secondar y bone healing with callus formation, exhibited varus migration as a result of loss of fixation. The non-union case retained stable fixation. The difference in outcome may indicate that callus formation was promoted by interfragmentary motion secondary to loss of fixation. Conversely, in absence of fixation failure, callus formation was suppressed by stable fixation with a stiff locking plate construct which reduced interfragmentary motion. These observations suggest that locked plating constructs should be sufficiently flexible when applied for bridge plating of comminuted fractures to promote callus formation.

Henderson, Christopher E.; Bottlang, Michael; Marsh, J. Lawrence; Fitzpatrick, Dan C.; Madey, Steven M.

2008-01-01

53

Outcome of locking compression plates in humeral shaft nonunions  

PubMed Central

Background: Nonunion of diaphyseal fractures of the humerus are frequently seen in clinical practice (incidence of up to 15% in certain studies) and osteosynthesis using dynamic compression plates, intra medullary nails and Ilizarov fixators have been reported previously. Locking compression plates (LCP) are useful in the presence of disuse osteoporosis, segmental bone loss and cortical defects that preclude strong fixation. We report a prospective followup study of the outcome of the use of LCP for humeral nonunion following failed internal fixation in which implants other than LCP had been used. Materials and Methods: Twenty four patients with nonunion of humeral shaft fractures following failed internal fixation were included in the study. The mean followup period was 3.4 years (range: 2.4 to 5.7 years) and the minimum followup period was 2 years. Mean age of the patients was 41.04 years (range: 24 to 57 years). All 24 patients underwent osteosynthesis using LCP and autologous bone grafting (cortico-cancellous iliac crest graft combined with or without fibular strut graft). Main outcome measurements included radiographic assessment of fracture union and pre and postoperative functional evaluation using the modified Constant and Murley scoring system. Results: 23 out of 24 fractures united following osteosynthesis. Average time to union was 16 weeks (range: 10 to 28 weeks). Complications included delayed union (n = 2), transient radial nerve palsy (n = 2) and persistent nonunion (n = 1). Functional evaluation using the Constant and Murley score showed excellent results in 11, good in 10, fair in two and poor outcome in one patient. Conclusions: Locking compression plating and cancellous bone grafting is a reliable option for achieving union in humeral diaphyseal nonunion with failed previous internal fixation and results in good functional outcome in patients with higher physiological demands.

Kumar, Malhar N; Ravindranath, V Pratap; Ravishankar, MR

2013-01-01

54

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

Microsoft Academic Search

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

Daniel Hamman; Derek Lindsey; Jason Dragoo

2011-01-01

55

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

PubMed Central

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

2012-01-01

56

LOCKING FUEL DOORS™ - Chrome Plated Aluminum  

Microsoft Academic Search

Replace your factory fuel door with one of Westin's custom Locking Fuel Doors. Westin's Fuel Doors are manufactured from high quality cast aluminum then chrome plated for added protection and a custom look. Machined for secure trouble free opening and closing, fits snugly into the factory opening, and covers the area around the gas cap. Give your vehicle that finishing

CHEVY Tahoe; GMC Yukon; Yukon XL

57

Locking plates for displaced fractures of the lateral end of clavicle: Potential pitfalls  

PubMed Central

Roughly a quarter of all clavicle fractures occur at the lateral end. Displaced fractures of the lateral clavicle have a higher rate of nonunion. The management of fractures of the lateral clavicle remains controversial. Open reduction internal fixation with a superiorly placed locking plate is a recently developed technique. However, there are no randomized controlled trials to evaluate the efficacy of this procedure. We present a series of four cases which highlight the technical drawbacks with this method of fixation for lateral clavicle fractures. Two cases show that failure of the plate to negate the displacing forces at the fracture site can lead to plate pullout. Two cases illustrate an unusual complication of an iatrogenic injury to the acromioclavicular joint capsule which led to joint instability and dislocation. We advise caution in using this method of fixation. Recent studies have described the success of lateral clavicle locking plate fixation augmented with a coracoclavicular sling. This augmentation accounts for the displacing forces at the fracture site. We would recommend that when performing lateral clavicle locking plate fixation, it should be reinforced with a coracoclavicular sling to prevent plate failure by lateral screw pullout.

Sajid, Soha; Fawdington, Ross; Sinha, Maneesh

2012-01-01

58

The use of locking plates in complex midfoot fractures  

PubMed Central

INTRODUCTION Complex fracture dislocations of the midfoot are uncommon. Improved outcomes have been demonstrated where it has been possible to restore and maintain the length and alignment of the medial column as well as the congruity of the articular surfaces. We present our experience with the use of angle-stable locking plates in the stabilisation of complex midfoot fracture dislocations. METHODS Twelve patients were identified on a prospective trauma database between 2003 and 2009. All fractures involved the medial column with four associated fracture subluxations of the lateral column also. Patients underwent open reduction internal fixation (ORIF) with restoration of the medial column axis, reduction of the articular surface congruity and stabilisation with angle-stable locking plates. RESULTS There were no post-operative infections or neurological injuries. Ten of the twelve patients required metalwork removal. There were no implant failures prior to removal of the metalwork. At a mean follow-up of 12.4 months (range: 4–32 months), 11 patients had minimal symptoms of swelling, discomfort or stiffness in the midfoot. This did not restrict their daily activities. One patient developed post-traumatic arthritis and collapse of the medial longitudinal arch. Two patients declined removal of the metalwork. CONCLUSIONS Angle-stable locking plates provide satisfactory stabilisation following ORIF of complex midfoot fracture dislocations. Most patients will require removal of the metalwork. Following removal of metalwork, the majority of patients will maintain the length, alignment and stability of the midfoot.

Bayley, E; Duncan, N; Taylor, A

2012-01-01

59

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

60

Lapidus bunionectomy: Early evaluation of crossed lag screws versus locking plate with plantar lag screw.  

PubMed

We compared outcomes of the Lapidus bunionectomy fixated with crossed lag screws versus a locking plate with a plantar lag screw. Forty patients who underwent Lapidus bunionectomy between August 2001 and May 2006 were evaluated in a combined retrospective and prospective fashion. Crossed lag screws were used in 19 of the patients, and a locking plate with a plantar lag screw was used in 21 of the patients. Other than fixation, the only interventional difference pertained to postoperative weight bearing, where those receiving the plate initiated full weight bearing on the operated foot at 4 weeks postoperative, as compared to 6 weeks for those receiving crossed screws. Overall, the mean preoperative AOFAS hallux score was 41.75 +/- 2.52, and the postoperative score was 90.48 +/- 8.41 (P < .0001). The overall mean preoperative first intermetatarsal angle was 15.3 degrees +/- 2.32 degrees , and long term the angle was 5.03 degrees +/- 2.86 degrees (P < .0001). When comparisons were made based on the method of fixation, use of an adjunct Akin osteotomy and surgery performed before 2003 were statistically significantly associated with crossed screw fixation, and the preoperative AOFAS score was statistically significantly higher in the locking plate fixation group. There were no statistically significant differences related to postoperative complications between the 2 fixation groups. In conclusion, the Lapidus bunionectomy fixated with a locking plate and a plantar lag screw allows earlier weight bearing in comparison with crossed lag screws, without a difference in complications. Level of Clinical Evidence: 2. PMID:19232969

Saxena, Amol; Nguyen, Aidan; Nelsen, Elise

2009-01-01

61

Knee Fusion Using Dual Platings With the Locking Compression Plate  

Microsoft Academic Search

Knee arthrodesis is often used as a salvage procedure for infected, nonreconstructable total knee arthroplasties. We report 3 cases of infected total knee arthroplasties treated with knee fusion using locking compression plates. After at least 2 years of follow-up, these patients have healed with improvement in both symptoms and mobility.

Alfred C. Kuo; John P. Meehan; Mark Lee

2005-01-01

62

A biomechanical comparison between two volar locking plate systems for distal radius fractures.  

PubMed

The biomechanical properties of two distal radius volar locking plate systems were investigated. A cadaveric model simulating distal radius fractures with dorsal comminution was selected. The biomechanical properties of fracture fixation using the Synthes volar locking T-plate and the Hand Innovation DVR plate were characterized. The average stiffness was 137.1 +/- 19.9 N/mm for the DVR group and 119.1 +/- 9.9 N/mm for the Synthes group (P = .49), and the average changes of the opening angle describing plastic deformation were 10.1 degrees +/- 4.0 degrees and 8.6 degrees +/- 13.2 degrees, respectively (P = .23). This study demonstrates that both the Synthes T-plate and Hand Innovations DVR plate fixation systems show comparable biomechanical characteristics. PMID:17061419

Chen, Li; Dai, Qiang; Wongworawat, Montri D

2006-10-01

63

Static and Dynamic Differences in Fixation Stability between a Spacer Plate and a Small Stature Plate Fixator Used for High Tibial Osteotomies: A Biomechanical Bone Composite Study  

PubMed Central

Background. The objective of the present study was to compare mechanical strength and stability of the newly designed spacer plate with the gold standard plate for the treatment of medial knee joint osteoarthritis. Materials and Methods. Ten fourth-generation tibial bone composites underwent a medial open-wedge high tibial osteotomy (HTO) according to standard techniques, using five TomoFix plates and five Contour Lock plates. Static compression load to failure and load-controlled cyclical fatigue failure tests were performed. Forces and horizontal displacements were measured; plastic deformations and dynamic stiffness were determined. Results and Discussion. In all samples, rotation of the tibial head and fracture of the opposite cortex were observed. Behaviors of the specimens under static loading were comparable between groups. Cyclic testing revealed lateral significant higher stiffness until failure for the Contour Lock compared to the TomoFix plate. No visible implant failure was observed in any group. Conclusion. Considering the static analysis, both plates offered sufficient stability under physiologic loads of up to 3000?N. The Contour Lock plate-fixated specimens showed a higher stability during the cyclic testing, supposedly due to the wider distance between the fixation screws.

Maas, Stefan; Dueck, Klaus; Pape, Dietrich

2013-01-01

64

Locked volar plating for complex distal radius fractures: Patient reported outcomes and satisfaction  

PubMed Central

Background Distal radius fractures are common. The increasing prevalence of osteoporosis contributes to frequently complex articular injuries sustained even after low energy falls. The best method of treating complex type C distal radius fractures is debated. Locked volar plating and external fixation are both widely used with good reported results. Measures of success are traditionally based on technical measurements or the perception of the surgeon. Patient reported measures of outcome are increasingly recognised as important markers of surgical success. We report our experience using locked volar plating for complex type C distal radius fractures as well as patient reported measures of success and satisfaction. Methods Over a 12 month period we treated 21 patients with type C distal radius fractures using locked volar plating. These patients were followed up for at least 12 months and the outcome was assessed using clinical examination, grip strength measurements, radiographs and Patient Rated Wrist Evaluation (PRWE) scoring. Results The 21 patients studied had an average age of 48 years. There were 8 men and 13 women. All of the fractures had united by 3 months. There were no cases of wound infection or tendon injury/irritation. Patients reported low pain scores, good patient rated wrist evaluation scores and high levels of satisfaction. Conclusions Locked volar plating for complex distal radius fractures produces good results when assessed using patient reported measures of outcome. Further work should address whether locked volar plating offers superior outcomes and patient satisfaction compared to external fixation.

2010-01-01

65

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

PubMed Central

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

Zafra-Jimenez, Jose Alberto; Rodriguez Martin, Juan

2010-01-01

66

Custom-made Locked Plating for Acetabular Fracture: A Pilot Study in 24 Consecutive Cases.  

PubMed

Clinical implementation of site-specific locking plates for acetabular fracture remains untested. Custom-made locking plates were manufactured using computer-aided design and computer-aided manufacture techniques for acetabular fractures to test this procedure. The 3-dimensional images constructed from computed tomography data of pelvises in patients with acetabular fractures were used for preoperative planning and to design the plates. Data for each plate were input into software for programming, and the generated code was transferred into a computerized numerical control digital milling machine for manufacturing. These plates were clinically implemented, and the implementation parameters, reduction quality, and Postel Merle d'Aubigné score were evaluated. Forty-nine custom-made locking plates were manufactured for 24 unilateral acetabular fractures. The manufacturing process for the plates averaged 6.9±2.2 days. Processing the plates delayed operations by 2.6±1.3 days in one-third of the cases. Plate contouring was avoided in 48 plates. The plates had anatomical shapes, excellently matching reduced bone surface. The screws locked with the obtained plates avoided intra-articular penetration and provided secure fixation that allowed early out-of-bed rehabilitation. No indications of implant failures or observations of screw back-outs were observed during follow-up. The clinical application of such plates is associated with the avoidance of plate contouring, low risk of intra-articular penetration, early out-of-bed rehabilitation, and a low rate of implant failure. Implementing such plates in clinical practice is worthy of further investigation, with a focus on selecting patient population and minimizing the time required for and cost of plate manufacturing. PMID:24992064

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

2014-07-01

67

Biomechanical comparison of volar locked plate constructs using smooth and threaded locking pegs.  

PubMed

The goal of this study was to determine whether there is any biomechanical difference in terms of construct strength with axial loading between volar fixed-angle locking plates with threaded locking vs smooth locking pegs. The control group comprised 7 cadaveric specimens with threaded locking pegs, and the test group comprised 7 cadaveric specimens from the same donor with smooth locking pegs. The DVR plate (Biomet, Warsaw, Indiana) was applied to the volar surface. A 15-mm dorsal wedge osteotomy was created near the level of Lister's tubercle. The radii were potted in polymethylmethacrylate for biomechanical testing. The loading protocol consisted of 3 parts: ramp loading, cyclic loading, and failure loading. The outcome measures of stiffness and failure were used to test the plates fixed with threaded and smooth locking pegs. When comparing each cycle, the difference in mean stiffness between threaded and smooth locking pegs was as follows: 122 N/mm, -9.09 N/mm, -14.7 N/mm, 49.4 N/mm, 57.4 N/mm, 71.9 N/mm, 52.3 N/mm, 35.8 N/mm. The difference in mean failure load between the threaded and smooth locking pegs was -11.3 N. There was no difference in stiffness throughout all cycles. Failure analysis showed no significant difference between the smooth (962 N) and threaded (951 N) locking pegs. The difference in stiffness between the 2 constructs (smooth minus threaded locking pegs) in ramp loading ranged from -122 to 15 N/mm. The results of this study showed no significant differences in stiffness and failure load between constructs consisting of threaded locking pegs or smooth locking pegs in the distal rows of the DVR distal radius volar locking plate. Based on the results of this study, there may be no benefit to using threaded locking pegs vs smooth locking pegs when treating distal radius fractures with a volar locking plate. PMID:24679204

Yao, Jeffrey; Park, Min Jung; Patel, Chirag S

2014-02-01

68

Retrograde intramedullary nails with distal screws locked to the nail have higher fatigue strength than locking plates in the treatment of supracondylar femoral fractures: A cadaver-based laboratory investigation.  

PubMed

We investigated a new intramedullary locking nail that allows the distal interlocking screws to be locked to the nail. We compared fixation using this new implant with fixation using either a conventional nail or a locking plate in a laboratory simulation of an osteoporotic fracture of the distal femur. A total of 15 human cadaver femora were used to simulate an AO 33-A3 fracture pattern. Paired specimens compared fixation using either a locking or non-locking retrograde nail, and using either a locking retrograde nail or a locking plate. The constructs underwent cyclical loading to simulate single-leg stance up to 125,000 cycles. Axial and torsional stiffness and displacement, cycles to failure and modes of failure were recorded for each specimen. When compared with locking plate constructs, locking nail constructs had significantly longer mean fatigue life (75,800 cycles (SD 33,900) vs 12,800 cycles (SD 6100); p = 0.007) and mean axial stiffness (220 N/mm (SD 80) vs 70 N/mm (SD 18); p = 0.005), but lower mean torsional stiffness (2.5 Nm/° (SD 0.9) vs 5.1 Nm/° (SD 1.5); p = 0.008). In addition, in the nail group the mode of failure was either cut-out of the distal screws or breakage of nails, and in the locking plate group breakage of the plate was always the mode of failure. Locking nail constructs had significantly longer mean fatigue life than non-locking nail constructs (78,900 cycles (SD 25,600) vs 52,400 cycles (SD 22,500); p = 0.04). The new locking retrograde femoral nail showed better stiffness and fatigue life than locking plates, and superior fatigue life to non-locking nails, which may be advantageous in elderly patients. PMID:24395321

Pekmezci, M; McDonald, E; Buckley, J; Kandemir, U

2014-01-01

69

A randomized comparison of locking and non-locking palmar plating for unstable Colles’ fractures in the elderly  

Microsoft Academic Search

This study compared the effectiveness of locking and non-locking palmar plating for unstable Colles’ fractures in the elderly. The patients treated with locking plates included 4 men and 18 women with a mean age of 68 years (Group A) and those treated with non-locking plates included 3 men and 28 women with a mean age of 74 years (Group B).

M. Koshimune; M. Kamano; K. Takamatsu; H. Ohashi

2005-01-01

70

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.

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

2014-01-01

71

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

72

Infections associated with locking reconstruction plates: A retrospective review  

Microsoft Academic Search

Purpose: In this study, we examined the incidence of infection with the use of a locking reconstruction bone plate\\/system. Patients and Methods: All patients, treated with a locking reconstruction bone plate\\/screw system for mandible fractures in the Oral and Maxillofacial Surgery service over a 28-month period at a level I trauma center, were evaluated through a retrospective chart review by

David Kirkpatrick; Rahul Gandhi; Joseph E. Van Sickels

2003-01-01

73

Locking v/s non-locking reconstruction plates in mandibular reconstruction  

PubMed Central

Purpose: To compare the efficacy of locking plates to non-locking plates in the osteosynthesis of mandibular fractures on the basis of clinical parameters. Materials and Methods: A prospective randomized clinical trial was conducted at the Faculty of Dental Science, CSMMU (formerly King Georges Medical College), Lucknow, to treat consecutive mandible fractures. The patients were randomly divided into two groups. The patients underwent osteosynthesis—group 1 with 2.4-mm locking titanium plates and group 2 with 2.7 mm non-locking titanium plates. The cause of trauma, the number of days from injury to surgery, average age, gender, and site distribution were all reviewed. The assessment of the patients was done at 1, 3, and 6 weeks and 3 months using the clinical parameters. Results: A total of 12 patients with mandibular fractures met the inclusion criteria. In our study, a statistically significant difference was not found in the clinical parameters such as infection, paraesthesia, hardware failure, and mobility between the fracture segments. A statistically significant difference was found between pain and swelling from the previous follow-up visit in groups 1 and 2. In locking group, pain decreases significantly at 3rd week, 6th week, 12th week from 1st week and pain was absent after 3 week. In non-locking group, pain decreases significantly at 3rd week, 6th week and 12th week from 1st week but pain was present till 12th week. Pre-operative swelling was present only in case of non-locking group. Swelling was present in 66.7% of non-locking group and 0% in locking group. After one week swelling was absent in 100% patients at 3rd, 6th and 12th week. Swelling was considerably decreased in locking group as compared to the non-locking group. Conclusion: These findings show that the use of locking plates in mandibular fracture was efficacious enough to bear the masticatory loads during osteosynthesis of the fracture. The locking plates provide the advantage of a greater stability, with clinical results almost similar to those seen with non-locking plate osteosynthesis.

Harjani, Bhupendra; Singh, R K; Pal, U S; Singh, Geeta

2012-01-01

74

One- or two-plate fixation of mandibular angle fractures?  

PubMed

Standard treatment of mandibular angle fractures with miniplates, according to the recommendations of Champy et al. (1976), consists of fixation with one plate at the superior border of the mandible ventral to the external oblique line. In certain constellations, a second miniplate at the lower mandibular margin may provide additional stability. In contrast, extremely high complication rates following two-plate fixation of mandibular angle fractures were reported by Ellis and Walker (1994). In a prospective randomized study, 31 consecutive patients were treated with 2.0 mm (mini) plates (Synthes Co., Switzerland). One group was treated with one plate, the other one with two plates. In none of the patients was intermaxillary immobilization used. Follow-up was performed 6 months postoperatively, consisting of clinical and radiographic examination. No significant differences (P = 0.74 for infection, and P = 1.0 for occlusal and postoperative sensory disturbance) in postoperative short- or long-term complications were found between the two groups. The results are compared with our experimental investigations presented at the annual congress of the Germany Society of Oral and Maxillofacial Surgery, 1995. Two-plate fixation may not offer advantages over single-plate fixation in general. However, individual fracture constellations may benefit from variation in plate(s) localization. Factors contributing to complications in mandibular angle fractures are discussed. PMID:9234097

Schierle, H P; Schmelzeisen, R; Rahn, B; Pytlik, C

1997-06-01

75

Outcome of locking compression plating for proximal humeral fractures: a prospective study.  

PubMed

PURPOSE. To evaluate the outcome of open reduction and internal fixation using locking compression plates for proximal humeral fractures. METHODS. 54 men and 16 women aged 28 to 79 (mean, 54) years underwent open reduction and internal fixation using a locking compression plate for closed 2-part (n=22), 3-part (n=38), and 4-part (n=10) proximal humeral fractures. 10 of the patients also had dislocation of the humeral head; 4 had fractures extending to the shaft. Wound condition, functional outcome, bone union, amount of collapse, and malalignment were assessed. Functional outcome was assessed using the Constant-Murley score. RESULTS. The mean follow-up period was 15 (range, 6-24) months. All fractures achieved union after a mean of 9 (range, 6-12) weeks. The mean Constant- Murley scores for the injured and normal shoulders were 72 and 82, respectively (88% of normal). The final outcome was excellent in 14 patients, good in 28, moderate in 22, and poor in 6. In the latter 6 patients, 2 had screw penetration, 2 had plate impingement, one had a mal-reduced greater tuberosity, and one had adhesive capsulitis. All were preventable. In all, 18 patients had 20 complications: subacromial impingement of the plate (n=6), mal-reduction of the greater tuberosity (n=6), screw penetration (n=2), adhesive capsulitis (n=2), superficial infection (n=2), and haematoma (n=2); 12 of these complications were technique-related. CONCLUSION. Locking proximal humeral plates enabled stable fixation in all Neer-type proximal humeral fractures. Most complications were technique-related. PMID:24781604

Chowdary, U; Prasad, H; Subramanyam, P K

2014-04-01

76

Distal radius fractures: strategic alternatives to volar plate fixation.  

PubMed

Volar locking plates have provided surgeons with enhanced capability to reliably repair both simple and complex fractures and avoid the hardware-related complications associated with dorsal plating. However, there have been an increasing number of published reports on the frequency and types of complications and failures associated with volar locked plating of distal radius fractures. An informed, critical assessment of distal radius fracture characteristics will allow surgeons to select an individualized treatment strategy that maximizes the likelihood of a successful outcome. Knowledge of the anatomy, patterns, and characteristics of the diverse types of distal radius fractures and the complications and failures associated with volar locked plating will be helpful to orthopaedic surgeons who treat patients with these injuries. PMID:24720291

Dy, Christopher J; Wolfe, Scott W; Jupiter, Jesse B; Blazar, Philip E; Ruch, David S; Hanel, Douglas P

2014-01-01

77

Arthrodesis of the thumb metacarpophalangeal joint with plate fixation.  

PubMed

This is a surgical technique for arthrodesis of the thumb metacarpophalangeal joint using a low-profile plate. Using the principles of tension band fixation and interfragmentary compression, a high rate of fusion is achieved with a low incidence of complications. The technique is versatile allowing fixation at any desired position. It can be used in porotic bone and avoids the need for postoperative immobilization. PMID:23160554

Rao, Sudhir B

2012-12-01

78

Biomechanical Comparison of Different Volar Fracture Fixation Plates for Distal Radius Fractures  

PubMed Central

The purpose of this study was to compare the biomechanical properties of four volar fixed-angle fracture fixation plate designs in a novel sawbones model as well as in cadavers. Four volar fixed angle plating systems (Hand Innovations DVR-A, Avanta SCS/V, Wright Medical Lo-Con VLS, and Synthes stainless volar locking) were tested on sawbones models using an osteotomy gap model to simulate a distal radius fracture. Based on a power analysis, six plates from each system were tested to failure in axial compression. To simulate loads with physiologic wrist motion, six plates of each type were then tested to failure following 10,000 cycles applying 100N of compression. To compare plate failure behavior, two plates of each type were implanted in cadaver wrists and similar testing applied. All plate constructs were loaded to failure. All failed with in apex volar angulation.The Hand Innovations DVR-A plate demonstrated significantly more strength in peak load to failure and failure after fatigue cycling (p value?plates in synthetic bone. The cadaveric model demonstrated the same mode of failure as the sawbones. None of the volar plates demonstrated screw breakage or pullout, except the tine plate (Avanta SCS/V) with 1 mm of pullout in 2 of 12 plates. This study demonstrates the utility of sawbones in biomechanical testing and indicates that volar fixation of unstable distal radius fractures with a fixed angle device is a reliable means of stabilization.

Sobky, Kareem; Baldini, Todd; Thomas, Kenneth; Bach, Joel; Williams, Allison

2007-01-01

79

Comparative study of locking plates in mandibular reconstruction after ablative tumor surgery: THORP versus UniLOCK system  

Microsoft Academic Search

PurposeThis retrospective study compared 2 types of rigid locking plates (THORP and UniLOCK; Stratec Medical, Oberdorf, Switzerland) in 107 patients undergoing reconstruction for bridging mandibular defects following ablative tumor surgery.

Nils-Claudius Gellrich; Maria Mercedes Suarez-Cunqueiro; Xose Luis Otero-Cepeda; Ralf Schön; Rainer Schmelzeisen; Ralf Gutwald

2004-01-01

80

Polyaxial locking and compression screws improve construct stiffness of acetabular cup fixation: a biomechanical study.  

PubMed

Bone ingrowth into uncemented acetabular components requires intimate cup-bone contact and rigid fixation, which can be difficult to achieve in revision hip arthroplasty. This study compares polyaxial compression locking screws with non-locked and cancellous screw constructs for acetabular cup fixation. An acetabular cup modified with screw holes to provide both compression and angular stability was implanted into a bone substitute. Coronal lever out, axial torsion and push-out tests were performed with an Instron testing machine, measuring load versus displacement. Polyaxial locking compression screws significantly improved construct stiffness compared with non-locked or cancellous screws. This increased construct stiffness will likely reduce interfacial micromotion. Further research is required to determine whether this will improve bone ingrowth in vivo and reduce cup failure. PMID:24360790

Milne, Lachlan P; Kop, Alan M; Kuster, Markus S

2014-05-01

81

Surgical treatment of unstable distal radius fractures with volar locking plates  

Microsoft Academic Search

Background  Surgical treatment of unstable distal radius fractures does not always yield a satisfactory outcome. The several surgical\\u000a strategies available have problems associated with them. This study was undertaken to determine if volar locking plate fixation\\u000a could be useful for treating unstable distal radius fractures.\\u000a \\u000a \\u000a \\u000a Methods  This retrospective follow-up study assessed 24 fractures in 24 patients with unstable distal radius fractures surgically

Kenichi Murakami; Yoshihiro Abe; Kazuhisa Takahashi

2007-01-01

82

Analysis of early failure of the locking compression plate in osteoporotic proximal humerus fractures  

Microsoft Academic Search

Background  Although there has been continuous evolution in the management of fracture fixation, treatment for osteoporotic proximal humerus\\u000a fractures is still challenging to trauma surgeons. The purpose of this study was to report early failure of the locking compression\\u000a plate (LCP) in the treatment of osteoporotic proximal humerus fracture and characterize the mode of failure.\\u000a \\u000a \\u000a \\u000a Methods  Nine patients, older than 65 years,

Ivan D. Micic; Kyung-Chun Kim; Dong-Ju Shin; Sang-Jin Shin; Poong-Taek Kim; Il-Hyung Park; In-Ho Jeon

2009-01-01

83

Locking Effects for the Reissner-Mindlin Plate Model.  

National Technical Information Service (NTIS)

We analyze the robustness of various standard finite element schemes for the Reissner-Mindlin plate and obtain asymptotic convergence estimates that are uniform in terms of the thickness d. We identify h version schemes that show locking, i.e. for which t...

M. Suri I. Babuska C. Schwab

1992-01-01

84

Magnetically Operated Holding Plate And Ball-Lock Pin  

NASA Technical Reports Server (NTRS)

Magnetically operated holding plate and ball-locking-pin mechanism part of object attached to, or detached from second object. Mechanism includes tubular housing inserted in hole in second object. Plunger moves inside tube forcing balls to protrude from sides. Balls prevent tube from sliding out of second object. Simpler, less expensive than motorized latches; suitable for robotics applications.

Monford, Leo G., Jr.

1992-01-01

85

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.

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

2010-01-01

86

Trace metal analysis following locked volar plating for unstable fractures of the distal radius.  

PubMed

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

87

Does plate adaptation affect stability? A biomechanical comparison of locking and nonlocking plates  

Microsoft Academic Search

Purpose: The purpose of this investigation was to determine whether the degree of plate adaptation and effects of locking influenced the mechanical behavior of the plate\\/screw\\/substrate system for 2.0-mm monocortical superior border plates and 2.4-mm reconstruction plates secured at the inferior border intended to stabilize simulated mandibular angle fractures. Materials and Methods: A total of 130 polyurethane synthetic mandible replicas

Richard H. Haug; Michele Goltz

2002-01-01

88

Appendicular fracture repair in dogs using the locking compression plate system: 47 cases.  

