Sample records for hybrid external fixator


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    Nageshwara Rao


    Full Text Available AIMS AND OBJECTIVES: Distal tibial fractures represent a significant challenge to orthopaedicians . The low energy fractures get dramatic results with open reduction and internal fixation. But high energy fractures have a high amount of complications due to soft tissue coverage, skin necrosis, infections and also the usually comminuted nature of the fr actures. Conservative treatment by cast application leads to prolonged immobilization, ankle and knee stiffness affecting quality of life of the patient. The Hybrid External Fixator combines the advantages of the monolateral pin fixators and the circular I lizarov wire fixators. The tensioned wires provide improved fixation in the small distal cancellous fragment, as they have rapid and straight forward application, reduced surgical time and is minimally invasive. It is adjustable, hence reduction can be eas ily attained after frame assembly. With rigid fixation it also allows immediate mobilization of the knee and ankle joints and early weight bearing. Aim of this present study is to study and establish the results and functional outcome in surgical treatment of distal metaphyseal fractures of Tibia using a Hybrid External Fixator. MATRIALS AND METHODS: 25 patients with distal tibial metaphyseal fractures were studied from June 2010 to July 2012 in department of Orthopaedics, Government General Hospital, Kurno ol and followed up for a period of 6 - 10 months. Ovadia and Beals 1 scoring system of objective and subjective evaluation was used in this study to assess the results. RESULTS: All the fractures consolidated with average of 13 weeks. All the studied fracture s resulted in good union. Three of the 5 compound fractures and 2 of the 20 simple fractures developed pin tract infections. Twelve patients had ankle stiffness from 20 - 90% of total ankle movement. Two cases had a malunion with an anterior angulation of 5 degrees but had a good ankle function. At 6 months, results were based on

  2. Emergent and delayed hybrid external fixation management of tibial pilon fractures: A multicentric retrospective analysis of 80 patients

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    Giuseppe Rollo


    Full Text Available Objective: To report our experience with the hybrid external fixator in emergency. Methods:We assessed 80 cases of pilon fracture treated with the external fixator during the period of January 2009 and December 2016:55 men (69% and 30 women (33% with a mean age of 40 years (range between 16 and 70 . About 45 occurred as isolated trauma, 35 instead were politrauma. Each patient underwent standard radiographic examination and a CT examination. There were 28 open fractures (35%, (Gustilo type 1, 2 and 3 while closed fractures showed soft tissue involvement of various grade (2-3 Tscherne classification. In all cases, the external fixation, sometimes associated with other reduction and synthesis techniques, was used. The timing of surgery was dictated by the condition of the soft tissues. For clinical evaluation, the Mazur score with mean follow-ups at 12 months was utilized. Results: The final range of ankle motion was 15° dorsal and 10 plantar flexion. In about 80 cases there was an average Mazur score of83. The mean score was 90; in open fractures 85 to 72. Radiographic healing of fractures in 60 patients occurred in 120 days (mean 105 days, at the time when the external fixator was removed. Conclusion: Pilon fractures are complex and often present complications; the definitive treatment, in emergency or delayed, with hybrid external fixator permits a stable synthesis with minimal soft tissue damage. Weight bearing maybe allowed early and functional recovery is generally good.

  3. The accuracy of fine wire tensioners: a comparison of five tensioners used in hybrid and ring external fixation. (United States)

    Roberts, Craig S; Antoci, Valentin; Antoci, Valentin; Voor, Michael J


    To compare the accuracy of 5 commonly available fine wire tensioners used in hybrid and ring external fixation. A laboratory investigation. The testing of 5 commonly available tensioners was performed with a servohydraulic test frame (MTS Bionix 858, Minneapolis, MN). The real wire tension data of each tensioner provided by the MTS were compared with corresponding nominal values. The percent error for each tensioner was calculated. Clinical ease of usage of the wire tensioners was also evaluated. The EBI tensioner was the most accurate (-0.17% to 0.09% error). The Smith and Nephew tensioner had a -13.97% to -8.61% error, the How medica tensioner a -12.48% to -10.86% error, and the Synthes tensioner a -0.2% to 24.28% error. The DePuyACE tensioner was the least accurate, with errors ranging from -36.76% to -30.92%. The Howmedica tensioner was the easiest to use, followed by the Smith and Nephew tensioner, the DePuyACE tensioner, the Synthes tensioner, and the EBI tensioner. Most commonly available tensioners tend to undertension. Future efforts should focus on the development of wire tensioners that combine accuracy and ease of usage.

  4. Stabilization of juxta-physeal distal tibial and fibular fractures in a juvenile tiger using a hybrid circular-linear external fixator. (United States)

    Coomer, Alastair R; Lewis, Daniel D; Wiedner, Ellen; Isaza, Ramiro; Winter, Matthew D; Aloisio, Fabio; Pool, Roy


    To report stabilization of closed, comminuted distal metaphyseal transverse fractures of the left tibia and fibula in a tiger using a hybrid circular-linear external skeletal fixator. Clinical report. Juvenile tiger (15 months, 90 kg). From imaging studies, the tiger had comminuted distal metaphyseal transverse fractures of the left tibia and fibula, with mild caudolateral displacement and moderate compression. Multiple fissures extended from the fractures through the distal metaphyses, extending toward, but not involving the distal tibial and fibular physes. A hybrid circular-linear external skeletal fixator was applied by closed reduction, to stabilize the fractures. The fractures healed and the fixator was removed 5 weeks after stabilization. Limb length and alignment were similar to the normal contralateral limb at hospital discharge, 8 weeks after surgery. Two weeks later, the tiger had fractures of the right tibia and fibula and was euthanatized. Necropsy confirmed pathologic fractures ascribed to copper deficiency. Closed application of the hybrid construct provided sufficient stability to allow this 90 kg tiger's juxta-articular fractures to heal with minimal complications and without disrupting growth from the adjacent physes. © Copyright 2011 by The American College of Veterinary Surgeons.

  5. Bicondylar tibial fractures: Internal or external fixation?

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    Gunasekaran Kumar


    Full Text Available 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.

  6. Flexible fixation and fracture healing: do locked plating 'internal fixators' resemble external fixators? (United States)

    Schmal, Hagen; Strohm, Peter C; Jaeger, Martin; Südkamp, Norbert P


    External and internal fixators use bone screws that are locked to a plate or bar to prevent periosteal compression and associated impairment of blood supply. Both osteosynthesis techniques rely on secondary bone healing with callus formation with the exception of compression plating of simple, noncomminuted fractures. External fixation uses external bars for stabilization, whereas internal fixation is realized by subcutaneous placement of locking plates. Both of these "biologic" osteosynthesis methods allow a minimally invasive approach and do not compromise fracture hematoma and periosteal blood supply. Despite these similarities, differences between the two fixation methods prevail. Locked plating "internal fixators" allow a combination of biomechanical principles such as buttressing and dynamic compression. Periarticular locking plates are anatomically contoured to facilitate fixation of articular fractures. They allow for subchondral stabilization using small-diameter angular stable screws as well as buttressing of the joint and the metaphyseal component of a fracture. Biomechanically, they can be far stiffer than external fixators, because subcutaneous plates are located much closer to the bone surface than external fixator bars. External fixators have the advantage of being less expensive, highly flexible, and technically less demanding. They remain an integral part of orthopaedic surgery for emergent stabilization, for pediatric fractures, for definitive osteosynthesis in certain indications such as distal radius fractures, and for callus distraction.

  7. Comparison of Outcomes of Operatively Treated Bicondylar Tibial Plateau Fractures by External Fixation and Internal Fixation

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    CC Chan


    Full Text Available The outcome of bicondylar tibial plateau fractures treated with either external fixation (35 patients or internal fixation (24 patients was reviewed. Outcome measures included the Rasmussen score, clinical complications, development of osteoarthritis and the requirement for total knee replacement (TKR. Twenty-two (92% anatomical reductions were achieved in the internal fixation group compared to 27 (77% in the external fixation group. Infective complications were more common in the external fixation group (9 patients, 26% due to pin tract infection. There were no deep infections in the internal fixation group. The mean Rasmussen score was not significantly different (mean score 32 in external fixation and 29 in internal fixation between the two groups and the incidence of osteoarthritis was the same in both groups. Four patients in the external fixation group underwent a TKR compared to 5 patients in the internal fixation group. Bicondylar tibial plateau fractures have similar outcomes following external or internal fixation.

  8. [Improvement of Hoffmann external fixation apparatus]. (United States)

    Niimura, T


    The resurgence of external fixators for the management of skeletal and joint injuries has generated an increasing number of reports. In addition, many types of fixators have been developed in the last ten years. Of these, the Hoffmann external fixator is the most popular one. Is it possible for the patient with a tibial comminuted fracture to walk with the fixator? This study has been pursued to investigate this question and to improve on the fixator. Bone models were made from tubed polyester resin strengthened by glass fiber (elastic module: 9.46 kg/mm2, outside diameter: 35 mm, inside diameter: 30 mm). Each bone model was transfixed by two Steinmann pins (phi: 4.5 mm) with 43 mm between, and a pair of models was framed with two straight bars, with 30 mm from model to bar. The Steinmann pins and straight bars were connected to each attachment. The experiment focused on four main studies: Measurement of the Young's modulus of the Steinmann pin. Compression load test and bending load test framed bone models with each attachment. Observation and measurement of the ground reaction force of ambulation on stilt framed with experimental external fixator. Determination of S-N curve of the Steinmann pin. Results were as follows: The Young's modulus of the Steinmann pin were 1.8 X 10(4) kg/mm2. 0.2% proof of the pin was 110 kg/mm2. The bone models framed with the conventional method were destructed at the universal ball joint at 68 kgf in the compression load test, and 6.8 kgf in the bending load test. The models framed with the conventional method fitted with spring washers at ball joints were not destructed until 203 kgf in compression load, but after several trials the spring washers were crushed. The models fabricated by using a vice with rods and articulation coupling were not damaged until 210 kgf in compression load and were not damaged until 15 kgf in bending load even after several trials. The displacement between the models were 2.8 mm at 80 kgf and 8.5 mm at 210

  9. LCP external fixation--external application of an internal fixator: two cases and a review of the literature. (United States)

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


    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.

  10. 21 CFR 878.3250 - External facial fracture fixation appliance. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External facial fracture fixation appliance. (a) Identification. An external facial fracture fixation...

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


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


    Abstract 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...

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

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    Wong Merng-Koon


    Full Text Available Abstract 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.

  13. LCP external fixation - External application of an internal fixator: two cases and a review of the literature (United States)


    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

  14. VAC® for external fixation of flail chest

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    Rikke Winge


    Full Text Available A large anterior chest wall defect following tumor resection was reconstructed with a Gore- Tex® membrane and a combined musculocutaneous rectus femoris and tensor fasciae latae free flap. Subsequent paradoxical respiration impeded weaning from the ventilator. Appliance of Vacuum Assisted Closure® (VAC® resulted in immediate chest wall stability and a decrease in the patient’s need for respiratory support. Shortly thereafter, the VAC® was discontinued and the patient was discharged from the intensive care unit (ICU. This case report is the first to describe the successful use of VAC® as an adjuvant to a one-stage procedure for large thoracic wall reconstruction, allowing sufficient temporary external fixation to eliminate paradoxical respiration and plausibly shorten the stay in the ICU. No adverse effects on flap healing or haemodynamics were recorded. It is likely that external VAC® can improve thoracic stability and pulmonary function in a patient with flail chest and decrease the need for mechanical ventilation.

  15. Use of a small bilateral external fixator for ankle fusion. (United States)

    Schoenhaus, Harold D; Lam, Steven; Treaster, Amber; Troiano, Michael


    A variety of methods are available for surgeons to use in an effort to achieve fusion ankle arthrodesis. Among these, external fixation devices have proven to be effective. In this article, we describe the use of a small external fixation frame that is affixed to the medial and lateral aspects of transfixation pins, and used to compress the arthrodesis interface.

  16. External skeletal fixation of the tibial shaft fractures

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    Milenković Saša


    Full Text Available Aim. To present the possibility of a successful use of external skeletal fixation in treating the open and closed tibial shaft fractures with Mitković’s external fixator. Methods. External fixation was used in 115 patients with 118 fresh tibial shaft fractures, 82 males (71.3% and 33 females (28.7%, average age 43.92 years (16−84. Open tibial shaft fractures were present in 37 (31.36%. All the fractures were treated with Mitković’s external fixator type M 20. Results. The results of external fixation were excellent or good in 94.07% of the cases, and bad in 5.08%. Pin tract infection appeared in 7 (5.93% patients. In only 3 cases an external fixator was removed and treatment continued with the functional braces. Nonunion occurred in 6 (5.08% patients, of which 4 were with open fractures (2 Gustilo type IIIB, 1 Gustilo type IIIA, 1 Gustilo type II and 2 with the segment fractures. Compartment syndrome was observed in 1 (0.85% patient with closed fracture. Malunion was found in 2 (1.69% patients. Conclusion. External fixation of tibial shaft fractures is a simple and effective method to enable the safe healing of fractures, early mobilization of the patients, early weight-bearing, as well as early rehabilitation. Fixation of tibial shaft fractures was unilateral with convergent pins orientation, and there was also a possibility of compression and distraction.

  17. Monitoring in vivo load transmission through an external fixator. (United States)

    Grasa, J; Gómez-Benito, M J; González-Torres, L A; Asiaín, D; Quero, F; García-Aznar, J M


    This work presents a portable non-invasive external fixator to assess and monitor fracture healing in real time. To evaluate the potential of this fixator, a transverse osteotomy was performed in the tibia of six adult sheep (mean age 3+/-0.5 years and weight 63+/-5 kg). The fractures were stabilized by a specially designed unilateral external fixator, which was instrumented by means of a set of strain gauges. Strains in the external surface of the fixator were monitored during all the healing process. A wireless, remote monitoring of the implant was developed through a specially designed external telemetric device. The strain gauges were arranged in two different half-bridge Wheatstone configurations, allowing easy post-processing of the signal. Thus, bending loads were measured in two planes of the external fixator acting as a load cell. The load through the fixator was evaluated for the gait cycle during all the healing process. Full weight bearing of the injured leg was observed from the beginning. The load transmission mechanism in the fixator was quite similar in all operated tibias and radiographic images showed a successful healing in all animals. Although the fixator has only been tested in an animal model, after further testing this system may have clinical potential.

  18. Complex femur fractures in children: treatment with external fixation. (United States)

    Kirschenbaum, D; Albert, M C; Robertson, W W; Davidson, R S


    External fixation was used to treat complex femur fractures in 10 children. These injuries were associated with head trauma, cerebral palsy, epidermolysis bullosa, open wounds, and failed casting. The duration of external fixation averaged 8 weeks, and the mean follow-up was 5 years 8 months. At follow-up, one patient had 2.6 cm of residual shortening, and two had overgrowth. Complications included one refracture. Three children developed superficial pin site drainage. Although most femur fractures can be treated with traction or casting, external fixation may simplify overall care in children with multiple injuries and is effective in controlling unacceptable femoral shortening and angulation.

  19. Hexapod External Fixation of Tibia Fractures in Children. (United States)

    Iobst, Christopher A


    Most tibia fractures in children can be treated nonoperatively. For fractures that do require surgery, however, the most common methods of management include plating or flexible nail insertion. Some fracture patterns, such as periphyseal fractures, fractures with bone and/or soft tissue loss, or fractures with delayed presentation, are not easily amenable to these techniques. Hexapod external fixators are especially helpful in these difficult cases. The purpose of this review is to discuss the principles of performing hexapod circular external fixation applied to pediatric tibia fractures. Some of the additional capabilities of the hexapod external fixator will also be highlighted.

  20. Hybrid Fixation for Ankle Fusion in Diabetic Charcot Arthropathy. (United States)

    El-Mowafi, Hani; Abulsaad, Mazen; Kandil, Yasser; El-Hawary, Ahmed; Ali, Samer


    Ankle fusion is difficult to achieve in the diabetic Charcot ankle Brodsky type 3a because of the poor quality of the bone and the inability to achieve a stable biomechanical construct. The aim of this study was to report the outcome of ankle fusion using a combination of an intramedullary nail and a circular external fixator in patients with diabetic Charcot arthropathy. We prospectively studied 24 patients with diabetic Charcot arthropathy of the ankle who were treated by fusion of the tibiotalar joint using a combined retrograde intramedullary nail and Ilizarov external fixator. Their mean age was 50.7 ± 6.9 (range, 43-62) years. The mean follow-up after surgery was 36.4 ± 5.8 (range, 24-98) months. Twenty-two patients (92%) achieved clinical and radiographic solid bony fusion. No patients in this series needed amputation. All the patients were pain free, and the mean American Orthopaedic Foot and Ankle Society Score (AOFAS) improved significantly from 34.6 ± 6.8 to 66.4 ± 4.5 at the last follow-up. Two patients developed an ulcer over the heel due to a prominent nail. The ulcer healed after nail removal. Eight patients developed pin tract infection. We report a successful outcomes of ankle fusions using combined intramedullary nail locked only proximally and ring external fixator (hybrid fixation) in patients with diabetic Charcot arthropathy. Level IV, case series.