PubMed

The locking compression plate (LCP) has combination screw holes, making it possible to use the implant in three different ways; as a pure internal fixator using locking head screws, as a conventional compression plate using compression screws, or as a hybrid of the two. The experience with the LCP system in veterinary fracture repair is limited. The objective of this study was to evaluate the outcome of appendicular fractures in dogs, which were repaired with the LCP system combined with less invasive surgical techniques. Medical records and radiographs from 47 dogs were studied retrospectively. Thirty-four percent of the fractures were simple, six percent wedge and 60% comminuted fractures of the humerus (11 %), radius and ulna (30 %), femur (34 %) and of the tibia and fibula (25 %). The fractures were treated using the LCP as an internal fixator; in some cases as a plate and rod construct. Forty-six of 47 fractures reached radiographic union. Mean healing time of the fractures was seven weeks (95% confidence interval from 5.8 to 8.3 weeks). There were statistically significant differences in healing time between juvenile (age under one year) and adults. Complications in the form of implant failures and infections were encountered in approximately 11% of the cases. All implant failures were due to surgical errors. The LCP system in combination with a less invasive surgical approach was found advantageous in comminuted fractures where the LCP was used as a bridging plate, in situations when exact plate contouring was difficult, and when other implants prevented the use of bi-cortical screws. PMID:19597631

Haaland, P J; Sjöström, L; Devor, M; Haug, A

2009-01-01

89

Fixation of zygomatic and mandibular fractures with biodegradable plates  

PubMed Central

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

Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

2013-01-01

90

Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures  

PubMed Central

Purpose To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. Methods We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. Results At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. Conclusions Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types.

Mignemi, Megan E.; Byram, Ian R.; Wolfe, Carmen C.; Fan, Kang-Hsien; Koehler, Elizabeth A.; Block, John J.; Jordanov, Martin I.; Watson, Jeffry T.; Weikert, Douglas R.; Lee, Donald H.

2013-01-01

91

Correction osteotomy of distal radius malunion stabilised with dorsal locking plates without grafting.  

PubMed

The purpose of this study was to evaluate the results of our correction osteotomies of distal radial malunions without a bone graft. Eleven consecutive patients (mean age 52 years, range 18-71) were treated. A dorsal approach was utilised to perform an opening-wedge osteotomy which then was stabilised with two dorsal columnar plates without filling the osteotomy gap. All patients went on to radiographic union with a filling of the osteotomy gap within a mean period of 3 months (range 2-6 months). All patients had satisfactory results in terms of function and pain. Correction osteotomy and stabilisation with bicolumnar locked plate fixation without a bone graft provides sufficient stability to allow the highly vascularised metaphysis to heal. In patients without risk factors predisposing to non-union, this procedure is safe and feasible. PMID:24610600

Tiren, D; Vos, D I

2014-04-01

92

Mandibulotomy fixation: a laboratory analysis  

Microsoft Academic Search

Purpose: Mandibulotomy is an access osteotomy technique associated with significant complications. Critical evaluation of available fixation systems is required to aid in the selection of the most stable fixation method. This study was designed to provide data on the stability of traditionally used plating configurations and a low-profile 2.0-mm locking plate (mandibular locking plate, Synthes MLP; Synthes Maxillofacial, Paoli, PA).Materials

Stephen L Engroff; Remy H Blanchaert; J. Anthony von Fraunhofer

2003-01-01

93

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

PubMed Central

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

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

2012-01-01

94

Screw locking elements: a means to modify the flexibility of osteoporotic fracture fixation with DCPs without compromising system strength or stability.  

PubMed

This paper analyses whether it is possible to use dynamic compression plates (DCPs) and screw locking elements (SLEs) to vary the flexibility of osteoporotic fracture fixation without compromising the strength and stability of the construct. Compression, torsion and four-point bending static strength tests were conducted. Cyclic load tests of up to 10,000 load cycles were also carried out to determine stiffness performance. Four fixation systems were mounted onto polyurethane bone models. Group 1 consists of the DCP and six cortical screws. Group 2, idem, but with the addition of two SLEs. Group 3, idem, but with the addition of six SLEs. Group 4 used the locking compression plate (LCP) and locking screws. The results indicated no significant difference (p>0.05) in the strength of groups 2-4. It was also observed that the torsional stiffness of group 3 (0.30 Nm/°) was higher than that of group 2 (0.23 Nm/°) and similar to that of group 4 (0.28 Nm/°). Compression stiffness of group 4 (124 N/mm) was higher than that of group 2 (102 N/mm), but lower than that of group 3 (150 N/mm). No notable differences were observed for structural bending stiffness. It is concluded that by using the DCP with SLEs it is possible to modify the stiffness of the fixation construct for the repair of osteoporotic fractures and, in this way, facilitate the conditions suitable on secondary bone healing. PMID:21982962

Yánez, A; Cuadrado, A; Carta, J A; Garcés, G

2012-07-01

95

Locking Plate for Proximal Humeral Fracture in the Elderly Population: Serial Change of Neck Shaft Angle  

PubMed Central

Background We conducted this radiographic study in the elderly population with proximal humeral fracture aiming to evaluate 1) the serial changes of neck-shaft angle after locking plate fixation and 2) find relationship between change in neck shaft angle and various factors such as age, fracture pattern, severity of osteoporosis, medial support and initial reduction angle. Methods Twenty-five patients who underwent surgical treatment for proximal humeral fracture with locking plate between September 2008 and August 2010 are included. True anteroposterior and axillary lateral radiographs were made postoperatively and at each follow-up visit. Measurement of neck shaft angle was done at immediate postoperative, 3 months postoperative and a final follow-up (average, 11 months; range, 8 to 17 months). Severity of osteoporosis was assessed using cortical thickness suggested by Tingart et al. Results The mean neck shaft angles were 133.6° (range, 100° to 116°) at immediate postoperative, 129.8° (range, 99° to 150°) at 3 months postoperative and 128.4° (range, 97° to 145°) at final follow-up. The mean loss in the neck-shaft angle in the first 3 months was 3.8° as compared to 1.3° in the period between 3 months and final follow-up. This was statistically significant (p = 0.002), indicating that most of the fall in neck shaft angle occurs in the first three months after surgery. Relationship between neck shaft angle change and age (p = 0.29), fracture pattern (p = 0.41), cortical thickness (p = 0.21), medial support (p = 0.63) and initial reduction accuracy (p = 0.65) are not statistically significant. Conclusions The proximal humerus locking plate maintains reliable radiographic results even in the elderly population with proximal humerus fracture.

Pawaskar, Aditya C; Lee, Kee-Won; Kim, Jong-Min; Park, Jin-Woong; Aminata, Iman W; Jung, Hong-Jun; Chun, Jae-Myeung

2012-01-01

96

Use of a 2.0-mm locking plate\\/screw system for mandibular fracture surgery  

Microsoft Academic Search

Purpose: In this study, we examined the use of a 2.0-mm locking bone plate\\/screw system in mandibular surgery. Patients and Methods: All patients who were treated with a 2.0-mm locking bone plate\\/screw system during an 8-month period for fractures of the mandible or other defects of the mandible were prospectively studied. Ease of use of locking plate\\/screw system, characteristics of

Edward Ellis; John Graham

2002-01-01

97

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

98

Semi-automatic customization of internal fracture fixation plates.  

PubMed

A new method for customization of fixation plates for repairing bone fractures is proposed. Digital models of plates are typically available as CAD models that contain smooth analytic geometry representations including NURBS. With the existing pre-operative planning solutions, these models are converted to polygonal meshes and adapted manually to the patient's bone geometry by the user. Based on the deformed model, physical bending is then performed by the surgeon in operating room. With the proposed approach, CAD models are semi-automatically adapted using NURBS to generate customized plates that conform to the desired region of the bone surface of patients. This enables an efficient and accurate approach that is also computationally suitable for interactive planning applications. Moreover, the patient-specific customized plates can then be produced directly from the adapted CAD models with a standard CNC machine before surgery. This may dramatically reduce time spent in OR, improve precision of the procedure and as a result improve the patient's outcome. PMID:22254380

Musuvathy, Suraj; Azernikov, Sergei; Fang, Tong

2011-01-01

99

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

PubMed

Objective: Metaphyseal-diaphyseal fractures of the distal radius are a major treatment dilemma and orthopaedic surgeons have to pay due consideration to restoration of anatomy of distal radius together with rotation of the radial shaft and maintenance of radial bow and interosseous space. We performed this study to evaluate the clinic-radiological outcome of metaphyseal-diaphyseal fractures of the distal radius treated with long volar locking plates. Methods: This prospective study involved 27 patients (22 males and 5 females) with metaphyseal-diaphyseal fracture of the distal radius. Their mean age was (30.12+/-11.48) years (range 19-52 years) and the follow-up was 26.8 months (range 22-34 months). All patients underwent open reduction and internal fixation with a long volar locking plate. According to AO/OTA classification, there were 7 type A3, 13 type C2 and 7 type C3 fractures. Subjective assessment was done based on the disabilities of the arm, shoulder and hand (DASH) questionnaire. Functional evaluation was done by measuring grip strength and range of motion around the wrist and the radiological determinants included radial angle, radial length, volar angle and ulnar variance. The final assessment was done according to Gartland and Werley scoring system. Results: Postoperative radiological parameters were well maintained throughout the trial, and there was significant improvement in the functional parameters from 6 weeks to final follow-up. The average DASH scores improved from 37.5 at 6 weeks to 4.2 at final follow-up. Final assessment using Gartland and Werley scoring system revealed 66.67% (n equal to 18) excellent and 33.33% (n equal to 9) good results. There was one case of superficial infection which responded to antibiotics and another carpel tunnel syndrome which was managed conservatively. Conclusion: Volar locking plate fixation for metaphyseal-diaphyseal fractures of distal radius is associated with excellent to good functional outcome, early rehabilitation and minimal complications. PMID:24295579

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

2013-12-01

100

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

PubMed

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

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

2013-09-01

101

A comparative in vitro study of fixation of mandibular fractures with paraskeletal clamps or screw plates.  

PubMed

The use of porcine rib pairs as an in vitro analog for the edentulous mandible is described. Using this model, the relative degree of fixation achieved with a screw plate (Champy) and a paraskeletal clamp plate (Mennen) has been evaluated. The fractured plated ribs failed at significantly lower bending forces than the non-sectioned controls. However, no statistically significant difference in force at failure between the two different methods of plate fixation could be demonstrated. PMID:2329396

Crofts, C E; Trowbridge, A; Maung Aung, T; Brook, I M

1990-05-01

102

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

PubMed Central

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

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

2009-01-01

103

Shoulder arthrodesis with plate fixation: Functional outcome analysis.  

PubMed

Fifty-seven patients underwent shoulder arthrodesis with a single plate. The technique utilized included both glenohumeral and acromiohumeral arthrodesis. A 10-hole plate was used for internal fixation. The position utilized was 30° abduction, 30° internal rotation, and 30° flexion. Forty-six patients underwent the procedure for brachial plexus injury, six patients for multidirectional shoulder instability, two patients for osteoarthritis, two patients for failed total shoulder arthroplasties, and one for infection. The patients were independently reviewed by a research clinician and their function assessed according to their ability to perform activities of daily living, subjective satisfaction with the procedure, and the degree of pain they felt in their shoulder. Fifty-four shoulders fused within 10° of the desired position. Three patients required secondary bone grafting. The complication rate was 14%. Patient satisfaction was highest in those patients undergoing the procedure for brachial plexus injury, osteoarthritis, and failed total shoulder arthroplasty (p = 0.0046). Four patients with multidirectional shoulder instability continued to complain of instability in spite of solid arthrodesis (p < 0.01). The difference in the cumulative activities of daily living score between the brachial plexus injury and poor hand function group and the multidirectional shoulder instability group and patients with other diagnoses was significant (p = 0.0001). Preoperative diagnosis, hand function, and work status were significant determinants of patient satisfaction and the cumulative activities of daily living score (p = 0.0001). PMID:22959501

Richards, R R; Beaton, D; Hudson, A R

1993-09-01

104

Distal Ulna Hook Plate: Angular Stable Implant for Fixation of Distal Ulna  

PubMed Central

Distal ulna fractures, especially styloid injuries, classically have not been repaired, and only recently have these injuries been considered important. Certain fracture patterns of the distal ulna contribute to distal radioulnar joint (DRUJ) incongruity and potential instability. Appropriate fixation of the distal ulna is frequently difficult for several reasons: (1) high incidence of osteoporois in the affected patient population, (2) proximity of the injury to articular surfaces, and (3) lack of a proper implant to treat these injuries. The 2.0-mm locking compression distal ulna plate (LC-DUP) is an anatomically contoured implant with a low profile and fixed angle that provides proper stability to treat injuries of the distal ulna. The plate was designed for the treatment of distal ulna fractures, but its success has led to an extension of its indications to be used in treating symptomatic basistyloid ulnar nonunions and in ulnar shortening osteotomy for ulnocarpal abutment syndrome. The authors' description of the techniques used for each indication as well as their perspectives in the treatment of distal ulna injuries are described in detail in this report.

Nunez, Fiesky A.; Li, Zhongyu; Campbell, Douglas; Nunez, Fiesky A.

2013-01-01

105

Transpedicular plate fixator as effective system of spine stabilisation: biomechanical characteristics  

Microsoft Academic Search

Introduction  Zespol fixator, which was created in Poland by Ramatowski and Granowski, has an angular stable connection of screws and plate.\\u000a These properties of this plate fixator, that is effective and not an expensive system of osteosynthesis of shaft of long bone\\u000a widely used in Poland, impelled us to adapt it as a transpedicular plate fixator of spine.\\u000a \\u000a \\u000a \\u000a Aim  The aim of

Piotr Paw?owski; Maciej Araszkiewicz; Tomasz Topoli?ski; Dariusz M?tewski

2008-01-01

106

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

107

Transarticular (transpedicular) metal plate fixation for stabilization of the lumbar and thoracic spine  

Microsoft Academic Search

Summary The operation of metal plate fixation of the articular column with the screws traversing the anterior vertebral arch (ventral pedicles) and anchored within the vertebral body is described in detail. The method can be recommended as easy to perform. It gives sufficiently stable fixation in cases where instability of the thoracic or lumbar spine can be expected during an

H. D. Herrmann; H. D. Herrrnann

1979-01-01

108

Locking of a Metacarpo-Phalangeal Joint Caused by a Haemangioma of the Volar Plate  

Microsoft Academic Search

A case of locking of a metacarpo-phalangeal joint in a 47-year-old woman is reported, Full movement of the joint was restored after excision of a haemangioma which had arisen from the volar plate. Other causes of locking are described and recommendations for treatment are made.

G. N. FERNANDEZ

1988-01-01

109

A Preliminary Study of Bending Stiffness Alteration in Shape Changing Nitinol Plates for Fracture Fixation  

Microsoft Academic Search

Nitinol is a promising biomaterial based on its remarkable shape changing capacity, biocompatibility, and resilient mechanical\\u000a properties. Until now, very limited applications have been tested for the use of Nitinol plates for fracture fixation in orthopaedics.\\u000a Newly designed fracture-fixation plates are tested by four-point bending to examine a change in equivalent bending stiffness\\u000a before and after shape transformation. The goal

Gavin Olender; Ronny Pfeifer; Christian W. Müller; Thomas Gösling; Stephan Barcikowski; Christof Hurschler

2011-01-01

110

Mechanical Locking between Multi-Layer Printed Wiring Board Conductors and Through-Hole Plating.  

National Technical Information Service (NTIS)

This invention relates to the field of electrical printed wiring board structure and to the manufacture of such boards. A plated through-hole conductor structure for a multiple layer laminate electronic printed wiring board includes mechanical locking of ...

E. Taylor

1984-01-01

111

Management of extra-articular fractures of the distal tibia: intramedullary nailing versus plate fixation.  

PubMed

Intramedullary nailing and plate fixation represent two viable approaches to internal fixation of extra-articular fractures of the distal tibia. Although both techniques have demonstrated success in maintaining reduction and promoting stable union, they possess distinct advantages and disadvantages that require careful consideration during surgical planning. Differences in soft-tissue health and construct stability must be considered when choosing between intramedullary nailing and plating of the distal tibia. Recent advances in intramedullary nail design and plate-and-screw fixation systems have further increased the options for management of these fractures. Current evidence supports careful consideration of the risk of soft-tissue complications, residual knee pain, and fracture malalignment in the context of patient and injury characteristics in the selection of the optimal method of fixation. PMID:23118133

Casstevens, Chris; Le, Toan; Archdeacon, Michael T; Wyrick, John D

2012-11-01

112

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.

2012-01-01

113

Volar plate fixation of intra-articular distal radius fractures: a retrospective study.  

PubMed

Background Intra-articular fractures of the distal radius represent a therapeutic challenge as compared with the unstable extra-articular fractures. With the recent development of specifically designed internal fixation materials for the distal radius, treatment of these fractures by fragment-specific implants using two or more incisions has been advocated. Purpose The purpose of this study was to investigate the efficacy of a fixed-angle locking plate applied through a single volar approach in maintaining the radiographic alignment of unstable intra-articular fractures as well as to report the clinical outcomes. We only excluded those with massive comminution, as is discussed in greater detail in the text. Patients and Methods This is a multicentered, retrospective study involving three hospitals situated in Spain, Switzerland, and the United States. In the period between January 2000 and March 2006, 97 patients with 101 intra-articular distal radius fractures, including 13 volarly displaced and 88 dorsally angulated fractures were analyzed. Over 80% were C2/C3 fractures, based on the AO classification. 16 open fractures were noted. Results With an average follow-up of 28 months (range 24-70 months), the range of movement of the wrist was very satisfactory, and the mean grip strength was 81% of the opposite wrist. The Disabilities of the Arm, Shoulder, and Hand (DASH) score was 8. The complications rate was < 5%, including loss of reduction in two patients. All fractures healed by 3 months postinjury. Conclusions Irrespective of the direction and amount of initial displacement, a great majority of intra-articular fractures of the distal radius can be managed with a fixed-angle volar plate through a single volar approach. Level IV retrospective case series. PMID:24436824

Fok, Margaret W M; Klausmeyer, Melissa A; Fernandez, Diego L; Orbay, Jorge L; Bergada, Alex Lluch

2013-08-01

114

Comparison of different distal radius dorsal and volar fracture fixation plates: A biomechanical study  

Microsoft Academic Search

Purpose: To compare the biomechanical properties of 6 dorsal and volar fracture fixation plate designs in a cadaver model. Method: Six different plating techniques were used on surgically simulated, unstable, extra-articular distal radius fractures in fresh-frozen cadavers. Specimens were tested to failure in axial compression with the Materials Testing System machine, and were analyzed with a motion analysis system. The

Denju Osada; Steven F. Viegas; Munir A. Shah; Randal P. Morris; Rita M. Patterson

2003-01-01

115

Locking Plates for Corrective Osteotomy of Malunited Dorsally Tilted Distal Radial Fractures: A Biomechanical Study  

Microsoft Academic Search

The purpose of the study was to compare the biomechanical properties of five different palmar fixation plate designs in a distal radius osteotomy cadaver model. A 1 cm metaphyseal osteotomy gap was made to simulate a corrective osteotomy and the osteotomy plated. Axial load was applied to the distal end of each construct by a material testing machine under control

D. KLITSCHER; L. RUDIG; D. MEHLER; P. M. ROMMENS; K. J. PROMMERSBERGER

2006-01-01

116

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

117

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

118

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

PubMed Central

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

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

2013-01-01

119

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

PubMed Central

Background and purpose There is considerable uncertainty about the optimal treatment of displaced 4-part fractures of the proximal humerus. Within the last decade, locking plate technology has been considered a breakthrough in the treatment of these complex injuries. Methods We systematically identified and reviewed clinical studies on the benefits and harms after osteosynthesis with locking plates in displaced 4-part fractures. Results We included 14 studies with 374 four-part fractures. There were 10 case series, 3 retrospective observational comparative studies, 1 prospective observational comparative study, and no randomized trials. Small studies with a high risk of bias precluded reliable estimates of functional outcome. High rates of complications (16–64%) and reoperations (11–27%) were reported. Interpretation The empirical foundation for the value of locking plates in displaced 4-part fractures of the proximal humerus is weak. We emphasize the need for well-conducted randomized trials and observational studies.

2011-01-01

120

Dorsally Comminuted Fractures of the Distal End of the Radius: Osteosynthesis with Volar Fixed Angle Locking Plates  

PubMed Central

Background. Dorsally comminuted distal radius fractures are unstable fractures and represent a treatment challenge. The objective of this study was to evaluate the functional and radiological outcome of dorsally comminuted fractures of the distal radius fixed with a volar locking plate. Patients and Methods. Thirty-three consecutive patients with dorsally comminuted fractures of the distal end of the radius were treated by open reduction and internal fixation with AO 2.4?mm (n = 19)/3.5?mm (n = 14) volar locking distal radius plate (Synthes, Switzerland, marketed by Synthes India Pvt. Ltd.). There were 7 type A3, 8 type C2, and 18 type C3 fractures. The patients were followed up at 6 weeks, 3 months, 6 months, and 1 year postoperatively. Subjective assessment was done as per Disabilities Arm, Shoulder, and Hand (DASH) questionnaire. Functional evaluation was done by measuring grip strength and range of motion around the wrist; the radiological determinants were radial angle, radial length, volar angle, and ulnar variance. The final assessment was done as per Demerit point system of Saito. Results. There were 23 males and 10 females with an average age of 44.12 ± 18.63 years (18–61 years). Clinicoradiological consolidation of the fracture was observed in all cases at a mean of 9.6 weeks (range 7–12 weeks). The average final extension was 58.15° ± 7.83°, flexion was 54.62° ± 11.23°, supination was 84.23° ± 6.02°, and pronation was 80.92° ± 5.54°. Demerit point system of Saito yielded excellent results in 79% (n = 26), good in 18% (n = 6), and fair in 3% (n = 1) patients. Three patients had loss of reduction but none of the patients had tendon irritation or ruptures, implant failure, or nonunion at the end of an one-year followup. Conclusion. Volar locking plate fixation for dorsally comminuted distal radius fractures results in good to excellent functional outcomes despite a high incidence of loss of reduction and fracture collapse.

Selhi, Harpal Singh; Devgan, Ashish; Magu, Narender Kumar; Yamin, Mohammad

2013-01-01

121

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.

2014-01-01

122

Fractures of the Distal Tibia Treated with Polyaxial Locking Plating  

Microsoft Academic Search

We evaluated the healing rate, complications, and functional outcomes in 32 adult patients with very short metaphyseal fragments\\u000a in fractures of the distal tibia treated with a polyaxial locking system. The average distance from the distal extent of the\\u000a fracture to the tibial plafond was 11 mm. All fractures healed and the average time to union was 14 weeks. Six

Hong Gao; Chang-Qing Zhang; Cong-Feng Luo; Zu-Bin Zhou; Bing-Fang Zeng

2009-01-01

123

Dose distribution near thin titanium plate for skull fixation irradiated by a 4-MV photon beam  

PubMed Central

To investigate the effects of scattered radiation when a thin titanium plate (thickness, 0.05 cm) used for skull fixation in cerebral nerve surgery is irradiated by a 4-MV photon beam. We investigated the dose distribution of radiation inside a phantom that simulates a human head fitted with a thin titanium plate used for post-surgery skull fixation and compared the distribution data measured using detectors, obtained by Monte Carlo (MC) simulations, and calculated using a radiation treatment planning system (TPS). Simulations were shown to accurately represent measured values. The effects of scattered radiation produced by high-Z materials such as titanium are not sufficiently considered currently in TPS dose calculations. Our comparisons show that the dose distribution is affected by scattered radiation around a thin high-Z material. The depth dose is measured and calculated along the central beam axis inside a water phantom with thin titanium plates at various depths. The maximum relative differences between simulation and TPS results on the entrance and exit sides of the plate were 23.1% and – 12.7%, respectively. However, the depth doses do not change in regions deeper than the plate in water. Although titanium is a high-Z material, if the titanium plate used for skull fixation in cerebral nerve surgery is thin, there is a slight change in the dose distribution in regions away from the plate. In addition, we investigated the effects of variation of photon energies, sizes of radiation field and thickness of the plate. When the target to be irradiated is far from the thin titanium plate, the dose differs little from what it would be in the absence of a plate, though the dose escalation existed in front of the metal plate.

Shimozato, Tomohiro; Yasui, Keisuke; Kawanami, Ryota; Habara, Kousaku; Aoyama, Yuichi; Tabushi, Katsuyoshi; Obata, Yasunori

2010-01-01

124

Optimization of fixation-free rehalogenating bleach for BB-640 holographic plates  

NASA Astrophysics Data System (ADS)

Fixation-free rehalogenating bleaching is an interesting process for the production of phase holograms. The shrinkage of the emulsion is reduced in comparison with other bleaching methods (reversal bleaching or rehalogenating bleaching with fixation). In this paper we present experimental results for fixation-free rehalogenating bleached holograms derived from the novel BB- 640, a red-sensitive ultra-fine grain emulsion from Holographic Recording Technologies. The influence of the Potassium bromide concentration in the bleach solution on the final quality of the holograms is also studied. The concentrations of the different components of the bleach solution are adjusted to obtain the highest values of the diffraction efficiency. We studied transmission and reflection fixation-free bleached holograms. We will show that really high diffraction efficiencies can be obtained, as high as 87% for transmission bleached holograms recorded on BB-640 plates, and 72% for reflection bleached holograms.

Neipp, Cristian; Belendez, Augusto; Pascual, Inmaculada V.

2000-10-01

125

A preliminary study of bending stiffness alteration in shape changing nitinol plates for fracture fixation.  

PubMed

Nitinol is a promising biomaterial based on its remarkable shape changing capacity, biocompatibility, and resilient mechanical properties. Until now, very limited applications have been tested for the use of Nitinol plates for fracture fixation in orthopaedics. Newly designed fracture-fixation plates are tested by four-point bending to examine a change in equivalent bending stiffness before and after shape transformation. The goal of stiffness alterable bone plates is to optimize the healing process during osteosynthesis in situ that is customized in time of onset, percent change as well as being performed non-invasively for the patient. The equivalent bending stiffness in plates of varying thicknesses changed before and after shape transformation in the range of 24-73% (p values <0.05 for all tests). Tests on a Nitinol plate of 3.0 mm increased in stiffness from 0.81 to 0.98 Nm² (corresponding standard deviation 0.08 and 0.05) and shared a good correlation to results from numerical calculation. The stiffness of the tested fracture-fixation plates can be altered in a consistent matter that would be predicted by determining the change of the cross-sectional area moment of inertia. PMID:21286815

Olender, Gavin; Pfeifer, Ronny; Müller, Christian W; Gösling, Thomas; Barcikowski, Stephan; Hurschler, Christof

2011-05-01

126

Corrective Osteotomy for Deformity of the Distal Radius Using a Volar Locking Plate  

Microsoft Academic Search

Dorsally angulated malunions of the distal radius have historically been corrected with an opening wedge osteotomy fixed with\\u000a a dorsal plate. Volar locking plates may facilitate a less morbid approach to corrective osteotomies of the wrist. Eight consecutive\\u000a patients with an average age of 40 years (range, 15–52 years) underwent correction of a distal radius deformity through a\\u000a volar approach. Clinical follow-up

Brett Peterson; Varun Gajendran; Robert M. Szabo

2008-01-01

127

Locking free quadrilateral continuous/discontinuous finite element methods for the Reissner-Mindlin plate  

NASA Astrophysics Data System (ADS)

We develop a finite element method with continuous displacements and discontinuous rotations for the Mindlin-Reissner plate model on quadrilateral elements. To avoid shear locking, the rotations must have the same polynomial degree in the parametric reference plane as the parametric derivatives of the displacements, and obey the same transformation law to the physical plane as the gradient of displacements. We prove optimal convergence, uniformly in the plate thickness, and provide numerical results that confirm our estimates.

Hansbo, Peter; Larson, Mats G.

2014-02-01

128

Palmar locking plate for treatment of unstable dorsal dislocated distal radius fractures  

Microsoft Academic Search

Introduction This study investigates the clinical and radiological results of open reduction and internal fixation of unstable distal radial fractures using a palmar placed interlocking plate system with no substitutes for treatment of the dorsal metaphyseal fracture void. Materials and methods Nineteen patients with a mean age of 61 years (range 49-78 years) and a dorsally dis- placed distal radial

R. Arora; M. Lutz; D. Fritz; R. Zimmermann; J. Oberladstätter; M. Gabl

2005-01-01

129

Wrist Arthrodesis Using a Sliding Radial Graft and Plate Fixation  

Microsoft Academic Search

In a retrospective study, the results of 18 wrist fusions with a radial sliding graft and a dynamic compression plate are reviewed. All 18 fusions united, with an average position of 16? of extension and 7? of ulnar deviation. Wrist strength and stability and diminished pain allowed improved function. However, decreased manoeuvrability impaired function for some activities.

R. SORIAL; M. A. TONKIN; C. GSCHWIND

1994-01-01

130

Internal fixation of distal metacarpal fractures: new uses for an old plate.  

PubMed

Certain metacarpal fracture patterns require operative fixation to restore anatomy and optimize results. Compared with dorsal plating, the width of the minicondylar blade plate buttresses the deforming volar pull of the intrinsics and provides a stronger construct. The implant provides firm fixation in the juxta-articular fragment with minimal space requirements. Therefore, the purpose of this study was to examine the outcomes following the use of a minicondylar blade plate for the treatment of distal metacarpal fractures. Twenty-two distal metacarpal fractures in 20 patients treated with a minicondylar blade plate were retrospectively reviewed. Outcome measures collected included postoperative grip strength, range of motion, return to work, and radiographic evidence of osseous union. Average range of motion of the metacarpophalangeal joint was 62° postoperatively. Eighty-two percent (18/22) of fractures were able to flex their digits to their distal palmar crease. Seventy-one percent (12/17) of patients had at least 75% return to grip strength compared with the contralateral side. Seventeen patients returned to full activity at a mean of 2.5 months (range, 1-3 months) postoperatively; 1 patient was on disability, and data were not available for the final 2 patients. No major complications occurred. The minicondylar blade plate is a safe and effective technique for stabilizing unstable periarticular metacarpal fractures. Stable fixation allows for early range of motion, rapid return to strength, and a relatively quick return to full work duty. PMID:24025009

Sibley, Paul A; Jacoby, Sidney M; Abzug, Joshua M; Waddell, Christina L; Rivlin, Michael; Bednar, John M

2013-09-01

131

Pin guidance of reconstruction plate contour: an expanded role of external fixation.  

PubMed

This article presents a modification of intraoperative external fixation for mandibular reconstruction with free tissue flaps. This technique is indicated when preregistration of the reconstruction plate is not possible due to transmandibular tumor extension. Once standard external fixation has been carried out and prior to segmental mandibulectomy, additional pins are fixed to the connecting rod that delineate the mandibular contour in three-dimensional (3D) space. Following mandibulectomy, these pins allow accurate contouring of the reconstruction plate and improved restoration of mandibular contour, projection, and dental occlusion. A step-by-step description of the technique using models and intraoperative photos is presented. This method of mandibular reconstruction is a simple and time-effective alternative to intraoperative computer navigation and 3D modeling in select cases of oral carcinoma where tumor infiltration of the outer mandibular cortex precludes prebending of the reconstruction plates. PMID:22024840

Jaquet, Yves; Higgins, Kevin M; Enepekides, Danny J

2011-09-01

132

Early results in the treatment of proximal humeral fractures with a polyaxial locking plate  

Microsoft Academic Search

Objectives  We report early results using a second generation locking plate, non-contact bridging plate (NCB PH®, Zimmer Inc. Warsaw, IN, USA), for the treatment of proximal humeral fractures. The NCB PH® combines conventional plating technique with polyaxial screw placement and angular stability.\\u000a \\u000a \\u000a \\u000a Design  Prospective case series.\\u000a \\u000a \\u000a \\u000a Setting  A single level-1 trauma center.\\u000a \\u000a \\u000a \\u000a Patients  A total of 50 patients with proximal humeral fractures were treated

Johannes B. Erhardt; G. Roderer; K. Grob; T. N. Forster; K. Stoffel; M. S. Kuster

2009-01-01

133

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).

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

2005-01-01

134

Fixation Strategies to Prevent Screw Cut-Out and Malreduction in Proximal Humeral Fracture Fixation  

PubMed Central

Fixation of proximal humerus fractures with precontoured, fixed angle devices has improved operative management of these difficult injuries, particularly in patients with osteoporosis. However, recent data has revealed that fixation with these constructs is not without complications, particularly screw cut-out and loss of reduction. Multiple strategies have been developed to decrease the number of complications. We offer a surgical technique combining suture augmentation of the proximal humerus with locked plate fixation utilizing short screws.

Namdari, Surena; Lipman, Adam J.; Ricchetti, Eric T.; Tjoumakaris, Fotios P.; Huffman, G. Russell

2012-01-01

135

Coronoid plate fixation of type II and III coronoid process fractures: outcome and prognostic factors  

Microsoft Academic Search

The purpose of the present study was to determine the clinical outcome and prognostic factors after applying the coronoid\\u000a plate fixation technique who had sustained type II or III coronoid process fractures. Fifteen consecutive patients were enrolled\\u000a in this study. The mean arc of flexion–extension was 116° with a mean flexion and flexion contracture of 126° and 11°, respectively.\\u000a The

Sang Ki Lee; Ha Yong Kim; Kap Jung Kim; Dae Suk Yang; Won Sik Choy

136

Comparison of palmar fixed-angle plate fixation with K-wire fixation of distal radius fractures (AO A2, A3, C1) in elderly patients.  

PubMed

The objective of this prospective, randomized, controlled trial was to compare the results of two operative techniques used for the treatment of unstable distal radius fractures in elderly patients classified as AO types A2, A3, and C1. Patients were treated with either fixed-angle volar plates or K-wires using a combined Kapandji and Willenegger technique. The functional results were determined after 3, 6, and 12 months. We included 40 patients aged over 65 years. Twenty-one patients were treated with plate fixation and 19 with K-wire fixation. The functional results, after 1 year, were nearly the same in both treatment groups, suggesting that either method is suitable for the treatment of unstable distal radius fractures of AO types A2, A3, and C1 in elderly patients. Sixteen of 21 patients with plate fixation and 17 of 19 patients with K-wire fixation present good results as assessed by the Castaing score. The median DASH score was three in both groups after 1 year. The patients with plate fixation were able to resume activities of daily living 4 weeks earlier. The most common complication was an intermediate post-traumatic median nerve irritation. Both methods are suitable for the treatment of elderly patients with unstable distal radius fractures of AO types A2, A3, and C1. If early functional post-operative care is important, palmar fixed-angle plate fixation is an ideal treatment approach. Otherwise, K-wire fixation is an effective, minimally invasive method with comparable clinical results. PMID:23677960

Goehre, F; Otto, W; Schwan, S; Mendel, T; Vergroesen, P P; Lindemann-Sperfeld, L

2014-03-01

137

Evaluation of defects in composite plates under convective environments using lock-in thermography  

NASA Astrophysics Data System (ADS)

Lock-in thermography is a technique which is increasingly being used for the evaluation of subsurface defects in composite materials such as carbon-fibre-reinforced polymers (CFRPs) in aircraft structures. Most CFRP structures have a finite thickness and non-destructive inspection is performed in a natural ambient environment. In this paper, a photothermal model is developed in order to investigate the behaviour of thermal waves in homogeneous plates and layered plates with finite thicknesses under convective conditions. The model is then utilized to predict the phase differences produced by multi-layer subsurface defects and optimum inspection parameters. The theoretical results are compared with the experimental results. The detectivity of lock-in thermography for CFRP is also presented in this paper.

Bai, W.; Wong, B. S.

2001-02-01

138

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.

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

2014-01-01

139

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

PubMed

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

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

2014-07-01

140

Minimization of intra-operative shaping of orthopaedic fixation plates: a population-based design.  

PubMed

In this paper we present a new population-based method for the design of bone fixation plates. Standard pre-contoured plates are designed based on the mean shape of a certain population. We propose a computational process to design implants while reducing the amount of required intra-operative shaping, thus reducing the mechanical stresses applied to the plate. A bending and torsion model was used to measure and minimize the necessary intra-operative deformation. The method was applied and validated on a population of 200 femurs that was further augmented with a statistical shape model. The obtained results showed substantial reduction in the bending and torsion needed to shape the new design into any bone in the population when compared to the standard mean-based plates. PMID:21995055

Bou-Sleiman, Habib; Ritacco, Lucas E; Nolte, Lutz-Peter; Reyes, Mauricio

2011-01-01

141

Roles of plate locking and block rotation in the tectonics of the Pacific Northwest  

Microsoft Academic Search

The Pacific Northwest has potential for huge megathrust earthquakes. The influence of plate locking in the Cascadia subduction zone dominates crustal deformation off the shores of Washington and Oregon, but does not much affect areas far from the trench. The maximum principal strain rate epsilon 1 is -0.013 +\\/- 0.007 mustrain\\/yr in the Olympic Peninsula, 0.007 +\\/- 0.005 mustrain\\/yr in

Zuoli Ning

2003-01-01

142

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

PubMed Central

The locking compression plate (LCP) is an angle-stable fixator intended for intracorporeal application. In selected cases, it can be applied externally in an extracorporeal location to function as a monolateral external fixator. We describe one patient with Schatzker V tibial plateau fracture and one patient with Gustillo IIIB open tibia shaft fracture treated initially with traditional external fixation for whom exchange fixation with externally applied LCPs was performed. The first case went on to bony union while the second case required bone grafting for delayed union. Both patients found that the LCP external fixators facilitated mobilization and were more manageable and aesthetically acceptable than traditional bar-Schanz pin fixators.

2010-01-01

143

The calcar screw in angular stable plate fixation of proximal humeral fractures - a case study  

PubMed Central

Background With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws ('calcar screw') has increasingly been discussed. The purpose of this study was to investigate the influence of calcar screws on secondary loss of reduction and on the occurrence of complications. Methods Patients with a proximal humeral fracture who underwent angular stable plate fixation between 01/2007 and 07/2009 were included. On AP views of the shoulder, the difference in height between humeral head and the proximal end of the plate were determined postoperatively and at follow-up. Additionally, the occurrence of complications was documented. Patients with calcar screws were assigned to group C+, patients without to group C-. Results Follow-up was possible in 60 patients (C+ 6.7 ± 5.6 M/C- 5.0 ± 2.8 M). Humeral head necrosis occurred in 6 (C+, 15.4%) and 3 (C-, 14.3%) cases. Cut-out of the proximal screws was observed in 3 (C+, 7.7%) and 1 (C-, 4.8%) cases. In each group, 1 patient showed delayed union. Implant failure or lesions of the axillary nerve were not observed. In 44 patients, true AP and Neer views were available to measure the head-plate distance. There was a significant loss of reduction in group C- (2.56 ± 2.65 mm) compared to C+ (0.77 ± 1.44 mm; p = 0.01). Conclusions The placement of calcar screws in the angular stable plate fixation of proximal humeral fractures is associated with less secondary loss of reduction by providing inferomedial support. An increased risk for complications could not be shown.

2011-01-01

144

Treatment of grade-IIIb open tibial fractures. A prospective randomised comparison of external fixation and non-reamed locked nailing.  

PubMed

Severe open fractures of the tibia have a high incidence of complications and a poor outcome. The most usual method of stabilisation is by external fixation, but the advent of small diameter locking intramedullary nails has introduced a new option. We report the early results of a randomised, prospective study comparing external fixation with non-reamed locked nails in grade-IIIb open tibial fractures. Of 29 patients, 15 were treated by nails and 14 by external fixation. Both groups had the same initial management, soft-tissue procedures, and early bone grafting. All 29 fractures healed within nine months, but the nailed group had slightly better motion and less final angulation. Complications included one deep infection and two pin-track infections in the external fixator group and one deep infection and one vascular problem in the nailed group. Although the differences in healing and range of motion were not statistically significant, we found that the nailed fractures were consistently easier to manage, especially in terms of soft-tissue procedures and bone grafting. It is the treatment preferred by patients and does not require the same high level of patient compliance as external fixation. The only factors against nailing are the longer operating time and the greater need for fluoroscopy. We consider that locked non-reamed nailing is the treatment of choice for grade-IIIb open tibial fractures. PMID:8300656

Tornetta, P; Bergman, M; Watnik, N; Berkowitz, G; Steuer, J

1994-01-01

145

Currents of plate osteosynthesis in osteoporotic bone.  

PubMed

Osteoporotic fractures are becoming more prevalent with ageing of populations worldwide. Inadequate fixation or prolonged immobilization after non-surgical care leads to serious life-threatening events, poor functional results and lifelong disability. Thus, a stable internal fixation and rapid initiation of rehabilitation are required for faster return of function. Conventional internal fixation attempts to achieve the exact anatomy, often with extended soft-tissue stripping and compression of the periosteum, causing disturbance of the metaphyseal and comminuted fracture's bone blood supply. This technique relies on frictional forces between bone and plate. Osteoporotic bone might not be able to generate enough torque with the screw to securely fix the plate to bone. Thus, this surgical management have resulted in increased incidence of poor results in elderly, osteoporotic patients. The newly developed locked internal fixators, locking compression plates and less invasive stabilization system, consist of plate and screw systems where the screws are locked in the plate, minimizing the compressive forces exerted between plate and bone. Thus, the plate does not need to compress the bone nor requires precise anatomical contouring of a plate disturbing the periosteal blood supply. These fixators allowed the development of the minimal invasive percutaneous osteosynthesis. Nowadays, locking plates are the fixation method of choice for osteoporotic, diaphyseal or metaphyseal, severely comminuted fractures. PMID:23543044

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

2014-05-01

146

The influence of distal locking on the need for fibular plating in intramedullary nailing of distal metaphyseal tibiofibular fractures.  

PubMed

Using human cadaver specimens, we investigated the role of supplementary fibular plating in the treatment of distal tibial fractures using an intramedullary nail. Fibular plating is thought to improve stability in these situations, but has been reported to have increased soft-tissue complications and to impair union of the fracture. We proposed that multidirectional locking screws provide adequate stability, making additional fibular plating unnecessary. A distal tibiofibular osteotomy model performed on matched fresh-frozen lower limb specimens was stabilised with reamed nails using conventional biplanar distal locking (CDL) or multidirectional distal locking (MDL) options with and without fibular plating. Rotational stiffness was assessed under a constant axial force of 150 N and a superimposed torque of ± 5 Nm. Total movement, and neutral zone and fracture gap movement were analysed. In the CDL group, fibular plating improved stiffness at the tibial fracture site, albeit to a small degree (p = 0.013). In the MDL group additional fibular plating did not increase the stiffness. The MDL nail without fibular plating was significantly more stable than the CDL nail with an additional fibular plate (p = 0.008). These findings suggest that additional fibular plating does not improve stability if a multidirectional distal locking intramedullary nail is used, and is therefore unnecessary if not needed to aid reduction. PMID:24589796

Attal, R; Maestri, V; Doshi, H K; Onder, U; Smekal, V; Blauth, M; Schmoelz, W

2014-03-01

147

Patient-tailored plate for bone fixation and accurate 3D positioning in corrective osteotomy.  

PubMed

A bone fracture may lead to malunion of bone segments, which gives discomfort to the patient and may lead to chronic pain, reduced function and finally to early osteoarthritis. Corrective osteotomy is a treatment option to realign the bone segments. In this procedure, the surgeon tries to improve alignment by cutting the bone at, or near, the fracture location and fixates the bone segments in an improved position, using a plate and screws. Three-dimensional positioning is very complex and difficult to plan, perform and evaluate using standard 2D fluoroscopy imaging. This study introduces a new technique that uses preoperative 3D imaging to plan positioning and design a patient-tailored fixation plate that only fits in one way and realigns the bone segments as planned. The method is evaluated using artificial bones and renders realignment highly accurate and very reproducible (d(err) < 1.2 ± 0.8 mm and ?(err) < 1.8° ± 2.1°). Application of a patient-tailored plate is expected to be of great value for future corrective osteotomy surgeries. PMID:23054377

Dobbe, J G G; Vroemen, J C; Strackee, S D; Streekstra, G J

2013-02-01

148

Proximal femoral locking plate with cannulated screws for the treatment of femoral neck fractures.  

PubMed

The purpose of this study was to evaluate the efficacy and safety of the proximal femoral locking plate with cannulated screws for the treatment of femoral neck fractures. A prospective study was performed in 41 patients with femoral neck fractures treated with a proximal femoral locking plate with cannulated screws between January 2005 and December 2008. Twenty-five men and 16 women had a mean age of 47 years (range, 21-65 years). The time from injury to surgery ranged from 2 hours to 7 days. Three patients had a Garden type I fracture, 9 a type II, 18 a type III and 11 a type IV. Operative time, intraoperative blood loss, fracture healing time, Harris Hip Score for hip function, and complications were recorded to evaluate treatment effects.Mean operative time was 63.6 minutes (range, 40-90 minutes), with mean intraoperative blood loss of 84.2 mL (range, 50-200 mL). Mean time to union was 15.5 weeks (range, 12-36 weeks). Two patients (Garden type III and type IV) did not achieve union, and 4 patients (1 Garden type III and 3 type IV) had avascular necrosis of the femoral head. In patients with nonunion, 1 (Garden type III) underwent intertrochanteric osteotomy, and the other underwent total hip replacement (THR). In patients with avascular necrosis, 2 required THR and the others (1 Garden type III) required no further surgery. Twenty-six (63%) patients had excellent results, 8 (20%) had good results, 3 (7%) had moderate results, and 4 (10%) had poor results. These findings suggest that the proximal femoral locking plate with cannulated screws for the treatment of femoral neck fractures is effective and results in fewer complications, especially for Garden type I, II, and III fractures. PMID:22229598

Lin, Dasheng; Lian, Kejian; Ding, Zhenqi; Zhai, Wenliang; Hong, Jiayuan

2012-01-01

149

Design considerations in development of a prototype, piezoelectric internal fixation plate: a preliminary report.  

PubMed

The piezoelectric internal fixation plate represents a new concept in orthopaedic implants. The purpose of this device is to provide stable bone fixation while delivering internally generated, microampere direct currents to prevent or treat nonunion of a fracture or osteotomy. Clinically, currents of this type have been effective in treatment of nonunion, but application has required separate, implanted, or external battery or radiofrequency powered circuits. The "piezoplate" being developed contains an integral piezoelectric element that generates current in response to either physiological loading such as weightbearing or to externally applied ultrasound. Currents are processed by a rectifying circuit for delivery to bone by electrodes. Specially designed series/parallel piezoelectric elements and dual processing circuits are required to generate optimum rectified currents from the low-frequency, high-voltage signals generated by weightbearing, as well as the high-frequency, low-voltage signals produced by ultrasound. This paper reports on the current status of development and describes design parameters of this device which combines the modalities of mechanical fixation and electrical stimulation in a single implant. PMID:3495657

Cochran, G V; Johnson, M W; Kadaba, M P; Palmieri, V R; Mahaffey, G

1987-01-01

150

Roles of plate locking and block rotation in the tectonics of the Pacific Northwest  

NASA Astrophysics Data System (ADS)

The Pacific Northwest has potential for huge megathrust earthquakes. The influence of plate locking in the Cascadia subduction zone dominates crustal deformation off the shores of Washington and Oregon, but does not much affect areas far from the trench. The maximum principal strain rate epsilon 1 is -0.013 +/- 0.007 mustrain/yr in the Olympic Peninsula, 0.007 +/- 0.005 mustrain/yr in the Puget Sound, -0.005 +/- 0.005 mustrain/yr at Mt. Rainier, -0.004 +/- 0.005 mustrain/yr along the northern Oregon coast, and 0.011 +/- 0.006 mustrain/yr in central Oregon. The minimum principal strain rate epsilon2 is -0.083 +/- 0.008 mustrain/yr N56°E in the Olympic Peninsula, -0.034 +/- 0.007 mustrain/yr N63°E in the Puget Sound, -0.020 +/- 0.006 mustrain/yr N53°E at Mt. Rainier, -0.051 +/- 0.014 mustrain/yr N85°E along the northern Oregon coast, and -0.010 +/- 0.006 mustrain/yr N71°E in central Oregon. A new model of plate locking on the Cascadia subduction zone is similar to a model (1997). The uncertainty of the widths of the locked and transition zone in the model is about 25km--40km. Guided by computed site velocities, seismicity patterns, heat flow, volcanic data, and geological structures, we find it is necessary to divide the crust in the Pacific Northwest into separate moving blocks. We have analyzed a model in which the Oregon block is separated from the Washington block at latitude 46°. The Washington block has been further divided into 5-subblocks, three in the forearc and two in eastern Washington. We remove contributions of JDF plate locking from the site velocity field and determine a rotation pole and a strain rate for each sub-block. We conclude that Juan de Fuca plate locking has little direct effect on crustal earthquake occurrence in the Pacific Northwest (except for periodic megathrust earthquakes). In the Oregon block, plate locking and rigid block rotation are sufficient to explain GPS observations and the lower rate of seismicity in Oregon. The Washington block is more. The southwestern Washington sub-blocks have higher rotation rates and smaller residual strain rates than the northern sub-blocks. The Olympic sub-block shows the greatest north-south compression (0.017 mustrain/yr). The Puget Lowland sub-block and Mt. Rainier sub-block are shortening along a NNE direction, roughly consistent with the direction of maximum principal stress from fault plane solutions. The overall north-south shortening across the Puget Sound is 3mm/yr, sufficient to generate M7+ earthquakes in the future. NS compression dominates eastern Washington near Yakima which is also consistent with principal stress directions derived from fault plane solutions. Northeast Washington sub-block is currently poorly constrained by GPS data. As western Washington is pushed northward against the British Columbia, block rotation in Oregon is slowed down in Washington and the motion produces NS compression in northern Washington. The sub-blocks in southwestern WA act as a transition zone between Oregon and British Columbia. Residual strain rate is proportional to crustal seismicity. The great variation of residual strain rate in WA compared to Oregon may explain their crustal seismicity difference. GPS derived velocities in NE Washington are still too uncertain to determine the details of block rotation and strain rate there.

Ning, Zuoli

151

Transscleral fixation of a dislocated silicone plate haptic intraocular lens via the pars plana.  

PubMed

A method for transscleral fixation of silicone plate haptic posterior chamber intraocular lenses (PC IOLs) via the pars plana is described. One 10-0 polypropylene transscleral suture passed through the sclera and the PC IOL hole and a similar suture passed through the sclera only were withdrawn outside the eye thorough the pars plana and tied together. Pulling up the scleral end of one suture placed the PC IOL haptic in the sulcus and the knot was pulled outside the eye. Perfluorocarbon liquid was used during the procedure to safely manipulate the PC IOL. The PC IOL was well centered at 3 months of follow-up. Posteriorly dislocated silicone plate haptic PC IOLs can be safely sutured to the sclera via the pars plana by this method. PMID:9640578

Akduman, L

1998-06-01

152

Volar plate fixation of recalcitrant scaphoid nonunions with volar carpal artery vascularized bone graft.  

PubMed

Chronic scaphoid fracture nonunion continues to present a significant challenge to the treating orthopedic surgeon. Internal fixation with threaded compression screws leads to high union rates, and is currently the gold standard, but there are certainly circumstances where a scaphoid screw does not provide the stability necessary for nonunion repair. Results using a volar buttress plate have been promising, but have not been described in conjunction with the use of vascularized bone graft. Vascularized bone grafts have been shown to be highly effective in achieving rapid and reproducible rates of union. We describe a novel combination of a vascularized volar distal radius wedge autograft pedicled on the volar carpal artery and volar buttress plating for salvage treatment of chronic scaphoid nonunion. PMID:24275760

Dodds, Seth D; Patterson, Joseph T; Halim, Andrea

2014-03-01

153

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

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

154

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

155

Unusual radial nerve injury by a locking compression plate for humerus fracture.  

PubMed

The management of primary and secondary radial nerve palsy associated with humeral shaft fractures is still controversial. Radial nerve function is likely to return spontaneously after primary as well as secondary radial nerve palsy in the absence of any level of neurotmesis. Identification and protection of the radial nerve during surgery may prevent secondary nerve palsy, but is not always performed and depends on the location of the fracture, and the experience and preference of the surgeon. We report a case of a healthy 40-year-old woman, referred to our hospital with a complete radial nerve palsy and a failed plate fixation of a right humeral shaft fracture. During exploration of the radial nerve and surgical revision of the fracture, we found the nerve entrapped by the plate and partially transected by a screw. Full recovery of radial nerve function occurred after neurolysis and microscopic neurorrhaphy. PMID:24862412

Kinaci, Ahmet; Kloen, Peter; Videler, Annemieke; Kreulen, Mick

2014-01-01

156

Vertically unstable sacral fractures with neurological insult: outcomes of surgical decompression and reconstruction plate internal fixation  

PubMed Central

During a 4-year period, 32 patients with type C unstable sacral fractures were treated in our university hospital. All patients had neurological deficits as a result of their sacral fracture. The average age was 31.2 (range 22–54) years and the average Hannover Polytrauma Score (PTS) was 24 (range 19–40) points. Twelve patients had zone I fracture, ten had zone II fracture and ten patients had comminuted fractures involving both zones. All patients underwent surgical decompression and reconstruction plate internal fixation. The average follow up period was 24.4 (range 19–47) months. Twenty-one patients (65.6%) had complete neurological recovery, eight patients (25%) had partial recovery and three patients (9.4%) had no recovery. The relationship between radiological and functional scores was evident but insignificant (P?=?0.434). Significantly, the neurological recovery was less favourable in older age groups, pedestrian trauma, vertical shear injuries, comminuted fractures, fifth lumbar root involvement, very low motor power grades and in patients presenting late. Concerning complications, four patients (12.5%) had early infection and five patients (15.6%) had late urological problems and heterotopic ossification. Consequently, we conclude that patients undergoing very early surgical decompression and only reconstruction plate internal fixation can achieve safe early ambulation and better neurological, functional and radiological results.

2007-01-01

157

The MetaHUS(®) fixation system versus pinning and plating in 5th metacarpal neck fractures.  

PubMed

The treatment of fifth metacarpal neck fractures is controversial. The aim of this work was to modify the intermetacarpal pinning technique with an external connector, and to compare the results of this modified technique to those of intramedullary pinning and locking plate techniques. Our series included 56 extra-articular fractures of the neck of the fifth metacarpal treated by intramedullary pinning (group A), locking plate Aptus(®) MEDARTIS™ (group B) and MetaHUS(®) Arex™ (group C); the last one consisted in intermetacarpal percutaneous pinning and connecting the pins externally. There were no statistically significant differences for all criteria except active mobility, which was less important for group B. In groups A and B, 6 complications were noted, in group C, one. Our results showed that blocked intermetacarpal K-wires is a technique of choice for the treatment of displaced fifth metacarpal neck fractures, not only because it is easy to assemble and to remove, but also because it allows immediate active mobilization. PMID:24857636

Zemirline, A; Vaiss, L; Lebailly, F; Gouzou, S; Liverneaux, P A; Facca, S

2014-06-01

158

[Multidirectional locking volar plate in distal radius fractures. Secondary loss of reduction--correct implantation is essential].  

PubMed

In recent years a trend has evolved from unidirectional to multidirectional locking plates. Different technical solutions have been developed and the quality of the angle stability of all methods has been described as sufficient. Published trials describing the necessary shearing forces are rarely published. We report two cases with loss of reduction after the use of a variable angle locking implant used in distal radius fractures. PMID:23344695

Michelitsch, C; Acklin, Y P; Sommer, C

2013-12-01

159

Locking plates for corrective osteotomy of malunited dorsally tilted distal radial fractures: a biomechanical study.  

PubMed

The purpose of the study was to compare the biomechanical properties of five different palmar fixation plate designs in a distal radius osteotomy cadaver model. A 1cm metaphyseal osteotomy gap was made to simulate a corrective osteotomy and the osteotomy plated. Axial load was applied to the distal end of each construct by a material testing machine under control of a motion analysis video system. The specimens were arranged into five implant groups of eight specimens each. No test group developed deformity and movement of the fracture gap greater than 2mm with a load of 100N. Increasing the load to 250N revealed statistically significant differences in stiffness and failure load between the different plates. Axial failure strength and stiffness were greater for the radial correction plates than for the other implants. The former may provide enough stability for corrective osteotomy of dorsally angulated distal radial malunions, even when the osteotomy gap is only filled with cancellous bone graft instead of cortical bone graft. PMID:16930790

Müller, L P; Klitscher, D; Rudig, L; Mehler, D; Rommens, P M; Prommersberger, K J

2006-10-01

160

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.

Pereira, Cassiano Costa Silva; Leticia dos Santos, Pamela; Jardim, Ellen Cristina Gaetti; Junior, Idelmo Rangel Garcia; Shinohara, Elio Hitoshi; Araujo, Marcelo Marotta

2012-01-01

161

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.

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

2013-01-01

162

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

SciTech Connect

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

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

1997-08-01

163

Corrective distal radius osteotomy following fracture malunion using a fixed-angle volar locking plate.  

PubMed

Post-traumatic distal radius deformity may cause severe morbidity, and corrective osteotomy is often necessary to realign the functional axis of the wrist to correct symptomatic malunion. The aim of this retrospective study was to review the short-term results of a single surgeon's series of distal radius corrective osteotomies following fracture malunion using a fixed-angle volar locking plate for 20 patients (26 women) of an average age of 57 (range 19-83) years. At short-term follow up (average 14 months, range 12-15 months), no complications were noted and radiological union was confirmed in all cases at an average of 3 months. The average post-operative Disability of the Arm, Shoulder and Hand score was 13.48 (range 0-48.33) and an objective improvement was noted in movements at the wrist joint. A statistically significant improvement was achieved in ulnar variance, radial inclination, dorsal tilt, and supination. PMID:24051477

Opel, S; Konan, S; Sorene, E

2014-05-01

164

Fixation updates for hallux valgus correction.  

PubMed

Fixation options for hallux valgus correction vary. Although some methods are newer and more advanced, even the older techniques are successful in appropriate situations. Kirschner wires and cerclage wiring have their place in proximal phalanx and first metatarsal osteotomies. They are useful for fusion procedures, depending on patient bone quality. Advancements with staple fixation allow the surgeon to apply compression with this device. One of the most stable forms of fixation is the bone screw. By providing a stable construct with good interfragmentary compression, primary bone healing is facilitated. The more recent use of rigid locking plates has allowed for earlier weight bearing following fusion procedures. PMID:24685192

Ben-Ad, Rotem

2014-04-01

165

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

166

Quality of life after volar locked plating: a 10-year follow-up study of patients with intra-articular distal radius fractures  

PubMed Central

Background This study aimed to present functional results and patient’s health related quality of life (HRQOL) data ten years after volar locked plate fixation (VPF) of unstable intra-articular distal radial fractures (DRF). Methods Thirty-nine patients with a mean age of sixty-one years were operatively treated with VPF after intra-articular distal radial fractures. They were evaluated two, six, and ten years postoperatively according to the Gartland and Werley score. For subjective evaluation the Short Form 36 (SF-36) and the Disability of Arm, Shoulder and Hand (DASH) questionnaires were adopted. Results Overall, wrist function did not differ significantly two, six and ten years after the operation. Over 90% patients achieved “good” or “excellent” results ten years after surgery according to the Gartland and Werley score. Ten years postoperatively the results of the SF 36 did not differ significantly from the two- and six-year follow-up. Overall findings from the SF-36 did not differ significantly from the data of Austrian and American norm populations. Only in the subscale of mental health (MH) the ten-year follow-up did show significantly poorer results (p?=?0.045) compared to the Austrian norm population. The median DASH scores did not show significant differences during the ten-year follow-up period. Conclusion The ten-year results of this single-center study suggest that operative treatment of intra-articular DRF with volar locked plates is a useful and satisfactory therapy option, both in terms of function and HRQOL.