  1. Flexible external fixation for craniodorsal coxofemoral luxations in dogs. (United States)

    McLaughlin, R M; Tillson, D M


    An external fixator consisting of two Ellis pins connected by a flexible band was developed and evaluated as a treatment for craniodorsal coxofemoral luxations in dogs. The technique for closed application of the fixator without injury to the coxofemoral joint or sciatic nerve was developed in six dog cadavers. The coxofemoral joints were then surgically destabilized and the limbs were manipulated through a full range of motion to assess the efficacy of the fixator in maintaining joint reduction. The fixator maintained joint reduction and stability after a surgically created craniodorsal luxation except when the femur was externally rotated 90 degrees. A flexible external fixator was then applied unilaterally in four healthy dogs. The dogs tolerated the fixator well and were bearing weight on the limb within 2 days after surgery; the range of motion was not limited by the fixator. The efficacy of a flexible external fixator in maintaining joint reduction after craniodorsal coxofemoral luxation was then evaluated in eight large dogs. The right coxofemoral joint in each dog was luxated surgically by removal of the dorsal joint capsule and transection of the ligament of the head of the femur and deep gluteal muscle. The joint was reduced and the fixator pins were applied in a closed fashion. In four dogs, a flexible external band was applied to the pins. Luxation did not reccur in these four dogs. The bands were not applied initially in four control dogs. Luxation occurred in three of the four control dogs within 24 hours of surgery. The joints that luxated were reduced and the flexible bands applied. Luxation did not recur after the bands were in place. The dogs tolerated the external fixators well, were bearing weight within 2 days of surgery, and walking with only minimal lameness 5 days after surgery. Luxation of the coxofemoral joints did not occur during the 2-week period in which the fixators were in place. The joints remained stable 1 week after removal of the

  2. Femoral fractures : indications an[d] biomechanics of external fixation

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    A.H. Broekhuizen (Tom); B. van Linge


    textabstractInternal fixation can be carried out in various ways. For femoral shaft fractures, an (interlocking) nail is becoming increasingly popular, instead of open realignment of the fracture. External fixation, which has become a generally accepted method of treating fractures of the lower

  3. Pin tract infection with external fixation of pediatric fractures. (United States)

    Schalamon, Johannes; Petnehazy, Thomas; Ainoedhofer, Herwig; Zwick, Ernst B; Singer, Georg; Hoellwarth, Michael E


    This study aimed to evaluate the incidence and severity of pin tract infections in a series of pediatric trauma patients. All pediatric trauma patients with external fixation who were treated at our institution between 1998 and 2003 were included. The charts of 30 children (20 males; 10 females; mean age, 13.2 years; range, 7-19 years) with 37 episodes of external fixation were reviewed. The average duration of external fixation was 17.5 weeks (range, 1-94 weeks). Pin tract infections were graded using the Dahl classification. Bacterial cultures were obtained in case of drainage from the pin site. In 18 (48%) of 37 external fixations, no signs of infection occurred during the treatment period. In the remaining 19 (52%) external fixations, 35 episodes of infection were documented. Most infections were mild or moderate, whereas only 3 (9%) severe deep infections were noted (grade 5). Six (17%) infections healed with local application of rifamycin, whereas 27 (77%) of 35 infections were successfully treated with systemic antibiotics (cefuroxime, clindamycin). The remaining 2 infections (6%) required removal of a pin. Pin tract infection occurred in half of the patients who were treated with external fixations. Most of the pin site infections in the present series were mild and could be managed by local or systemic application of antibiotics. The occurrence of pin tract infections did not require a change of the method of stabilization.


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    Prasanth Maddila


    Full Text Available BACKGROUND Open fractures which occur close to any fracture need immobilisation for the soft tissues to heal. Some open fractures are even fixed with provisional fixations to maintain the alignment of the fractures. The provisional fixation needs to be augmented with external support, which can be given by spanning external fixators across a joint. MATERIALS AND METHODS Our study consists of 38 open fractures of the lower limbs, which are of Gustilo-Anderson’s type IIIB, an MT4 of AO-ASIF soft tissue injury classification essentially requiring open wound management as well as fracture fixation. Wound lavage and debridements are carried out till the soft tissues show granulations. The position in which joint is immobilised is functional and with access to open wound for dressings and inspection without any displacement of the fracture as well as creeping granulation tissue. RESULTS All the cases in our study are maintained with functional position till soft tissue cover is achieved and provisional fixation is done with definitive fixation after soft tissue cover with skin grafting. CONCLUSION Spanning external fixators are useful in maintaining functional positions as well as augmenting the provisional fixation of the compound fractures.

  5. Gustilo grade IIIB tibial fractures requiring microvascular free flaps: external fixation versus intramedullary rod fixation. (United States)

    Rohde, Christine; Greives, Matthew R; Cetrulo, Curtis; Lerman, Oren Z; Levine, Jamie P; Hazen, Alexes


    Gustilo IIIB fractures involve high-energy tibial fractures for which there is inadequate soft tissue coverage. In addition to orthopedic fixation, these injuries require soft tissue reconstruction, often in the form of a microvascular free flap. Although the majority of orthopedic literature favorably compares intramedullary rod fixation to external fixation in open tibial fractures, these studies have not focused on the role of either method of fixation in relation to the soft tissue reconstruction. Because we had noted numerous complications after providing free-flap coverage over intramedullary rodded fractures, we sought to investigate whether there were differences in outcomes between free flap-covered lower-extremity fractures which were fixated by external fixation versus intramedullary rods. A retrospective chart review was performed on all patients in our institution who had lower-extremity free flaps for coverage of Gustilo IIIB fractures from 1995-2005 in relation to the type of bony fixation. Of the 38 patients studied, 18 underwent external fixation of the tibial fracture, and 20 had intramedullary rodding. Overall flap survival was 95%, with 1 failure in each group. However, the intramedullary rod group had higher incidences of wound infection, osteomyelitis, and bony nonunion (25%, 25%, and 40%, respectively) than the external fixation group (6%, 11%, 17%, respectively). For Gustilo IIIB fractures that require free-flap coverage, the added bony and soft tissue manipulation required for intramedullary rodding may disrupt the surrounding blood supply and lead to higher rates of complications that threaten the overall success of the reconstruction. Plastic and orthopedic surgeons should discuss the optimal method of bony fixation for complex tibial fractures when a free flap will likely be needed for soft tissue coverage. This integrated team approach may help minimize complications.

  6. Prevention of Thumb Web Space Contracture With Multiplanar External Fixation. (United States)

    Harper, Carl M; Iorio, Matthew L


    Thumb web space contracture following hand trauma can be disabling with numerous reconstructive procedures existing to correct the resultant deformity. Following marked soft tissue injury to the hand we utilized the Stryker Hoffmann II Micro External Fixator System to link the first and second metacarpals by a multiplanar system using 1.6 or 2.0 mm self-drilling half-pins and 3 mm carbon fiber connecting rods. This facilitated placement of the thumb in maximal palmar abduction as well as allowed adjustment of thumb position throughout the postoperative period. This technique was performed on 5 patients. Two patients were treated with a first web space external fixator for table saw injuries to the radial aspect of the hand. An additional 2 patients were treated with a first web space external fixator following metacarpophalangeal joint capsular release in the setting of thermal burns. A fifth patient underwent second ray amputation, trapeziectomy and trapezoidectomy for squamous cell carcinoma with subsequent stabilization with the external fixator. The external fixator was left in place until soft tissues were healed (average 5.5 wk). The patients were allowed to mobilize their hand in as much as the external fixator allowed, and no device-associated complications were noted. Thumb web space was preserved with passive and supple thumb circumduction and web space abduction/adduction in all patients at an average follow-up of 5 months. The average Quick Dash Score was 35±5 and the average Modern Activity Subjective Survey of 2007 was 30±8.

  7. External fixation in HIV-positive

    African Journals Online (AJOL)

    Introduction. Open fractures may be complicated by sepsis and septic non- union. Septic complications markedly increase patient morbidity and treatment costs. Thorough debridement and external fixation to achieve bony stability is an accepted approach to management. Septic outcome in HIV positive patients has been ...

  8. Rigidity of unilateral external fixators - A biomechanical study

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    P.T.P.W. Burgers (Paul); M.P.J.M. Riel (Marcel); L.M.M. Vogels (Lucas); R.W. Stam (Ronald); P. Patka (Peter); E.M.M. van Lieshout (Esther)


    textabstractIntroduction: External fixation is the primary choice of temporary fracture stabilisation for specific polytrauma patients. Adequate initial fracture healing requires sufficient stability at the fracture site. The purpose of this study was to compare the rigidity of the Dynafix

  9. Open segmental fractures of the tibia treated by external fixation

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    Golubović Ivan


    Full Text Available Introduction. Open segmental fractures of the tibia are rare but severe injuries. In these fractures the wide zone of injury (damage of all structures of the lower leg creates very unsuitable biological conditions for healing of the fracture. Objective. The aim of our work was to present the results of treatment of patients with segmental open fractures of the tibia treated by external fixation. Methods. We analyzed treatment results of 21 patients with open segmental tibial fractures who were treated using the method of external fixation at the Clinical Center Niš from January 1, 1995 to July 31, 2010. The average age of the patients was 53 years; the youngest patient was 27 years and the oldest one 80 years. According to the Gustilo open fracture classification, there were 3 (14.3% type I, 6 (28.6% type II, 8 (38.1% type IIIA, and 4 (19.0% type IIIB. All the patients were treated by a unilateral type Mitković external fixator by Traffix Company. Results. Union was attained in 16 (76.2% fractures without severe complications (pseudoarthrosis, chronic osteitis and angular deformities of over 10 degrees. Among severe complications associated with open segmental tibial fractures, in two cases we registered septic pseudoarthrosis, in one aseptic pseudoarthrosis and in two large angular deformities of the tibia after union, with a valgus of over 10 degrees and extremity shortening of over 2 cm which required additional surgery. Conclusion. External fixation by the use of Mitković external fixator is one of the methods of choice in the treatment of open segmental tibial fractures, which incorporated with antibiotic therapy provides good biomehanical conditions for segmental fracture healing that enables good stability of the segmental tibial fracture and decreases the risk of deep infections. [Projekat Ministarstva nauke Republike Srbije, br. 41017: Virtuelni koštano­zglobni sistem čoveka i njegova primena u pretkliničkoj i kliničkoj praksi

  10. Results of application of external fixation with different types of fixators

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    Grubor Predrag


    Full Text Available Introduction. Extra-focal or external fixation is the method of fracture fixation through the healthy part of the bone using pins or wires. Objective. The aim was to determine which external splints (Ortofix, Mitković, Charnley and Ilizarov had the best biomechanical properties in primary stabilization of spiral, transverse and commutative bone fractures. Methods. To determine the investigation methodology of biomechanical characteristics of the external fixator we used mathematical and computer simulator (software, juvidur physical model and clinical examination. Results. Values of advancing fragments in millimetres obtained by the study of mathematical and computer simulator (software: Charnley - 0.080 mm, Mitković M 20 - 0.785 mm, Ilizarov - 2.245 mm and Ortofix - 1.400 mm. In testing the juvidur model the following values were obtained: the external fixator Mitković M20 - 1.380 mm, Ortofix - 1.470 mm, Ilizarov - 2.410 mm, and Charnley - 2.510 mm. Clinical research of biomechanical characteristics of the effect of vertical force yielded the following results: Mitković M20 - 0.89 mm, Ortofix - 0.14 mm, Charnley - 0.80 mm and Ilizarov - 1.23 mm. Conclusion. When determining the total number of the stability test splints under the effect of vertical force (compression and force effect in antero-posterior, later-lateral plane of cross, spiral and comminuted long bone fractures, the best unified biomechanical stability was shown by the following external fixators: firstly, Mitković M20 (0.93mm, secondly, Charnley fixator (1.14 mm, thirdly, Ortofix (1.22 mm, and fourthly, Ilizarov (1.60 mm.

  11. Treatment of Gustilo grade III leg fractures by external fixation associated with limited internal fixation. (United States)

    Zhang, Chun-qiang; Zheng, Hong-yu; Wang, Bing; Huang, He; He, Fei; Zhao, Xue-ling


    To explore the clinical effects of external fixation associated with limited internal fixation on treatment of Gustilo grade III leg fractures. From July 2006 to December 2008, 40 cases of Gustilo grade III leg fractures were emergently treated in our unit with external fixation frames. Soft tissue injuries were grouped according to the Gustilo classification as IIIA in 17 cases, IIIB in 13 cases, and IIIC in 10 cases. All the patients were debrided within 8 hours, and then fracture reposition was preformed to reestablish the leg alignment. Limited internal fixation with plates and screws were performed on all the Gustilo IIIA cases and 10 Gustilo IIIB cases at the first operation. But all the Gustilo IIIC cases and 3 Gustilo IIIB cases who had severe soft tissue injuries and bone loss only received Vacuum-sealing drainage (VSD). Broad-spectrum antibiotics were regularly used and VSD must be especially maintained easy and smooth for one week or more after operation. Limited internal fixation and transplanted free skin flaps or adjacent musculocutaneous flaps were not used to close wounds until the conditions of the wounds had been improved. The first operations were completed within 90-210 minutes (170 minutes on average). The blood transfusions were from 400 ml to 1500 ml (those used for anti-shock preoperatively not included). All the 40 patients in this study were followed up for 6-28 months, 20.5 months on average. The lower limb function was evaluated according to the comprehensive evaluation standards of leg function one year after operation and the results of 28 cases were excellent, 9 were good and 3 were poor. External fixation associated with limited internal fixation to treat Gustilo grade III leg fractures can get satisfactory early clinical therapeutic effects.

  12. Surgical treatment of neglected clubfoot using external fixator

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    Rodrigo Mota Pacheco Fernandes

    Full Text Available ABSTRACT The definition of neglected clubfoot (NC includes a variable range of complex deformities of the foot that are refractory to conventional treatments or are treated inappropriately. Several etiologies may be related to this. The Ilizarov method has become established as a tool for treating these deformities. It minimizes soft-tissue damage through gradual correction of the deformity, with a high success rate in relation to achieving a plantigrade foot, with low incidence of recurrence. The indications for treatment include severe rigid deformities (Dimeglio III and IV, or adverse skin conditions. Careful clinical and radiological examination is fundamental for proper planning and installation of the external fixator. The techniques used include selection of external fixation assemblies, which can be closed when there is a connection between the leg, hindfoot and forefoot. This closed assembly may or may not be constricted, according to whether hinges are provided or whether use of the natural anatomical hinges during correction of the deformity is envisaged. An open assembly makes it possible to add flexibility to the foot through histogenesis, while allowing closed corrections of greater precision later on. Hexapod fixators are an innovation with high potential for accuracy in correcting deformities. Procedures associated with external fixation include soft-tissue release and bone procedures. These procedures enable corrections that are more anatomical, for different degrees of severity and stiffness of deformity. It can be concluded from analyzing this case series that treatment of neglected clubfoot using an external fixator has a high rate of good and excellent results, with low frequency of complications.

  13. The economic impact of reprocessing external fixation components. (United States)

    Horwitz, Daniel S; Schabel, Kathryn L S; Higgins, Thomas F


    The trend toward temporizing external fixation of complex fractures has resulted in increased expenditures for these devices. Increasing pressure to reduce health-care expenditures has led to exploration of reuse of equipment intended for single use. Devices must be tested and recertified prior to redeployment in hospital stock. We report the rate of manufacturer recertification and institutional cost savings associated with a reuse program approved by the United States Food and Drug Administration. All Hoffmann-II external fixation components that had been removed at our institution during the study period were submitted to the manufacturer for visual inspection and mechanical testing. Pass rates for original components and previously recycled components were determined. With use of a conservative pass rate and the assumption of a maximum of three recertifications of each component, the total potential hospital savings on external fixation were calculated. The first pass rate was 76%. The second pass rate (i.e., the rate for components that had already been recertified once and had been sent for a second recertification) was 83%, but that rate was derived from a limited sample. On the basis of a conservative pass-rate estimate of 75%, the predicted average number of uses of a recyclable component was 2.7. The recertified components were sold back to our hospital at 50% of the original price. Because carbon-fiber bars and half-pins are not recycled, 85% of the charges expended on a new external fixation component are spent on portions of the system that are recyclable. The potential total savings on reusable components was found to be 32%, with a total savings of 27% for the whole external fixation system. No recertified components failed in clinical use over the course of the study. With the expansion of cost-control efforts, the recycling of medical devices appears inevitable. Previous data have demonstrated the safety of reuse of external fixation devices, and

  14. Biomechanical analysis of four external fixation pin insertion techniques

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    Dillon Arango


    Full Text Available Having multiple external fixation pin designs and insertion techniques has led to debate as to which combination creates the stiffest construct. This study sought to biomechanically evaluate construct strength using self-drilling (SD and self-tapping (ST pins inserted with either bicortical or unicortical fixation. SD and ST 5.0 mm stainless steel pins were used in combination with bicortical self-drilling (BCSD, bicortical self-tapping (BCST, unicortical self-drilling (UCSD, and unicortical selftapping (UCST techniques. Pre-drilling for the self-tapping pins was completed with a 4.0 mm drill bit using ¾ inch polyvinyl chloride (PVC pipe as the insertional medium. The PVC pin constructs were then loaded to failure in a cantilever bending method using a mechanical testing system. Ten trials of each technique were analyzed. BCSD insertion technique had the highest maximum failure force and stiffness of all tested techniques (P<0.0001. SD pins were significantly stronger to bending forces than ST pins in both the unicortical and bicortical setting (P<0.0001. Three point bending tests of the 5.0 mm SD and ST threaded area showed that threaded portion of the SD pins had a 300 N greater maximum failure force than the ST pins. Biomechanical analysis of external fixation pin insertion techniques demonstrates that bicortical fixation with SD pins achieved the greatest resistance to bending load. Despite both pins being 5.0 mm and constructed from stainless steel, ST and SD behaved differently with regard to maximum failure force and stiffness. This study demonstrates that insertion technique and pin selection are both important variables when attempting to achieve a stiff external fixation construct.