2014-01-01

167

Sternocostal dislocation following open correction of pectus excavatum-"stairway phenomenon": complication management by means of sternocostal locking titanium plate osteosynthesis.  

PubMed

Introduction?Some open surgical methods describe complete sternocostal dissection with subsequent resynthesis. Lack of consolidation with painful sternocostal instability and retrosternal dislocation of sternal rib tips are possible complications. Materials and Methods?Seven patients with symptomatic unilateral sternocostal dislocation were included in this study. After diagnosis, confirmed by three-dimensional computed tomography (CT), patients underwent open surgery. All affected ribs were reset and fixed to the sternum with the aid of titanium implants. Results?The patients had, on average, unilateral dislocation of 3.4 rib joints with 15.4?mm retrosternal dislocation, which was fixed with 2.3 plates. A titanium splint was also employed. The recurrent nature of the problem made procedures very time-consuming (average operation time: 3 hours 25 minutes). One patient suffered strong intraoperative bleeding requiring transfusion of blood products and access enlargement. Follow-up examinations showed high patient satisfaction (grade of 1.7; rating scale 1-6). Remaining rib instabilities were observed just as infrequently as were material failures. The sternocostal rib splint in the costal cartilage became loose and was removed. One patient exhibited a pectoral muscle asymmetry. No other complications were observed. Conclusion?The term "stairway phenomenon" describes the dislocation of sternocostal joints. Observed after open pectus excavatum correction it can trigger substantial physical complaints. Thus, preserving those joints during pectus repair is strongly recommended. Locking titanium plates are a safe alternative to sternocostal suture fixation and is characterized by high patient satisfaction. PMID:24127362

Schulz-Drost, Stefan; Syed, Julia; Besendoerfer, Manuel; Carbon, Roman T

2014-04-01

168

Fixation of distal radius fractures in adults: a review.  

PubMed

In patients for whom function is a priority, anatomic reduction and stable fixation are prerequisites for good outcomes. Several therapeutic options exist, including orthopedic treatment and internal fixation with pins (intra- and extrafocal), external fixation which may or may not bridge the wrist, and different internal fixation techniques with dorsal or palmar plates using or not, locking screws. Arthroscopy may be necessary in case of articular fracture. In the presence of significant metaphyseal bone defects, filling of the comminution with phosphocalcic cements provides better graft stability. The level of evidence is too low to allow recommending one type of fixation for one type of fracture; and different fixation options to achieve stable reduction exist, each with its own specific complications. With the new generations of palmar plate, secondary displacement is becoming a thing of the past. PMID:23518070

Obert, L; Rey, P-B; Uhring, J; Gasse, N; Rochet, S; Lepage, D; Serre, A; Garbuio, P

2013-04-01

169

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

170

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

171

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

172

Prospective blind comparative clinical study of two point fixation of zygomatic complex fracture using wire and mini plates  

PubMed Central

Background The zygomatic maxillary complex (ZMC) fractures are one of the most frequent injuries of the facial skeleton due to its position and facial contour. Assaults, road traffic accidents and falls are the principal etiologic factors that may cause fractures of zygomatic bone. The different fixation methods are applied to treat the zygomatic bone fractures, with many more classifications which have been described in the literature for the ease of management. The type of the fracture, its severity and associated facial fractures usually interferes the treatment modality. Purpose of study The aim of this paper is to show the results of 18yrs prospective blind comparative study using wire and plate osteosynthesis which needed open reduction and internal fixation involving Type II to Type IV Spissel and Schroll ZMC fractures. Materials and methods Total 80 cases included in the study out of 1780 ZMC cases which were treated using wire and plate osteosynthesis over a period of 18 yrs, involving only Type II to Type IV Spissel and Schroll ZMC fractures. Other types excluded from study to prevent observer bias. All the fixations carried out through Standard Dingman's incision using stainless steel 26 gauze wire and titanium 1.5 mm mini plate system under general anesthesia by single maxillofacial surgeon and evaluated by another maxillofacial surgeon who is blinded for surgical procedure after 2 and 4 wks of follow-up for facial symmetry, wound healing, functional assessment (mouth opening, diplopia), and sensory disturbance. All the data tabulated in Excel software (Microsoft) for statistical analysis. P-value calculated to know the Significance of treatment modality in all aspects. Results Result shows no significant p-values indicating both the operating techniques are equally efficient in the surgical management of ZMC fracture. Conclusion Osteosynthesis by mini plates is simple, logical and effective treatment compared to wire osteosynthesis in regard to stability of fracture fragments. Wire osteosynthesis will be helpful in emergency surgeries or where the mini plates are not available. Even though the wire osteosynthesis is economical compared to mini plate fixation; but the time and skill is required for fixation of wires.

2012-01-01

173

Augmentation of implant fixation in osteoporotic bone.  

PubMed

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

Jones, Clifford B

2012-12-01

174

The Outcome and Complications of the Locked Plating Management for the Periprosthetic Distal Femur Fractures after a Total Knee Arthroplasty  

PubMed Central

Background The osteosynthesis of the periprosthetic fractures following a total knee arthroplasty (TKA) can be technically difficult with the relatively small satisfactory outcomes and the high complication rates. The purpose of the study is to analyze the mid-term radiological and functional outcomes following the locked plating of the distal femur periprosthetic fractures after a TKA. Methods Records of 20 patients with a periprosthetic distal femur fracture following TKA treated by the locked plate osteosynthesis were retrospectively evaluated. The union rate, complications and functional outcome measures were analyzed. Results Successful union was achieved in 18 of the 19 patients available for the follow-up. The mean follow-up was 39 ± 10 months. Significant reductions (p < 0.05) in the range of motion and Western Ontario and McMaster Universities Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were evident in the follow-up. Secondary procedures were required in 5 patients to address the delay in union and the reduced knee range of motion. The osteosynthesis failed in 1 patient who underwent a revision TKA. Conclusions The satisfactory union rates can be achieved with the locked plate osteosynthesis in the periprosthetic distal femur fractures after TKA. Prolonged rehabilitation coupled with the un-modifiable risk factors can decrease the activity and satisfaction levels, which can significantly alter the functional outcome.

Tummala, Naveen Chowdary; Subramanian, Muthukumar

2013-01-01

175

Use of a 1.5 mm butterfly locking plate for stabilization of atlantoaxial pathology in three toy breed dogs.  

PubMed

The objective of this study was to describe the use of a titanium 1.5 mm locking plate in the stabilization of atlantoaxial pathology in three toy breed dogs. Two dogs with atlantoaxial subluxation and another dog with an axial fracture, confirmed by diagnostic imaging, were stabilized via a ventral approach with a 1.5 mm titanium 5-hole locking butterfly-plate. Surgical reduction and stabilization were assessed by computed tomography and radiography after surgery. Follow-up evaluation for resolution of neurological signs and possible complications was performed in all three dogs. For long-term assessment, a telephone follow-up was performed. A considerable improvement of neurological signs occurred within two to four weeks after surgery. An excellent clinical outcome was identified in all three patients. Adequate stabilization and resolution of neurological signs in all three dogs was achieved. The stabilization of atlantoaxial surgical conditions in toy breeds with the 1.5 mm titanium 5-hole butterfly locking plate appears to be an effective means of surgical treatment. PMID:21327294

Dickomeit, M; Alves, L; Pekarkova, M; Gorgas, D; Forterre, F

2011-01-01

176

Should unstable extra-articular distal radial fractures be treated with fixed-angle volar-locked plates or percutaneous Kirschner wires? A prospective randomised controlled trial  

Microsoft Academic Search

Fractures of the distal radius are commonly treated with cast immobilisation; however, those potentially unstable injuries with dorsal comminution may need operative intervention. This intervention is usually with manipulation and Kirschner wires but advances in locking-plate technology have enabled surgeons to achieve anatomical reconstruction of complex fracture patterns, even in poor-quality osteoporotic bone.To ascertain if fixed-angle volar-locked plates confer a

I. McFadyen; J. Field; P. McCann; J. Ward; S. Nicol; C. Curwen

2011-01-01

177

Intraoral external oblique ridge compared with transbuccal lateral cortical plate fixation for the treatment of fractures of the mandibular angle: prospective randomised trial  

Microsoft Academic Search

Since the initial description by Michelet et al. and research by Champy et al. the placement of a single, four-hole, monocortical, osteosynthesis plate has been considered an acceptable method of fixation for a fracture of the mandibular angle. We investigated the null hypothesis that there is no difference in the incidence of postoperative removal of an infected plate between miniplates

S. Laverick; P. Siddappa; H. Wong; P. Patel; D. C. Jones

178

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

PubMed

The locking compression plate (LCP) is an angle-stable fixator intended for intracorporeal application. In selected cases, it can be applied externally in an extracorporeal location to function as a monolateral external fixator. We describe one patient with Schatzker V tibial plateau fracture and one patient with Gustillo IIIB open tibia shaft fracture treated initially with traditional external fixation for whom exchange fixation with externally applied LCPs was performed. The first case went on to bony union while the second case required bone grafting for delayed union. Both patients found that the LCP external fixators facilitated mobilization and were more manageable and aesthetically acceptable than traditional bar-Schanz pin fixators. PMID:20302664

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

2010-01-01

179

Coracoid bone graft osteolysis after Latarjet procedure: A comparison study between two screws standard technique vs mini-plate fixation  

PubMed Central

Aims: One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. Materials and Methods: A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. Results: The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P < 0.01). Discussion: To our knowledge, there are no studies in literature that show the causes of coracoid bone graft osteolysis after Latarjet procedure. Conclusion: Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level of Evidence: Level 4. Clinical Relevance: Prospective case series, Treatment study.

Giacomo, Giovanni Di; Costantini, Alberto; de Gasperis, Nicola; De Vita, Andrea; Lin, Bernard K. H.; Francone, Marco; Beccaglia, Mario A. Rojas; Mastantuono, Marco

2013-01-01

180

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.

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

2014-01-01

181

Biomechanical stability of four fixation constructs for distal radius fractures.  

PubMed

Implants available for distal radius fracture fixation include dorsal nonlocked plating (DNLP), volar locked plating (VLP), radial-ulnar dual-column locked plating (DCPs), and locked intramedullary fixation (IMN). This study examines the biomechanical properties of these four different fixation constructs. In 28 fresh-frozen radii, a wedge osteotomy was performed, creating an unstable fracture model and the four fixation constructs employed (DNLP, VLP, DCPs, and IMN). Dorsal bending loads were applied and bending stiffness, load to yield 5 mm displacement, and ultimate failure were measured. Bending stiffness for VLP (16.7 N/mm) was significantly higher than for DNLP (6.8 N/mm), while IMN (12.6 N/mm) and DCPs (11.8 N/mm) were similar. Ultimate load to failure occurred at 278.2 N for the VLP, 245.7 N for the IMN, and 52.0 N for the DNLP. The VLP was significantly stronger than the DNLP and DCPs, and the IMN and DCPs were stronger than the DNLP. The VLP has higher average bending stiffness, ultimate bending strength, and resistance to 5 mm displacement than the other constructs and significantly higher ultimate bending strength than the DCPs and DNLP. There was no statistically significant difference between the VLP and IMN. VLP and IMN fixation of distal radius fractures can achieve comparable stability. PMID:19194766

Capo, John T; Kinchelow, Tosca; Brooks, Kenneth; Tan, Virak; Manigrasso, Michaele; Francisco, Kristin

2009-09-01

182

Fixation-free rehalogenating bleached reflection holograms recorded on BB-640 plates  

NASA Astrophysics Data System (ADS)

Fixation-free rehalogenating bleaching is an interesting process for the production of phase reflection holograms. The shrinkage of the emulsion is reduced in comparison with other bleaching methods (reversal bleaching or rehalogenating bleaching with a fixation step), which is particularly interesting in the case of reflection holograms. In this communication, we present experimental results for fixation-free rehalogenating bleached holograms derived from the novel BB-640 emulsion, a red-sensitive ultra-fine grain emulsion from Holographic Recording Technologies using an R-10 type bleach bath. The influence of the potassium bromide concentrations in the bleach solution on the final quality of the holograms is also studied. The concentrations of the different components of the bleach solution are adjusted to obtain the highest diffraction efficiencies. A high diffraction efficiency of 72% is obtained.

Neipp, C.; Pascual, I.; Beléndez, A.

2000-08-01

183

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

PubMed Central

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

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

2013-01-01

184

Plates, pins, and interlocking nails.  

PubMed

Evidence-based criteria that promise the best treatment outcome for bovine fracture patients have not been established. Internal fixation with plates and screws allows successful management of many long bone fractures in calves as well as in heavier cattle. Intramedullary pins may be better or equally suited for repair of humerus or femoral fractures in calves, respectively. In richly comminuted fractures in heavy cattle, methods of external fixation are still indicated. With newly introduced locking plates, treatment options for repair of long bone fractures in cattle have further improved, but high costs and a guarded prognosis limit their application. PMID:24534661

Nuss, Karl

2014-03-01

185

Comparison of single coracoclavicular suture fixation and hook plate for the treatment of acute unstable distal clavicle fractures  

PubMed Central

Background Surgical managements are recommended for unstable distal clavicle fractures because of a high incidence of nonunion. A variety of methods have been previously reported, but there is no current consensus regarding which method is the most suitable. Methods Between December 2004 and August 2010, we treated 68 patients with Neer type IIB distal clavicle fractures using single coracoclavicular suture fixation with Mersilene tape (M group) or clavicular hook plate (H group). Sixty-eight patients were followed at least 24 months (mean, 37.9 months). We retrospectively compared the functional outcome, parameters, and perioperative course of the two treatments. Statistical analysis was performed with independent sample t test and chi-square test. Results The M group presented significantly less operation time (P?=?0.005) and intra-operative blood loss (P?=?0.010) than the H group. The mean University of California at Los Angeles (UCLA) shoulder rating scale, Oxford shoulder score, VAS scale, and satisfaction score revealed no significant difference between the M group and the H group. The M group had better range of motion in the operated shoulder during forward flexion and abduction at 3 and 6 months postoperatively. However, the range of motion at 1 and 2 years after operation revealed almost the same results. Two acromial osteolysis and one acromial fracture were noted in the H group and one superficial wound infection and one frozen shoulder in the M group during follow-up. Finally, there was no significant difference in the complication rate between the two groups, and all fractures achieved union clinically at final follow-up. Conclusions Both single coracoclavicular suture fixation and clavicular hook plate offered effective treatment in acute unstable distal clavicle fractures. However, single coracoclavicular suture fixation with Mersilene tape provided early recovery of shoulder motion and avoided further morbidity of the acromion.

2014-01-01

186

Rigid internal fixation of mandibular fractures using autologous bone grafts: the autologous bone plate  

Microsoft Academic Search

The mandible is the second most commonly fractured part of the maxillofacial skeleton because of its position and prominence.\\u000a Over the past three decades, many different techniques and approaches have been described in the literature to surgically\\u000a correct facial fractures. The present study has attempted to study the role of bone grafts in open reduction and internal\\u000a fixation of mandibular

Arun Kumar Singh; Devi Prasad Mohapatra; Vijay Kumar

2010-01-01

187

Internal Fixation for Fractures  

MedlinePLUS

... implants, such as plates, screws, nails and wires. Internal fixation allows shorter hospital stays, enables patients to ... position) of broken bones. The implants used for internal fixation are made from stainless steel and titanium, ...

188

Motional Effects in Retardation Plates and Mode Locking in Ring Lasers.  

National Technical Information Service (NTIS)

The effect of a relative velocity v between source and retardation plate is to create an additional retardation, delta phi, proportional to (v/c) (l/lambda), where c is the velocity of light, l the plate thickness, and lambda the wavelength of the light. ...

R. G. Newburgh

1971-01-01

189

Biomechanical comparison of a new technique of mandibular angle fractures: biplanar and bicortical superior proximal 3 holes and bicortical inferior plate fixation.  

PubMed

Miniplates have been used for mandibular angle fractures during the past 2 decades. The technique of placing single miniplate at the upper border based on the tension lines of the fracture was proposed by Michelet and Champy. The need for a second miniplate to be applied to the lower mandible has been discussed recently. Biomechanical comparison of biplanar and monoplanar dual-miniplate fixation techniques was investigated by Haug. Our hypothesis is in dual-miniplate fixation; the proximal 3 holes of superior border miniplate could be fixated by bicortical screws. The first 2 are at the proximal bone segment and are not related to the tooth and also superior to the alveolar nerve. Generally, the third molar tooth is extracted because it is at the fracture site. Hence, the proximal third hole could also be fixated by bicortical screws. We define a biplanar dual-miniplate technique in which the lower plate and the proximal 3 holes of the upper plate are fixated by bicortical screws. We have designed a study for biomechanical comparison of our method and popular types of mandibular fixation methods. PMID:18362721

Turgut, Gürsel; Kayali, Mahmut Ulvi; Kayah, Mahmut Ulvi; Soydan, Ali Tufan; Gündüz, O?uzhan; Salman, Serdar; Oktar, Faik; Ba?, Lütfü

2008-03-01

190

Application of 2.0 mm Titanium Plates in Rigid Internal Fixation of Mandibular Angle Fractures  

Microsoft Academic Search

Purpose  The present study aimed to evaluate the efficacy and stability of 2.0 mm Titanium plates in treatment of mandibular angle\\u000a fractures.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and Methods  A randomized, prospective study was carried out on 17 patients treated by ORIF with 2.0 mm titanium plates. Operative handling\\u000a of the plate and clinical stability were qualitatively analyzed.\\u000a \\u000a \\u000a \\u000a \\u000a Results  The 2.0 mm plate showed good intra-operative handling and adequate clinical

Samrat Sabhlok; Pushkar Waknis; Ajit Bhagwat

2010-01-01

191

High Security Internal Locking System.  

National Technical Information Service (NTIS)

The present invention relates to multiple lock control of a locking system and more particularly to an improved multiple lock control of a locking system which has a protective plate and a lock control of the boltwork drive mechanism. The present method o...

H. L. Self

1984-01-01

192

[Fixation of acetabular Fractures. a novel method of Pre-Operative Omega Plate contouring].  

PubMed

PURPOSE OF THE STUDY The aim of the study was to describe a novel Omega plate and the procedure for obtaining an accurate pelvic inlet view, the mode of pre-operative plate contouring, the surgical procedure used and the evaluation of results in the first 15 patients treated using this method. MATERIAL AND METHODS In the period 2009-2011, a total of 232 patients underwent osteosynthesis for pelvic fractures. Out of them, 52 were treated by the modified Stoppa approach and 12 with the original Omega plate. Between July 2010 and January 2014, a novel 3.5-mm Omega plate was used in 12 men and 3 women. The average duration of follow-up was 8.5 months in 11 patients; four were shortly after surgery. The multi-functional Omega plate is described in detail. An exact pelvic inlet projection, named the "computer tomography-defined (CTD) view", was based on pre-operative CT examination. It facilitates pre-operative contouring of the plate according to a mirror image of the uninjured half of the pelvis. The surgical procedure enables us to apply the contoured plate to the correct position; the plate completes reduction, restores normal pelvic anatomy and makes operative time shorter. The radiographic evaluation of post-operative results was done using the Matta classification and functional outcome was assessed by the Harris Hip Score. RESULTS Surgery using the isolated Stoppa approach was carried out in 11 patients and a procedure combining the Stoppa approach with another method was used in four patients. All operations were successfully completed, during two of them the external iliac vein was injured and treated by vascular suturing. No other vascular or nerve injury occurred. One deep wound infection successfully healed was recorded. The post-operative radiographic results were excellent or satisfactory in 12 and poor in three patients. At follow-ups of 6 to 12 months, no failure of fracture reduction or osteosynthesis was recorded in 11 patients. Neither avascular necrosis of the femoral head nor heterotopic ossification was found. One patient showed signs of post-injury arthritis at 6 months after surgery. The functional result assessed by the Harris Hip Score was excellent in seven patients, good in two (one of them with gonarthrosis), satisfactory in one patient with contralateral total hip replacement and ipsilateral gonarthrosis, and poor in one patient with hemiparesis after a stroke. DISCUSSION Shape and size variability in CTD pelvic inlet views do not allow us to create a unified anatomically correct implant. Contouring during the operative procedure may not be accurate enough and significantly prolongs the time of surgery. Therefore, a custom-made plate for each patient seems to be an optimal method. It has been demonstrated on a group of 50 patients that CTD images of the right and left halves of the pelvis are identical in 68% and very similar (variation in length up to 5 mm and in curvature up to 3 mm) in 18%. At present plate contouring according to a mirror image of the acetabulum, which will be obtained by 3D printing, is prepared. CONCLUSIONS Pre-operative contouring of an Omega plate based on a post-injury CT scan of the uninjured half of the pelvis is over 80% accurate or almost accurate. The multi-functional 3.5-mm pelvic plate Omega allows us to stabilise complicated fractures of the superior ramus of the pubic bone, anterior acetabular column or quadrilateral plate as well as fractures above the linea arcuata or uncomplicated fractures of the posterior column. The stabilisation of all fragments of the anterior column and quadrilateral plate is very firm and the Omega plate is resistant to fragment redisplacement. Also, it is its advantage that it can remain in situ if total hip arthroplasty is required later. Key words:acetabular fracture, CT-defined inlet projection, modified Stoppa approach, Omega plate, 3D printing. PMID:24945390

Taller, S; Srám, J; Lukáš, R; Endrych, L; Džupa, V

2014-01-01

193

Intraoral external oblique ridge compared with transbuccal lateral cortical plate fixation for the treatment of fractures of the mandibular angle: prospective randomised trial.  

PubMed

Since the initial description by Michelet et al. and research by Champy et al. the placement of a single, four-hole, monocortical, osteosynthesis plate has been considered an acceptable method of fixation for a fracture of the mandibular angle. We investigated the null hypothesis that there is no difference in the incidence of postoperative removal of an infected plate between miniplates placed on the mandibular external oblique ridge and those placed on the buccal surface of the mandible through a transbuccal approach to treat a fracture of the angle of the mandible. Patients were randomised to having their angle fractures treated with a ridge plate placed intraorally or transbucally. Other variables were investigated including the effect of smoking, drinking alcohol, oral hygiene, and the method of holding the reduction on removal of the plate, occlusal outcome, and degree of preoperative anatomical displacement and postoperative reduction. We also studied the operating time required for the two techniques, the effect of the presence and consequent removal of a wisdom tooth in the line of the fracture, and the effect of delay in taking the patient to theatre for subsequent removal of the plate for infection. Of the 261 angle fractures 34 (13%) plates were removed because of infection, and 6 of these (18%) required a further period of fixation, such as intermaxillary fixation, to treat non-union. The transbuccal plate had a significantly lower postoperative infection rate (6/124, 5%) than the ridge plate (28/137, 20%) (p=0.001). Smoking adversely affected the healing of angle fractures (p=0.000). Displacement of fractures is related to the infection rate (p=0.003), and there are no significant relations between delay in going to theatre or the presence and potential removal of a wisdom tooth in the line of the fracture and infection rate. There was a highly significant difference between the rate of removal of plates placed intraorally on the external oblique ridge, and plates placed transbucally (p=0.000). Transbuccal plates were far less likely to need removal for infection than ridge plates, odds ratio 5.05. PMID:22421389

Laverick, S; Siddappa, P; Wong, H; Patel, P; Jones, D C

2012-06-01

194

The early results of joint-sparing proximal tibial replacement for primary bone tumours, using extracortical plate fixation.  

PubMed

This paper describes the preliminary results of a proximal tibial endoprosthesis which spares the knee joint and enables retention of the natural articulation by replacing part of the tibial metaphysis and diaphysis. In eight patients who had a primary malignant bone tumour of the proximal tibia, the distal stem, which had a hydroxyapatite-coated collar to improve fixation, was cemented into the medullary canal. The proximal end had hydroxyapatite-coated extracortical plates which were secured to the remaining proximal tibial metaphysis using cortical screws. The mean age of the patients at operation was 28.9 years (8 to 43) and the mean follow-up was for 35 months (4 to 48). The mean Musculoskeletal Tumour Society score was 79% (57% to 90%), the mean Oxford Knee score was 40 points of 48 (36 to 46) and the mean knee flexion was 112 degrees (100 degrees to 120 degrees). In one patient, revision to a below-knee amputation through the prosthesis was required because of recurrence of the tumour. Another patient sustained a periprosthetic fracture which healed with a painful malunion. This was revised to a further endoprosthesis which replaced the knee. In the remaining six patients the prosthesis allowed preservation of the knee joint with good function and no early evidence of loosening. Further follow-up is required to assess the longevity of these prostheses. PMID:19794175

Spiegelberg, B G I; Sewell, M D; Aston, W J S; Blunn, G W; Pollock, R; Cannon, S R; Briggs, T W R

2009-10-01

195

Brucellosi Animali: Rassegna sul Fenomeno delle Aspectificita e deel Disconrdanze tra Sieroagglutinazione Rapida con Antigene al Rosa bengala e Fissazione del Complemento) Animal Brucellosis Diagnosis: Causes of Nonspecific Reactions in Serological Tests Rose Bengal Plate Test and Complement Fixation Test).  

National Technical Information Service (NTIS)

For the eradication of animal bruccllosis, diagnosis is made on the basis of the detection of significant levels of specific antibody by using the Rose Bengal Plate (RBP) and Complement Fixation (CF) tests, used as screening and individual assay, respecti...

F. Ciuchini R. Adone P. Pasquali C. Marianelli M. Tarantino

2005-01-01

196

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.

Park, Jun Hyung

2013-01-01

197

Mechanical comparison of two types of fixation for ludloff oblique first metatarsal osteotomy.  

PubMed

The Ludloff oblique metatarsal osteotomy is an effective method to correct hallux valgus deformity, although a number of problems have been associated with it, including inherent instability, delayed union, dorsal malunion, and fixation failure. The purpose of the present study was to compare the mechanical characteristics of fixation of the Ludloff osteotomy in 20 identical synthetic bone models, 10 fixated using 2 screws (group I) and 10 fixated using 2 screws augmented with a mini locking plate (group II). Each specimen was loaded to failure, and the mean average load to failure, stiffness, and absorbed energy to failure were compared using unpaired Student's t test. The mean average stiffness of the Ludloff osteotomy fixed with 2 screws (group I) and with the supplementary mini locking plate (group II) was 172.7 ± 31.7 N/mm and 193.3 ± 39 N/mm, respectively (p = .21). The mean average load to failure for groups I and II was 278.4 ± 64.4 N and 356.2 ± 77.9 N, respectively (p = .025). The mean average energy absorbed before failure for groups I and II was 506.7 ± 206.4 Nmm and 769.8 ± 339.4 Nmm, respectively (p = .05). The use of a medially applied supplementary mini locking plate offers a simple and effective method to improve the mechanical stability of the Ludloff oblique osteotomy. PMID:21813302

Tsilikas, Stavros P; Stamatis, Emmanouil D; Kourkoulis, Stavros K; Mitousoudis, Athanasios S; Chatzistergos, Panayiotis E; Papagelopoulos, Panayiotis J

2011-01-01

198

Leveraging the plate: reliably restoring volar tilt of distal radius fractures.  

PubMed

Restoration of volar tilt is critical when performing open reduction and internal fixation of distal radius fractures. A reproducible technique is required to consistently achieve this goal. A simple technique using the locking plate and an electrocautery scratch pad as reduction tools can reliably generate volar tilt. This technique can be performed with minimal aid from surgical assistants. PMID:24579208

McLawhorn, Alexander S; Cody, Elizabeth A; Kitay, Alison; Goldwyn, Elan M; Golant, Alexander; Quach, Tony

2013-12-01

199

Variable fixation of staphylococcal slime by different histochemical fixatives  

Microsoft Academic Search

A variety of histochemical fixatives were used to compare the fixation of bacterial films produced by a standard slime-producing strain ofStaphylococcus epidermidis on plastic tissue culture plates. Some reagents were completely ineffective in fixing the slime layer, whereas others gave variable results. The best alternative to the fixative of the reference method, the potentially explosive Bouin's reagent, was air drying.

L. Baldassarri; W. A. Simpson; G. Donelli; G. D. Christensen

1993-01-01

200

Minimally Invasive Plate Osteosynthesis with Systems with Angular Stability in Complex Distal Femoral Fractures. Design, Biomechanics and Clinical Results  

Microsoft Academic Search

The Less Invasive Stabilization System-Distal Femur (LISS-DF) and Locked Compression Plate-Distal Femur (LCP-DF) systems are internal fixators which avoid the problems related to the bone-implant interfaces. The purpose of this study is to present the biomechanics of the internal fixators as well as to evaluate the results in treating the complex distal femoral fractures using these systems. The clinical study

P. D. Sirbu; E. Carata; T. Petreus; R. Asaftei; P. Botez

2009-01-01

201

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

PubMed Central

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

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

2014-01-01

202

A new radiological method to detect dorsally penetrating screws when using volar locking plates in distal radial fractures. The dorsal horizon view.  