  15. Nonlinear stiffness profiles of external fixators constructed with composite rods. (United States)

    Carlson, Kimberly R; Kraus, Karl H; Kowaleski, Michael P


    To determine if composite connecting rods confer nonlinear stiffness characteristics on unilateral and bilateral external skeletal fixators (ESF) in cranial-caudal bending and axial loading. Mechanical testing performed on models. Six models of 6-pin ESF constructs composed of birch dowels, a commercial ESF system, and composite connecting rods. Unilateral and bilateral ESF configurations were assembled using either specially designed composite titanium and silicone (composite group) or solid titanium (solid group) connecting rods. Mechanical testing was performed in axial loading and 4-point cranial-caudal bending. Stiffness was determined at a low and high-load range, and was considered increasing and nonlinear if the stiffness at high loads was greater than at low loads. The stiffness of the solid group was linear in all testing modes and configurations. Bilateral composite fixators had a nonlinear increasing stiffness in axial loading and cranial-caudal bending. Unilateral composite fixators had a nonlinear increasing stiffness in axial loading, but not cranial-caudal bending. Solid connecting rods conferred a higher stiffness in all testing modes and configurations. Composite connecting rods resulted in nonlinear increasing axial and bending stiffness in bilateral fixators, and in axial load in unilateral fixators. Conventional ESF can be constructed so that the stiffness increases as load increases. This provides the surgeon with additional options to control the local mechanical environment of a healing fracture, which may be used to enhance fracture healing.

  16. High-energy tibial plateau fractures: external fixation versus plate fixation. (United States)

    Yu, Liang; Fenglin, Zhong


    Whether external or plating fixation is more appropriate for high-energy tibial plateau fractures is still being disputed, our aim was to test the hypothesis whether external fixation can provide a fair outcome with fewer complications, when compared to the results with previously reported data of plating fixation for high-energy tibial plateau fractures. An Ovid of Medline, Embase, and Cochrane Library search was conducted for the relevant English orthopedic journals, and eligible studies, including twenty-four case series and one comparative study containing 885 patients associated with 892 fractures, were enrolled. The results showed there were a higher proportion of men, open fractures, malunion, knee instability, and posttraumatic arthritis occurred in external fixation group than those in plating group (P=0.007, P=0.000, P=0.024, P=0.006, P=0.000, respectively), while valgus deformity happened at a significantly higher rate in plate group (P=0.014). No significant differences were found between the two groups in terms of age, Schatzker type, follow-up, mean time to union, mean range of knee motion, and rate of reoperation. With regard to the functional and radiological outcome assessment, despite what assessment tools were used, most of these studies presented less than 90% good/excellent results in their high-energy fracture series. Besides, there was a trend for patients in plating group to have a higher risk than those in external fixation group in terms of heterotopic ossification and local irritation (1.23 vs 0.17%, 4 vs 1.94%, accordingly). Although lack of good quality randomized control trials, there are rather enough samples supporting the current available results. Meanwhile, future multicentered, randomized, controlled studies should be implemented to test these outcomes.

  17. Management of proximal humeral fractures by the Ilizarov external fixator. (United States)

    Meselhy, Mohammed Anter; Singer, Mohamed Salah


    External fixation can be performed in poor bone and soft tissue conditions, and can be used in patients with poor general conditions or multiple injuries as a rapid, mini-invasive procedure. The purpose of the current study was to evaluate the effectiveness and safety of the Ilizarov external fixator in the management of proximal humeral fractures. Between May 2011 and December 2013, 14 patients with displaced proximal humeral fractures were enrolled in the current study. Nine patients were males and five were females, with mean age 42.9 years (range 21-55). All fractures were acute. The mode of injury was road traffic accident in eight patients and fall in six patients. There were six patients with two-part fracture, one of them with fracture dislocation, and eight patients presented with three-part fracture, two of them with fracture dislocation. All fractures were fixed using the Ilizarov external fixation. The average operative time was about 67 min (range 50-90). The mean follow-up period was (18) months (range 12-28). Healing was obtained in all 14 patients in a mean of 10.4 weeks (range 8-14). At the final follow-up, the mean constant score was 73.1 points (range 60-97 points), the mean visual analog score (VAS) for pain 3.2 (range 1-5), the mean DASH score 31.8 points (range 10-55 points), and the mean satisfaction VAS 7.6 (range 4-10). The Ilizarov external fixation is an effective technique in managing proximal humeral fractures with good outcome and low complication rates. Level IV, case series.


    Directory of Open Access Journals (Sweden)

    Jagadeesh Kumar


    Full Text Available Calcaneal fracture, the most common tarsal bone fracture, occurs predominantly in manual labors and subsequently has got considerable socioeconomic implications. Treatment modality which can offer early weight bearing and early return to work is therefore needed for those patient s. We have used a biplanar percutaneous external fixator for treating calcaneal fractures per operative visualization of the fractures. We have treated 20 calcaneal fractures in 18 patients, 12 intra articular and five extra articular, with our percutaneou s external fixator system with under image intensifier and achieving the fracture reduction. Functional outcome was measured using the American Orthopaedic Foot and ankle society Hind foot score. All fractures united with a mean of 55 days. Partial weight bearing was possible in a mean of 1.8 days and full bearing was possible in a mean of 11.6 days. All the patients were returned to their original work within six weeks. Minor infectious complications occurred in 17.6 percent of cases. The average AOFAS sco re at six months follow up was 83.8. We conclude that our percutaneous external fixator technique for fracture calcaneum is an effective alternative to the currently available – surgical and conservative treatment modalities especially in lower socio econo mic labor population who need to return to their job as early as possible. Level of Evidence – IV Case series

  19. Fixation of patella fractures with a minimally invasive tensioned wire method: compressive external fixation. (United States)

    Wardak, Mohammed Ismail; Siawash, Abdul Razaqu; Hayda, Roman


    Current fixation methods of patella fractures are associated with hardware prominence, infection, and failure of fixation. These complications necessitate repeat surgical treatment, increase costs, and limit function. We investigated whether a novel device can effectively treat patella fractures with few complications. A consecutive series of patients with displaced patella fractures with transverse and select other patterns were treated with the technique of compressive external fixation (CEF), a device based on an external tensioned wire construct. Patients were allowed unrestricted motion and weight bearing postoperatively. Patient outcomes were evaluated retrospectively. Eighty-four fractures (26 open) were treated with CEF with 23 performed percutaneously. All of the fractures attained union. The device was removed in the office at 6 weeks. Sixty-one patients regained excellent motion with a mean Insall knee score of 97 points, at an average follow-up of 4 years. Minor complications presented in 11% of patients but did not affect the overall outcome. Complications included minor wire irritation in 14 patients and one case of poor knee motion in a patient presenting with fibroankylosis of the joint. Treatment using the CEF technique is a safe and effective method of treatment of patella fractures with advantages over traditional forms of fixation particularly in cases with a poor soft tissue envelope, salvage situations, and in locations with limited resources. It allows for rapid recovery with minimal complications and no secondary surgery. Its use should be considered in the treatment of these injuries. V, therapeutic study.

  20. Analyze of Ortho-SUV™, software base hybrid fixation on three planar femur deformity

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    Mohammadreza Effatparvar


    Full Text Available Background: Application of Hybrid 6 degrees of freedom fixation could lead to space motion in each 3 anatomic plates together and decrease the time of complex deformities correction. This study is an investigation on the function of hybrid external fixation and the influence of it on decreasing the treatment time. About this case utilize of Ortho-SUV Frame (OSF system is explained for the first time in Iran and report of its novel. These robotic systems are divided into two groups: active and passive, about active system all movements are done by actuators in joints and links. And in passive, the system needs an operator or patient to actuates Sturats by hand. Methods: The femur bone has been investigated was non:union: with deformity in sagittal, frontal and transversal planes. Ilizarov external fixation was applicate firstly, with this condition that the OSF systems jacks were replaced instead of simple rods in side of fracture. Software work was done on February of 2016 in Ayatollah Taleghani Hospital, Tehran, Iran. Fractures were happened in a car accident and some other operating were perforemed for this patient without any result. Results: The correction of studied deformity needs 3 planar moving. Acting this movement by Ilizarov requirements 33 mm displacement in frontal plane, 12 mm horizontal distraction and 48 mm displacement in sagittal plane. Due to the rate of correction in Ilizarov which is 1 mm per day, this bone needs 93 days for general correction and three times changing in shape of rings connections. While, by using the hybrid external fixation, all displacements were corrected in 46 days and first connection had supported all planes.    Conclusion: According to that the decreasing of treatment time is one of the main goal, the hybrid external fixation systems could be an appointment choice in complex deformities and replaced with some common fixation. In addition to, using of updated software increases the accuracy of

  1. Knee flexion contracture in haemophilia: treatment with circular external fixator. (United States)

    Balci, H I; Kocaoglu, M; Eralp, L; Bilen, F E


    Haemophilia, a bleeding disorder, causes recurrent intra-articular bleeding of the joints result-ing in chronic haemophilic arthropathy with fixed knee flexion deformity. Mid-long-term results (between 2002 and 2006) of deformity correction in haemophilic patients with Ilizarov type circular external fixators were retrospectively evaluated. There were six patients (five haemophilia A and one haemophilia B). The mean age was 14.7 years (range, 8-22 years) at the time of initial surgery. The mean knee flexion contracture was 45 degrees (range, 30-75 degrees). The mean arc of motion was 58.3 degrees (range, 40-100) before the surgery. The mean duration of follow-up was 8 years (range, 5.5-10 years). The mean duration of external fixation was 4.4 months (range, 2.5-10.5 months). Full extension of the knee joint was obtained in all patients in the early postoperative period. No bleeding, neurological or vascular complications were encountered. The mean amount of recurrence in knee flexion contracture was 10 degrees (range, 0-15 degrees). The amount of the correction was significant (P = 0.0012) and the mean arc of motion was 51.6 degrees (range, 25-90 degrees) that show a decrease of 6.7 degrees (P = 0.04) at the end of follow-up. The circular external fixator is an important, safe and less invasive alternative surgical treatment modality with low recurrence rate. Using the external hinges and distraction during the correction has a protective effect on the joint. It requires a team-work consisting of a haematologist, an orthopaedic surgeon and a physical therapist. © 2014 John Wiley & Sons Ltd.

  2. Biomechanical analysis of dynamic external fixation devices for the treatment of distal radial fractures

    NARCIS (Netherlands)

    Goslings, J. C.; Ferguson, S. J.; Perren, R. A.; Tepic, S.


    Several dynamic external fixation devices have been introduced to permit early functional treatment of unstable distal radial fractures. An intact cadaver wrist was spanned by a dynamic external fixator. Forces between the fixator and the radius were recorded during passive motion using a single,

  3. Mini External Fixator Assisted Metacarpal Lengthening With The Distraction Method

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    Kilinc Bekir Eray


    Full Text Available Phalangeal brachydactyly, which is caused by the abnormal development of the metacarpal, is characterized by shortness that can be seen in a single finger or in all fingers of the hands. Although brachydactyly is usually thought of as congenital, it can occur due to metabolic disorders or trauma. A twelve-year-old girl was admitted to our clinic with complaints of shortness in the fourth finger of the left hand. Osteotomy was applied with the drilling-osteotomy technique. The screws holding the upper and lower segments were adapted to the external fixator. Lengthening began one week after the osteotomy. The lengthening rate was organized as 0.25×2 mm/day. The amount of elongation was planned not to exceed 40% of the original bone length. Distraction was terminated after the planned elongation amount was reached, and the bone was allowed to heal. In patients under twenty years of age, the results from progressive distraction without bone grafting are close to perfect. Although the technique of successfully lengthening metacarpal fractures in children is simple, strict rules should not be ignored. Primarily, the external fixator and the distraction system should be sufficiently stable, lightweight, and should be appropriate for the size of a child’s hand.

  4. External Fixation versus two-stage Open Reduction Internal Fixation of distal intra-articular Tibia fractures; a Systematic Review

    DEFF Research Database (Denmark)

    Ladeby Erichsen, Julie; Jensen, Carsten; Damborg, Frank Lindhøj

    Internal Fixation (ORIF) or External Fixation (EF). Method : A search was conducted using PUBMED, Embase, Cochrane Central, Open Grey, Orthopaedic Proceedings and WHO International Clinical Trials Registry Platform. Studies with level of evidence I-IV comparing EF with two-stage ORIF of DIATF in patients...

  5. External fixation in the treatment of open tibial shaft fractures

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    Golubović Zoran


    Full Text Available Background/Aim. Besides the conquasant fractures, open tibia shaft fractures belong to the group of the most severe fractures of tibia. Open tibia shaft fracture is one of the most common open fractures of long bones. They most frequently occur as a result of traffic accidents caused by the influence of a strong direct force. Methods. Within the period from January, 2000 to December 31, 2005. at the Clinic for Orthopaedics and Traumatology, Clinical Center Nis, 107 patients with open tibial fractures were treated. We analyzed 96 patients with open tibial fracture. In the series analyzed, the male sex was prevalent - there were 74 men (77.08%. The mean age was 47.3 years. The youngest patient was 17 years old, while the oldest patient was 79. According to the classification of the Gustilo et al. in the analysed group there were 30 (31.25% open tibial fractures of the I degree, 31 (32.29% of the II degree, 25 (26.05% of the III A degree, 8 (8.33% of the III B degree and 2 (2.08% of the III C degree. In 95 of the patients the treatment of open tibia shaft fractures consisted of the surgical treatment of wound and the external fixation of the fractured bone using "Mitkovic" type external fixator with a convergent method of pin applications. One primary amputations had been done in patients with grade IIIC open tibial fracture with large soft tissue defect. Results. Of the 96 open tibial fractures available for follow-up, 73 (76.04% healed without severe complications (osteitis, pseudoarthrosis, valgus malunion and amputation. Ther were nine (9.38% soft tissue pin track infections and six (6.25% superficial wound infections. The mean time of union was 21 (14-36 week. Among severe local complications associated with open tibial fractures, in eight patients (8.33% was registered osteitis, and in nine patients (9.38% fracture nonunion and the development of pseudoarthrosis. Three of the patients (3.13% had more than 10 degree valgus malunion. In one

  6. Postoperative complications associated with external skeletal fixators in cats. (United States)

    Beever, Lee; Giles, Kirsty; Meeson, Richard


    The objective of this study was to quantify complications associated with external skeletal fixators (ESFs) in cats and to identify potential risk factors. A retrospective review of medical records and radiographs following ESF placement was performed. Case records of 140 cats were reviewed; fixator-associated complications (FACs) occurred in 19% of cats. The region of ESF placement was significantly associated with complication development. Complications developed most frequently in the femur (50%), tarsus (35%) and radius/ulna (33%). Superficial pin tract infection (SPTI) and implant failure accounted for 45% and 41% of all FACs, respectively. SPTI occurred more frequently in the femur, humerus and tibia, with implant failure more frequent in the tarsus. No association between breed, age, sex, weight, fracture type (open vs closed), ESF classification, number of pins per bone segment, degree of fracture load sharing, and the incidence or type of FAC was identified. No association between region of placement, breed, age, sex, weight, fracture type (open vs closed), ESF classification, number of pins per bone segment, fracture load sharing and the time to complication development was identified. Complication development is not uncommon in cats following ESF placement. The higher complication rate in the femur, tarsus and radius/ulna should be considered when reviewing options for fracture management. However, cats appear to have a lower rate of pin tract infections than dogs.

  7. Emergency department external fixation for provisional treatment of pilon and unstable ankle fractures

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    Craig R Lareau


    Full Text Available Unstable ankle fractures and impacted tibial pilon fractures often benefit from provisional external fixation as a temporizing measure prior to definitive fixation. Benefits of external fixation include improved articular alignment, decreased articular impaction, and soft tissue rest. Uniplanar external fixator placement in the Emergency Department (ED ex-fix is a reliable and safe technique for achieving ankle reduction and stability while awaiting definitive fixation. This procedure involves placing transverse proximal tibial and calcaneal traction pins and connecting the pins with two external fixator rods. This technique is particularly useful in austere environments or when the operating room is not immediately available. Additionally, this bedside intervention prevents the patient from requiring general anesthesia and may be a cost-effective strategy for decreasing valuable operating time. The ED ex-fix is an especially valuable procedure in busy trauma centers and during mass casualty events, in which resources may be limited.

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

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    Vigdorchik Jonathan M


    Full Text Available Abstract 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.

  9. Incidence and risk factors for pin tract infection in external fixation of ...

    African Journals Online (AJOL)

    Background: Pin tract infection is a complication when using external fixation. The objective of this study was to estimate the incidence, rate and risk factors for pin tract infections after external fixation in the orthopedics wards in a major teaching hospital in Togo (West Africa). Methods: A one year prospective cohort study ...

  10. Report About the Design of External Fixator for Treatment of Pelvis and Acetabulum Fractures

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    Martin JANEČKA


    Full Text Available Main point in this contribution is the design of external fixators applied in traumatology and orthopaedics. These fixators can be used in the treatment of open and unstable (i.e. complicated fractures of pelvis and its acetabulum. Numerical modelling (i.e. Finite Element Method, together with CAD modelling, experiments, material engineering, and nanotechnology are presented as a support for developing of a new design of external fixators.


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    Sanjeev Kumar Kare


    Full Text Available BACKGROUND Fracture of the distal radius (‘broken wrist’ is a common clinical problem. It can be treated conservatively usually involving wrist immobilisation in a plaster cast or surgically. A key method of surgical fixation is external fixation. MATERIALS AND METHODS A prospective study was carried out on 66 patients admitted between June 2014 to May 2016 for evaluation of conservative and surgical management of distal radius fractures. RESULTS Excellent, fair or good result was noticed in around 85% of cases managed conservatively and in above 90% of cases managed by external fixator. CONCLUSION There is some evidence to support the use of external fixation for dorsally displaced fractures of the distal radius in adults. Though, there is insufficient evidence to confirm a better functional outcome, external fixation reduces redisplacement gives improved anatomical results and most of the excess surgically-related complications are minor.

  12. Fracture fixation. (United States)

    Taljanovic, Mihra S; Jones, Marci D; Ruth, John T; Benjamin, James B; Sheppard, Joseph E; Hunter, Tim B


    The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of the injured bone, and to return early mobility and full function of the injured extremity. Fractures can be treated conservatively or with external and internal fixation. Conservative fracture treatment consists of closed reduction to restore the bone alignment. Subsequent stabilization is then achieved with traction or external splinting by slings, splints, or casts. Braces are used to limit range of motion of a joint. External fixators provide fracture fixation based on the principle of splinting. There are three basic types of external fixators: standard uniplanar fixator, ring fixator, and hybrid fixator. The numerous devices used for internal fixation are roughly divided into a few major categories: wires, pins and screws, plates, and intramedullary nails or rods. Staples and clamps are also used occasionally for osteotomy or fracture fixation. Autogenous bone grafts, allografts, and bone graft substitutes are frequently used for the treatment of bone defects of various causes. For infected fractures as well as for treatment of bone infections, antibiotic beads are frequently used. Copyright RSNA, 2003

  13. A comparative study of blade plate fixation and external fixation in osteotomies for slipped capital femoral epiphysis. (United States)

    Kitoh, Hiroshi; Kitakoji, Takahiko; Hattori, Tadashi; Kaneko, Hiroshi; Mishima, Kenichi; Matsushita, Masaki; Ishiguro, Naoki


    We have performed corrective osteotomies for moderate or severe slipped capital femoral epiphysis (SCFE) using an original blade plate (BP) until 2006 and using a hybrid external fixator (EF) since 2007. We designed a comparative study of the short-term results between BP and EF devices in the treatment of proximal femoral osteotomies in SCFE. Nineteen SCFE patients (12 BP; seven EF) who underwent corrective osteotomies at our institution were included. Clinical and radiographic valuables including the operative time, intraoperative blood loss, postoperative improvement of head shaft angle, and posterior tilting angle, Harris hip score, limb-length discrepancy, and associated complications were compared between the two groups. Although there were no significant differences between the two groups in postoperative improvement of head shaft angle and posterior tilting angle, Harris hip score, and limb-length discrepancy, the EF group showed significantly shorter operative time and less intraoperative blood loss. Serious complications were observed in two patients of the BP group (deep infection and chondrolysis, respectively) and one of the EF group (chondrolysis). Percutaneous proximal femoral osteotomy using an EF appears to be safe, easy, and effective in correcting multiplanar deformities associated with SCFE. It has potential advantages over commonly used open techniques in terms of simplicity and less invasiveness.

  14. Results of open tibial fracture treatment using external fixation

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    Golubović Ivan


    Full Text Available Introduction. Open lower leg fractures are the most common open fractures of the locomotor system and their treatment is associated with a number of complications. Objective. The aim of the paper was to present the results of the treatment of 68 patients with open lower leg fractures, as well as the complications that accompany the treatment of these fractures. Methods. In the analyzed group, there were 45 (66.18% men and 23 (33.82% women. The majority of patients - 33 (48.53% of them - were injured in motor vehicle accidents, whereas 24 (35.29% patients sustained injuries due to falls from heights. In two (2.94% patients the cause of open tibial fractures was gunshot injuries. In the analyzed group, there were 18 (26.47% type I open fractures, 21 (30.88% type II open fractures, 19 (27.94% type IIIA open fractures, seven (10.29% type IIIB open fractures, and three (4.41% type IIIC open fractures. Results. The tibial shaft fracture healed without serious complications in 50 (73.53% patients, whereas in 18 (26.47% patients we observed some complications. Nonunion was found in 10 (14.71% patients, osteitis in four (5.88, malunion in two (2.94% patients. Milder complications such as soft tissue pin tract infection developed in 13 (19.12% patients, infection of the open fracture wound soft tissue was observed in four (5.88% patients. Conclusion. Basic principles in the treatment of open lower leg fractures in this study are thorough primary open fracture wound treatment followed by the delayed wound closure, stable fracture fixation using unilateral external skeletal device, proper antibiotic treatment and tetanus prophylaxis. The results correlate with similar studies. [Projekat Ministarstva nauke Republike Srbije, br. III 41017: Virtual Human Osteoarticular System and its Application in Preclinical and Clinical Practice

  15. Management of complex diabetic foot wound by external fixation: An effective way for limb salvage

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    Biswaranjan Nayak


    Conclusion: External fixation provides limb off-loading, immobilization, skeletal fixation, wound care, preservation of vascular structures and simultaneously allow the soft tissue healing in complex diabetic wound. So it is a better method of limb salvaging than the traditional methods with encouraging results.

  16. Step-by-step external fixation of unstable pelvis with separate anterior and posterior modules

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    Ivan Viktorovich Borozda


    Conclusions: The modular approach applied is the advantage of the transosseous osteosynthesis allowing for a separate anterior (anti-shock fixation and final posterior reposition of the pelvic ring preceded by the stabilization of vital functions. The above mentioned method gives an opportunity to increase the amount of techniques applied for the pelvic external fixation in polytrauma cases.

  17. [Historical aspects of external fixation and possibilities for the future developement]. (United States)

    Lesić, A R; Gojković-Bukarica, Lj; Cobeljić, G N; Bumbasirević, M Z


    External fixation is not such a novel method, but it is interesting to learn its history, countries in which it has developed and the time when it gained full expert acceptance in treating not only fractures but orthopedic disorders, inequalities, and articular arthrodeses. The beginnings of external fixation are associated to the name of Malgaigne, followed by the authors of Western European, German and American school of external fixation. In the U.S.A., this method was accepted as late as in 1950s; being accepted in Russia through Ilizarov. In our country, the method was accepted in 1950s, through the work of Prof. Bumbaireviae and Prof. Raduloviae, who are the founders of modem external fixation in our country.

  18. Dynamic vs static external fixation of distal radial fractures: A randomized study

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    Vikas Kulshrestha


    Materials and Methods : Sixty adult patients with displaced unstable comminuted fractures of the distal radius were randomly allocated either to the dynamic (n=30 or static (n=30 fixator groups. Patients in the dynamic fixator group were managed with closed reduction and application of Penning-type articulated fixator (Orthofix, Srl, Italy; the injured wrist was partially dynamized at 3 weeks. Patients in the static group were managed with monoplanar static external fixator of Joshi′s external stabilizing system (JESS type fixator. In both groups, the fixator was maintained for 6-8 weeks. The patients were followed-up over 2 years. The primary outcome measures were the functional outcome as measured using the Gartland and Werley and DASH scores and anatomical outcome as measured using the Lindstrom score. The secondary objective was to correlate anatomical and functional outcomes and to look at overall local complications. Results : Palmar tilt was better restored in the Penning fixator group (P<0.0001. There was reduced loss of ulnar tilt (P=0.05 and radial height (P=0.04 in the Penning fixator group. Gartland and Werley score was better in the Penning fixator group at each time point of the follow-up. The DASH score was similar in the two groups at 2 years (P=0.14. There was poor correlation (0.19 between functional outcome and anatomical restoration at 2 years. Conclusions : In the management of displaced unstable comminuted fracture of the distal radius, use of an articulated multiplanar external fixator, allowing partial dynamization of the injured wrist at 3 weeks, resulted in improved early functional and anatomical outcome as compared to static external fixation. However, there was no significant difference in functional outcome at 2 years.

  19. Nonrigid external fixation of the elbow, coxofemoral, and tarsal joints in dogs. (United States)

    Schwartz, Zeev; Griffon, Dominique


    Nonrigid external fixation of a joint is designed to restrict abnormal joint movement and facilitate healing of traumatized ligaments and capsule tissue with minimizing the impact of immobilization on articular homeostasis and cartilage metabolism. Weight bearing and joint motion minimize muscle atrophy and loss of bone mineral and allow controlled loading of the ligaments, thereby improving their strength and functionality. This article describes simple, cost effective techniques for the percutaneous application of external fixators to the elbow, coxofemoral, and tarsal joint of dogs.

  20. Additional external hinged fixator after open repositioning and internal fixation of acute elbow instability in non-compliant patients

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    Sebastian Tobias Berendes


    Full Text Available This is a retrospective analysis of the clinical and radiological outcome in 11 patients with complex acute posttraumatic elbow instability after dislocation. These patients had also been treated with a hinged external fixator after open reduction, capsular and ligamentous reconstruction and internal fixation, because of an expected diminished compliance, to avoid a secondary dislocation of the internal fixation. Concentric stability and a sufficient range of motion of the elbow joint were achieved in all cases. Non-compliant patients were classified by the surgeon as not compliant or not able or not willing to cooperate post-operatively for various reasons, such as alcoholism, drug abuse, mental disability, cerebral trauma or senile dementia. Non-compliant patients had undergone open reduction and internal fixation of an acute posttraumatic unstable elbow. The addition of a hinged external fixator allows early intensive mobilization, and can protect and improve the clinical outcome after these complex elbow injuries. This evaluation remains, of course, largely subjective and decision making is not easy because in most cases, the patient was not known before surgery. Thus, the only patient exclusion criteria in this study was surgeon classification as “compliant”.


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    Pavlin Apostolov


    Full Text Available The authors represent a distraction external pelvic fixation technique, which they use in pelvic fractures caused by a lateral compression. They consider the indications and mounting techniques. The authors recommend the early movement activities (on the 3rd - 5th day after the external fixator placement. This method had been used in 8 patients and 3 cases are analyzed in details. The priority of this technique over open reduction and internal fixation (ORIF mainly are: (1 the implementation of good reduction of the fracture preventing the risk of ORIF; (2 the possibility for early movement activities for the patient.

  2. External fixation for the treatment of open fractures of the proximal humerus caused by firearms

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    Mirić Dragan


    Full Text Available Nine patients with open fractures of the proximal humerus were treated using an external fixation device. All of them had grade III open fractures resulting from high-velocity missile and explosive injuries with massive foreign body contamination. Radial nerve injury was present in five and two multiply injuried patients with thoracic wall and abdominal viscera were present. There were no major arterial injuries. Chronic osteitis with fistula and sequestra developed in one. There were no nonunions and no refractures. Minor painless limitation of shoulder and elbow motion presented in all patient. Upper-third humeral open fractures due to firearms are a unique type of open fractures. They are usually highly comminuted therefore, stable fixation is difficult or impossible to achieve. On the other hand, the risk of infection is high following plate fixation. External fixation allows adequate management of the soft tissue wounds, provides stable bone fixation and allows early mobilization of the shoulder and elbow.

  3. Treatment of neglected elbow dislocations with the help of hinged external fixator: Report of two cases

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    Özgür Karakoyun


    Full Text Available Elbow dislocations are cases that have to be treated in emergency conditions. Neglected elbow dislocations are seen very rarely and the treatment of such cases are more complicated than acute cases. We present two cases of neglected elbow dislocations treated with open reduction and hinged external fixators. Case 1: 23 year old female patient had a neglected posterior dislocation of left elbow with ipsilateral humeral shaft fracture caused by car accident. The patient was treated after 3 months of initial trauma. We have performed open reduction for the joint. After that we fixed the joint whit a hinged external fixator. The humeral shaft fracture was also fixed with the components of the external fixator. Case 2: 33 year male patient had a large bone and soft tissue defect around the left elbow accompanying with neglected medial elbow dislocation. He presented to our clinic with a delay of 2 months. The patient was treated with open reduction and hinged external fixator after reconstruction of bone defect of distal humerus. Conclusion: The treatment of neglected cases is quite challenging. Open reduction and external fixation has satisfactory results in treatment of late cases of elbow dislocation with the possibility of early rehabilitation. This method can be considered as an option for such cases. J Clin Exp Invest 2014; 5 (2: 443-446

  4. A New Articulated Elbow External Fixation Technique for Difficult Elbow Trauma


    von Knoch, Fabian; Marsh, J Lawrence; Steyers, Curtis; McKinley, Todd; O?Rourke, Michael; Bottlang, Michael


    Articulated external fixation of the elbow allows aggressive elbow range of motion while protecting the joint and periarticular structures from excessive forces. A technique for aligning a monolateral hinged fixator to the rotational axis of the elbow without the use of an invasive axis pin has been developed. Thirteen patients with acute and chronic post-traumatic elbow problems were treated over a four year period with this technique. An average arc of motion of 84 degrees was achieved in t...

  5. Comparison of hybrid fixation versus dual intramedullary nailing fixation for forearm fractures in older children: Case-control study. (United States)

    Feng, Yongzeng; Shui, Xiaolong; Wang, Jianshun; Cai, Leyi; Wang, Gang; Hong, Jianjun


    The aim of the present study was to compare the clinical outcomes of hybrid fixation using elastic stable intramedullary nailing (ESIN) for the radius and plate screw fixation for the ulna (Hybrid group) with dual ESIN fixation (D-ESIN group) for both-bone forearm fractures in children between 10 and 16 years of age. Fifty patients with both-bone forearm fractures (28 patients in the Hybrid group and 22 patients in the D-ESIN group) were reviewed. Functional outcomes were evaluated according to the criteria of Price et al. Radiological results were assessed by fracture union at three and six months and bone union time. Postoperative complications were also recorded. The times of fluoroscopy intraoperatively and duration of immobilization postoperatively were significantly lower in the Hybrid group (P < 0.05). The union rate of the ulna at three months postoperatively in the hybrid group was significantly higher than that in the D-ESIN group (P < 0.05). The average time of bone union was significantly shorter in the hybrid group than that in the D-ESIN group (P < 0.05). There were no differences according to the satisfactory rate and degree, the major and minor complications between the groups. Hybrid fixation is superior in terms of the times of fluoroscopy intraoperatively, duration of immobilization postoperatively, delayed union rate of the ulna and the average time of bone union. Therefore, hybrid fixation is an alternative treatment for both-bone forearm fractures in children between 10 and 16 years of age. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  6. Radial nerve injury following elbow external fixator: report of three cases and literature review. (United States)

    Trigo, Luis; Sarasquete, Juan; Noguera, Laura; Proubasta, Ignacio; Lamas, Claudia


    Radial nerve palsy is a rare but serious complication following elbow external fixation. Only 11 cases have been reported in the literature to date, but the incidence may be underreported. We present three new cases of this complication. We analyzed the three cases of radial palsy seen in our center following the application of an external fixator as treatment for complex elbow injuries. Mean patient age at surgery was 50 years. Two patients were female and one was male. In the three cases, the initial lesion was a posterior elbow dislocation, associated with a fracture of the radial shaft in one and a radial head fracture and coronoid fracture, respectively, in the other two. Due to persistent elbow instability, an external fixator was applied in all three cases. The fixator pins were introduced percutaneously in two cases and under direct vision in an open manner in the third case. Radial palsy was noted immediately postoperatively in all cases. It was permanent in two cases and temporary in the third. Radial nerve palsy after placement of an external elbow fixator was resolved in only 1 of our 3 cases and in 6 of the 11 cases in the literature to date. Although the event is rare, these alarming results highlight the need for recommendations to avoid this complication.