PubMed

Penetration of the dorsal screw when treating distal radius fractures with volar locking plates is an avoidable complication that causes lesions of the extensor tendon in between 2% and 6% of patients. We examined axial fluoroscopic views of the distal end of the radius to observe small amounts of dorsal screw penetration, and determined the ideal angle of inclination of the x-ray beam to the forearm when making this radiological view. Six volar locking plates were inserted at the wrists of cadavers. The actual screw length was measured under direct vision through a dorsal approach to the distal radius. Axial radiographs were performed for different angles of inclination of the forearm at the elbow. Comparing axial radiological measurements and real screw length, a statistically significant correlation could be demonstrated at an angle of inclination between 5° and 20°. The ideal angle of inclination required to minimise the risk of implanting over-long screws in a dorsal horizon radiological view is 15°. PMID:23908427

Haug, L C; Glodny, B; Deml, C; Lutz, M; Attal, R

2013-08-01

203

Failure of femoral head fixation: a cadaveric analysis of lag screw cut-out with the gamma locking nail and AO dynamic hip screw  

Microsoft Academic Search

The most commonly reported failure mode of sliding hip screws in published literature is cut-out of the lag screw. This study investigates the resistance to failure of the femoral head, with lag screws used in two types of sliding hip screws, the gamma locking nail (Howmedica) and the dynamic hip screw (DHS) (Synthes). The investigation consisted of biomechanical tests under

R. C. Haynes; R. G. Pöll; A. W. Miles; R. B. Weston

1997-01-01

204

Intramedullary fixation of proximal humerus fractures: do locking bolts endanger the axillary nerve or the ascending branch of the anterior circumflex artery? A cadaveric study  

PubMed Central

Background Proximal humerus fractures are one of the most common fractures. Intramedullary locked nailing is becoming a popular alternative treatment, especially for easier fracture patterns. Although axillary nerve injury has been reported, no study has compared the safety of the proximal locking options relative to the axillary nerve and the ascending branch of the anterior circumflex artery. Method Six different commercially available proximal humeral nails were implanted in 30 shoulders of 18 cadavers. After fluoroscopically guided implantation the shoulders were carefully dissected and the distance between the locking screws, the axillary nerve and the ascending branch of the anterior circumflex artery was measured. Results The course of the axillary nerve varies. A mean distance of 55.8 mm (SD = 5.3) between the lateral edge of the acromions and the axillary nerve at the middle of the humerus in a neutrally rotated position was observed. The minimum distance was 43.4 mm, the maximum 63.9 mm. Bent nails with oblique head interlocking bolts appeared to be the most dangerous in relation to the axillary nerve. The two designs featuring such a bend and oblique bolt showed a mean distance of the locking screw to the axillary nerve of 1 mm and 2.7 mm respectively Sirus (Zimmer®) and (Stryker®) T2 PHN (Proximal Humeral Nail)). Regarding the ascending branch of the anterior circumflex artery, there was no difference between the nails which have an anteroposterior locking option. Conclusion It is of great importance for surgeons treating proximal humerus fractures to understand the relative risk of any procedure they perform. Since the designs of different nailing systems risk damaging the axillary nerve and ascending branch, blunt dissection, the use of protection sleeves during drilling and screw insertion, and individual risk evaluation prior to the use of a proximal humeral nail are advocated.

Nijs, Stefaan; Sermon, An; Broos, Paul

2008-01-01

205

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.

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

2014-01-01

206

Fuel assembly locking apparatus  

SciTech Connect

The fuel assembly locking apparatus comprises a rotatable plate capable of simultaneously and positively engaging all four legs of the bottom nozzle of a fuel assembly for uniformly holding the fuel assembly while the spent fuel rods are pulled from the fuel assembly. The rotatable plate has four notched corners arranged to be rotated over a ledge on each leg of the bottom nozzle of the fuel assembly thereby preventing movement of the fuel assembly. The rotatable plate is also capable of being rotated 45/sup 0/ so that the four corners of the plate are rotated clear of the legs of the bottom nozzle of the fuel assembly thereby allowing the fuel assembly to be placed on or removed from the locking apparatus. The locking apparatus is also provided with a torque actuator for remotely rotating the plate.

Tolino, R. W.; Toler Sr., C. E.

1984-10-02

207

Ultracytochemical localization of acetylcholine-like cations in excited motor end-plates by means of ionic fixation  

Microsoft Academic Search

Summary  Using rapid ionic fixation with molybdic or tungstic heteropolyanions (strong precipitating agents of quaternary ammonium\\u000a cations such as choline and acetylcholine), acetylcholine-like cations were localized aspoint-like precipitates in the synaptic vesicles of resting (electrically nonstimulated) motor nerve terminals. When performed\\u000a at low temperature, the same procedure revealedspot-like precipitates (presumed to be exocytotically released acetylcholine-like cations) in the synaptic cleft in

S. Tsuji

1985-01-01

208

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.

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

2014-01-01

209

[Treatment of bilateral distal tibial nonunions. Use of an intramedullary compression nail and a modified locking compression plate osteosynthesis].  

PubMed

Operative treatment of distal tibial fractures remains a challenge for the surgeon even today. The soft tissues demand atraumatic operative techniques, although an anatomical reduction of the articular fracture component is mandatory. The nonunion rate increases with disturbed local blood supply, widened fracture gap, unstable fixation. If a nonunion occurs, an individual treatment concept is required, so that even difficult situations can be successfully managed, as described in our case with bilateral tibial nonunions. PMID:17051353

Mückley, T; Wilharm, A; Marintschev, I; Hofmann, G O; Bühren, V

2007-03-01

210

Cranial reduction and fixation with a resorbable plate combined with cerebrospinal fluid shunting for difficult-to-manage macrocephaly related to hydrocephalus.  

PubMed

The management of newborns with extreme macrocephaly related to hydrocephalus can be difficult; balancing the treatment of severe cranial deformity with optimal hydrocephalus management can be complicated. Excessive CSF drainage can result in significant suture overlap that leads to difficulties in patient positioning, secondary synostosis, and long-term aesthetic complications. Delayed cranial reduction and remodeling procedures carry significant risk, and the aesthetic outcomes have sometimes been poor. The authors describe a newborn with severe macrocephaly who underwent shunt placement followed by a limited cranial reduction and fixation procedure using an absorbable plate within the 1st week of life. The procedure produced an immediate intracranial volume reduction of 49%. This novel management strategy facilitated patient positioning, simplified hydrocephalus management, and provided an excellent aesthetic outcome. PMID:23231470

Manwaring, Jotham C; Truong, Devon; Deukmedjian, Armen R; Carey, Carolyn M; Storrs, Bruce B; Rodriguez, Luis F; Tetreault, Lisa; Tuite, Gerald F

2013-02-01

211

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

PubMed Central

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

2012-01-01

212

Precision locks  

Microsoft Academic Search

This paper describes a new method for controlling data base concurrency, called precision locks (PL). The name is derived from the fact that they lock precisely the set of tuples required to guarantee data base consistency, phantoms included. This results in maximum concurrency among all tuple-level locking methods, including predicate locks. A framework for comparing locking systems which indicates the

J. R. Jordan; J. Banerjee; R. B. Batman

1981-01-01

213

Very low frequency earthquakes related to small asperities on the plate boundary interface at the locked to aseismic transition  

Microsoft Academic Search

Very low frequency (VLF) seismic signals observed in southwestern Japan are evidently radiated from shear slips on the upper surface of the subducting Philippine Sea Plate. We used grid moment tensor inversion and centroid moment tensor inversion to calculate 242 moment tensor solutions with moment magnitudes between 3.1 and 3.8 from continuous seismograms recorded over a 5 year period by

Yoshihiro Ito; Kazushige Obara; Takanori Matsuzawa; Takuto Maeda

2009-01-01

214

Five- to ten-year outcome following medial opening-wedge high tibial osteotomy with rigid plate fixation in combination with an artificial bone substitute.  

PubMed

Between 2003 and 2007, 99 knees in 77 patients underwent opening wedge high tibial osteotomy. We evaluated the effect of initial stable fixation combined with an artificial bone substitute on the mid- to long-term outcome after medial opening-wedge high tibial osteotomy (HTO) for medial compartmental osteoarthritis or spontaneous osteonecrosis of the knee in 78 knees in 64 patients available for review at a minimum of five years (mean age 68 years; 49 to 82). The mean follow-up was 6.5 years (5 to 10). The mean Knee Society knee score and function score improved from 49.6 (SD 11.4, 26 to 72) and 56.6 (SD 15.6, 5 to 100) before surgery to 88.1 (SD 12.5, 14 to 100) and 89.4 (SD 15.6, 5 to 100) at final follow-up (p < 0.001) respectively. There were no significant differences between patients aged ? 70 and < 70 years. The mean standing femorotibial angle was corrected significantly from 181.7° (SD 2.7°, 175° to 185°) pre-operatively to 169.7° (SD 2.4°, 164° to 175°) at one year's follow-up (p < 0.001) and 169.6° (SD 3.0°, 157° to 179°) at the final follow-up (p = 0.69 vs one year). Opening-wedge HTO using a stable plate fixation system combined with a bone substitute is a reliable procedure that provides excellent results. Although this treatment might seem challenging for older patients, our results strongly suggest that the results are equally good. PMID:24589788

Saito, T; Kumagai, K; Akamatsu, Y; Kobayashi, H; Kusayama, Y

2014-03-01

215

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.

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

2014-01-01

216

A meshfree model without shear-locking for free vibration analysis of first-order shear deformable plates  

Microsoft Academic Search

Difficulty in imposing essential boundary conditions in the standard element-free Galerkin method (EFG) is due to the lack of Kronecker’s delta function property of shape functions generated by moving least square approximation (MLS). In this paper, we further apply a meshfree model based on the moving Kriging interpolation method (MK) to free vibration analysis of first-order shear deformable plates. The

Tinh Quoc Bui; Minh Ngoc Nguyen; Chuanzeng Zhang

2011-01-01

217

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.

2013-01-01

218

Automatic locking radioisotope camera lock  

Microsoft Academic Search

A radioisotope camera lock for locking the source isotope in a safe, shielded position in the camera when not in use is described. The lock prevents the source isotope from being moved to an operative position outside of the camera, unless intentionally released by a key and reverse movement of source pigtail. A hollow lock casing is secured to and

Rosauer

1976-01-01

219

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.

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

2013-01-01

220

Locking hinge  

NASA Technical Reports Server (NTRS)

The space station configuration currently studied utilizes structures which require struts to be hinged in the middle in the stowed mode and locked into place in the deployed mode. Since there are hundreds of hinges involved, it is necessary that they have simple, positive locking features with a minimum of joint looseness or slack. This invention comprises two similar housings hinged together with a spring loaded locking member which assists in making as well as breaking the lock. This invention comprises a bracket hinge and bracket members with a spring biased and movable locking member. The locking or latch member has ear parts received in locking openings where wedging surfaces on the ear parts cooperate with complimentary surfaces on the bracket members for bringing the bracket members into a tight end-to-end alignment when the bracket members are in an extended position. When the locking member is moved to an unlocking position, pivoting of the hinge about a pivot pin automatically places the locking member to retain the locking member in an unlocked position. In pivoting the hinge from an extended position to a folded position, longitudinal spring members are placed under tension over annular rollers so that the spring tension in a folded position assists in return of the hinge from a folded to an extended position. Novelty lies in the creation of a locking hinge which allows compact storage and easy assembly of structural members having a minimal number of parts.

Wesselski, Clarence J. (inventor)

1988-01-01

221

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

PubMed

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

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

2014-03-01

222

Biomechanical evaluation of a new system to improve screw fixation in osteoporotic bones.  

PubMed

In this paper an experimental analysis is undertaken of the affect a new screw-to-bone fixation system has on the stiffness of fixation systems of osteoporotic fractures based on osteosynthesis plates. The proposed system, which we have named the screw locking element (SLE), is made with elements manufactured from a biocompatible polymer material known as polyetheretherketon (PEEK) which act like a lock nut, holding the end of the threaded screw shank after this has passed through both bone corticals. Seventy-two osteoporotic synbone simulated fracture models were instrumented with one of four constructs: locking compression plate with 6 locking screws (LCP), dynamic compression plate with 6 cortical screws (DCP), DCP with 2 SLEs or DCP with 6 SLEs (DCP+6SLEs). Each group of 18 simulated fracture models were further split into 3 subgroups of 6. One subgroup was tested under cyclic cantilever bending, another under cyclic compression and the third under cyclic torsion. Loss of stiffness was determined in each test every 1,000 load cycles, between 0 and 30,000 cycles. Regardless of the load type, it was seen that the DCP system had the highest stiffness loss percentages of all the tested systems. The inclusion of SLEs significantly decreased the stiffness loss of the DCP system. Unlike the cyclic compression loads, where the LCP performed slightly better, on terminating the cantilever bending and torsion load cycles no statistically significant difference was noted (Tukey test, p>0.05) between the percentage stiffness loss of the DCP+6SLEs system and the LCP system. It is concluded that the proposed SLEs enable DCPs to lower the high failure rate that these exhibit in osteoporotic fracture repairs, at significantly lower costs than those resulting from the use of LCPs. PMID:20227321

Yánez, A; Carta, J A; Garcés, G

2010-06-01

223

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

224

Multifragmentary Tibial Pilon Fractures: Midterm Results After Osteosynthesis with External Fixation and Multiple Lag Screws  

PubMed Central

Osteosynthesis of intraarticular tibial pilon fractures is preferably achieved using locking plates via a minimally invasive technique. If combined with severe soft tissue damage there is a high risk of wound-healing deficits after plate osteosynthesis. Thus our aim was to find an alternative method of treatment for those cases with combined soft tissue injuries. We report on five cases with comminuted fractures of the joint surface combined with critical soft tissue condition that were treated with lag screws and external fixation (AO) applied across the ankle joint. All five patients were followed up, undergoing clinical and radiological examination. Using this approach we achieved fracture healing of comminuted fractures without further complications. Clinical follow-up after an average of 55.6 (36–75) months revealed a mean AOFAS score of 81 (62–100). We therefore propose combined treatment using lag screws with external fixation as a practical treatment option for those fractures for which lag screws combined with a locking plate are not feasible or when there is a high risk of wound-healing deficits due to severe soft tissue damage.

Kiene, Johannes; Herzog, Jan; Jurgens, Christian; Paech, Andreas

2012-01-01

225

49 CFR 236.335 - Dogs, stops and trunnions of mechanical locking.  

Code of Federal Regulations, 2010 CFR

...and trunnions of mechanical locking. 236.335 Section 236...and trunnions of mechanical locking. Driving pieces, dogs...shall be rigidly secured to locking bars. Swing dogs shall have full and free movement. Top plates shall be maintained...

2009-10-01

226

49 CFR 236.335 - Dogs, stops and trunnions of mechanical locking.  

Code of Federal Regulations, 2010 CFR

...and trunnions of mechanical locking. 236.335 Section 236...and trunnions of mechanical locking. Driving pieces, dogs...shall be rigidly secured to locking bars. Swing dogs shall have full and free movement. Top plates shall be maintained...

2010-10-01

227

Complications of Rigid Internal Fixation  

PubMed Central

Over the past 20 years, there have been many advances in the development of bone fixation systems used in the practice of craniomaxillofacial surgery. As surgical practices have evolved, the complications of each technologic advance have changed accordingly. Interfragmentary instability of interosseous wiring has been replaced by the risk of exposure, infection, and palpability of plate and screw fixation systems. The improved rigidity of plate fixation requires anatomic alignment of fracture fragments. Failure to obtain proper alignment has led to the phenomenon known as “open internal fixation” of fracture fragments without proper reduction. The size of the plates has decreased to minimize palpability and exposure. However limitations in their application have been encountered due to the physiologic forces of the muscles of mastication and bone healing. In the pediatric population, the long-standing presence of plates in the cranial vault resulted in reports of transcranial migration and growth restriction. These findings led to the development of resorbable plating systems, which are associated with self-limited plate palpability and soft tissue inflammatory reactions. Any rigid system including these produces growth restriction in varying amounts. In this discussion, we review the reported complication rates of miniplating and microplating systems as well as absorptive plating systems in elective and traumatic craniofacial surgery.

Campbell, Chris A.; Lin, Kant Y.

2009-01-01

228

Valve lock  

NASA Astrophysics Data System (ADS)

A valve security lock is provided which secures a double union ball valve. The lock is formed from a band inserted through slits in a tube, with that combination being positioned over the valve stem to be secured, and the ends of the band wrapped around the circumference of the double union ball valve. The apparatus is secured around the double union ball valve by insertion of the shank of a lock of known kind through holes in the ends of the band. In a fluid control system, the valve security lock provides a highly visible means to prevent accidental turn-ons or turn-offs during system maintenance, but which can be easily disengaged by persons having the key or combination to the shank type lock.

Burley, Richard K.; Guirguis, Kamal S.

1992-11-01

229

Femoral plating.  

PubMed

We have demonstrated that we are able to meet both trauma and orthopedic goals with immediate plate fixation of femoral fractures in patients with blunt polytrauma. Our femoral fracture mortality rate is less than our predicted institutional mortality rate of patients with comparative injury severity scores. Ipsilateral femoral neck and shaft fractures are easily repaired with femoral plating. Infections, even in open fractures and systemically unstable patients, are rare. Implant failures have been infrequent and are easily reconstructed with intramedullary nails. Knee motion has been restored reliably. Stainless steel DCP plate fixation requires primary bone grafting. Achieving union and subsequent knee rehabilitation often requires that patients remain on crutches for up to 6 months. Our experience with titanium LCDCP plates is preliminary, but we are seeing a significant amount of callus formation and, perhaps, earlier union and bearing weight. PMID:8090475

Riemer, B L; Foglesong, M E; Miranda, M A

1994-10-01

230

Locking support for nuclear fuel assemblies  

SciTech Connect

A locking device is described for supporting and locking a nuclear fuel assembly within a cylindrical bore formed by a support plate. The locking device includes a support and locking sleeve having upwardly extending fingers forming wedge shaped contact portions arranged for interaction between an annular tapered surface on the fuel assembly and the support plate bore as well as downwardly extending fingers having wedge shaped contact portions arranged for interaction between an annularly tapered surface on the support plate bore and the fuel assembly whereby the sleeve tends to support and lock the fuel assembly in place within the bore by its own weight while facilitating removal and/or replacement of the fuel assembly.

Ledin, E.

1980-03-25

231

Locking support for nuclear fuel assemblies  

SciTech Connect

A locking device for supporting and locking a nuclear fuel assembly within a cylindrical bore formed by a support plate, the locking device including a support and locking sleeve having upwardly extending fingers forming wedge shaped contact portions arranged for interaction between an annular tapered surface on the fuel assembly and the support plate bore as well as downwardly extending fingers having wedge shaped contact portions arranged for interaction between an annularly tapered surface on the support plate bore and the fuel assembly whereby the sleeve tends to support and lock the fuel assembly in place within the bore by its own weight while facilitating removal and/or replacement of the fuel assembly.

Ledin, Eric (San Diego, CA)

1980-01-01

232

Can plate osteosynthesis of periprosthethic femoral fractures cause cement mantle failure around a stable hip stem? A biomechanical analysis.  

PubMed

Periprosthetic femoral fractures (PFF) are a serious complication after total hip arthroplasty. Plate fixation with screws perforating the cement mantle is a common treatment option. The study objective was to investigate hip stem stability and cement mantle integrity under dynamic loading. A cemented hip stem was implanted in 17 composite femur models. Nine bone models were osteotomised just distal to the stem and fixed with a polyaxial locking plate the other eight constructs served as the control group. All specimens were tested in a bi-axial material testing machine (100000 cycles). There were no statistically significant differences in axial nor in medial (varus) stem migration. No cement cracks were detected in both groups. Plate fixation of a PFF with a stable, cemented prosthesis did not lead to cement mantle failure in this in vitro study. PMID:24439999

Giesinger, Karlmeinrad; Ebneter, Lukas; Day, Robert E; Stoffel, Karl K; Yates, Piers J; Kuster, Markus S

2014-06-01

233

Torsional moment to failure for carbon fibre polysulphone expandable rivets as compared with stainless steel screws for carbon fibre-reinforced epoxy fracture plate fixation.  

PubMed

A method of securing carbon fibre-reinforced epoxy bone plates with carbon fibre polysulphone expanding rivets was investigated. Six carbon fibre-reinforced epoxy bone plates were secured to rods with carbon fibre polysulphone rivets and six were secured with standard cortical stainless steel screws. These constructions were then subjected to pure torsional load to failure. The carbon fibre expandable rivets failed at a greater torsional moment. PMID:2720038

Sell, P J; Prakash, R; Hastings, G W

1989-04-01

234

Volar fixed-angle plate fixation for unstable distal radius fractures in the elderly patient 1 1 One or more of the authors have received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article  

Microsoft Academic Search

PurposeIncreased incidence of falls and osteoporosis combine to make distal radius fractures a major cause of morbidity for the elderly patient. This report presents our experience treating distal radius fractures in the elderly population using a volar fixed-angle internal fixation plate.

Jorge L Orbay; Diego L Fernandez

2004-01-01

235

Guide thimble captured locking tube in a reconstitutable fuel assembly  

SciTech Connect

This patent describes a reconstitutable fuel assembly including a top nozzle with an adapter plate having at least one passageway, at least one guide thimble with an upper end portion, and an attaching structure for mounting the top nozzle adapter plate in releasable locking engagement upon the guide thimble upper end portion. The attaching structure includes a groove defined in the adapter plate passageway, a bulge defined in the guide thimble upper end portion and at least one slot axially defined in the guide thimble upper end portion so as to allow inward elastic collapse of the upper end portion to permit insertion and withdrawal of the bulge into and from a locking relation with the groove in the adapter plate passageway. The improvement which comprises: (a) a locking tube mounted within the guide thimble upper end portion for movement between an upper locking position where the adapter plate and guide thimble upper end portion are maintained in the locking engagement and a lower unlocking position where the adapter plate is releasable from the guide thimble upper end portion; and (b) at least one protrusion attached on the locking tube to extend outward and through the slot in the guide thimble upper end portion. The protrusion is yieldable for engaging the passageway groove of the adapter plate to retain the locking tube at its upper locking position and for releasing from the passageway groove to allow movement of the locking tube to its lower unlocking position.

Gjertsen, R.K.; Shallenberger, J.M.; Wilson, J.F.

1987-08-04

236

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

237

Guide thimble captured locking tube in a reconstitutable fuel assembly  

SciTech Connect

A reconstitutable fuel assembly is described including a top nozzle with an adapter plate having at least one passageway, at least one guide thimble with an upper end portion, and an attaching structure for mounting the top nozzle adapter plate in releasable locking engagement upon the guide thimble upper end portion, the improvement which comprises: (a) a locking tube mounted within the guide thimble upper end portion for movement relative between an upper locking position where the adapter plate and guide thimble upper end portion are maintained in the locking engagement and a lower unlocking position where the adapter plate is releasable from the guide thimble upper end portion; and (b) cooperating means defined on the locking tube and the guide thimble for releasably retaining the locking tube at either of the upper and lower positions in the guide thimble.

Paul, G.E.

1987-08-04

238

A biomechanical comparison of unilateral and bilateral String-of-Pearls™ locking plates in a canine distal humeral metaphyseal gap model.  

PubMed

Objective: To compare the in vitro biomechanical performance of two String-of-Pearls (SOP) plate constructs in a canine distal humeral metaphyseal gap model. Methods: Seven pairs of canine cadaveric humeri, including the elbow joints, were prepared. One group consisted of a unilateral medially placed SOP plate with bicortical screws (UNI). The second group consisted of bilateral caudo-medial and caudo-lateral SOP plates applied with monocortical screws (BI). A 2 cm ostectomy was performed immediately proximal to the supratrochlear foramen. Constructs were tested in torsion and axial compression. Results: The UNI constructs had significantly lower stiffness in torsion and axial compression than the BI group. However, UNI constructs had a significantly higher ultimate strength than BI constructs. All UNI constructs failed by bending of the transcondylar screw and SOP plate. All BI constructs failed by axial pullout of the distal most screws. Clinical significance: In stabilizing canine supracondylar humeral fractures as modeled here, both the UNI model and the BI model demonstrated biomechanical advantages. The incorporation of a transcondylar screw through the medial plate appears to be beneficial to construct strength. PMID:24763388

Hurt, R J; Syrcle, J A; Elder, S; McLaughlin, R

2014-05-19

239

Biologic Fixation through Bridge Plating for Comminuted Shaft Fracture of the Clavicle: Technical Aspects and Prospective Clinical Experience with a Minimum of 12-Month Follow-up  

PubMed Central

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

Park, Chang-Min; Kim, Jae-Do

2013-01-01

240

Locking Protocols: From Exclusive to Shared Locks  

Microsoft Academic Search

This paper is concerned with the problem of developing a family of locking protocols which employ both SHARED and EXCLUSIVE locks and which ensure the consistency of database systems that are accessed concurrently by a number of asynchronously running transactions. First, a general result concerning extensions of all protocols that employ EXCLUSIVE locks only to also employ SHARED locks is

Zvi M. Kedem; Abraham Silberschatz

1983-01-01

241

49 CFR 236.779 - Plate, top.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Plate, top. 236.779 Section 236.779 Transportation...AND APPLIANCES Definitions § 236.779 Plate, top. A metal plate secured to a locking bracket to prevent the cross locking from...

2010-10-01

242

49 CFR 236.779 - Plate, top.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Plate, top. 236.779 Section 236.779 Transportation...AND APPLIANCES Definitions § 236.779 Plate, top. A metal plate secured to a locking bracket to prevent the cross locking from...

2013-10-01

243

49 CFR 236.779 - Plate, top.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 2009-10-01 false Plate, top. 236.779 Section 236.779 Transportation...AND APPLIANCES Definitions § 236.779 Plate, top. A metal plate secured to a locking bracket to prevent the cross locking from...

2009-10-01

244

Functional Outcome Following Fixed-Angle Volar Plating or Intrafocal K-Wire Fixation for Extraarticular Fractures of the Distal Part of the Radius  

Microsoft Academic Search

Purpose: The objective of this retrospective study was to compare the results of two operative techniques used for the treatment of distal radius fractures classified as AO type A3. Patients and Methods: Patients were treated with either fixed-angle volar plates or intrafocal Kirschner wires (K-wires) using a Kapandji-like technique. The functional results were determined with the Gartland & Werley Score

Axel Jubel; Axel Prokop; Jonas Andermahr; Benjamin Orth; Klaus E. Rehm

2005-01-01

245

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.

2011-05-09

246

Early results with the new internal fixator systems LCP and LISS: a prospective study.  

PubMed

The Locking Compression Plate (LCP) and the Less Invasive Stabilisation System (LISS) are new implants with angular stability developed by the AO/ASIF. They offer an alternative for internal fixation in complex intra-articular fractures and high-energy diaphyseal fractures of the long bones. The new system was used in a prospective study to treat 113 patients (76 women, 37 men; average age: 53.1 years) with 122 injuries (multifragment shaft fractures or complex intra-articular, delayed/ non-union, malunion) from October 2002. Of these, 13 affected the humerus, 20 the radius, 2 the ulna, 21 the femur, 42 the tibia, 10 the fibula, 2 the acetabulum and 12 the calcaneus. Because of severe concomitant injuries, 18 fractures were first treated with an external fixator and definitively stabilised more than two weeks after the injury. Thirty-one patients were operated on after failure of other implants and non-union. Clinical and radiographic findings as well as complications were followed prospectively over a mean period of 20 months (range: 13 to 30). One patient was lost to follow-up. A total of 112 patients underwent a standardised follow-up examination. The outcome correlated with the severity of the fracture, anatomic reduction, adequate positioning of the plate and concomitant injuries. Despite the large number of open and comminuted fractures, no serious complications such as deep infections, vascular lesions, deep venous thrombosis or non-unions were noted. We found the new internal fixator system to be a safe and reliable procedure. It offers numerous fixation possibilities and has proven its value in complex fracture situations and in revision operations. A good knowledge of biomechanics is essential as well as precise preoperative planning. PMID:17441660

Hernanz González, Yolanda; Díaz Martín, Andrés; Jara Sánchez, Fernando; Resines Erasun, Carlos

2007-02-01

247

Use of an "antibiotic plate" for infected periprosthetic fracture in total hip arthroplasty.  

PubMed

Periprosthetic fracture and infection are dreaded complications after total hip arthroplasty. We present the case of a 50-year-old man who suffered an early postoperative Vancouver B1 periprosthetic fracture, which was further complicated by concurrent infection after open reduction and internal fixation. We report the novel use of an antibiotic-impregnated cement coated locking plate during the staged treatment of concomitant periprosthetic fracture and chronic total hip arthroplasty infection. At 1-year follow-up, the patient is pain free and ambulating independently with full range of motion. PMID:21804411

Liporace, Frank A; Yoon, Richard S; Frank, Matthew A; Gaines, Robert J; Maurer, James P; Polishchuk, Daniil L; Choung, Edward W

2012-03-01

248

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

249

Fixation compliance in a mouse osteotomy model induces two different processes of bone healing but does not lead to delayed union.  

PubMed

Delayed unions are a problematic complication of fracture healing whose pathophysiology is not well understood. Advanced molecular biology methods available with mice would be advantageous for investigation. In humans, decreased fixation rigidity and poor reduction are generally associated with delayed unions. In this study, these two factors were combined to observe their effect on bone healing in mice. Two plates with locking screws, one with 14 the bending stiffness of the other, were used to stabilize a 0.45mm gap osteotomy. muCT, radiographs, 4pt-bending tests and histological analysis demonstrated that the different plate types led to two different healing pathways. The less flexible bridging plate induced only intramembranous ossification whereas the more flexible bridging plate induced a mixture of endochondral and intramembranous ossification. However, the different plates led to a delay in healing of only 3-5 days in the period between 14 and 21 post-operative days. In mice, considerable fixation flexibility is necessary to induce secondary bone healing similar to that which occurs in humans, but this was not sufficient to induce a substantial delay in bone healing as would be expected in humans. PMID:19643416

Gröngröft, Ina; Heil, Petra; Matthys, Romano; Lezuo, Patrick; Tami, Andrea; Perren, Stephan; Montavon, Pierre; Ito, Keita

2009-09-18

250

Hand held tool for removing and replacing a top nozzle locking tube  

SciTech Connect

This patent describes a reconstitutable fuel assembly including a top nozzle with an adapter plate having at least one passageway, at least one guide thimble with an upper end portion and an attaching structure having a hollow locking tube for releasably locking the upper end portion of the guide thimble within the passageway of the top nozzle adapter plate, the locking tube having upper and lower opposite edges, a tool for removing the locking tube from its locking position. It comprises an elongated hollow tubular assembly having upper and lower opposite end portions, the lower end portion of the tubular assembly being insertable in the locking tube.

Wood, J.D.; Fernandez, J.J.