  7. Coupled external fixator and skin flap transposition for treatment of exposed and nonunion bone

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    ZHAO Yong-gang


    Full Text Available 【Abstract】Objective: To discuss the effect of coupled external fixator and skin flap transposition on exposed and nonunion bones. Methods: The data of 12 cases of infected nonunion and exposed bone following open fracture treated in our hospital during the period of March 1998 to June 2008 were analysed. There were 10 male patients, 2 female patients, whose age were between 19-52 years and averaged 28 years. There were 10 tibial fractures and 2 femoral fractures. The course of diseases lasted for 12-39 months with the mean period of 19 months. All the cases were treated by the coupled external fixator and skin flap transposition. Results: Primary healing were achieved in 10 cases and delayed healing in 2 cases in whom the tibia was exposed due to soft tissue defect and hence local flap transposition was performed. All the 12 cases had bony union within 6-12 months after operation with the average time of 8 months. They were followed up for 1-3 years and all fractures healed up with good function and no infection recurrence. Conclusion: The coupled external fixator and skin flap transposition therapy have shown optimal effects on treating infected, exposed and nonunion bones. Key words: External fixators; Fracture fixation; Infection; Surgical flap

  8. A biomechanical analysis of the Ilizarov external fixator

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    Kourkoulis S.K.


    Full Text Available The objective of the present study is the construction of a reliable numerical model of the standard Ilizarov fixator that will permit a detailed parametric investigation of various factors influencing the effectiveness of the technique. Mechanical tests of a standard Ilizarov frame were performed under axial and torsional loads. To eliminate the pretension loss due to wire slippage metal nuts with M1.8 thread were manufactured. A numerical analysis followed based on the Finite Element Method. The model constructed simulated accurately all the geometrical details of the experimental model, the load application mode (axial and torsional and the mechanical characteristics of the materials used to assemble the frame. Comparison of the predictions of the model with the respective experimental data yields excellent agreement for the case of tension and rather satisfactory one for torsion.

  9. Reconstruction after external hemipelvectomy using tibia-hindfoot rotationplasty with calcaneo-sacral fixation. (United States)

    Kong, George Yx; Rudiger, Hannes A; Ek, Eugene Th; Morrison, Wayne A; Choong, Peter Fm


    External hemipelvectomy is associated with high post operative morbidity and a poor functional outcome. We aim to explore a reconstruction technique to improve function and post operative appearance for patients who undergo external hemipelvectomy. We present a Case where extensive cancer involvement of pelvis and femur was managed with a novel surgical technique, which involved a calf sparing modified anterior flap hemipelvectomy combined with rotationplasty of the spared calf and fixation of calcaneus to the sacrum, thereby recreating a new thigh stump. Tibia-hindfoot rotationplasty result in good functional outcome and appearance for selected patients undergoing external hemipelvectomy with unaffected external iliac and femoral vessels.

  10. Corrective lower limb osteotomies in children using temporary external fixation and percutaneous locking plates. (United States)

    Bar-On, Elhanan; Becker, Tali; Katz, Kalman; Velkes, Steven; Salai, Moshe; Weigl, Daniel M


    We describe a new method for corrective osteotomy and the fixation of lower limb deformities in children. Following osteotomy, the desired position is obtained and temporarily stabilized using an external fixator. Definitive fixation is performed with a plate and locking screws inserted percutaneously under fluoroscopic guidance. The procedure was performed in 18 segments in 11 patients. Corrections were performed in all planes. The mean follow up was 18 months (range 6-36 months). All patients were corrected to within 2 degrees of that which was planned. Union was obtained in 16 segments in ten patients within 6-16 weeks. The method was found to be effective for the correction of deformity in the pediatric population. Advantages compared to conventional methods include minimal soft tissue dissection and the ability to adjust the position before definitive fixation.

  11. External fixation using locking plate in distal tibial fracture: a finite element analysis. (United States)

    Zhang, Jingwei; Ebraheim, Nabil; Li, Ming; He, Xianfeng; Schwind, Joshua; Liu, Jiayong; Zhu, Limei


    External fixation of tibial fractures using a locking plate has been reported with favorable results in some selected patients. However, the stability of external plate fixation in this fracture pattern has not been previously demonstrated. We investigated the stability of external plate fixation with different plate-bone distances. In this study, the computational processing model of external fixation of a distal tibial metaphyseal fracture utilizing the contralateral femoral less invasive stabilization system plate was analyzed. The plate was placed on the anteromedial aspect of tibia with different plate-bone distances: 1, 10, 20, and 30 mm. Under axial load, the stiffness of construct in all groups was higher than intact tibia. Under axial load with an internal rotational force, the stiffness of construct with 1 and 10 mm plate-bone distances was similar to that of an intact tibia and the stiffness of the construct with 20 and 30 mm distances was lower than that of an intact tibia. Under axial load with an external rotational force, the stiffness of the construct in all groups was lower than that of an intact tibia. The maximum plate stresses were concentrated at the two most distal screws and were highest in the construct with the 10 mm plate-bone distance, and least in the construct with a 1 mm plate-bone distance. To guarantee a stable external plate fixation in distal tibial fracture, the plate-bone distance should be less than 30 mm.

  12. Comparison of Hybrid Fixation to Dual Plating for Both-Bone Forearm Fractures in Older Children. (United States)

    Cai, Leyi; Wang, Jianshun; Du, Shenghu; Zhu, Shaoyu; Wang, Te; Lu, Di; Chen, Hua

    When operative stabilization of forearm fractures in older children is necessary, the optimal method of fixation is controversial. This study compared the radiographic and functional outcomes of dual plating to a hybrid fixation construct with elastic intramedullary nailing of the radius and plate fixation of the ulna of forearm fractures in children aged between 10 and 16 years. Nineteen patients were treated using a hybrid fixation construct and 13 patients were treated with dual plating fixation. The 2 groups were compared retrospectively according to perioperative data and patient outcome measures. The hybrid fixation construct group had 19, with a mean age of 13.3 years (range, 10-16 years) and the dual plate group had 13 patients, with a mean age of 12.9 years (range, 10-16 years). Groups were similar for sex, arm injured, and fracture location. Duration of surgery and tourniquet use was significantly shorter in the hybrid fixation construct group. There was no significant difference in either time to union or Price scores for function evaluation between the 2 groups. Complication rates were also similar between groups, with 1 ulna delayed unions, 1 superficial infection at entry of nail in hybrid fixation construct group, and 1 ulna delayed unions in the dual plating group. Hybrid fixation, using open reduction and internal fixation with a plate-and-screw construct on the ulna and closed reduction and elastic intramedullary fixation of the ulna, is an acceptable method for treating both-bone diaphyseal forearm fractures in skeletally immature patients aged 10-16 years.

  13. A hinged external fixator for complex elbow dislocations: A multicenter prospective cohort study

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    Verleisdonk Egbert JMM


    Full Text Available Abstract Background Elbow dislocations can be classified as simple or complex. Simple dislocations are characterized by the absence of fractures, while complex dislocations are associated with fractures of the radial head, olecranon, or coronoid process. The majority of patients with these complex dislocations are treated with open reduction and internal fixation (ORIF, or arthroplasty in case of a non-reconstructable radial head fracture. If the elbow joint remains unstable after fracture fixation, a hinged elbow fixator can be applied. The fixator provides stability to the elbow joint, and allows for early mobilization. The latter may be important for preventing stiffness of the joint. The aim of this study is to determine the effect of early mobilization with a hinged external elbow fixator on clinical outcome in patients with complex elbow dislocations with residual instability following fracture fixation. Methods/Design The design of the study will be a multicenter prospective cohort study of 30 patients who have sustained a complex elbow dislocation and are treated with a hinged elbow fixator following fracture fixation because of residual instability. Early active motion exercises within the limits of pain will be started immediately after surgery under supervision of a physical therapist. Outcome will be evaluated at regular intervals over the subsequent 12 months. The primary outcome is the Quick Disabilities of the Arm, Shoulder, and Hand score. The secondary outcome measures are the Mayo Elbow Performance Index, Oxford Elbow Score, pain level at both sides, range of motion of the elbow joint at both sides, radiographic healing of the fractures and formation of periarticular ossifications, rate of secondary interventions and complications, and health-related quality of life (Short-Form 36. Discussion The outcome of this study will yield quantitative data on the functional outcome in patients with a complex elbow dislocation and who are

  14. Comparison of locking anatomic volar plate fixation and external fixation in the treatment of AO type C radius distal-end fractures

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    Kenan Guvenc


    Conclusion: Better functional and clinical results were obtained for patients with complex fractures associated with joint of radius distal-end fractures compared with the group treated with an external fixator. At further stages, there was no difference in terms of arthritic changes between the two fixation methods. This result shows that according to AO classification, in the case of type C radius distal-end fractures, except for very distal fractures not amenable to plate fixation, locked volar plating provides a safe and stable fixation and hence why it is the preferred method. [Hand Microsurg 2017; 6(1.000: 15-20

  15. Management of the proximal tibia fractures by mini external fixation: A case series of 30 cases

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    Samar K Biswas


    Full Text Available Background: Management of high velocity trauma is a challenging problem because of morbidity of trauma and sometime residual problems of failure of proper healing of fractures with the restriction of movements of knee, shortening, and added risk of compartment syndrome in the proximal tibia fracture. There is always risk of post-operative infection and infected non-union in extensive open surgical procedure and internal fixation. Hence, there is always look out for the middle path procedure for a solution to the above said problems with the added advantage of less hospital stay and early return to work by minimal invasive procedure and stabilization of fracture reduction by multiple K-wire fixation with a frame applied externally. Stabilization of fracture with reduced pain allows early movements of neighbouring joint knee and ankle; hence, reduces the chances of fracture diseases. With this we have been stimulated to take-up the study of managing the proximal tibia fracture by mini external fixator. Aim: The aim of this study was to manage proximal tibia fractures by mini external fixator and evaluate the results and efficacy of this method. Material and Method: A total of 30 patients having proximal tibial fractures admitted at our center between 2008 and 2010 were taken and the procedure carried out was closed manipulative reduction and stabilization with mini external fixator. All acute proximal tibia fractures including tibial plateau fractures above 17 years of age of either sex were included in the study. Fracture more than 3 weeks old were excluded from the study. Result: Out of 30 cases 13 were excellent, 14 cases good, and 3 showed fair. It was found that type 5 and 6 of Schatzker′s classification have lesser outcome type of fractures Conclusion: We have found that management of the proximal tibia fractures by mini external fixation method has a better outcome. Early mobilization of knee in the proximal tibia fractures after

  16. Nonlinear increasing axial gap stiffness in type II external skeletal fixation: a mechanical study. (United States)

    Kowaleski, Michael P; Marston, Mathew T; Kraus, Karl H


    To quantify the effect on gap stiffness and cranial to caudal bending stiffness of conversion of the 6 distal clamps of planar bilateral fixator models to sliding clamps and the effect of attachment of composite beams to the sliding clamp models. Mdash;Mechanical testing performed on models. Five models using birch dowels and a commercially available external skeletal fixator system. A segmentally comminuted, middiaphyseal fracture was simulated with the use of wooden dowels, and a bilateral 6-pin fixator was applied to create each of 5 models. The models were mechanically tested with all fixed clamps, with the 6 distal clamps converted to sliding clamps and with composite beams attached to the sliding clamp models. Testing was carried out in axial loading with physiologically relevant loads for a canine model, and in bending in the cranial to caudal plane. Sliding clamp fixators with composite beams attached exhibited a nonlinear increase in axial loading gap stiffness as load increased. The composite beam group also exhibited an increase in cranial to caudal bending stiffness as compared with fixed clamp and sliding clamp models. Using composite beam elements, planar bilateral external fixators can be constructed such that the fracture site would undergo controlled amounts of displacement at low loads and lessening displacement at higher loads. The nonlinear stiffness profile attained by the addition of composite beam elements to a planar external fixator allows controlled axial micromotion at the fracture site. Because controlled axial micromotion appears to stimulate fracture healing, a nonlinear stiffness profile of this type should enhance fracture healing. Copyright 2003 by The American College of Veterinary Surgeons

  17. Outcomes following the treatment of bicondylar tibial plateau fractures with fine wire circular frame external fixation compared to open reduction and internal fixation: A systematic review. (United States)

    Boutefnouchet, Tarek; Lakdawala, Ayaz S; Makrides, Panayiotis


    The aim of this study was to determine whether circular frame external fixation provides better outcome and fewer complications when compared to open reduction internal fixation. A systematic search was carried out and studies were critically appraised with narrative data synthesis. The systematic search yielded 131 titles and following a rigorous review only five articles were found to directly compare the two treatment methods. Fine wire frame external fixation offers a modest advantage of better soft tissue outcomes. All in all, there is no current high-level evidence to suggest that newer osteosynthesis plates provide better results.

  18. Stress corrosion cracking of an aluminum alloy used in external fixation devices. (United States)

    Cartner, Jacob L; Haggard, Warren O; Ong, Joo L; Bumgardner, Joel D


    Treatment for compound and/or comminuted fractures is frequently accomplished via external fixation. To achieve stability, the compositions of external fixators generally include aluminum alloy components due to their high strength-to-weight ratios. These alloys are particularly susceptible to corrosion in chloride environments. There have been several clinical cases of fixator failure in which corrosion was cited as a potential mechanism. The aim of this study was to evaluate the effects of physiological environments on the corrosion susceptibility of aluminum 7075-T6, since it is used in orthopedic external fixation devices. Electrochemical corrosion curves and alternate immersion stress corrosion cracking tests indicated aluminum 7075-T6 is susceptible to corrosive attack when placed in physiological environments. Pit initiated stress corrosion cracking was the primary form of alloy corrosion, and subsequent fracture, in this study. Anodization of the alloy provided a protective layer, but also caused a decrease in passivity ranges. These data suggest that once the anodization layer is disrupted, accelerated corrosion processes occur. (c) 2007 Wiley Periodicals, Inc.


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    Nageshwara Rao


    Full Text Available BACKGROUND & OBJECTIVES: Infected non - union of tibia per se is a challenge to treat. Subcutaneous bone causes susceptibility to compartment syndrome, non - responsive infection, non - union, fibrosis, sinuses, deformities, shortening and various other sets of problems which are assoc iated with it. Ilizarov External fixation provides correction of all the complications associated with non - union, bone gap, infection, shortening, and deformities. Objective of this study is to assess the efficacy and safety of Ilizarov fixator method of t reatment in infected non - union tibia and to study various complications associated with Ilizarov external fixation. MATERIALS AND METHODS: 23 patients admitted and treated in Government General Hospital under the Department of Orthopaedics during the perio d of May 2010 to December 2012 were included in the study. Results were evaluated according to ASAMI criteria . 1 RESULTS : 59% patients had excellent bony results, 27.3% had good bony results, 9.1% had fair bony results, 4.6% had poor bony results. 68.1% had excellent functional results, 9.1% had good functional results, 9.1% had fair functional results, 13.7% had poor functional results. CONCLUSION : Ilizarov external fixator system is the best device and best solution for infected non - union tibia management.

  20. External Fixation vs. Skeletal Traction for Treatment of Intertrochanteric Fractures in the Elderly. (United States)

    Kazemian, Gholam Hossein; Emami, Mohammad; Manafi, Alireza; Najafi, Farideh; Najafi, Mohammad Amin


    Hip fractures are one of the causes of disability amongst elderly patients. External fixator and skeletal traction are two modes of treatment. The aim of this study is to compare two different treatment modes for intertrochanteric fractures in elderly patients. Sixty elderly patients with intertrochanteric fractures were randomized for treatment with either skeletal traction (Group A) or an external fixation (Group B). In this study patients at least 60 years of age, with AO/OTA A1 or A2 type fracture and intertrochanteric fracture as a result of minor trauma, were enrolled. Acceptable reduction was achieved in eight and 26 patients of group A and B, respectively. The mean duration of hospitalization in Group A and Group B was 14.3 ± 1.1 and 2.2 ± 0.6 days, respectively. Significant differences between the two groups were observed, regarding acceptable reduction and duration of hospitalization. Less pain was observed in group B, at five days and twelve months after surgery; the average HHS was 57 and 66, in group A and B, respectively (P > 0.05). Treatment with an external fixator is an effective treatment modality for intertrochanteric fractures in elderly high-risk patients. The advantages include rapid and simple application, insignificant blood loss, less radiation exposure, adequate fixation, pain reduction, early discharge from the hospital, low cost and more favorable functional outcome.