1991-08-06

251

Surface polishing positively influences ease of plate and screw removal.  

PubMed

Difficulties removing temporary fracture fixation devices due to excessive bony on-growth results in extended surgical time leading to excessive blood loss, debris contamination and potentially refracture. Commercially available locking plates and screws are manufactured for clinics with a micro-rough surface, which contributes to the excessive bony on-growth reported. We have applied polishing technology to commercially pure titanium locking compression plates (LCP) and titanium-6%aluminium-7%niobium (TAN) plates and screws to assess if it can alleviate problems with strong bony overgrowth. Samples were implanted for 6, 12 and 18 months in a bilateral sheep tibia non fracture model and assessed for screw removal torque, percentage of bone contact and tissue-material response. Both electropolishing (p=0.001) and paste polishing (p=0.010) of TAN screws significantly reduced the mean torque required for removal compared to their micro-rough counterparts. This was accompanied by a trend for a lower percentage of bone contact for polished screws. This difference in bone contact was significant for paste polished TAN screws (p<0.001 parallel but not electropolished TAN screws (p=0.066). Ex vivo, soft tissue removal was much easier (approximately five minutes) for polished constructs, which was difficult and at least four times longer for standard micro-rough constructs. We suggest that polishing of locked plate/screw systems will improve ease of removal and reduce implant related removal complications encountered due to excessive strong bony on-growth while maintaining biocompatibility and implant stability. Future studies aim to assess the potential of this technology in the next level of complication, a fracture model. PMID:20186671

Hayes, J S; Seidenglanz, U; Pearce, A I; Pearce, S G; Archer, C W; Richards, R G

2010-01-01

252

Limb lengthening over plate  

PubMed Central

Background: The limb lengthening over plate eliminates the associated risk of infection with limb lengthening over intramedullary nail. We present our experience of limb lengthening in 15 patients with a plate fixed on the proximal segment, followed by corticotomy and application of external fixator. Materials and Methods: 15 patients (7 females, 8 males) were included in this consecutive series. The average age was 18.1 years (range 8–35 years). Fifteen tibiae and one femur were lengthened in 15 patients. Lengthening was achieved at 1 mm/day followed by distal segment fixation with three or four screws on reaching the target length. Results: The preoperative target length was successfully achieved in all patients at a mean of 4.1 cm (range 1.8–6.5 cm). The mean duration of external fixation was 75.3 days (range 33–116 days) with the mean external fixation index at 19.2 days/cm (range 10.0–38.3 days/cm). One patient suffered deep infection up to the plate, three patients had mild procurvatum deformities, and one patient developed mild tendo achilles contracture. Conclusion: Lengthening over a plate allows early removal of external fixator and eliminates the risk of creating deep intramedullary infection as with lengthening over nail. Lengthening over plate is also applicable to children with open physis.

Kulkarni, Ruta; Singh, Nishant; Kulkarni, Govind S; Kulkarni, Milind; Kulkarni, Sunil; Kulkarni, Vidisha

2012-01-01

253

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

254

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

255

Orthopedic prosthesis fixation.  

PubMed

The fixation of orthopedic implants has been one of the most difficult and challenging problems. The fixation can be achieved via: (a) direct mechanical fixation using screws, pins, wires, etc.; (b) passive or interference mechanical fixation where the implants are allowed to move or merely positioned onto the tissue surfaces; (c) bone cement fixation which is actually a grouting material; (d) biological fixation by allowing tissues to grow into the interstices of pores or textured surfaces of implants; (e) direct chemical bonding between implant and tissues; or (f) any combination of the above techniques. This article is concerned with various fixation techniques including the potential use of electrical, pulsed electromagnetic field, chemical stimulation using calcium phosphates for the enhancement of tissue ingrowth, direct bonding with bone by glass-ceramics and resorbable particle impregnated bone cement to take advantages of both the immediate fixation offered by the bone cement and long term fixation due to tissue ingrowth. PMID:1449228

Park, J B

1992-01-01

256

Fixation of proximal humeral fractures with the Polarus nail  

Microsoft Academic Search

Thirty patients with fractures of the proximal humerus were treated by internal fixation with an intramedullary locked nail. Fourteen of these patients were more than 60 years of age; 23 patients had 2-part fractures (surgical neck fractures) and were operated on within an average of 3 days after injury. At follow-up, 20 (80%) of 25 patients showed satisfactory to excellent

C. Rajasekhar; P. S. Ray; M. S. Bhamra

2001-01-01

257

Bicondylar tibial fractures: Internal or external fixation?  

PubMed Central

Bicondylar fractures of the tibia, representing the Schatzker V and VI fractures represent a challenging problem. Any treatment protocol should aim at restoring articular congruity and the metaphyseo-diaphsyeal dissociation (MDD)—both of these are equally important to long-term outcome. Both internal and external fixations have their proponents, and each method of treatment is associated with its unique features and complications. We review the initial and definitive management of these injuries, and the advantages and disadvantages of each method of definitive fixation. We suggest the use of a protocol for definitive management, using either internal or external fixation as deemed appropriate. This protocol is based on the fracture configuration, local soft tissue status and patient condition. In a nutshell, if the fracture pattern and soft tissue status are amenable plate fixation (single or double) is performed, otherwise limited open reduction and articular surface reconstruction with screws and circular frame is performed.

Kumar, Gunasekaran; Peterson, Nicholas; Narayan, Badri

2011-01-01

258

External fixation of open humerus fractures.  

PubMed

Fifteen patients with open shaft of humerus fractures were treated with a monolateral external fixator. Nine patients presented with nerve palsies. Two radial nerves were disrupted and required grafting. Of the seven others, six spontaneously recovered and one brachial plexus partially improved. All fractures healed. The average duration of external fixation was 21 weeks. Four patients required additional procedures prior to healing (external fixator reapplication-2, plating and bone grafting-2). Two of these four experienced breakage of 4.5 mm external fixation pins. Eight patients developed pin tract infections, which all resolved with local care and antibiotics. Thirteen patients were contacted at an average of 63 months after injury. Eleven reported they were satisfied with their result, nine had no functional limits, and eight reported no pain. PMID:10847515

Marsh, J L; Mahoney, C R; Steinbronn, D

1999-01-01

259

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

PubMed Central

A change in the practice of a single surgeon provided an opportunity for retrospective comparison of comparable cohorts treated with percutaneous fixation (17 patients) or a volar plate and screws (23 patients) an average of 30 months after surgery. The final evaluation was performed according to the Gartland and Werley and Mayo rating systems and the DASH questionnaire. There were no significant differences on the average scores for the percutaneous and volar plating groups, respectively: Gartland and Werley, 4 vs 5; Mayo, 82 vs 83; and DASH score 13 for both cohorts. Motion, grip, and radiographical parameters were likewise comparable. Volar internal plate and screw fixation can achieve results comparable to percutaneous fixation techniques in the treatment of fractures of the distal radius.

Lozano-Calderon, Santiago A.; Doornberg, Job N.

2007-01-01

260

Safety of Navigation Locks  

SciTech Connect

The author's observations and studies of safety of navigation locks are described. A mathematical model of lock reliability and its graphical interpretation are presented. The possibility of determination of the accident risk level by processing statistical data is discussed.

Kolosov, M. A. [St. Petersburg State University for Water Communications (Russian Federation)

2002-03-15

261

Minimally invasive plate osteosynthesis for distal radius fractures  

PubMed Central

Background: Fractures of distal radius are common injury in all age groups. Cast treatment with or without close reduction is a viable option. However, the results are often unsatisfactory with restricted function. The open reduction and internal fixation often results in extensive soft tissue dissection and associated high rates of infect and delayed/nonunion. The distractor/external fixator have reported good functional and anatomical results but the incidence of pin traction infection nerve injury and cosmedic deformity are high. We introduced a modified operative technique for minimally invasive plate osteosynthesis (MIPO) for distal radial fracture and evaluated the functional outcomes and complications. Materials and Methods: 22 distal radial fractures (10 left, 12 right) were treated using the MIPO technique and two small incisions with a palmar locking plate from August 2009 to August 2010. The wrist function was assessed according to Dienst wrist rating system, and postoperative complications were recorded. Results: According to Dienst wrist rating system, 13 patients showed excellent results, 6 cases showed good results and 3 patients had moderate results. No patient had poor results. Thus, the excellent and good rate was 86.4%. One patient had anesthesia in the thenar eminence and this symptom disappeared after 3 months. One patient had delayed healing in the proximal wrist crease. Two patients had mild pain on the ulnar side of the wrist and two patients had limited wrist joint function. Conclusion: The MIPO technique by using two small palmar incisions is safe and effective for treatment of distal radial fractures.

Wei, Xu-ming; Sun, Zhen-zhong; Rui, Yong-jun; Song, Xiao-Jun

2014-01-01

262

Biomechanical testing of unstable humeral shaft fracture plating.  

PubMed

This study compared the biomechanical performance of 4.5-mm limited-contact dynamic compression plates (DCPs) and 3.5-mm locking compression plates (LCPs) for the fixation of unstable humeral shaft fractures. Composite humeri were divided into two groups: 3.5-mm LCPs and 4.5-mm DCPs. Osteotomy gaps of 5 mm, simulating diaphyseal comminution, were created. Stiffness tests were performed in anterior-posterior (AP) bending, medial-lateral (ML) bending, torsion, and axial compression. Results showed that while construct stiffnesses in ML bending and torsional loading are significantly higher for the 4.5 DCP group (p < .05), no statistically significant differences were observed in AP bending or axial compression. Fatigue characteristics under cyclic AP bending conditions were also evaluated, although no failures occurred. Data from the literature suggest that stiffness results for the LCP constructs perhaps afford sufficient fixation strength capable of supporting the physiologic loads most commonly applied during postoperative rehabilitation. However, results indicate that the DCP construct is mechanically advantageous for stabilizing diaphyseal comminuted fractures. PMID:19995496

Catanzarite, Joshua; Alan, Rodney; Baig, Rafath; Forno, Phil; Benson, Lisa

2009-01-01

263

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

264

Locks with Constrained Sharing  

Microsoft Academic Search

In this paper, we propose a new mode for locks that permits sharing in a constrained manner. We develop a family of locking protocols, the strictest of which is the two phase locking protocol while the most permissive recognizes all conflict-preserving serializable histories. This is the first locking-based protocol that can recognize the entire class of conflict-preserving serializable histories.

Divyakant Agrawal; Amr El Abbadi

1990-01-01

265

Laser injection locking  

Microsoft Academic Search

The basic principles of laser injection locking are discussed and the status of recent experimental work is reviewed. The subject is introduced by means of appropriate lower frequency and microwave injection-locking circuits. These are used to explore the basic physical phenomena involved and to illustrate the essential role of gain saturation in laser injection locking. Oscillators and below-threshold regenerative amplifiers

CARL J. BUCZEK; ROBERT J. FREIBERG; M. L. Skolnick

1973-01-01

266

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

267

Lock For Valve Stem  

NASA Technical Reports Server (NTRS)

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

Burley, Richard K.; Guirguis, Kamal S.

1991-01-01

268

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.

2014-01-01

269

Lumbar and thoracic spinal fusion with transpedicular fixation (Including a novel distraction and compression device)  

Microsoft Academic Search

Experience with three different systems of transpedicular fixation in fusion of the lumbar and thoracic spine over 4 years is reported. The Roy-Camille plates, Louis plates, and the Balgrist turn-buckle arrangement are compared. The Balgrist device allows both extension and compression, and affords better stability. Far better clinical results were obtained with transpedicular fixation in general than with the Harrington

Y. Suezawa; H. A. C. Jacob

1986-01-01

270

Hybrid Fixation of Tibial Eminence Fractures in Skeletally Immature Patients  

PubMed Central

Tibial eminence fractures most commonly occur in children and adolescents. When treating displaced fractures of the tibial eminence, some surgeons prefer screw fixation whereas others prefer suture fixation. The ultimate goal is to limit morbidity through early return to range of motion and activity. In this technical note, we describe 2 hybrid fixation techniques for fixing tibial eminence fractures, one for type III and the other for type IV fractures. The first technique (variation A) is used to treat type III fractures and combines use of both a bioabsorbable compression screw and suture for fixation. The second technique (variation B) is used to treat type IV fractures and combines use of both a bioabsorbable compression screw and shoulder anchor fixation. We have found that these methods provide efficient, secure, and reliable fixation using standard techniques common to arthroscopic surgery. In addition, the growth plates are spared in children and adolescents, and the need for reoperation to remove hardware is eliminated.

Gans, Itai; Babatunde, Oladapo M.; Ganley, Theodore J.

2013-01-01

271

Fixation of an ulnodorsal fragment when treating an intra-articular fracture in the distal radius.  

PubMed

If fixation of an ulnodorsal fragment in an intra-articular fracture of the distal radius is not stable, it is sometimes caused by dorsal displacement after surgery. Hence, we recommend the volar plate fixation with an additional dorsal approach and fixation of irreducible ulnodorsal fragments using a low-profile dorsal mini plate. The details of the surgical procedure and indications are discussed in this article. PMID:24641759

Ikeda, Kazuo; Osamura, Naoki; Tada, Kaoru

2014-01-01

272

Packer locking apparatus  

SciTech Connect

This patent describes an apparatus for locking a packer in a run-in position and preventing premature actuation of the packer in a wellbore. It comprises: a sleeve connectable to an outer portion of the packer; mandrel means disposed in the sleeve for connecting to an actuating mandrel of the packer; a locking member having a portion adjacent to the sleeve. The locking member being longitudinally and rotatably fixed with respect to the mandrel means; a lug extending from one of the sleeve and locking member; lug receiving means on the other of the sleeve and locking member for receiving the lug therein when in a locked position such that relative longitudinal movement between the mandrel means and the sleeve is prevented; and lock disengaging means for disengaging the lug from the lug receiving means at a predetermined position in the wellbore, thereby allowing relative longitudinal movement between the mandrel means and the sleeve.

Burns, T.D.; Caskey, K.D.; Winslow, D.W.

1991-02-05

273

[Screw fixation of craniocervical junction].  

PubMed

In recent years an increase has been observed of the use of screw techniques for the fixation of the craniocervical junction. For clinical use two techniques have been introduced: (1) transarticular screw fixation, and (2) transpedicular screw fixation. In the former the screw is inserted through the C2 lateral mass, the fissure of the C1-C2 joint, and the C1 lateral mass. (2) in the latter the screw is inserted into the C2 pedicle and anchored in C2 vertebral body. Transarticular or pedicle screws can be easily connected to longitudinal elements such as rods or plates, and combined with lateral mass screws of the remaining cervical vertebrae or occipital screws. In comparison to sublaminar wiring or interlaminar clamping the screw techniques: (a) strengthen the stiffness of the construct and speed up fusion, (b) allow fixation in the absence or deficiency of laminae as a result of trauma or laminectomy, and (c) can selectively include only the affected segments. Increased construct stiffness is due to deep anchorage of the screw in bone providing thus a solid grip on the vertebra. Both techniques require preoperative assessment of the course of the vertebral artery using imaging methods. In about 18% of cases abnormal course of the artery precludes screw use. Pedicle screw insertion requires direct control of the medial and superior walls of C2 pedicle with dissector introduced into the vertebral canal, which requires removal of the atlantoaxial ligament. Additional control can be achieved with lateral fluoroscopy. The entry point for transarticular screw is on the lateral mass of the odontoid 2-3 mm laterally to the medial margin of C2 facet and 2-3 mm above the C1/C2 articular fissure. The screw trajectory is 0-10 degrees in horizontal plane and towards the anterior C1 tuberculum in sagittal plane. PMID:10791042

Maciejczak, A; Radek, A

1999-01-01

274

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

275

Bioabsorbable miniplating versus metallic fixation for metacarpal fractures.  

PubMed

Bioabsorbable implants offer an attractive alternative to metallic implants to stabilize small bone fractures in the hand. Self-reinforced bioabsorbable miniplating for metacarpal fractures was studied in bones from cadavers and compared with standard metallic fixation methods. One hundred twelve fresh-frozen metacarpals from humans had three-point bending and torsional loading after transverse osteotomy followed by fixation using seven methods: (1) dorsal and (2) dorsolateral 2-mm self-reinforced polylactide-polyglycolide 80/20 plating, (3) dorsal and (4) dorsolateral 2-mm self-reinforced poly-L/DL-lactide 70/30 plating, (5) dorsal 1.7-mm titanium plating, (6) dorsal 2.3-mm titanium plating, and (7) crossed 1.25-mm Kirschner wires. In apex dorsal and palmar bending, dorsal self-reinforced polylactide-polyglycolide and poly-L/DL-lactide plates provided stability comparable with dorsal titanium 1.7-mm plating. When the bioabsorbable plates were applied dorsolaterally, apex palmar rigidity was increased and apex dorsal rigidity was decreased. Bioabsorbable platings resulted in higher torsional rigidity than 1.7-mm titanium plating and in failure torque comparable with 2.3-mm titanium plating. Low-profile selfreinforced polylactide-polyglycolide and poly-L/DL-lactide miniplates provide satisfactory biomechanical stability for metacarpal fixation. These findings suggest that bioabsorbable miniplating can be used safely in the clinical stabilization of metacarpal and phalangeal fractures. PMID:12771846

Waris, Eero; Ashammakhi, Nureddin; Happonen, Harri; Raatikainen, Timo; Kaarela, Outi; Törmälä, Pertti; Santavirta, Seppo; Konttinen, Yrjö T

2003-05-01

276

Efficacy of different fixation devices in maintaining an initial reduction for surgically managed distal radius fractures  

PubMed Central

Background Fracture of the distal radius is a common injury. Many treatment options exist for the surgical management of extra-articular and intra-articular distal radius fractures. The best method of treatment for these fractures remains controversial. We sought to examine radiographic outcomes of patients treated with non-spanning external fixator (NSEF), open reduction and internal fixation (ORIF) with locking plates and screws or closed reduction and percutaneous pinning (CRPP) and compare their ability to maintain radiographic parameters over the initial 6-week postoperative period. Methods We performed a retrospective review of radiographs showing 211 distal radius fractures treated with NSEF, ORIF or CRPP. We examined the images for a variety of radiological parameters. Measurements were taken immediately postoperatively and at 6-week follow-up to determine whether there was any loss of reduction. Results Of the 211 fractures, 104 (49.3%) were type-A fractures, 12 (5.7%) were type-B fractures and 95 (45.0%) were type-C fractures. The 3 treatments maintained the reduction obtained at surgery until healing. The CRPP and ORIF treatments failed to maintain correction in ulnar variance for the 6-week period; however, only ORIF actually changed the ulnar variance from presurgical values. Conclusion Treatment with ORIF for comminuted, intra-articular distal radius fractures produces good radiographic results with maintenance of surgical radiographic parameters, whereas NSEFand CRPP of less complex fractures also provide good results. This suggests that fracture-specific fixation with CRPP or NSEF are sufficient for certain distal radius fractures.

Geller, Loren; Bernstein, Mitchell; Carli, Alberto; Berry, Greg; Reindl, Rudy; Harvey, Edward

2009-01-01

277

Composite Abortable Locks  

Microsoft Academic Search

The need to allow threads to abort an attempt to ac- quire a lock (sometimes called a timeout) is an interest- ing new requirement driven by state-of-the-art database applications with soft real-time constraints. This paper presents a new composite abortable lock (CAL), a com- bination of abortable queue-based (QL) and test-and- set based backoff (BL) lock mechanisms, which provides non-blocking

Virendra J. Marathe; Mark Moir; Nir Shavit

2006-01-01

278

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.

279

12. LOCK, ELECTRICAL SYSTEM, LOCK, DAM, AND NAVIGATION LIGHTING UNITS ...  

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

12. LOCK, ELECTRICAL SYSTEM, LOCK, DAM, AND NAVIGATION LIGHTING UNITS (October 1935) - Mississippi River 9-Foot Channel Project, Lock & Dam No. 18, Upper Mississippi River, Gladstone, Henderson County, IL

280

VIEW OF LOCK GATE CLOSED AND THE LOCK FILLED TO ...  

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

VIEW OF LOCK GATE CLOSED AND THE LOCK FILLED TO THE HIGH SIDE LEVEL. - Wilson Dam & Hydroelectric Plant, Navigation Lock, Spanning Tennessee River at Wilson Dam Road (Route 133), Muscle Shoals, Colbert County, AL

281

76. LOCK, ELECTRICAL SYSTEM, LOCK, DAM AND NAVIGATION LIGHTING UNITS. ...  

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

76. LOCK, ELECTRICAL SYSTEM, LOCK, DAM AND NAVIGATION LIGHTING UNITS. February 1938 - Mississippi River 9-Foot Channel Project, Lock & Dam No. 17, Upper Mississippi River, New Boston, Mercer County, IL

282

Lock 1 View north of wall west of lock ...  

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

Lock 1 - View north of wall west of lock 1. Note the wood pile and plank foundation (believed to be similar under lock 1 walls) - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

283

49. FEEDER LOCK OR 'BROOKLYN' LOCK TO LAKE HOPATCONG. THE ...  

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

49. FEEDER LOCK OR 'BROOKLYN' LOCK TO LAKE HOPATCONG. THE NAME BROOKLYN COMES FROM THE NEAR BY BROOKLYN FORGE (AN IRON WORKS). THIS LOCK CONS DIRECTLY WITH LAKE HOPATCONG. - Morris Canal, Phillipsburg, Warren County, NJ

284

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

285

Locking tube insertion fixture and method in a reconstitutable fuel assembly  

SciTech Connect

A method is described, for use with a reconstitutable fuel assembly including a top nozzle with an adapter plate having at least one passageway, at least one guide thimble with an upper end portion and an attaching structure having a hollow locking tube for releasably locking the upper end portion of the guide thimble within the passageway of the top nozzle adapter plate. The method described is for inserting the locking tube into its locking position and comprises: (a) releasably disposing a locking tube within an opening in a tool guide; (b) locking the tool guide on the top nozzle so as to align its opening with the passageway of the top nozzle adapter plate and the locking tube disposed within the opening in alignment with the upper end portion of the guide thimble positioned within the passageway; and (c) moving a tool holder having a locking tube insertion tool mounted thereon toward the tool guide so as initially to cause the tool to extend through the guide opening and locking tube and into the upper end portion of the guide thimble and thereafter to engage the locking tube. This causes its release from the tool guide opening and insertion into the guide thimble upper end portion to its locking position therein.

Shallenberger, J.M.; Ferlan, S.J.

1987-01-27

286

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.

287

Minimal internal fixation of tibial fractures.  

PubMed

Flexible wire and small pins cause minimal disturbance of osseous blood supply, and introduce minimal foreign material into the wound. Supplemental support by a plaster cast or by traction is required, but the external support can generally be discontinued early for joint mobilization. Several simple auxillary fixation devices extend the usefulness of wire fixation. Removal of metal is not required. Many common fractures of the tibia are amenable to this method of minimal internal fixation. In the diaphysis, long oblique fractures are the most suitable for this application; the firmness of their fixation by cerclage is augmented by muscle pull. Rotation is effectively controlled by a plate which is L-shaped in cross section, and is held in position by cerclage. In the metaphysis, articular fractures of the knee and ankle are securely fixed by a flattened loop of wire and two washers (wire-washer set), supplemented sometimes by pins or hand-made staples. Two pins alone provide excellent fixation of the medial malleolus. A single pin, or a single wire loop through drill holes, may be sufficient to impart stability to an unstable tibial fracture. A key-type graft of iliac bone, maintained by crossed wire loops through cortical drill holes, is effective in the tibial diaphysis. Autogenous iliac cancellous chips provide minimal and effective internal fixation for an infected ununited fracture of the tibia. The surgical instrument most important for making wire fixation highly successful is a tightener-twister which protects wire loops from excessive strain during application, and permits twisting at a predetermined and therefore reproducible tension. Other special and ordinary instruments are valuable assets. PMID:1093765

Rhinelander, F W

1975-01-01

288

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

289

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) [Albuquerque, NM; Sanderson, Stephen N. (Albuquerque, NM) [Albuquerque, NM

1984-01-01

290

Locke's Criticism on Innateness  

Microsoft Academic Search

The concept of 'Innate ideas' which is the main que stions of epistemology throughout the history of philosophy is one of the basic points of which John Locke deals with while he is developing his own phi losophy. The thesis that some ideas or moral principles are innate in human mind is dangerous acccording to Locke for it may cause

Tayfun TORUN; Anahtar Terimler

291

Adjustable locking device  

NASA Technical Reports Server (NTRS)

Adjustable locking device is used for taking up end play of shaft without displacing shaft radially. Coincidentally threaded collars fastened to one or both ends of shaft are threaded in and out of one another for adjustment of end play. Intrinsic feature is its ability to be locked in any translatory position without axial displacement of shaft.

Fincannon, O. J.

1972-01-01

292

Reusable locking tube insertion and removal fixture and method in a reconstitutable fuel assembly  

SciTech Connect

This patent describes a locking tube insertion and removal fixture for use with a reconstitutable fuel assembly. The process includes a top nozzle with an adapter plate having at least one passageway, at least one guide thimble with an upper end portion, and an attaching structure having a hollow locking tube insertable and removable into and from a locking position in the upper end portion of the guide thimble for releasably locking the upper end portion of the guide thimble within the passageway of the top nozzle and adapter plate.

Shallenberger, J.M.; Ferlan, S.J.

1987-05-12

293

Universal lock and key  

US Patent & Trademark Office Database

A universal lock and key assembly in which the lock is re-keyable and the key is also changeable. The key has a shank portion having a longitudinally extending tooth slot in its top surface. A plurality of teeth have their bottom ends inserted into the tooth slot in any desired sequence to give a predetermined profile to the teeth of the key. The bottom pin cylinder of the lock has mating bottom pins for each of the respective teeth. These are then arranged in a coordinated sequence in the bottom pin cylinder of the lock. The structure of the system allows an individual to change both the configuration of the key and also the mating structure within the lock so it will be operable.

1993-05-18

294

Scarf osteotomy without internal fixation to correct hallux valgus.  

PubMed

Scarf osteotomy of the first metatarsal bone to correct hallux valgus deformity has benefited from a number of improvements over the past two decades, most notably regarding the internal fixation method. Internal fixation was deemed mandatory by the authors of early case-series studies. Maestro suggested eliminating the proximal screw by locking the two fragments distally: a notch was created via a medial extension of the cephalic part of the osteotomy, the plantar fragment was displaced laterally, and the distal end of the proximal fragment was then fit into the notch (secondary cut and interlocking joint technique). To further develop this concept and to increase the potential range of translation, we developed an original technique involving distal locking without shortening and proximal stabilisation by impaction of a cortical-cancellous bone graft taken from the medial overhanging edge of the proximal fragment. This original technical variant has not been reported previously. PMID:23142299

Leemrijse, T; Maestro, M; Tribak, K; Gombault, V; Devos Bevernage, B; Deleu, P-A

2012-12-01

295

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.

2014-01-01

296

Open reduction and internal fixation versus external fixation and/or kirschner wires for distal radius fractures. A systematic review.  

PubMed

(Full text is available at http://www.manu.edu.mk/prilozi). The aim of this study was to compare open reduction and plate fixation in the treatment of distal radius fractures with percutaneous fixation methods (external fixation and/or K-wires) regarding the outcome, using self-reported questionnaires (PRWE - Patient rated wrist evaluation, DASH - Disabilities of the Arm, Shoulder and Hand) as a primary aim, and grip strength and radiological parameters as a secondary aim. Data Source: We performed a systematic review of available evidence through a search of the electronic Medline PubMed database. Study Selection: Randomized clinical trials were included, as well as nonrandomized retrospective studies if they directly compared percutaneous fixation with ORIF, in the last ten years. Data extraction: Functional (PRWE, DASH), objective (grip strength), as well as radiographic outcomes were extracted and reported. Data synthesis: Ten studies were analysed, a total of 647 distal radius fractures (DRF) were included in the meta-analysis, 140 fractures treated with external fixation, 179 with K-wires (total 319 percutaneous fixation), and 328 fractures treated with ORIF. The meta-analysis showed no statistically significant differences between the results for the DRF treatment with ORIF or percutaneous methods at 3, 6 and 12 months regarding PRWE scores and grip strength, as well as final radiological outcome (volar tilt, radial length, radial tilt, ulnar variance). At 3 and 6 months there was a significant difference in the DASH score favouring open reduction and plate fixation, but at 12 months the meta-analysis showed no significant difference between the two methods compared. Conclusions: The results of this meta-analysis for the operative treatment of distal radius fractures did not clearly demonstrate a relevant advantage of any of the fixation methods. Key words: distal radius fracture, meta-analysis, open reduction and internal fixation, external fixation. PMID:24802315

Kasapinova, K; Kamiloski, V

2014-01-01

297

Femoral nailing with transverse locking screws through the femoral neck  

Microsoft Academic Search

We treated 55 patients with subtrochanteric or comminuted femoral fractures with a transverse locking femoral nail (Alta, Howmedica). This nail was positioned more cephalad than usual so that at least one fixation screw was located in the femoral neck or head. Forty-seven fractures (20 subtrochanteric and 27 diaphyseal) were available for follow-up averaging 12 months (3-35). The time to radiographic

B. H. Ziran; A. D. Wasan; M. W. Chapman

2001-01-01

298

Photographic fixative poisoning  

MedlinePLUS

Photographic developer poisoning; Hydroquinone poisoning; Quinone poisoning; Sulfite poisoning ... Hydroquinones Quinones Sodium thiosulfate Sodium sulfite/bisulfite Boric acid Photographic fixative can also break down (decompose) to form sulfur dioxide gas.

299

Ab externo sulcus fixation.  