  1. Multipurpose external fixation for unstable comminuted intraarticular fracture of distal radius. (United States)

    Siripakarn, Yongyuth; Suntarapa, Thongchai; Chernchujit, Bancha


    Most of the Intraarticular distal radius fractures are complex and unstable. They are caused by high-energy injuries. The optimal and appropriate treatment remains a topic of controversy. Many different methods of treatment have been advocated such as closed reduction maintained by cast, K-wire fixation with cast, and opened reduction with internal fixation with plate and screws or external fixation with or without K-wire augmentation. To study the efficacy of the TU Model External Fixator for the treatment of unstable intraarticular fracture of distal radius. This was assessed by radiographic anatomical alignment and clinical functional outcome. Between January 2009 and March 2011, 147 cases of displaced unstable intra articular fracture of distal radius were treated at Thammasat University Hospital. Among these, 35 cases were treated by closed reduction and fixed by TU Model External Fixator Their anatomical alignment (Jupitor and Knirk grading) and clinical outcome (Modified Green and O'Brien score) were assessed with at least 18 months of follow-up. The inclusion criteria are age more than 18 year and AO Type A2 to Type C3 unstable comminuted intraarticular fracture. The patients were excluded if they were Type II Gustillo open fracture, cannot follow the treatment protocol for at least two months, and the cases with volar marginal intraarticular fracture (AO type B or volar Barton pattern), or were younger than 18 year The anatomical outcome were good to excellent in 28 of 30 cases = 93%. The clinical outcome was excellent in 21 cases. The functional result (Green & O'Brien) were good to excellent in 28 of 31 cases = 90%. The study shows the functional and/or anatomical outcome for the treatment of the unstable intraarticular fracture of distal radius by the TU Model external fixator It demonstrated equally the efficacy of this device when compared to the previous studies by the other researchers. Therefore, the TU Model external fixator could be a new device

  2. A meta-analysis of outcomes of external fixation versus plate osteosynthesis for unstable distal radius fractures. (United States)

    Margaliot, Zvi; Haase, Steven C; Kotsis, Sandra V; Kim, H Myra; Chung, Kevin C


    External fixation and open reduction and internal fixation have been the traditional techniques for surgical fixation of unstable distal radius fractures. The existing literature has not identified which is superior, primarily because of the lack of comparative trials. We performed a comprehensive systematic review and meta-analysis of the current literature on external fixation and internal fixation of distal radius fractures to determine the dominant strategy based on available scientific evidence. We searched MEDLINE and EMBASE for English-language articles published between 1980 and 2004 that satisfied predetermined inclusion and exclusion criteria. The outcomes of internal and external fixation were compared using continuous measures of grip strength, wrist range of motion, and radiographic alignment and categoric measures of pain, physician-rated outcome scales, and complication rates. Outcomes were pooled by random-effects meta-analysis and meta-regression analysis was used to control for patient age, presence of intra-articular fracture, duration of follow-up period, and date of publication. Sensitivity analyses were used to test the stability of the meta-analysis results under different assumptions. Forty-six articles were included in the review with 28 (917 patients) external fixation studies and 18 (603 patients) internal fixation studies. Meta-analysis did not detect clinically or statistically significant differences in pooled grip strength, wrist range of motion, radiographic alignment, pain, and physician-rated outcomes between the 2 treatment arms. There were higher rates of infection, hardware failure, and neuritis with external fixation and higher rates of tendon complications and early hardware removal with internal fixation. Considerable heterogeneity was present in all studies and adversely affected the precision of the meta-analysis. The current literature offers no evidence to support the use of internal fixation over external fixation for

  3. Infection after spanning external fixation for high-energy tibial plateau fractures: is pin site-plate overlap a problem? (United States)

    Laible, Catherine; Earl-Royal, Emily; Davidovitch, Roy; Walsh, Mike; Egol, Kenneth A


    The purpose of this study was to determine whether overlap between temporary external fixator pins and definitive plate fixation correlates with infection in high-energy tibial plateau fractures. Retrospective chart and radiographic review. Academic medical center. Seventy-nine patients with unilateral high-energy tibial plateau fractures formed the basis of this report. Placement of knee-spanning external fixation followed by delayed internal fixation for high-energy tibial plateau fractures treated at our institution between 2000 and 2008. Demographic patient information was reviewed. Radiographs were reviewed to assess for the presence of overlap between the temporary external fixator pins and the definitive plate fixation. Fisher exact and t test analyses were performed to compare those patients who had overlap and those who did not and were used to determine whether this was a factor in the development of a postoperative infection. Development of infection in those whose external fixation pin sites overlapped with the definitive internal fixation device compared with those whose pin sites did not overlap with definitive plate and screws. Six knees in six patients developed deep infections requiring serial irrigation and débridement and intravenous antibiotics. Of these six infections, three were in patients with closed fractures and three in patients with open fractures. Two of these six infections followed definitive plate fixation that overlapped the external fixator pin sites with an average of 4.2 cm of overlap. In the four patients who developed an infection and had no overlap, the average distance between the tip of the plate to the first external fixator pin was 6.3 cm. There was no correlation seen between infection and distance from pin to plate, pin-plate overlap distance, time in the external fixator, open fracture, classification of fracture, sex of the patient, age of the patient, or healing status of the fracture. Fears of definitive fracture

  4. External fixation to correct tarsal-metatarsal fracture in rock pigeon (Columba livia

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    Leandro Almeida Rui

    Full Text Available ABSTRACT Orthopedic conditions, such as bone fractures, are very common in avian medicine. External fixators have been considered the gold standard for birds, since they allow early movement of the limbs and minimal invasive surgery. Fractures in several bones have been successfully treated in pigeons. However, to the best of our knowledge, this case represents the first report of successful surgical repair of tarsal-metatarsal fracture in rock pigeon. External fixator was made with four 24G catheters, being inserted manually proximal and distal to the fracture and connected with polymerizable acrylic. Radiographic consolidation of fracture was observed 60 days post-surgery and anti-inflammatory and antibiotic protocols were successful on avoiding pain and infection during surgery and bone healing.

  5. Pin guidance of reconstruction plate contour: an expanded role of external fixation. (United States)

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


    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. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  6. Novel external fixation fracture method with circular locking mechanism compared with the application of dynamic axial external fixator on experimental tibial model ensures better stability in bending and favourable performance in dynamic loads. (United States)

    Pavic, Arsen; Kodvanj, Janos; Sabalic, Srecko; Cukelj, Fabijan; Bakota, Bore


    The aim of this study was to compare the biomechanical properties of a novel tibial external bone fracture fixator with a circular locking mechanism with standard dynamic axial external fixator. In order to investigate the prototype usability in experimental conditions, a biomechanical study was performed in which 42 polyacetal tubes set in 14 experimental groups and subgroups represented the fractured tibia that were fixed by a standard dynamic axial external fixator and a novel fixator. Displacements under static and dynamic loads were measured, with static ones corresponding to three directions of fragment movement and dynamic simulating the human gait. Analysis was performed in SPSS v13, with significance set at Pexternal fixator outperformed the novel one in the situations of bending with "fragments in contact" study groups. There were no significant differences in dynamic load, despite better numerical result of the novel fixator. The novel fixator is expectedly faster applicable and offers greater extent of external fixation flexibility. Further developments of this model thus seems justified in both construction improvement and on clinical application. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. External fixators and sudden-onset disasters: Médecins Sans Frontières experience. (United States)

    Boillot, Francois; Herard, Patrick


    Carrying out osteosynthesis is challenging, and controlling for results and complications is necessary to define the limits of acceptable complications. Within the context of sudden-onset disasters, comparing internal with external osteosynthesis remains controversial. The most recent and significant Médecins Sans Frontières (MSF) experience with osteosynthesis was following the earthquake in Haiti in 2010: 353 external fixators were used in the 12 months following the catastrophe, 62 of which were used in the first month. Carrying out internal osteosynthesis was possible two weeks following the earthquake. The most common indication for open tibial fracture was Gustillo grade 2 or 3. Conversion rate from external to internal osteosynthesis remains anecdotal for several practical reasons. Advantages and drawbacks of external fixators are discussed in the context of precarious situations frequently encountered by MSF. External osteosynthesis as a primary and definitive treatment for open fractures, especially of the leg, remains the most frequently used and best-adapted procedure in the context of sudden-onset disasters, even though not ideal.

  8. [Use of an external fixator in open tibial shaft fractures as definitive treatment]. (United States)

    Patiño-Domínguez, L A; Reyes-Pantoja, R; Silva-Méndez, J A; Vargas-Espinosa, J M


    We conducted a study evaluating the clinical and radiologic results of the open tibial shaft fractures using an external fixator as definitive treatment. Clinical, observational, descriptive, prospective and longitudinal study. Forty-six patients were included, 40 males (87%) and 6 females (13%), whose age was 31.02 +/- 14.62 years; the time elapsed from the accident to admission in the Emergency Room was 1-16 hours, with a mean of 5.1 +/- 3.35 hours. Ten patients (21.74%) had a Gustilo grade I open fracture, and 36 patients (78.26%) a Gustilo grade II fracture. They were also classified according to the AO classification, with the following resulting groups: 13 (28.9%) patients were A3, 12 (26.1%) were B3, 8 (17.4%) B1, 8 (17.4%) were B2, and 5 (10.9%) were A2. The dynamization of the fixator was done at a mean of 11.56 +/- 1.10 weeks. Forty-three patients had healing at 23.51 +/- 3.62 weeks; Gustilo I fractures healed at 22.8 +/- 3.5 weeks; Gustilo II fractures at 23.7 +/- 3.7 weeks, with a P value of 0.48. In 3 patients (6.53%), due to absence of healing, the external fixator was exchanged for an intramedullary nail with a bone graft, with healing occurring at 18 weeks. Six infections (13%) were reported at the nail insertion site; angulations ranged from 0 degrees to 8 degrees, which is tolerable. This fixator is safe in properly selected patients, since the few complications that occurred are similar to other reports using different internal fixation methods.


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    V. G. Vinogradov


    Full Text Available Objective: to determine the stability of bone fragments fixation with an external fixation device in the simulation of bilateral partly unstable pelvic injuries of B type according to AO/ASIF classification and to identify the role of different fixation elements in the stability of fixation. Material and methods: the study was performed on the finite element model of a system “an external fixation device - pelvis” developed for a software package MSCNastran. Formation of a fracture of pubic and ischial pelvic bones was accomplished by means of rupture in the finite element network and decrease of elasticity modulus in the ilio-sacral joint on both sides up to 35 mm at the site of a fracture. Loads were carried on top of the body of the first sacral vertebra with a force of 500H.The second area of application of the load was from the bottom-up on the acetabular roof with a force of 250H. In this study the effect of different elements of an external fixation device on the stiffness of bone fragments fixation was evaluated. Symmetrical elements were removed both separately and together. As a result, the stiffness of a system decreased and the displacement at the fracture site increased. Conclusion: in a model of partly stable pelvic injuries accompanied by general rotation instability in the horizontal and sagittal planes to 35 mm, an external fixation device provided high stability of bone fragments (to 3 mm due to introduction of bone rods in the iliac wings with the obligatory introduction of the rod in the vertical branches of pubic bones and strengthening the anterior lower bar between the subsystems. What is more, installing the anterior upper bar or introduction of bone rods in the bodies of iliac bone are not necessary.

  10. Comparative study on three surgical techniques for intra-articular calcaneal fractures: open reduction with internal fixation using a plate, external fixation and minimally invasive surgery

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    Missa Takasaka


    Full Text Available ABSTRACT OBJECTIVE: To evaluate, compare and identify the surgical technique with best results for treating intra-articular calcaneal fractures, taking into account postoperative outcomes, complications and scoring in the Aofas questionnaire. METHODS: This was a retrospective study on 54 patients with fractures of the calcaneus who underwent surgery between 2002 and 2012 by means of the following techniques: (1 open reduction with extended L-shaped lateral incision and fixation with double-H plate of 3.5 mm; (2 open reduction with minimal incision lateral approach and percutaneous fixation with wires and screws; and (3 open reduction with minimal incision lateral approach and fixation with adjustable monoplanar external fixator. RESULTS: Patients treated using a lateral approach, with fixation using a plate had a mean Aofas score of 76 points; those treated through a minimal incision lateral approach with screw and wire fixation had a mean score of 71 points; and those treated through a minimal incision lateral approach with an external fixator had a mean score of 75 points. The three surgical techniques were shown to be effective for treating intra-articular calcaneal fractures, without any evidence that any of the techniques being superior. CONCLUSION: Intra-articular calcaneal fractures are complex and their treatment should be individualized based on patient characteristics, type of fracture and the surgeon's experience with the surgical technique chosen.

  11. Hybrid fixation in the bilateral sagittal split osteotomy for lower jaw advancement

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    Felipe Ladeira Pereira


    Full Text Available Miniplate and screw fixation has been widely used in bilateral sagittal split osteotomy, but some issues remain unclear concerning its lack of rigidity when compared to Spiessl's bicortical technique. This paper demonstrates the hybrid fixation technique in a case report. A 34-year-old female patient underwent a double jaw surgery with counter-clockwise rotation of the mandible fixed using the hybrid fixation technique. The patient evolved well in the postoperative period and is still under follow up after 14 months, reporting satisfaction with the results and no significant deviation from the treatment plan up to now. No damage to tooth roots was done, maxillomandibular range of motion was within normality and regression of the inferior alveolar nerve paresthesia was observed bilaterally. The hybrid mandibular fixation is clearly visible in the panoramic and cephalometric control radiographs. It seems that the hybrid fixation can sum the advantages of both monocortical and bicortical techniques in lower jaw advancement, increasing fixation stability without significant damage to the mandibular articulation and the inferior alveolar nerve. A statistical investigation seems necessary to prove its efficacy.

  12. Results of a compression pin alongwith trochanteric external fixation in management of high risk elderly intertrochanteric fractures

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    Aydin Arslan


    Conclusions: Treatment of very elderly, high risk patients' with intertrochanteric fractures with external fixation is effective. Compression pin maintained stability better than standard pins after weight bearing, especially for unstable intertrochanteric fractures.

  13. Vibration Testing Procedures for Bone Stiffness Assessment in Fractures Treated with External Fixation. (United States)

    Mattei, Lorenza; Longo, Antonia; Di Puccio, Francesca; Ciulli, Enrico; Marchetti, Stefano


    A bone healing assessment is crucial for the successful treatment of fractures, particularly in terms of the timing of support devices. However, in clinical practice, this assessment is only made qualitatively through bone manipulation and X-rays, and hence cannot be repeated as often as might be required. The present study reconsiders the quantitative method of frequency response analysis for healing assessments, and specifically for fractures treated with an external fixator. The novelty consists in the fact that bone excitation and response are achieved through fixator pins, thus overcoming the problem of transmission through soft-tissues and their damping effect. The main objective was to develop and validate a test procedure in order to characterize the treated bone. More than 80 tests were performed on a tibia phantom alone, a phantom with pins, and a phantom with a complete fixator. Different excitation techniques and input-output combinations were compared. The results demonstrated the effectiveness of a procedure based on impact tests using a micro-hammer. Pins and fixator were demonstrated to influence the frequency response of the phantom by increasing the number of resonant frequencies. This procedure will be applied in future studies to monitor healing both in in vitro and in vivo conditions.

  14. Comparative analysis of uniplanar external fixator and retrograde intramedullary nailing for ankle arthrodesis in diabetic Charcot′s neuroarthropathy

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    Nakul S Shah


    Results: All five (100% patients treated by intramedullary nailing achieved radiological union on an average follow-up of 16 weeks. The external fixation group had significantly higher rate of complications with one amputation, four non unions (66.7% and a delayed union which went on to full osseous union. Conclusion: The retrograde intramedullary nailing for tibio-talar arthrodesis in Charcot′s neuroarthropathy yielded significantly better outcomes as compared to the use of uniplanar external fixator.


    Sternick, Marcelo Back; Dallacosta, Darlan; Bento, Daniela Águida; do Reis, Marcelo Lemos


    To analyze the rigidity of a platform-type external fixator assembly, according to different numbers of pins on each clamp. Computer simulation on a large-sized Cromus dynamic external fixator (Baumer SA) was performed using a finite element method, in accordance with the standard ASTM F1541. The models were generated with approximately 450,000 quadratic tetrahedral elements. Assemblies with two, three and four Schanz pins of 5.5 mm in diameter in each clamp were compared. Every model was subjected to a maximum force of 200 N, divided into 10 sub-steps. For the components, the behavior of the material was assumed to be linear, elastic, isotropic and homogeneous. For each model, the rigidity of the assembly and the Von Mises stress distribution were evaluated. The rigidity of the system was 307.6 N/mm for two pins, 369.0 N/mm for three and 437.9 N/mm for four. The results showed that four Schanz pins in each clamp promoted rigidity that was 19% greater than in the configuration with three pins and 42% greater than with two pins. Higher tension occurred in configurations with fewer pins. In the models analyzed, the maximum tension occurred on the surface of the pin, close to the fixation area.

  16. Biomechanical comparison of supraacetabular external fixation and anterior pelvic bridge plating. (United States)

    Çavuşoğlu, Ali Turgay; Erbay, Fatma Kübra; Özsoy, Mehmet Hakan; Demir, Teyfik


    Unstable pelvic ring injuries are complex and risky injuries due to high morbidity and mortality. Although anterior pelvic external fixator is a suitable method for rapid stabilization of an injured pelvic ring, due to some disadvantages such as high complication rate, nerve damage, and difficulties of patient's mobility and comfort, there has recently been increased searching for alternative methods for stabilization of the pelvic ring. Pubic symphysis zone freely moves in pelvic models. This study aims to evaluate the biomechanical stability of anterior pelvic bridge plating and compare it with supraacetabular external fixators in an untreated unstable pelvic fracture model. Samples were loaded statically with 2-mm/min loading rate in single leg standing position. Maximum load was 2.3 kN. When loading the samples, photographs were taken continuously. Stiffness values were calculated from the load displacement curves. Some reference parameters were described and were measured from unloaded and 2.3-kN-loaded photographs of the test. The mean stiffness values were 491.14 ± 52.22, 478.55 ± 41.44, and 470.25 ± 44.51 N/mm for anterior pelvic bridge plating group, supraacetabular external fixator group, and Control group, respectively. According to the measured parameters from photographs, the mean displacement at the pubic symphysis was 4.7 ± 0.32, 15.8 ± 2.01, and 18.2 ± 0.47 mm for anterior pelvic bridge plating, supraacetabular external fixator, and Control group, respectively. The highest displacement in the pubic symphysis was found in Control group, and minimum displacement was observed in anterior pelvic bridge plating group. When the perpendicular distance between the right and left lower end of ischium was examined, it was observed that displacement was minimum in anterior pelvic bridge plating group compared to other two groups, regarding to the high stability of pubic symphysis. In conclusion, this study revealed

  17. External fixation of femoral defects in athymic rats: Applications for human stem cell implantation and bone regeneration

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    Terasa Foo


    Full Text Available An appropriate animal model is critical for the research of stem/progenitor cell therapy and tissue engineering for bone regeneration in vivo. This study reports the design of an external fixator and its application to critical-sized femoral defects in athymic rats. The external fixator consists of clamps and screws that are readily available from hardware stores as well as Kirschner wires. A total of 35 rats underwent application of the external fixator with creation of a 6-mm bone defect in one femur of each animal. This model had been used in several separate studies, including implantation of collagen gel, umbilical cord blood mesenchymal stem cells, endothelial progenitor cells, or bone morphogenetic protein-2. One rat developed fracture at the proximal pin site and two rats developed deep tissue infection. Pin loosening was found in nine rats, but it only led to the failure of external fixation in two animals. In 8 to 10 weeks, various degrees of bone growth in the femoral defects were observed in different study groups, from full repair of the bone defect with bone morphogenetic protein-2 implantation to fibrous nonunion with collagen gel implantation. The external fixator used in these studies provided sufficient mechanical stability to the bone defects and had a comparable complication rate in athymic rats as in immunocompetent rats. The external fixator does not interfere with the natural environment of a bone defect. This model is particularly valuable for investigation of osteogenesis of human stem/progenitor cells in vivo.

  18. Evaluation of body image and self-esteem in patients with external fixation devices: a Turkish perspective. (United States)

    Büyükyilmaz, Funda; Sendir, Merdiye; Salmond, Susan


    This descriptive study aimed to describe the body image and self-esteem of patients with external fixation devices. Fifty patients with external fixation devices who came for follow-up to the Ilizarov Outpatient Clinic of a university hospital in Turkey were included in this study. Data were collected by using a Demographic Questionnaire Form, Multidimensional Body-Self Relations Questionnaire (MBSRQ), and Coppersmith Self-Esteem Inventory. The perceived body image (197.58 +/- 25.14) and self-esteem (65.28 +/- 17.97) of the patients with external fixation devices were in the moderate range. There was no significant correlation between body image and self-esteem. Self-esteem was correlated with one's perception of whether external fixation impacted one's appearance and whether one wanted to avoid being seen by certain individuals because of the appearance of the external fixator. The study highlighted that body image disturbance and threats to self-esteem are not universal with the use of external fixation and need to be assessed individually.

  19. Skeletal traction versus external fixation for pediatric femoral shaft fractures: a comparison of hospital costs and charges. (United States)

    Nork, S E; Hoffinger, S A


    To compare the hospital costs, charges, and reimbursement for treatment of pediatric femur fractures by two treatment methods: external fixation and 90-90 traction with spica casting. Retrospective clinical review. Department of Orthopaedic Surgery, Children's Hospital Oakland, regional pediatric trauma center. Twenty-nine consecutive patients between the ages of five and ten with a fracture of the femoral shaft were treated by one of two methods: external fixation (sixteen patients) or 90-90 skeletal traction followed by spica casting (thirteen patients). External fixation or 90-90 traction followed by spica casting. Hospital billing data including costs, charges, reimbursement for the initial inpatient hospitalization, and outpatient financial data until fracture union and cessation of treatment. There was no difference in age, total treatment time, mechanism of injury, or number of associated injuries between the two groups. The average charge for treatment with skeletal traction and spica casting was $32,094 per patient versus $21,439 for external fixation (p traction and spica casting was $22,396 per patient versus $11,520 for external fixation (p traction group than for the external fixation group (22.3 days versus 4.7 days, p skeletal traction followed by spica casting.

  20. Optimizing Bone Defect Reconstruction-Balanced Cable Transport With Circular External Fixation. (United States)

    Quinnan, Stephen Matthew; Lawrie, Charles


    Distraction osteogenesis has proven effective in the management of tibial bone loss from severe trauma and infection. Unfortunately, pain and scarring from wires and half pins dragging through the skin and the required prolonged time in the external fixator make treatment difficult. Cable bone transport has been shown to improve cosmesis and decrease pain during transport. However, the published methods have limitations in that they have poor control of transport segment alignment, do not allow for lengthening of the limb, and do not permit weight bearing during the treatment process. We describe a novel method of cable bone transport that addresses each of these limitations with excellent control of alignment including the transport segment, easy conversion to allow limb lengthening, and full weight bearing throughout the treatment process. In addition, the method facilitates multifocal transport and safe conversion to intramedullary nail fixation, both of which can be used to substantially shorten the time of reconstruction.

  1. Caudal Elbow Luxation in a Dog Managed by Temporary Transarticular External Skeletal Fixation

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    K. Hamilton


    Full Text Available This case report details a caudal unilateral traumatic elbow luxation in a 4-year-old male neutered Labrador following a road traffic trauma. This is a highly unusual injury in the dog. The pathogenesis and successful treatment by closed reduction followed by stabilisation with a temporary transarticular external skeletal fixator are discussed. The dog was assessed at 4 weeks and 6 months after surgery. Findings at 6 months after treatment demonstrated a normal gait with no pain or crepitation. A mild amount of soft tissue thickening around the elbow was noted. The range of motion of the elbow was limited to 45 degrees of flexion and 150 degrees of extension. This is the first case of a traumatic caudal luxation of the elbow in a dog described in the English veterinary literature and the first report of successful management of an elbow luxation in a dog by closed reduction and temporary transarticular fixation.

  2. Use of external fixators for damage-control orthopaedics in natural disasters like the 2005 Pakistan earthquake. (United States)

    Awais, Syed; Saeed, Ayesha; Ch, Asad


    In the 2005 Pakistan earthquake, the great many injured with multiple fractures and open wounds provided a unique opportunity to practice damage-control orthopaedics. External fixators remain a time-tested tools for operating surgeons on such occasions. The locally manufactured, readily available Naseer-Awais (NA) external fixator filled such needs of this disaster with good outcome. This is a retrospective descriptive study of 19,700 patients that presented over seven months to the two centres established by the lead author (SMA) in Muzaffarabad and Mansehra just one night after the 2005 earthquake. A series of local and foreign orthopaedic surgeon teams operated in succession. The computerised patient data collection of 1,145 operations was retrospectively analysed. Of the 19,700 patients presenting to the SMA centres, 50% had limb injuries. Total fracture fixations were 1,145, of which 295 were external fixations: 185 were applied on the lower limb and 90 on upper limb, the majority were applied on tibia. External fixators are valuable damage-control tools in natural disasters and warfare injuries. The locally manufactured NA external fixator served the needs of the many limb injuries during the 2005 Pakistan earthquake.

  3. Dicondylar humeral fracture stabilisation in a dog using a transilial rod and external fixation. (United States)

    Au, K; Mattern, K L; Lewis, D D


    Repair of a Salter-Harris type IV dicondylar humeral fracture was performed on a 15-week-old pitbull terrier. Interfragmentary compression of the intracondylar component of the fracture was achieved with a transilial rod and locking nuts (Trans-ilial Rod; IMEX Veterinary, Inc.). The transilial rod was articulated with a modified type I external fixator which functioned as adjunctive stabilisation for the supracondylar component of the fracture. Fracture healing was confirmed radiographically five weeks following surgery. The dog had no appreciable lameness when examined 12 months after fracture repair.

  4. Management of Femoral Shaft Fracture in Klippel-Trenaunay Syndrome with External Fixator

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    Yogendra Gupta


    Full Text Available Klippel-Trenaunay syndrome (KTS is a rare complex malformation characterized by the clinical triad of capillary malformations, soft tissue and bone hypertrophy, and venous/lymphatic malformation. Fractures of long bones in such cases are challenging to treat. A 12-year-old female with this syndrome presented with femoral shaft fracture of right thigh. She was initially kept on skeletal traction for two weeks and then she underwent closed reduction and immobilization with external fixator with uneventful intraoperative and postoperative period. Fracture united at four and half months.


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    Full Text Available Neglected traumatic posterior knee dislocations were rare in orthopaedic literature more so after a surgical intervention . Majority of the injuries are associated with vascular trauma and distal or proximal fractures and complete disruption of anterior and posterior cruciate ligaments and nerve traction injuries. Traumatic knee dislocations are therefore treated as an orthopaedic emergency. There were no definitive guide lines to open reduction as well as conservative methods of treatment. The end results of functional recovery are still controversial with residual posterior subluxation. Here we present a case of neglected posterior knee dislocation treated with closed manipulation and uni planar external fixator

  6. External fixator frames as interim damage control for limb injuries: experience in the 2010 Haiti earthquake. (United States)

    Lebel, Ehud; Blumberg, Nehemia; Gill, Amit; Merin, Ofer; Gelfond, Reuven; Bar-On, Elhanan


    An earthquake occurred in Haiti on January 12, 2010. The center of earthquake and the most extensive damage occurred near the capital Port-au-Prince. There were an estimated 230,000 deaths with more than 250,000 others injured. The Israeli Defense Forces Field Hospital (IDF hospital) is a military unit composed of army-recruited (volunteer) medical personnel that was sent to Haiti to serve as a stand-alone center for early response until larger medical missions could become functional and take on the task of more sophisticated and long-lasting medical support. This study describes the use of external fixator frames for orthopedic damage control whereby bone stabilization in conjunction with soft tissue care serves as a stopgap until more comprehensive therapy is forthcoming. Data were collected from patients' files (generated at the IDF hospital) regarding the use and immediate outcome of limbs stabilized by external fixator frames. During the 10 days of the IDF hospital's activity, a total of 1,111 patients were admitted; 244 surgical procedures were performed under general or regional anesthesia and of these, the orthopedists performed 221 (90%) surgical procedures. Seventy-three fractures were stabilized operatively by application of an external fixator. Most of the frames were applied on fractures (closed and open) of the lower limbs (48 on femur and 24 on tibia/fibula). All procedures were performed in a field-style operating room. Sterile technique was possible only for elements actually inserted into the patient. Limb alignment was based on manual palpation: intraoperative fluoroscopy was not available; soft tissue care followed bone stabilization. No patient died. All patients completed urgent stabilization at the IDF hospital and were transferred to other facilities or discharged for home care. We describe "orthopedic damage control" using external fixator frames for bone stabilization and soft tissue care as a viable approach in the context of a mass

  7. Correction of Blount's disease by a multi-axial external fixation system. (United States)

    Pandya, Nirav K; Clarke, Sylvan E; McCarthy, James J; Horn, B David; Hosalkar, Harish S


    Blount's disease is a multi-planar deformity affecting the pediatric population which leads to varus alignment of the lower extremities. The Multi-Axial Correction (MAC) monolateral external fixation system (Biomet, Parsippany, NJ, USA) is a non-circular fixator that was developed as a response to the technical difficulty for both patients and physicians of placing, managing, and tolerating a circular fixator. The purpose of this study was to determine the efficacy of the MAC system for the treatment of pediatric patients with Blount's disease. A retrospective analysis of 17 consecutive patients with surgically corrected Blount's disease using the MAC system with tibial and fibular osteotomies was identified. Patient charts and radiographs at three different time points (pre-operative, fixator removal, and final follow-up) were reviewed. The mechanical axis deviation (MAD), tibial-femoral angle (TFA), medial proximal tibial angle (MPTA), and posterior proximal tibial angle (PPTA) were measured in the MAC group at the three time points mentioned previously. The total wear time, total operative time, and post-operative complications were noted. The MAC system was able to correct the deformity of Blount's disease as measured by a decrease in the MAD (40.2 +/- 29.3 mm; P MAD (20.5 +/- 12.7 mm medial), TFA (8.0 +/- 4.1 degrees varus), and MPTA (83.7 +/- 8.1 degrees ) after correction with the MAC system were close to what is considered as normal for these indices. The most common complications noted were superficial pin tract infections and/or cellulitis, with no patients having nerve palsy, compartment syndrome, non-union, or leg length discrepancies. The total time that the fixator was on the patients prior to removal was 130.6 days (standard deviation [SD] = 44.8). The mean operative time was 120.6 min (SD = 21.2). Correction of Blount's disease with osteotomy of the tibia and fibula as well as dynamic fixation with the MAC system achieved deformity correction as

  8. External fixation in the treatment of severe tibial fractures complicated by soft tissue injury. (United States)

    Słuzałek, Maciej; Gaździk, Tadeusz S; Mrozek, Stanisław; Ryba, Jan


    Background. In recent years multiple injuries to the tibial shaft have become increasingly common. High-energy impacts cause comminuted fractures, often accompanied by damage to neural and vascular structures, muscle, and surface layers. The key to good healing is preserving normal blood supply. Serious damage to the tibia should be treated by external stabilization. Material and methods. A group of 23 patients with severe tibial fractures accompanied by soft-tissue injures were treated surgically, using Polfix, Ilizarov and Dynastab external stabilizers. Open fractures were classified according to the Gustillo-Anderson scale. Internal bone transport and the Ilizarov apparatus were used for the treatment of fractures with bone defect. Bone infections were treated with targeted antibiotic therapy and flush drainage. In cases with staphylococcus infection anti-vaccination was used. Plastic surgery was performed to cover soft tissue defects. Polfix stabilizers were removed after 35 weeks, Ilizarov after 45 weeks, and Dynastab after 18 weeks. The Sarmiento cast was applied in 6 cases. Results. In all patients treated with external fixation good results we observed. Conclusions. In the treatment of open tibial fractures complicated by significant bone defects and soft-tissue defects (type IIIB/C), the methods of choice are Ilizarov or Dynastab stabilizers. Polfix or Dynastab stabilizers are suitable for open fractures of types I-IIIA. Serious tibial injury necessitates the use of various kinds of skin grafts, so the best solution is regular cooperation with a plastic surgeon. Treatment with Sarmiento's functional plaster cast is a valuable supplement to external fixation.