PubMed

A new suturing method for sulcus fixation of posterior chamber lenses is described. This technique involves using a 28-gauge hollow-bore needle on an insulin syringe and a straight suture needle carrying 10-0 polypropylene. Both of these needles penetrate the eye wall in ab externo fashion, with measurements guiding their insertion. This technique promotes reproducible suture placement and reliable sulcus fixation of the implant. PMID:1792035

Lewis, J S

1991-11-01

300

Locking bandwidth of actively mode-locked semiconductor lasers  

Microsoft Academic Search

The locking bandwidth of an actively mode-locked semiconductor laser is a measure of its tolerance to variations in the input drive frequency. At frequencies outside the locking bandwidth, the output pulses from the laser exhibit large amplitude fluctuations and timing jitter. The authors investigate the locking bandwidths of fundamentally driven and harmonically driven high-repetition-rate actively mode-locked semiconductor lasers. They show

Zaheer Ahmed; Lu Zhai; Arthur J. Lowery; Noriaki Onodera; Rodney S. Tucker

1993-01-01

301

Intraoperative use of nylon bands in fracture fixation.  

PubMed

Nylon tie bands are introduced as an intraoperative aid in the application of internal fixation. Their use for holding metal plates on reduced fractures is advantageous over metal clamps in that they do not impede access to the fracture site, are easily applied, keep intraoperative injury to soft tissue at a minimum, and reduce manipulatory efforts at the fracture site, decreasing operating time. Scuffing of metal plates is eliminated. A technique for their use is described. Our experience with the nylon tie bands indicates that they are an effective adjunct, as opposed to conventional metal clamps, in open reduction and internal fixation of fractures in our institution. PMID:7471585

Schmidt, T L; Davis, W M

1981-01-01

302

Orthodontic skeletal anchorage using a palatal external plate.  

PubMed

We have developed the Anchor-Lock external plate system, which is fitted on the palate for the purpose of orthodontic skeletal anchorage. The aim of this study was to introduce the Anchor-Lock and assess its success rate. The Anchor-Lock is composed of titanium screws of 2·0-mm diameter and a titanium plate of 1·0-mm thickness. The external plate is rigidly interlocked with the heads of the screws, which are implanted trans-mucosally into palatal bone. Three types of Anchor-Lock are available. These were applied to 137 orthodontic patients (104 females and 33 males) aged 10-54 years. Two types of plate were used, a straight-shaped plate applied to the hard palate and to the anterior palate and a double-Y-shaped plate applied after tooth-borne rapid maxillary expansion. Success rate of the Anchor-Lock was 92·0% overall. No significant difference in success rate was found by age or sex of patients. Type or screw length of the Anchor-Lock did not affect success rate significantly. Success rate was significantly increased by the use of the surgical stent. The Anchor-Lock was effectively applied to distalize and/or intrude the upper molars. The Anchor-Lock system appears suitable for clinical use as an alternative to conventional screw- and plate-type orthodontic implants. PMID:24671290

Kobayashi, Masaru; Fushima, Kenji

2014-03-01

303

The variable finesse locking technique  

Microsoft Academic Search

Virgo is a power recycled Michelson interferometer, with 3 km long Fabry Perot cavities in the arms. The locking of the interferometer has been obtained with an original lock acquisition technique. The main idea is to lock the instrument away from its working point. Lock is obtained by misaligning the power recycling mirror and detuning the Michelson from the dark

F. Acernese; P. Amico; M. Al-Shourbagy; S. Aoudia; S. Avino; D. Babusci; G. Ballardin; R. Barillé; F. Barone; L. Barsotti; M. Barsuglia; F. Beauville; M. A. Bizouard; C. Boccara; F. Bondu; L. Bosi; C. Bradaschia; S. Braccini; A. Brillet; V. Brisson; L. Brocco; D. Buskulic; E. Calloni; E. Campagna; F. Cavalier; R. Cavalieri; G. Cella; E. Chassande-Mottin; C. Corda; A.-C. Clapson; F. Cleva; J.-P. Coulon; E. Cuoco; V. Dattilo; M. Davier; R. De Rosa; L. Di Fiore; A. Di Virgilio; B. Dujardin; A. Eleuteri; D. Enard; I. Ferrante; F. Fidecaro; I. Fiori; R. Flaminio; J.-D. Fournier; S. Frasca; F. Frasconi; A. Freise; L. Gammaitoni; A. Gennai; A. Giazotto; G. Giordano; L. Giordano; R. Gouaty; D. Grosjean; G. Guidi; S. Hebri; H. Heitmann; P. Hello; L. Holloway; S. Kreckelbergh; P. La Penna; V. Loriette; M. Loupias; G. Losurdo; J.-M. Mackowski; E. Majorana; C. N. Man; M. Mantovani; F. Marchesoni; F. Marion; J. Marque; F. Martelli; A. Masserot; M. Mazzoni; L. Milano; C. Moins; J. Moreau; N. Morgado; B. Mours; A. Pai; C. Palomba; F. Paoletti; S. Pardi; A. Pasqualetti; R. Passaquieti; D. Passuello; B. Perniola; F. Piergiovanni; L. Pinard; R. Poggiani; M. Punturo; P. Puppo; K. Qipiani; P. Rapagnani; V. Reita; A. Remillieux; F. Ricci; I. Ricciardi; P. Ruggi; G. Russo; S. Solimeno; A. Spallicci; R. Stanga; R. Taddei; D. Tombolato; M. Tonelli; A. Toncelli; E. Tournefier; F. Travasso; G. Vajente; D. Verkindt; F. Vetrano; A. Viceré; J.-Y. Vinet; H. Vocca; M. Yvert; Z. Zhang; M. Evans

2006-01-01

304

''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

305

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

PubMed

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

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

2014-05-01

306

Locking Nut and Bolt  

NASA Technical Reports Server (NTRS)

Threaded fastener locks parts securely together despite together large loosening torques, even under conditions of high temperature and vibration. Positive locking action is suitable for use where conventional fasteners tend to work loose--for example, on high-speed rotating machinery. Bolt, nut and key are joined together so key occupies alined slots in bolt and nut and prevents nut from rotating off bolt.

Bishop, R.

1983-01-01

307

Spring-Tab Lock Washer  

NASA Technical Reports Server (NTRS)

Improved spring-tab lock washer offers alternative to such positive-locking devices as cotter pins and lock wires and to conventional split-ring lock washers. Does not dig into fastened parts with sharp edges; less likely to inflict scratches causing cracks. Contains three winglike spring tabs and three alignment pips, pressed into mating dimples in surface of part to be fastened. Spring tabs on lock washer allow only clockwise rotation (tightening) of bolt or nut.

Finckenor, Jeff; Rogers, Dylan; Rodriguez, Pete

1993-01-01

308

Adapter plate assembly for adjustable mounting of objects  

DOEpatents

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

Blackburn, R.S.

1986-05-02

309

Adapter plate assembly for adjustable mounting of objects  

DOEpatents

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

Blackburn, Robert S. (Albuquerque, NM)

1987-01-01

310

Rush Pin Fixation Versus Traction and Casting for Femoral Fracture in Children Older than Seven years  

Microsoft Academic Search

Background: The optimal treatment for femoral fractures in children is controversial. The purpose of this study was to compare the results of Rush pin fixation with those of conservative treatment, and to evaluate the sequels of growth plate injury by internal fixation. Methods: Eighteen femoral shaft fractures in 17 children who had concomitant head injury or multiple traumas were treated

Zhon-Liau Lee; Chia-Hsieh Chang; Wen-E Yang; Shuo-Suei Hung

311

Safe Osteocutaneous Radial Forearm Flap Harvest with Prophylactic Internal Fixation  

PubMed Central

We studied the efficacy of prophylactic plate fixation technique and a modified harvest of the osteocutaneous radial forearm free flap (OCRFFF) to minimize the incidence of postoperative donor radius pathological fracture. We retrospectively studied of the first 70 consecutive patients undergoing OCRFFF harvest by the University of Kansas Head and Neck Microvascular Reconstruction Team. Mean follow-up was 13 months. One of two patients undergoing OCRFFF harvest without prophylactic fixation developed a pathological radius fracture. The 68 subsequent OCRFFF patients underwent prophylactic fixation of the donor radius, and none developed a symptomatic radius fracture. Five of 68 patients did have a radiographically visible fracture requiring no intervention. The plate fixation technique was further modified to exclude monocortical screws in the radius bone donor defect (subsequent 39 patients), without any further fractures detected. One patient required forearm hardware removal for an attritional extensor tendon tear. The described modified OCRFFF harvest and prophylactic plate fixation technique may eliminate postoperative pathological fracture of the donor radius. Donor morbidity is similar to that of the fasciocutaneous radial forearm free flap , affording safe use of OCRFFF in head and neck reconstruction.

Shnayder, Yelizaveta; Tsue, Terance T.; Toby, E. Bruce; Werle, Andreas H.; Girod, Douglas A.

2011-01-01

312

Microplate fixation of prefabricated subperiosteal orbital floor implants.  

PubMed

Microplating and miniplating systems are widely available for repairing fractures involving the orbit, face, cranium, and mandible. These plates are superior to traditional wiring techniques because the fractured bones are held in position immediately after the plates have been screwed into position (rigid fixation). Recently, we have found the T-shaped microplate quite helpful in securing the prefabricated subperiosteal orbital floor implants commonly used to augment orbital volume in anophthalmic sockets. PMID:7746632

Jordan, D R

1995-01-01

313

Improving carbon fixation pathways.  

PubMed

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

Ducat, Daniel C; Silver, Pamela A

2012-08-01

314

Improving Carbon Fixation Pathways  

PubMed Central

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

Ducat, Daniel C.

2012-01-01

315

Lock 1 View northwest of lock entrance. Notch for ...  

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

Lock 1 - View northwest of lock entrance. Notch for flash boards can be seen near center, gate pocket at left. - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

316

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

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

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

317

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

PubMed

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

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

1989-01-01

318

Radiographic Evaluation of Dorsal Screw Penetration After Volar Fixed-Angle Plating of the Distal Radius: A Cadaveric Study  

PubMed Central

Introduction Extensor tendon irritation and attritional tendon ruptures are potentially serious complications after open reduction and internal fixation of distal radius fractures. These complications are well recognized after dorsal plating of distal radii; and these are now being reported after errant screw placement during volar fixed-angle plating. Intraoperative detection of improper screw placement is critical, as corrective action can be taken before completion of the operative procedure. The purpose of this study was to define the extensor tendon compartments at risk secondary to dorsal screw penetration and to compare pronation and supination fluoroscopic images with standard lateral images in demonstrating dorsal screw prominence during volar locked plating. Methods Eight fresh-frozen human cadaveric upper extremities underwent fixation with a volar, fixed-angle distal radius locked plate (Wright Medical Technology, Arlington, TN). Three fluoroscopic views (lateral, supinated, and pronated) followed by dorsal wrist dissections were compared to determine accuracy in detecting dorsal screw prominence and extensor tendon compartment violation. Subsequently, screws measuring 2, 4, 6, 8, and 10(mm longer than the measured depths were sequentially inserted into each distal locking screw, with each image deemed either "in" (completely inside the bone) or "out" (prominent screw tip dorsally-would typically be exchanged for a shorter screw intraoperatively). Results The radial most distal locking screw (position 1) violated either the first (25%) or second (75%) extensor tendon compartments. The average screw prominence required for radiographic detection was: 6.5(mm for lateral views and 2(mm for supinated views. Pronated views did not identify prominent screws. Screws occupying plate position 2 consistently entered Lister's tubercle, with 5/8 exiting the apex and 3/8 exiting the radial base. The average screw prominences for radiographic detection were: 2.75(mm-lateral views and 3.0(mm-supinated views. Although the screws entered the second dorsal compartment, they did not encroach upon either of the tendons. Screws occupying plate position 3 violated the third extensor tendon compartment in 7/8 specimens with 1/8 exiting the Ulan base of Lister's tubercle. The average screw prominences for radiographic detection were: 3.5(mm-lateral views and 2.5(mm-pronated views. Supinated views did not identify prominent hardware. Screws occupying plate position 4 all violated the IV dorsal extensor compartment-2/8 screws were noted to tent the posterior interosseous nerve. The average screw prominences required for radiographic detection were: 4.0(mm-lateral views and 2.5(mm-pronated views. The supinated views did not identify prominent screws. Conclusions Volar fixed-angle plating has shown great promise in the advancement of distal radius fracture management. We have seen in our referral practices and in the literature an increase in the number of extensor tendon complications arising from unrecognized dorsally prominent screws, pegs, or tines. Standard PA and lateral radiographs cannot adequately visualize screw position and length secondary to the complex geometry of the dorsal cortex. We believe this study supports the routine application of intraoperative, oblique pronosupination fluoroscopic imaging for enhanced confirmation of distal locking screw position and length.

Maschke, Steven D.; Evans, Peter J.; Schub, David; Drake, Richard

2007-01-01

319

Biomechanical comparison of flexible stainless steel and titanium nails with external fixation using a femur fracture model.  

PubMed

There are several options available for surgical stabilization of pediatric femoral shaft fractures. The purpose of this study was to compare the stability afforded by Ender stainless steel nails, titanium elastic nails, and one-plane unilateral external fixators for the fixation using a synthetic adolescent midshaft femur fracture model. The anterior-posterior (sagittal plane) bending, lateral (coronal plane) bending, torsional, and axial stiffness values were calculated using 6 different fixation configurations. These included pairs of 3.5-mm-diameter Ender nails with and without distal locking, 3.5- and 4.0-mm-diameter titanium elastic nails as well as single- and double-stacked monolateral external fixators. Eight synthetic femur models, 4 each with simulated transverse and comminuted fracture patterns, were sequentially tested for stability afforded by the various fracture fixation configurations. External fixation exhibited significantly greater control of anterior-posterior angulation compared with all flexible-nailing systems. Although Ender nails were slightly superior to titanium nails in control of sagittal plane angulation, this was not statistically significant. Compared with the external fixation constructs, all 4 flexible nail constructs demonstrated higher torsional stability. For prevention of axial shortening, all fixation methods were similar for the transverse fracture pattern, whereas external fixation was superior to flexible nails in the comminuted fracture model. No significant benefit was demonstrated with double stacking of external fixators. These findings may help guide clinicians choose the optimal fixation method for treatment of pediatric femoral shaft fractures. PMID:16557131

Mani, Usha S; Sabatino, Christopher T; Sabharwal, Sanjeev; Svach, David J; Suslak, Adam; Behrens, Fred F

2006-01-01

320

Quick-Change Anode for Plating  

NASA Technical Reports Server (NTRS)

Proposed fastener for attaching electroplating anode improves quality of plating and increases productivity. Notches in twist-lock fastener mates with projections on end of anode bar. Fastener made of titanium for compatibility with copper-plating solution. Also constructed in snap-on, snap-off configuration.

Beasley, J. L.

1987-01-01

321

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

322

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

323

Carbon dioxide fixation.  

National Technical Information Service (NTIS)

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) conv...

E. Fujita

2000-01-01

324

Integrated optical phase locked loop.  

SciTech Connect

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

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

2010-12-01

325

Injection locking of excimer lasers  

SciTech Connect

Reliable injection locking of high-power unstable resonator excimer lasers can be achieved with extremely low reference oscillator power. The criteria for injection locking are discussed and experimental results are given.

Bigio, I.J.; Slatkine, M.

1981-01-01

326

Posterior transodontoid fixation: A new fixation (Kotil) technique  

PubMed Central

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

Kotil, Kad?r; Koksal, Neslihan sutpideler; Kayac?, Selim

2011-01-01

327

Controlling concurrency using locking protocols  

Microsoft Academic Search

This paper is concerned with the problem of developing locking protocols for ensuring the consistency of database systems that are accessed concurrently by a number of independent transactions. It is assumed that the database is modelled by a directed acyclic graph whose vertices correspond to the database entities, and whose arcs correspond to certain locking restrictions. Several locking protocols are

Zvi Kedem; Abraham Silberschatz

1979-01-01

328

Ball Lock Mechanism.  

National Technical Information Service (NTIS)

A ball lock mechanism has a shaft with an annular groove formed therearound. A first sleeve fitted on the shaft defines at least one channel between the first sleeve and the shaft. An opening facing away from the shaft is formed at the end of each channel...

1998-01-01

329

Pile Driver Hammer Lock.  

National Technical Information Service (NTIS)

Disclosed in the patent application is a safety locking mechanism that prevents a pile driving hammer from accidentally falling while it is in the elevated position on a lead or guide. The device automatically blocks and supports the weight of the hammer ...

W. F. Law L. M. Baez

1974-01-01

330

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

331

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

332

Releasable Lock Mechanism.  

National Technical Information Service (NTIS)

According to the present invention, in a preferred form, a novel releasable lock mechanism has been incorporated in a compact unit made up of relatively few working parts for the closing and opening of a pair of complementary jaws capable of gripping and ...

D. L. Read

1986-01-01

333

Self-Locking Connector  

NASA Technical Reports Server (NTRS)

Connector lock resists vibration, automatically compensates for wear, and exhibits no backlash when parts are seated. Mechanism built into coupling nut on outer connector body. Outer collar turned clockwise to tighten treaded coupling nut, transmitting torque to coupling nut through six radially oriented pins.

Gaspar, K.

1983-01-01

334

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

335

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

336

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

PubMed

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

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

2014-08-01

337

Measuring the onset of locking in the Peru-Chile trench with GPS and acoustic measurements  

Microsoft Academic Search

The subduction zone off the west coast of South America marks the convergence of the oceanic Nazca plate and the continental South America plate. Nazca-South America convergence over the past 23 million years has created the 6-km-deep Peru-Chile trench, 150km offshore. High pressure between the plates creates a locked zone, leading to deformation of the overriding plate. The surface area

Katie Gagnon; C. David Chadwell; Edmundo Norabuena

2005-01-01

338

Locking tube removal fixture and method in a reconstitutable fuel assembly  

SciTech Connect

A method is described for use with a reconstitutable fuel assembly including a top nozzle with an adapter plate having at least one passageway, at least one guide thimble with an upper end portion and an attaching structure having a hollow locking tube for releasably locking the upper end portion of the guide thimble within the passageway of the top nozzle adapter plate. The method described is for removing the locking tube from its locking position and comprises: (a) disposing a locking tube engaging means having a lower segmented rim within an opening in a tool guide and extending downward therefrom; (b) positioning the tool guide on the top nozzle so as to align its opening with the passageway of the top nozzle adapter plate and extend the locking tube engaging means through the locking tube in the upper end portion of the guide thimble positioned within the passageway with the segmented rim of the tube engaging means disposed at a level below a lower edge of the locking tube; and (c) moving a tool holder having an elongated actuating means mounted thereon and extending through the tube engaging means from a first to a second position so as to move the actuating means from a disengaged to an engaged position.

Shallenberger, J.M.; Ferlan, S.J.

1987-01-27

339

Early experiences with the AO calcaneal fracture plate  

Microsoft Academic Search

We describe our early experiences using the new AO plate for open reduction and internal fixation of displaced intra-articular fractures of the calcaneum. An overview of our operative technique based on 22 cases is given. The relative merits of the new plate are discussed and we conclude that the plate is a useful device for dealing with this complex injury.

P. S. Kerr; M. Pape; M. Jackson; R. M. Atkins

1996-01-01

340

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

PubMed Central

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

2013-01-01

341

A mixed 3D finite element for modelling thick plates  

NASA Astrophysics Data System (ADS)

Based on the Hellinger-Reissner variational principle, we formulate a mixed 3-d finite element for plate bending. This element is used to model thick plates and alleviates the problem of shear-locking in plates with large length/thickness ratios. The computer code which was used here, is available.

Asch, Mark; Bercovier, Michel

1994-09-01

342

Stability of cervical spine after one-level corpectomy using different numbers of screws and plate systems.  

PubMed

Anterior corpectomy and reconstruction using a plate with locking screws are standard procedures for the treatment of cervical spondylotic myelopathy. Although adding more screws to the construct will normally result in improved fixation stability, several issues need to be considered. Past reports have suggested that increasing the number of screws can result in the increase in spinal rigidity, decreased spine mobility, loss of bone and, possibly, screw loosening. In order to overcome this, options to have constrained, semi-constrained or hybrid screw and plate systems were later introduced. The purpose of this study is to compare the stability achieved by four and two screws using different plate systems after one-level corpectomy with placement of cage. A three-dimensional finite-element model of an intact C1-C7 segment was developed from computer tomography data sets, including the cortical bone, soft tissue and simulated corpectomy fusion at C4-C5. A spinal cage and an anterior cervical plate with different numbers of screws and plate systems were constructed to a fit one-level corpectomy of C5. Moment load of 1.0 N m was applied to the superior surface of C1, with C7 was fixed in all degrees of freedom. The kinematic stability of a two-screw plate was found to be statistically equivalent to a four-screw plate for one-level corpectomy. Thus, it can be a better option of fusion and infers comparable stability after one-level anterior cervical corpectomy, instead of a four-screw plate. PMID:24622982

Rosli, Ruwaida; Abdul Kadir, Mohammed R; Kamarul, Tunku

2014-04-01

343

Fixation-off sensitivity.  

PubMed

Fixation-off sensitivity (FOS) is a phenomenon induced by elimination of central vision/fixation, and may either manifest clinically with seizures or only represent an EEG abnormality. FOS is characterized by posterior or generalized epileptiform discharges that consistently occur after closing of the eyes and last as long as the eyes are closed. It is most commonly encountered in patients with idiopathic childhood occipital epilepsies, but may also be observed in cases of symptomatic or cryptogenic focal and generalized epilepsies, as well as in asymptomatic non-epileptic individuals. FOS should be differentiated from pure forms of scotosensitivity, in which EEG discharges or epileptic seizures are elicited by darkness, and from epileptiform discharges triggered by eye closure, which refer to eye closure sensitivity. Although FOS is probably associated with occipital hyperexcitability its intrinsic epileptogenic potential is presumed to be low. PMID:22925838

Brigo, F; Rossini, F; Stefani, A; Nardone, R; Tezzon, F; Fiaschi, A; Manganotti, P; Bongiovanni, L G

2013-02-01

344

Novel posterior fixation keratoprosthesis  

NASA Astrophysics Data System (ADS)

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

Lacombe, Emmanuel

1992-08-01

345

Locking of the Chile subduction zone controlled by fluid pressure before the 2010 earthquake  

NASA Astrophysics Data System (ADS)

Constraints on the potential size and recurrence time of strong subduction-zone earthquakes come from the degree of locking between the down-going and overriding plates, in the period between large earthquakes. In many cases, this interseismic locking degree correlates with slip during large earthquakes or is attributed to variations in fluid content at the plate interface. Here we use geodetic and seismological data to explore the links between pore-fluid pressure and locking patterns at the subduction interface ruptured during the magnitude 8.8 Chile earthquake in 2010. High-resolution three-dimensional seismic tomography reveals variations in the ratio of seismic P- to S-wave velocities (Vp/Vs) along the length of the subduction-zone interface. High Vp/Vs domains, interpreted as zones of elevated pore-fluid pressure, correlate spatially with parts of the plate interface that are poorly locked and slip aseismically. In contrast, low Vp/Vs domains, interpreted as zones of lower pore-fluid pressure, correlate with locked parts of the plate interface, where unstable slip and earthquakes occur. Variations in pore-fluid pressure are caused by the subduction and dehydration of a hydrothermally altered oceanic fracture zone. We conclude that variations in pore-fluid pressure at the plate interface control the degree of interseismic locking and therefore the slip distribution of large earthquake ruptures.

Moreno, Marcos; Haberland, Christian; Oncken, Onno; Rietbrock, Andreas; Angiboust, Samuel; Heidbach, Oliver

2014-04-01

346

Effects of overmodulation in fixation-free rehalogenating bleached holograms  

NASA Astrophysics Data System (ADS)

The mechanism for hologram formation by fixation-free rehalogenating bleaching has been treated by several authors. Experiments carried out with Kodak and Agfa photographic plates have led to the conclusion that the transfer of material from the exposed to the unexposed zones is the main mechanism that drives the process. We show that when BB-640 emulsion is used in the recording of holograms by means of fixation-free rehalogenating bleaching, the mechanism for the transfer of material from exposed to unexposed zones is efficient enough to create high refractive-index modulations. We also comment on the overmodulation effects, which result in a decrease in diffraction efficiency.

Neipp, Cristian; Pascual, Inmaculada; Beléndez, Augusto

2001-07-01

347

Minimally invasive plate osteosynthesis of distal fractures of the tibia  

Microsoft Academic Search

Minimally invasive plate osteosynthesis of distal tibial fractures is technically feasible and may be advantageous in that it minimizes soft tissue compromise and devascularization of the fracture fragments. The technique involves open reduction and internal fixation of the associated fibular fracture when present, followed by temporary external fixation of the tibia until swelling has resolved. Subsequent limited, but open reduction

David L. Helfet; Paul Y. Shonnard; David Levine; Joseph Borrelli

1997-01-01

348

Code lock with microcircuit  

NASA Astrophysics Data System (ADS)

A code lock with a microcircuit was invented which contains only a very few components. Two DD-triggers control the state of two identical transistors. When both transistors are turned on simultaneously the transistor VS1 is turned on so that the electromagnet YA1 pulls in the bolt and the door opens. This will happen only when a logic 1 appears at the inverted output of the first trigger and at the straight output of the second one. After the door is opened, a button on it resets the contactors to return both triggers to their original state. The electromagnetic is designed to produce the necessary pull force and sufficient power when under rectified 127 V line voltage, with the neutral wire of the lock circuit always connected to the - terminal of the power supply.

Korobka, A.; May, I.

1985-01-01

349

Releasable locking mechanisms  

NASA Technical Reports Server (NTRS)

In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.

Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)

2005-01-01

350

Releasable Locking Mechanisms  

NASA Technical Reports Server (NTRS)

In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.

Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)

2005-01-01

351

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

352

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.

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

2013-01-01

353

Frequency comb injection locking of mode locked lasers  

NASA Astrophysics Data System (ADS)

The two-frequency problem of synchronization of the pulse train of a passively mode locked soliton laser to an externally injected pulse train is solved in the weak injection regime. The source and target frequency combs are distinguished by the spacing and offset frequency mismatches. Locking diagrams map the domain in the mismatch parameter space where stable locking of the combs is possible. We analyze the dependence of the locking behavior on the relative frequency and chirp of the source and target pulses, and the conditions where the relative offset frequency has to be actively stabilized. Locked steady states are characterized by a fixed source-target time and phase shifts that map the locking domain.

Gat, Omri; Kielpinski, David

2013-03-01

354

Reusable locking tube in a reconstitutable fuel assembly  

SciTech Connect

This patent describes a reconstitutable fuel assembly including a top nozzle with an adapter plate having an interior wall forming at least one passageway, at least one guide thimble with an upper end portion, and an attaching structure having an outer socket formed by a circumferential groove defined in the adapter plate passageway wall and opening into the passageway and an inner socket formed by a circumferential bulge and at least one longitudinal slot defined in the upper end portion of the guide thimble. The circumferential bulge is capable of seating within the circumferential groove, an improved reusable tube for releasably locking the inner socket of the guide thimble upper end portion in locking engagement within the outer socket of the adapter plate passageway when the circumferential bulge is seated within the circumferential groove. The reusable tube comprises: (a) an elongated hollow tubular body capable of insertion within the adapter plate passageway and guide thimble upper end portion to a locking position therein such that the circumferential bulge of the inner socket is maintained seated in the locking engagement with the circumferential groove of the outer socket; and (b) at least a pair of dimples performed on the exterior of the tubular body prior to insertion of the body in the guide thimble upper end portion and to the locking position, the dimples being performed and configured to increase the thickness of the tubular body in relation to the remainder of the tubular body. The dimples are substantially resisting resilient yielding in relation to the remainder of the tubular body.

Shallenberger, J.M.; Ferlan, S.J.

1987-10-13

355

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

356

Nitrogen fixation 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.

Chen, Hao-Lin (Walnut Creek, CA) [Walnut Creek, CA

1984-01-01

357

Locking means for solar collector  

SciTech Connect

A locking mechanism for holding reflector elements of a solar collector array in a position protected from high wind and storm damage including locking bar means mounted between and rotating with pairs of reflectors, latching means mounted on support pylons between said reflectors and positioned to engage and hold said locking bar means thereby retaining the reflectors in the protected position, and a plurality of linked release means for simultaneous release of all said latching means.

Hutchison, J.A.

1985-04-02

358

Safe-haven locking device  

DOEpatents

Disclosed is a locking device for eliminating external control of a secured space formed by fixed and movable barriers. The locking device uses externally and internally controlled locksets and a movable strike, operable from the secured side of the movable barrier, to selectively engage either lockset. A disengagement device, for preventing forces from being applied to the lock bolts is also disclosed. In this manner, a secured space can be controlled from the secured side as a safe-haven. 4 figures.

Williams, J.V.

1984-04-26

359

Phase locking of relativistic magnetrons  

Microsoft Academic Search

Phase locking of relativistic magnetrons has been achieved at power levels of about 3 GW at 2.8 GHz, exceeding previous phase-locking power levels by 3 orders of magnitude. Two relativistic magnetrons interact directly through a short waveguide of length l about n lambda\\/2 to allow locking. Power-density enhancement due to source coherence is directly measured in the radiation field. Phase

J. Benford; H. Sze; W. Woo; R. R. Smith; B. Harteneck

1989-01-01

360

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

361

Comparison of theoretical fixation stability of three devices employed in medial opening wedge high tibial osteotomy: a finite element analysis  

PubMed Central

Background Medial open wedge high tibial osteotomy is a well-established procedure for the treatment of unicompartmental osteoarthritis and symptomatic varus malalignment. We hypothesized that different fixation devices generate different fixation stability profiles for the various wedge sizes in a finite element (FE) analysis. Methods Four types of fixation were compared: 1) first and 2) second generation Puddu plates, and 3) TomoFix plate with and 4) without bone graft. Cortical and cancellous bone was modelled and five different opening wedge sizes were studied for each model. Outcome measures included: 1) stresses in bone, 2) relative displacement of the proximal and distal tibial fragments, 3) stresses in the plates, 4) stresses on the upper and lower screw surfaces in the screw channels. Results The highest load for all fixation types occurred in the plate axis. For the vast majority of the wedge sizes and fixation types the shear stress (von Mises stress) was dominating in the bone independent of fixation type. The relative displacements of the tibial fragments were low (in ?m range). With an increasing wedge size this displacement tended to increase for both Puddu plates and the TomoFix plate with bone graft. For the TomoFix plate without bone graft a rather opposite trend was observed. For all fixation types the occurring stresses at the screw-bone contact areas pulled at the screws and exceeded the allowable threshold of 1.2 MPa for at least one screw surface. Of the six screw surfaces that were studied, the TomoFix plate with bone graft showed a stress excess of one out of twelve and without bone graft, five out of twelve. With the Puddu plates, an excess stress occurred in the majority of screw surfaces. Conclusions The different fixation devices generate different fixation stability profiles for different opening wedge sizes. Based on the computational simulations, none of the studied osteosynthesis fixation types warranted an intransigent full weight bearing per se. The highest fixation stability was observed for the TomoFix plates and the lowest for the first generation Puddu plate. These findings were revealed in theoretical models and need to be validated in controlled clinical settings.

2014-01-01

362

Phase locking of relativistic magnetrons  

NASA Astrophysics Data System (ADS)

Phase locking of relativistic magnetrons has been achieved at power levels of about 3 GW at 2.8 GHz, exceeding previous phase-locking power levels by 3 orders of magnitude. Two relativistic magnetrons interact directly through a short waveguide of length l about n lambda/2 to allow locking. Power-density enhancement due to source coherence is directly measured in the radiation field. Phase locking occurs in about 5 ns and is reproducible. Extension to 10-100 GW appears feasible with arrays of oscillators.

Benford, J.; Sze, H.; Woo, W.; Smith, R. R.; Harteneck, B.

1989-02-01

363

Chevron bunionectomy with microplate and screw fixation: a retrospective follow-up of 26 feet.  

PubMed

The authors report the results of 21 patients (26 feet) who had Chevron osteotomy of the first metatarsal head to correct hallux valgus. Fixation was achieved by using a small plating system consisting of one L-plate (8.5 mm x 17 mm x 0.8 mm) and four screws (1.6 mm). Results showed no capital fragment displacement, avascular necrosis, or plate deformation. One case of screw loosening was noted on x-rays. This patient noted occasional irritation over the plate while wearing shoes. Symptoms did not cause the patient to seek removal of the plate and screws. The small plate system allows the surgeon to perform the osteotomy as originally described by Austin, with the added security of rigid internal fixation. PMID:8986891

Yearian, P R; Brown, T; Goldman, F

1996-01-01

364

Plate position and angular stability: mechanical comparison in sawbone osteotomy models.  

PubMed

Proximal metatarsal osteotomies are inherently unstable and difficult to fix. The purpose of this study was to compare the mechanical stiffness in sawbone models of medially versus dorsally placed plates and then to compare semilocked versus nonlocked plates in different osteotomy configurations. Thirty sawbone models were constructed, fixed either with titanium self-locking or steel mini-fragment plates. They were divided in groups and their stiffness was measured. The stiffness of any model fixed with medial titanium or steel plates was on average 158% and 228% greater, respectively, compared to dorsal plates. Adding a dorsal shelf of bone to a proximal closing wedge osteotomy increases its stiffness. Using locked plates increased the mechanical stiffness in only one configuration. The article suggests that models fixed with medial plates have greater resistance to failure than models fixed with dorsal plates. Using locked plates does not increase the mechanical stiffness of the construct. PMID:24063797

Wagner, Emilio; Ortiz, Cristian; Keller, Andres; Verschae, Gregorio; Wagner, Pablo; Gould, John S

2013-01-01

365

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

366

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

367

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.

Walraven, Carla J.

2013-01-01

368

Bit-synchronizer lock detector  

NASA Technical Reports Server (NTRS)

Circuit measures phase error that exists in phase-locked loop between clock signal recorded in data on magnetic tape and reconstructed clock signal. Circuit presents error as digital word that can be compared with predetermined threshold to indicate lock status. With simple alterations, circuit can also be used as phase detector.

Huey, D. C.; Itri, B. A.

1978-01-01

369

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

370

Homodyne locking of a squeezer.  

PubMed

We report on the successful implementation of an approach to locking the frequencies of an optical parametric oscillator (OPO)-based squeezed-vacuum source and its driving laser. The technique allows the simultaneous measurement of the phase shifts induced by a cavity, which may be used for the purposes of frequency locking, as well as the simultaneous measurement of the sub-quantum-noise-limited (sub-QNL) phase quadrature output of the OPO. The homodyne locking technique is cheap, easy to implement, and has the distinct advantage that subsequent homodyne measurements are automatically phase locked. The homodyne locking technique is also unique in that it is a sub-QNL frequency discriminator. PMID:19684817

Heurs, M; Petersen, I R; James, M R; Huntington, E H

2009-08-15

371

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

372

49 CFR 236.766 - Locking, movable bridge.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

373

[Stable joint-bridging extension of malleolar dislocations and pilon fractures with the AO pinless external fixator].  

PubMed

The pinless external fixator, introduced into clinical practice for open tibial fractures, suggested itself for use as a traction substitute because of its pinless frame. The aim of this feasibility study was to replace the conventional calcaneal pin traction by a joint-bridging pinless fixator, inserted under local anesthesia. 10 patients with 6 malleolar dislocation fractures, 3 pilon tibial and 1 open distal tibial fracture were immobilised by a joint-bridging pinless fixator during 10.4 days (5-16 days) till swelling had subsided and definitive fracture treatment, consisting of plate fixation, took place. The implantation of the joint-bridging pinless fixator in local anaesthesia was well tolerated by all patients. This traction substitute offered good patient comfort and easy care. Although the provided stability was less than a conventional fixator, all patients were able to lift up their fractured extremity without pain. PMID:7960918

Babst, R; Renner, N; Rosso, R; Marx, A; Heberer, M; Regazzoni, P

1994-07-01

374

Stiffness characteristics of composite hybrid external fixators.  

PubMed

New composite hybrid fixators for fracture stabilization using single or multiple rings with monolateral bars and half-pin fixation may provide clinical advantages such as reduced bulk and easier skin access. However, the mechanical properties of these fixators are difficult to estimate from numerous design parameters. Addressing this problem the following research questions were asked: (1) Do composite hybrid fixators have similar stiffness properties to clinically proven triple-ring fixators; (2) How does the fixation mechanism affect the stiffness properties of external fixators, and, (3) Are there interferences between ring number and fixation method? An experimental study was done on simulated metaphyseal tibial fractures and stiffness of 12 fixators was measured for different loading conditions. The results showed that triple-ring fixators provide approximately 20% stiffer properties than double-ring and single-ring fixators. No influence of ring number on the AP bending properties was found and different fixation methods were associated with large differences in fixator stiffness, whereas significant interferences were found between ring number and fixation method. Although the mechanical properties investigated in the current study cannot predict directly the clinical performance of these fixators, the stiffness data provide useful information for making decisions regarding the treatment of fractures using external fixation. PMID:12461383

Windhagen, Henning; Glöckner, Roland; Bail, Hermann; Kolbeck, Stefan; Raschke, Michael

2002-12-01

375

Device and plate film batch permitting autoradiography  

Microsoft Academic Search

Available from the Commission of European Communities, Luxembourg. The ; invention relates to a device and to a plate film batch permitting ; autoradiographic recordings in the interior of containers enclosing a specific ; atmosphere. The device has a support capable to lodge the film batch between a ; sealing joint and a locking element. The batch consists of a

J. Removille; F. Schmit

1972-01-01

376

Mode locking the cell cycle  

NASA Astrophysics Data System (ADS)

A characteristic property of nonlinear oscillatory systems is their ability to mode lock to a periodic, external, driving signal. In an n:m mode-locked state, the driven system executes n oscillations to every m oscillations of the driving signal, with a constant phase relationship between the two oscillations. We investigate mode locking for a mathematical model of the cell cycle in budding yeast. We determine which variables are most effective in coupling an external stimulus to the cell cycle oscillator, and speculate about whether experiments are feasible and informative for this model organism.

Cross, Frederick R.; Siggia, Eric D.

2005-08-01

377

Molecular Biology of Nitrogen Fixation  

ERIC Educational Resources Information Center

Reports that as a result of our increasing knowledge of the molecular biology of nitrogen fixation it might eventually be possible to increase the biological production of nitrogenous fertilizer from atmospheric nitrogen. (GS)

Shanmugam, K. T.; Valentine, Raymond C.

1975-01-01

378

Polymeric Media for Tritium Fixation.  

National Technical Information Service (NTIS)

The synthesis and leach testing of several polymeric media for tritium fixation are presented. Tritiated bakelite, poly(acrylonitrile) and polystyrene successfully fixed tritium. Tritium leach rates at the tracer level appear to be negligible. Advantages ...

J. A. Franz L. L. Burger

1975-01-01

379

Assessment of biological nitrogen fixation  

Microsoft Academic Search

The four commonly used methods for measuring biological nitrogen fixation (BNF) in plants are: the total nitrogen difference (TND) method, acetylene reduction assay (ARA) technique, xylem-solute (or ureide production) method and the use of15N labelled compounds.

S. K. A. Danso

1995-01-01

380

Adapter Plate Assembly for Adjustable Mounting of Objects.  

National Technical Information Service (NTIS)

An adapter plate and two locking discs are together affixed to an optic table with machine screws or bolts threaded into a fixed array of internally threaded holes provided in the table surface. The adapter plate preferably has two, and preferably paralle...

R. S. Blackburn

1986-01-01

381

Molybdenum Trafficking for Nitrogen Fixation  

PubMed Central

The molybdenum nitrogenase is responsible for most biological nitrogen fixation, a prokaryotic metabolic process that determines the global biogeochemical cycles of nitrogen and carbon. Here we describe the trafficking of molybdenum for nitrogen fixation in the model diazotrophic bacterium Azotobacter vinelandii. The genes and proteins involved in molybdenum uptake, homeostasis, storage, regulation, and nitrogenase cofactor biosynthesis are reviewed. Molybdenum biochemistry in A. vinelandii reveals unexpected mechanisms and a new role for iron-sulfur clusters in the sequestration and delivery of molybdenum.

Hernandez, Jose A.; George, Simon J.; Rubio, Luis M.

2009-01-01

382

Plate Tectonics  

NSDL National Science Digital Library

In this activity students use data from underwater earthquakes to outline the location of plate boundaries. Data from the Northeast Pacific, eastern Equatorial Pacific, and North Atlantic are examined in more detail. Background information on plate tectonics is provided.

2002-01-01

383

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

384

Well tool locking system for staggered bore  

SciTech Connect

This patent describes a lock mandrel. It comprises: a locking key retainer sleeve; locking keys; a first set of windows in the locking key retainer sleeve, a locking sleeve slidably disposed within the locking key retainer sleeve, the locking sleeve being adapted to force the locking keys through the first set of windows; a longitudinally slidable no-go ring further comprising a split ring member adapted to circumferentially engage the locking sleeve and a unitary, outwardly extending locating dogs circumferentially spaced around the split ring member. The locking key retainer sleeve further comprising a second set of windows adapted to receive the locating dogs; and the locating dogs being further adapted to extend radially outward through the second set of windows.

Welch, W.R.

1990-10-16

385

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.

386

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

387

Operative treatment for volar plate avulsion fractures of the fingers.  

PubMed

We present our experience with 14 volar plate avulsion fractures of the fingers that were treated by excision or internal fixation and discuss the factors affecting the operative techniques and results. Fourteen cases were divided into two groups: the volar plate avulsions with excision (eight cases) and the volar plate avulsions with fixation (six). We compared clinical factors between fracture groups and between fixation methods. Fractures treated with fixation had the larger fragment, a shorter preoperative period, and the larger articular surface involvement than fractures treated with excision. Postoperative pain, average age, patients' satisfaction measured by VAS, DASH scores, grip, and pinch strength were not different between two groups. All fixated fractures healed and the time to union did not differ based on fixation method. The true size of the fracture fragment was larger than expected based on the X-ray and the fragments were usually rotated by pull of the volar plate or ligament. The size and shape of the avulsed fragment might be important factors to determine the treatment method, but the results after operation were not significantly different whether the fragment was excised or fixed. PMID:23892555

Lee, Sanglim; Jung, Eui Yub; Kim, Ji Yeong

2013-10-01

388

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.

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

2014-01-01

389

Assumed strain distributions for a finite strip plate bending element using Mindlin-Reissner plate theory  

NASA Technical Reports Server (NTRS)

A linear finite strip plate element based on Mindlin-Reissner plate theory is developed. The analysis is suitable for both thin and thick plates. In the formulation, new transverse shear strains are introduced and assumed constant in each two-node linear strip. The element stiffness matrix is explicitly formulated for efficient computation and computer implementation. Numerical results showing the efficiency and predictive capability of the element for the analysis of plates are presented for different support and loading conditions and a wide range of thicknesses. No sign of shear locking is observed with the newly developed element.

Chulya, Abhisak; Mullen, Robert L.

1989-01-01

390

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

391

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.

Foundation, Wgbh E.

2005-12-17

392

Nitrogen fixation (acetylene reduction) associated with duckweed (lemnaceae) mats.  

PubMed

Duckweed (Lemnaceae) mats in Texas and Florida were investigated, using the acetylene reduction assay, to determine whether nitrogen fixation occurred in these floating aquatic macrophyte communities. N(2)-fixing microorganisms were enumerated by plating or most-probable-number techniques, using appropriate N-free media. Results of the investigations indicated that substantial N(2)-fixation (C(2)H(2)) was associated with duckweed mats in Texas and Florida. Acetylene reduction values ranged from 1 to 18 mumol of C(2)H(4) g (dry weight) day for samples incubated aerobically in light. Dark N(2) fixation was always two- to fivefold lower. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea (7 to 10 muM) reduced acetylene reduction to levels intermediate between light and dark incubation. Acetylene reduction was generally greatest for samples incubated anaerobically in the light. It was estimated that 15 to 20% of the N requirement of the duckweed could be supplied through biological nitrogen fixation. N(2)-fixing heterotrophic bacteria (10 cells g [wet weight] and cyanobacteria (10 propagules g [wet weight] were associated with the duckweed mats. Azotobacter sp. was not detected in these investigations. One diazotrophic isolate was classified as Klebsiella. PMID:16345992

Zuberer, D A

1982-04-01

393

Pilon fractures: treatment with combined internal and external fixation.  

PubMed

The purpose of this study was to prospectively evaluate the use of limited internal fixation and the application of a hybrid external fixator (tensioned wires distally and 5.0 mm half pins proximally attached to a semicircular frame without crossing the ankle joint) in the treatment of severe distal tibia fractures. This technique involves accurate reduction and fixation of the intraarticular component through an incision based over a fracture site followed by stabilization of the metaphysis with the hybrid external fixator. We studied 26 patients 15-55 years of age who were followed for 8-36 months. All fractures were within 5 cm of the joint. Seventeen fractures were intraarticular, nine extraarticular, and six open. Eleven patients required bone grafting. The average time to healing was 4.2 months. Using clinically based criteria, there were 81% good and excellent results overall, 70.5% for the 17 intraarticular fractures, and 69% for Ruedi type III fractures. Complications included one superficial and one deep infection, one 10 degrees varus malunion, and three pin tract infections. This method yielded results comparable with previous studies while reducing the amount of soft tissue dissection necessary for the placement of large plates. Soft tissue complications were infrequent and the goals of early motion and fracture stability were not sacrificed. PMID:8308599

Tornetta, P; Weiner, L; Bergman, M; Watnik, N; Steuer, J; Kelley, M; Yang, E

1993-01-01

394

Endobutton technique for dynamic fixation of traumatic symphysis pubis disruption.  

PubMed

Plate fixation, the conventional treatment for traumatic symphysis pubis disruption, carries the risk of implant failure and demands extensive exposure. The goal of the present study was to evaluate the outcome of dynamic fixation with the Endobutton CL, which has a long successful record in anterior cruciate ligament reconstructions. Twenty-one APC-II injuries were treated from January 2006 to December 2009. The mean duration of follow-up was 23 months (18 to 26). All patients received Endobutton fixation. The incision length was 6.8 +/- 13 cm. The external blood loss was 106 +/- 15 mL. The average surgical time was 63 +/- 12 min. The symphysis distance after reduction was 4.1 +/- 1.2 mm. The symphysis distance at final visit was 4.2 +/- 1.2 mm. Loss of reduction was not significant during bone healing (p = 0.09). The Majeed scoring was excellent in 15 patients, good in 5 patients and fair in 1 patient. One malreduction was seen; there was no implant failure. Our results indicate that Endobutton fixation of the pubic symphysis might be used in the treatment of APC-II injuries. PMID:23547516

Chen, Linwei; Ouyang, Yuanming; Huang, Gao; Lu, Xiaolang; Ye, Xue-Shi; Hong, Jianjun

2013-02-01

395

Tibial plafond fractures: limited incision reduction with percutaneous fixation.  

PubMed

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

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

2007-01-01

396

Suitability of DCPs with screw locking elements to allow sufficient interfragmentary motion to promote secondary bone healing of osteoporotic fractures.  

PubMed

This paper analyses the suitability of a system comprising a Dynamic Compression Plate (DCP) and Screw Locking Elements (SLEs) to allow sufficient interfragmentary motion to promote secondary bone healing in osteoporotic fractures. Four fixation systems were mounted on bone-simulating reinforced epoxy bars filled with solid rigid polyurethane foam. Group 1, used for comparison purposes, represents a system comprised of a Locking Compression Plate (LCP) and eight locking screws. Groups 2 and 3 represent a system comprised of a DCP plate with eight cortical screws and two SLEs placed on the screws furthest from (group 2) and nearest to (group 3) the fracture. Group 4 represents the system comprised of a DCP plate with SLEs placed on all eight cortical screws. Cyclic compression tests of up to 10,000 load cycles were performed in order to determine the parameters of interest, namely the stiffnesses and the interfragmentary motion of the various configurations under consideration. Tukey's multiple comparison test was used to analyse the existence or otherwise of significant differences between the means of the groups. At 10,000 cycles, interfragmentary motion at the far cortex for group 2 was 0.60±0.04 mm and for group 3 0.59±0.03 mm (there being no significant differences: p=0.995). The mean interfragmentary motion at the far cortex of the LCP construct was 70% less than that of the two groups with 2SLEs (there being significant differences: p=1.1×10(-8)). In the case of group 4 this figure was 45% less than in groups 2 and 3 (there being significant differences: p=5.6×10(-6)). At 10,000 cycles, interfragmentary motion at the near cortex for group 2 was 0.24±0.06 mm and for group 3 0.24±0.03 mm (there being no significant differences: p=1.000). The mean interfragmentary motion at the near cortex of the LCP construct was 70.8% less than that of the two groups with 2SLEs (there being significant differences: p=0.011). In the case of group 4 this figure was 66.7% less than in groups 2 and 3 (there being significant differences: p=0.016). The mean stiffness at 10,000 cycles was 960±110 N mm(-1) for group 2 and 969±53 N mm(-1) for group 3 (there being no significant differences: p=1.000). For group 1 (the LCP construct) the mean stiffness at 10,000 cycles was 3144±446 N mm(-1), 3.25 times higher than that of groups 2 and 3 (there being significant differences: p=0.00002), and 1.6 times higher than that of the DCP+8SLEs construct (1944±408 N mm(-1), there being significant differences: p=0.007). It is concluded that using the DCP+2SLEs construct sufficient interfragmentary motion is ensured to promote secondary bone healing. However, if too many SLEs are used the result may be, as with the LCP, an excessively rigid system for callus formation. PMID:22998895

Cuadrado, A; Yánez, A; Carta, J A; Garcés, G

2013-06-01

397

Femoral Reconstruction Using External Fixation  

PubMed Central

Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD), limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD) and lateral distal femoral angle (LDFA) for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction.

Palatnik, Yevgeniy; Rozbruch, S. Robert

2011-01-01

398

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

Microsoft Academic Search

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

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

2010-01-01

399

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

PubMed

Locked intramedullary nailing and external fixation are alternatives for the stabilization of tibial shaft fractures. The goal of this study was to determine to what extent the mechanical conditions at the fracture site influence the healing process after unreamed tibial nailing compared to external fixation. A standardized tibial diastasis was stabilized with either a locked unreamed tibial nail or a monolateral fixator in a sheep model. Interfragmentary movements and ground reaction parameters were monitored in vivo throughout the healing period. After sacrifice, the tibiae were examined mechanically and histologically. Bending angles and axial torsion at the fracture site were larger in the nail group within the first five weeks post-operatively. Unlike the fixator group, the operated limb in the nail group did not return to full weight bearing during the treatment period. Mechanical and histomorphometrical observations showed significantly inferior bone healing in the nail group compared to the fixator group. In this study, unreamed nailing of a tibial diastasis did not provide rotational stability of the osteosynthesis and resulted in a significant delay in bone healing. PMID:15304281

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

2004-09-01

400

Locking tube removal and replacement tool and method in a reconstitutable fuel assembly  

SciTech Connect

This patent describes a reconstitutable fuel assembly including a top nozzle with an adapter plate having at least one passageway, at least one guide thimble with an upper end portion and an attaching structure having a hollow locking tube for releasably locking the upper end portion of the guide thimble within the passageway of the top nozzle adapter plate. A tool is described for removing the locking tube from its locking position, comprising: (a) an elongated inner hollow tubular force-transmitting member having upper and lower opposite ends, the force transmitting member being insertable at its lower end in the locking tube and including (i) an elongated inner tubular body having upper and lower ends, and (ii) a tubular extension having an upper end fixed to the lower end of the inner tubular body and extending therefrom in axial alignment therewith. An upper end portion of the tubular extension has a larger diameter than a lower end portion thereof so as to define a downwardly-facing shoulder on the tubular extension which abuts the locking tube when the lower end of the force-transmitting member is inserted therein; and (b) a force-receiving member fixedly attached to the upper end of the force-transmitting member.

Shallenberger, J.M.; Ferlan, S.J.

1987-02-03

401

A novel murine femoral segmental critical-sized defect model stabilized by plate osteosynthesis for bone tissue engineering purposes.  

PubMed

Mouse models are invaluable tools for mechanistic and efficacy studies of the healing process of large bone defects resulting in atrophic nonunions, a severe medical problem and a financial health-care-related burden. Models of atrophic nonunions are usually achieved by providing a highly stable biomechanical environment. For this purpose, external fixators have been investigated, but plate osteosynthesis, despite its high clinical relevance, has not yet been considered in mice. We hereby proposed and investigated the use of an internal osteosynthesis for stabilizing large bone defects. To this aim, a 3.5-mm-long segmental bone defect was induced in the mid-shaft of the femur using a Gigli saw and a jig. Bone fixation was performed using a titanium microlocking plate with four locking screws. The bone defect was either left empty or filled with a syngenic bone graft or filled with a coralline scaffold. Healing was monitored using radiographs. The healing process was further assessed using microcomputed tomography and histology 10 weeks after surgery. With the exception of one mouse that died during the surgical procedure, no complications were observed. A stable and reproducible bone fixation as well as a reproducible fixation of the implanted materials with full weight bearing was obtained in all animals tested. Nonunion was consistently observed in the group in which the defects were left empty. Bone union was obtained with the syngenic bone grafts, providing evidence that, although such defects were of critical size, bone healing was possible when the gold-standard material was used to fill the defect. Although new bone formation was greater in the coralline scaffold group than in the left-empty animal group, it remained limited and localized close to the bony edges, a consequence of the critical size of such bone defect. Our study established a reproducible, clinically relevant, femoral, atrophic nonunion, critical-sized defect, low morbidity mouse model. The present study was successful in designing and testing in a small animal model, a novel surgical method for the assessment of bone repair; this model has the potential to facilitate investigations of the molecular and cellular events involved in bone regeneration in load-bearing, segmental-bone defects. PMID:22953787

Manassero, Mathieu; Viateau, Véronique; Matthys, Romano; Deschepper, Mickael; Vallefuoco, Rosario; Bensidhoum, Morad; Petite, Hervé

2013-04-01

402

Cervical anterior transpedicular screw fixation. Part I: Study on morphological feasibility, indications, and technical prerequisites  

Microsoft Academic Search

Multilevel cervical spine procedures can challenge the stability of current anterior cervical screw-and-plate systems, particularly\\u000a in cases of severe three-column subaxial cervical spine injuries and multilevel plated reconstructions in osteoporotic bone.\\u000a Supplemental posterior instrumentation is therefore recommended to increase primary construct rigidity and diminish early\\u000a failure rates. The increasing number of successfully performed posterior cervical pedicle screw fixations have enabled

Heiko Koller; Axel Hempfing; Frank Acosta; Michael Fox; Armin Scheiter; Mark Tauber; Ulrich Holz; Herbert Resch; Wolfgang Hitzl

2008-01-01

403

Intertrochanteric fractures. The role of complications of fixation.  

PubMed

A review was made of 244 intertrochanteric fractures of the hip. The complications of fixation were examined; nail penetration, plate separation, or bending or breaking of the device. Factors associated with fewer such complications were (1) stable (noncomminuted) fractures, (2) nails that can accomodate to varus, (3) placement of the nail tip more than 10 mm from the subchondral cortex of the femoral head, (4) valgus reduction of the fracture, and (5) high osteoporosis grade (denoting less osteoporosis). Neither medial displacement osteotomy nor exact anatomic reduction of unstable fractures improved resuts. In most patients, complications of fixation did not adversely influence the clinical course measured in terms of altered walking capacity, need for secondary surgery, or residual hip pain. PMID:1115608

Laros, G S

1975-01-01

404

Self-reinforced bioabsorbable versus metallic fixation systems for metacarpal and phalangeal fractures: a biomechanical study.  

PubMed

Bioabsorbable fixation devices offer a useful option to treat small bone fractures of the hand if the prerequisite of reliable and stable osteofixation is met. We compared the stabilities of various bioabsorbable fixation devices with metallic fixation devices by using an oblique osteotomy model in radial to ulnar orientation. The 1.5-mm, self-reinforced, poly-L-lactide (SR-PLLA) pins provided fixation rigidity comparable with 1.5-mm K-wires in dorsal and palmar apex bending, whereas in lateral apex bending and in torsion the rigidity was equal to that of 1.25-mm K-wires. The 2.0-mm, self-reinforced, poly-L/DL-lactide (SR-P(L/DL)LA) 70/30 screws provided rigidity comparable with that of 1.5-mm K-wires in all testing modes. The bioabsorbable plate considerably enhanced the bending stabilities of the fixation system, but a single interfragmentary screw provided only limited rotational rigidity. The results show that by using ultra-high strength self-reinforced implants adequate fixation stability for hand fracture fixation can be achieved. PMID:12239683

Waris, Eero; Ashammakhi, Nureddin; Raatikainen, Timo; Törmälä, Pertti; Santavirta, Seppo; Konttinen, Yrjö T

2002-09-01

405

A new adhesive technique for internal fixation in midfacial surgery  

PubMed Central

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

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

2008-01-01

406

Autologous grafts of double-strut fibular cortical bone plate to treat the fractures and defects of distal femur: a case report and review of literature.  

PubMed

We reported a 23-year-old man who was involved in a high-speed motorcycle accident. He sustained a closed fracture at the right distal femur. The primary fracture happened on February 2008. He underwent open reduction and internal fixation with cloverleaf plate. And one hundred days after the surgery, the proximal screws were pulled-out, but the bone union was not achieved. Treatment consisted of exchanging the cloverleaf plate with a locking compression plate and using an auto-iliac bone graft to fill the nonunion gap. In July 2009, the patient had a sharp pain in the right lower limb. The X-ray revealed that the plate implanted last year was broken, causing a nonunion at the fracture site. Immediately the plate and screws were removed and an intramedullary nail was inserted reversely from the distal femur as well as a 7 cm long bone from the right fibula was extracted and longitudinally split into two pieces to construct cortical bone plates. Then we placed them laterally and medially to fracture site, drilled two holes respectively, and fastened them with suture. We carried on auto-iliac bone grafting with the nonunion bone grafts. The follow-up at 15 months after operation showed that the treatment was successful, X-ray confirmed that there was no rotation and no angular or short deformity. We briefly reviewed the literature regarding such an unusual presentation and discussed in details the possible etiology and the advantages of autologous double-strut fibular grafts to cope with such an intractable situation. PMID:21801670

Chen, Xu; Li, Jian-Jun; Kong, Zhan; Yang, Dong-Xiang; Yuan, Xiang-Nan

2011-01-01

407

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.

2014-01-01

408

Kerr-lens mode locking without dispersion compensation  

SciTech Connect

We propose and theoretically investigate a novel operating regime of femtosecond Kerr-lens mode-locked solid-state lasers that avoids group-velocity dispersion compensation by use of a nonresonant semiconductor plate in the focused resonator section that provides an overall negative nonlinear refractive index per round trip. The saturable loss of the laser resonator with an effective self-defocusing nonlinearity is derived from a generalized {ital ABCD} matrix formalism, and the correspondingly calculated steady-state pulse parameters show that a Kerr-lens mode-locked laser with an overall negative nonlinear refractive index generates stable femtosecond pulses without any dispersion compensation. {copyright} {ital 1996 Optical Society of America.}

Gatz, S.; Herrmann, J.; Mueller, M. [Max Born Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin (Germany)

1996-10-01

409

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

410

Homogeneous redox catalysis on co(2) fixation.  

National Technical Information Service (NTIS)

The twin problems of global warming and diminishing finite fossil fuels resources have stimulated research into CO2 fixation and utilization. Natural photosynthetic CO2 fixation utilizes sunlight and chlorophyll as the energy source and photocatalyst to g...

E. Fujita

2000-01-01

411

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

PubMed Central

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

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

2013-01-01

412