  9. Open Dislocation of Ankle without Fracture Treated with an External Fixator. (United States)

    Sayit, Emrah; Sayit, Asli Tanrivermis; Zan, Elcin


    Ankle dislocations are orthopedic emergencies that require immediate treatment to avoid neurovascular impairment. They are usually accompanied by one or more comminuted fractures of the ankle mortis. In rare circumstances, such as high-energy trauma, the ankle dislocations may not be accompanied by concomitant malleolar fractures and, thus, are named "pure ankle dislocations". We presented a very rare and interesting case of an open medial dislocation of the ankle without associated fracture in an 18-year-old man with no known predisposing risk factors. The patient was admitted to the emergency department after sustaining a catastrophic trampoline accident resulting in severe inversion of the right ankle. The patient was treated with an external fixator and was mobilized early in the post-surgical course. Despite initial presentation that revealed lack of posterior tibial pulse, the post-surgical course was uneventful, with full functional recovery and joint mobility. The primary goals of treatment are immediate reduction of the joint and relief of neurovascular stress. External fixation is a prompt, fairly easy treatment that one should keep in mind in pure ankle dislocations. Nonetheless, ligamentous restoration and early mobilization were the key elements as seen in our case for full functional recovery. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

  10. Plating, nailing, external fixation, and fibular strut grafting for non-union of humeral shaft fractures. (United States)

    Padhye, Kedar P; Kulkarni, Vidhisha S; Kulkarni, G S; Kulkarni, Milind G; Kulkarni, Sunil; Kulkarni, Ruta; Patil, Mayur D; Ravi, Priyanka Y


    To compare various treatment modalities (plating, Ilizarov external fixation, and non-vascular fibular cortical strut grafting) for non-union of humeral shaft fractures. Records of 9 women and 26 men aged 24 to 71 (mean, 42) years who presented with non-union of humeral shaft fractures were reviewed. The humeral shaft fractures were secondary to low-energy trauma (n=22) or vehicular accidents (n=13) and involved the proximal (n=9), middle (n=15), and distal (n=11) regions. 13 of the fractures were open. Infection was evident in 8 of the non-unions. For non-unions with infection (n=8), a 2-stage procedure entailing temporary Ilizarov fixation followed by plating was used. For non-unions without infection (n=23), one-stage plating and cancellous bone grafting was used. For non-unions of osteoporotic bone (n=4), one-stage non-vascularised fibular strut grafting was used. Outcome was measured using the Disabilities of the Arm, Shoulder and Hand (DASH) scoring system. The 35 patients were followed up for a mean of 16 (range, 6-60) months. All achieved bone union except for one (who had persistent infection). Respectively for non-unions with infection, nonunions without infection, and non-unions of osteoporotic bone, the mean times to bone union were 6.5 (range, 4-10), 5 (range, 4-8), and 10 (range, 6-14) months, the mean improvement in DASH score was 30, 43, and 18, and malalignment was noted in 5, 2, and one patient. Three patients had a preoperative radial nerve palsy for which standard tendon transfer was performed 6 weeks after treatment for non-union. Compression plating achieved the best results. An external fixator may be used temporarily for infected non-unions. Fibular strut grafting may be used when non-unions warrant additional stability.

  11. Technique and considerations when using external fixation as a standard treatment of femoral fractures in children. (United States)

    Hedin, Hanne; Larsson, Sune


    Femoral fractures in children can be treated effectively and with a low complication rate by using external fixation. However, as with most treatment modalities there is a learning curve to be considered. The aim of this paper is to report "tricks" and different considerations that we have learned to be of value based on experience gained during a prospective and consecutive study of 98 femoral fractures in children aged 3-15 years. Our experience is based on the use of a unilateral fixator with the option to apply axial dynamisation. Traction prior to operation is not needed if the child is operated on within 24h. During surgery a traction table will prevent significant malrotation and facilitate reduction prior to insertion of the pins. Four 4 or 5mm pins are sufficient for adequate stability in children. Transverse skin incisions are preferable for pin insertion as the scars become smaller and the soft tissue irritation during activity is less when compared with longitudinal incisions. Unrestricted weight-bearing can be allowed. A nihilistic approach to pin site care with daily showers is as effective as more aggressive treatment with local antiseptics. Pin infections can occur but are mild and can be treated locally or with a short period of antibiotics taken orally. Pin-loosening and deep infections are very uncommon. By using external fixation, malunion, overgrowth or delayed union can almost be avoided completely. Re-fractures are rare and occur only after significant trauma. Treatment time is relatively short. No physiotherapy or further protection of the leg is necessary during or after healing.

  12. Epoxy putty external skeletal fixation in a tibiotarsal fracture of a wild choroy parakeet (Enicognathus leptorhynchus

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    J. I. Arias


    Full Text Available Tibiotarsal fractures are common in birds because in most birds this is the longest, most exposed bone in the leg. Transverse fractures are most common and rotational and shear forces must be stabilized in order to achieve good bone regeneration. A 230g male Slender-billed Parakeet or Choroy parakeet (Enicognathus leptorhynchus, with more than five years of age, was received with non-weight bearing lameness with 24 hours duration. X-rays were taken, and these revealed a closed, complete, non-comminuted transverse fracture of the distal diaphysis of the left tibiotarsal bone. Fixation was planned with 10-minute fast-setting epoxy putty. In order to assess the temperature of polymerization of the epoxy dough and the possibility of heat-bone necrosis, the temperature was recorded every 30 seconds for 12 minutes with three different amounts of the epoxy material in an ex vivo test. The temperature of the pieces reached a peak of 50-60ºC, where the highest peak corresponds to the highest amount of material. When approximately 6g of putty were used, the peak temperature reached only 51ºC. This peak changed to 58ºC when 4 times more epoxy was mixed and measured. If the temperature of the pins inserted in the bone exceeds 70ºC, bone necrosis could occur. In light of these results, the fracture was treated with 6 g of epoxy putty that was allowed to polymerize over a 1A 2/2 external skeletal fixation, with 1-mm pins bent at 90º and joined together with cerclage wire. At 6 weeks after surgery the bird had formed a good primary bone callus, and the external fixators were therefore removed. With this approach a satisfactory recovery of the patient was achieved with normal use of the affected limb.

  13. Damage control orthopaedics: Variability of construct design for external fixation of the lower extremity and implications on cost. (United States)

    Logan, Catherine; Hess, Arthur; Kwon, John Y


    To evaluate relative cost of external fixator constructs applied for damage control purposes in a cohort of advanced orthopaedic trainees and orthopaedic staff traumatologists. We also sought to evaluate physicians' understanding of component cost. Participants were asked to apply an external fixator for three separate fracture patterns in damage control fashion. A total of 19 physicians (nine PGY-4 residents, five PGY-5 residents, two orthopaedic trauma fellows and three orthopaedic staff traumatologists) participated. Total construct cost was calculated. Participants provided an estimate of the cost of each component in a fill-in format survey. Main outcome measures included cost of external fixator construct applied and the estimated cost of external fixator components. Average whole sale cost of an external fixator construct was $5252 (±$1798). Of the three fracture types examined, the tibial plafond fracture external fixator construct on average cost the most, followed by the tibial plateau fracture and the femur fracture construct. The large ex-fix combination clamp was the major contributor to cost for each construct. The combination clamp may be substituted for a multi-pin clamp, resulting in significant cost savings. The self-drilling Schanz pin and the large ex-fix combination clamp were most highly underestimated (25% and 22% of their actual cost, respectively). Innumerous construct designs exist and even small changes can significantly impact cost. Knowledge of component cost is low among staff and trainees. Education of component cost is vital to allow adequate consideration of construct design prior to fixator application. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Lengthening With Monolateral External Fixation Versus Magnetically Motorized Intramedullary Nail in Congenital Femoral Deficiency. (United States)

    Szymczuk, Vivian L; Hammouda, Ahmed I; Gesheff, Martin G; Standard, Shawn C; Herzenberg, John E


    Limb lengthening for congenital femoral deficiency (CFD) with or without fibular hemimelia can be performed with both external and internal devices. The purpose of this study is to compare clinical outcomes of femoral lengthening utilizing monolateral external fixation versus a magnetically motorized intramedullary nail in patients with CFD with or without fibular hemimelia. This retrospective review included 62 patients with femoral lengthening, 32 patients had monolateral external fixation (group A), 30 patients had internal lengthening nail (group B). Mean age in years was 9.4±3.8 and 15.4±4.9 for groups A and B, respectively. Mean follow-up in years was 4.47±2.7 and 1.86±0.7 years for groups A and B, respectively. Mean lengthening achieved was 5.6±1.7 and 4.8±1.4 cm for group A and group B, respectively (P=0.052). Mean distraction index was 0.7±0.2 mm/d for group A and 0.7±0.2 mm/d for the group B (P=0.99). Mean consolidation index for group A was 29.3±12.7 and 34.8±11.2 d/cm for group B (P=0.08). Mean arc of motion before surgery and at final follow-up were similar between groups (P=0.35). Group A had significantly less range of motion at the end of distraction (P=0.0007) and at consolidation (P<0.0001). Both groups had similar rates of obstacles and complications. A significant difference between groups was found in the total problems (P<0.001) specifically with pin site/superficial infection (P<0.0001). The intramedullary nail had superior range of motion during the lengthening phase and at consolidation and an overall lower problem complication rate, while maintaining similar distraction and healing indices to monolateral external fixation. Internal lengthening nails represent a significant advance in technology for CFD lengthening. Level IV-therapeutic.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share

  15. Treatment of Gustilo grade III tibial fractures with unreamed intramedullary nailing versus external fixator: a meta-analysis. (United States)

    Fang, Xiao; Jiang, Lei; Wang, Ying; Zhao, Liangyu


    Unreamed Intramedullary nailing and external fixation are 2 major treatments widely used in Gustilo grade III open tibial fractures, but the difference in effectiveness and complication remains controversial. We retrieved original publications of comparative studies from medical literature databases and selected 9 of them for a meta-analysis. Observation items include malunion and deep infection rate, non-union and comparison of time to union. The analysis showed a lower malunion rate using unreamed intramedullary nailing than external fixation. No significant differences were revealed in deep infection/nonunion rate and time to union. More studies of larger scale and better design are needed to reach an ultimate and definite conclusion.

  16. Delayed treatment of unstable proximal interphalangeal joint fracture-dislocations with a dynamic external fixator. (United States)

    Shen, Xiao Fang; Mi, Jing Yi; Rui, Yong Jun; Xue, Ming Yu; Chou, Jiandong; Tian, Jian; Chim, Harvey


    Fracture-dislocations of the proximal interphalangeal joint (PIPJ) remain a challenging problem to treat. Although there are a number of papers describing the use of dynamic external fixators and force couples for treatment of unstable PIPJ fracture-dislocations acutely, the literature is scarce on delayed treatment of PIPJ fracture-dislocations, where malunion of the articular surface may theoretically compromise postoperative range of motion (ROM) at the PIPJ. The purpose of this study was to evaluate the effectiveness of dynamic distraction external fixation (DDEF) for the delayed treatment of PIPJ fracture-dislocations at least 3 weeks after the inciting injury. Ten consecutive patients were treated with delayed DDEF between 2010 and 2013. Postoperative ROM at the PIPJ was measured. Disabilities of the Arm, Shoulder and Hand (DASH) score and Michigan Hand Outcomes Questionnaire were administered to all patients postoperatively. Mean time from injury to surgery was 27.5 days. The mean follow-up period was 23.7 months (range 10-36). The mean active ROM at the PIPJ on final postoperative follow-up was 83.9° (range 52-100). None of the patients experienced pin-tract infections. Mean DASH score was 3.7+3.4 and mean Michigan Hand Outcomes Questionnaire score was 97.3+3.0. All patients returned to work and resumed normal activities. Delayed treatment of unstable PIPJ fracture-dislocations with a DDEF is effective in restoring function to the PIPJ. Nascent malunion of the PIPJ articular surface does not compromise postoperative outcomes and the joint surface undergoes remodelling over time to restore a smooth and functional articular surface. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Decreasing bacterial colonization of external fixation pins via nitric oxide release coatings (United States)

    Holt, Joshua; Hertzberg, Brian; Weinhold, Paul; Storm, Wesley; Schoenfisch, Mark


    Objective Bacterial infection of the pin tract represents the most common complication associated with external fixation. This study was designed to evaluate the antibacterial activity of nitric oxide (NO) releasing xerogel films applied to commercially pure titanium pins in a rat model. Methods Pins were coated with xerogel solution via a dip-coating procedure. Half of the xerogel coated implant pins were modified into NO-donors and served as the NO releasing group while the remaining pins were left unmodified to serve as non-NO releasing xerogel coated controls. Acid etched pins served as uncoated controls. Animal selection was randomized and every rat had one pin from each of the three groups randomly allocated to the 3rd, 4th, or 5th tail vertebrae. Quantification of bacterial infection was performed 48 days post-operatively and the tissue-implant interface was inspected for clinical signs of infection on days 14 and 28 post-implantation. Results Pin tract bacterial colony counts of the NO releasing group (170K±181K) were significantly lower than both the xerogel coated group (677K±675K) and the control group (1,181K±2,717K) 48 days postoperatively (pcoated group and the control group. The NO releasing group also had significantly fewer clinical signs of infection than both the coated and the control groups on postoperative day 28 (pcoatings can inhibit bacterial colonization of external fixation pins both during the initial postsurgical period and up to 48 days post-implantation. PMID:21637124

  18. External fixation by Joshi′s external stabilizing system in cases of proximal humerus fractures in elderly subjects

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    Soumya Ghosh


    Full Text Available Fracture of the proximal humerus is a common and debilitating injury occurring mainly in elderly females and accounts for 4-5% of all adult fractures. Patients with displaced, unstable proximal humeral fractures may have improved outcomes if managed operatively. Objectives: To study the effect of using Joshi′s external stabilizing system (JESS for the management of fractures of proximal humerus in elderly. Materials and Methods: This prospective study was conducted in a tertiary care hospital in West Bengal on 28 subjects with proximal humerus fractures. As per Neer′s classification, 3- and 4-part fractures were included and prepared for JESS fixation. The results of the treatment were evaluated as per Neer′s criteria. Patients were followed up for 10 − 12 months. Results: Among 18 females and 10 males, 22 had 3-part fracture and 6 had 4-part fracture. Mean duration of JESS application was 10 weeks. Among patients with 3-part fractures 4 cases had excellent result, 12 had satisfactory result, 4 had unsatisfactory result and treatment failed in 2 cases. With 4-part fractures, 2 cases had unsatisfactory result and 4 cases were failures. Conclusion: JESS is an alternative option for the treatment of proximal humerus fractures, especially in elderly patients with osteoporosis, showing excellent to good results in cases of Neer′s type 3-part fracture.

  19. Treatment of femoral shaft fractures with monoaxial external fixation in polytrauma patients [version 1; referees: 3 approved

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    Gianluca Testa


    Full Text Available Background: Femoral shaft fractures, typical in younger people, are often associated with polytrauma followed by traumatic shock. In these situations, despite intramedullary nailing being the treatment of choice, external fixation could be used as the definitive treatment. The aim of this study is to report evidence regarding definitive treatment of femoral shaft fractures with monoaxial external fixation. Methods: Between January 2006 and December 2015, 83 patients with 87 fractures were treated at the Department of Orthopaedics and Traumatology CTO of Turin, with a monoaxial external fixation device. Mean age at surgery, type of fracture, mean follow-up, time and modalities of treatment, non-weight bearing period, average healing, external fixation removal time, and complications were reported. Results: The average patient age was 31.43±15.19 years. In 37 cases (42.53% the right femur was involved. 73 (83.91% fractures were closed, and 14 (16.09% were open. The average follow-up time was 61.07±21.86 weeks.  In 68 (78.16% fractures the fixation was carried out in the first 24 hours, using a monoaxial external fixator. In the remaining 19 cases, the average delay was 6.80±4.54 days. Mean non-weight bearing time was 25.82±27.66 days (ranging from 0 to 120. The 87 fractures united at an average of 23.60±11.37 weeks (ranging from 13 to 102. The external fixator was removed after an average of 33.99±14.33 weeks (ranging from 20 to 120. Reported complications included 9.19% of delayed union, 1.15% of septic non-union, 5.75% of malunion, and 8.05% cases of loss of reduction. Conclusions: External fixation of femoral shaft fractures in polytrauma is an ideal method for definitive fracture stabilization, with minimal additional operative trauma and an acceptable complication rate.

  20. Dual Fixation of Calcaneal Tuberosity Avulsion with Concomitant Achilles Tendon Rupture: A Novel Hybrid Technique

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    Gautham Prabhakar


    Full Text Available Fracture of the calcaneal tuberosity with a concomitant Achilles tendon rupture presents a difficult challenge for the treating surgeon. The ultimate goal of treatment is to restore function of both the gastrocnemius-soleus complex and the Achilles tendon. This particular subset of fractures occurs often in diabetics and elderly patients with osteoporosis making fixation of the displaced fragment rather complex. If the Achilles tendon disruption is only discovered later once the fracture is healed, subsequent management is difficult with surgical treatment being more morbid. While this is a rare injury, the consequences of a missed chronic Achilles tendon disruption are severe with significant dysfunction. It is therefore important to have a high index of suspicion for concomitant injury and to be prepared for dual fixation. We present a novel hybrid surgical fixation technique, which may be used in this instance.

  1. Prevention of pin tract infection in external stainless steel fixator frames using electric current in a goat model

    NARCIS (Netherlands)

    van der Borden, Arnout J.; Maathuis, Patrick G. M.; Engels, Eefje; Rakhorst, Gerhard; van der Mei, Henny C.; Busscher, Henk J.; Sharma, Prashant Kumar

    Pin tract infections of external fixators used in orthopacclic reconstructive bone surgery are serious cornplications that can eventually lead to periostitis and osteomyelitis. In vitro experiments have demonstrated that bacteria adhering to stainless steel in a biotilm mode of growth detach under

  2. [Case-control study on T-shaped locking internal fixation and external fixation for the treatment of dorsal Barton's fracture]. (United States)

    Chen, Huan-qing; Wen, Xi-le; Li, Yang-ming; Wen, Cong-you


    To compare clinical effect of T-shaped locking internal fixation and external fixation in treating dorsal Barton's fracture,and investigate selective strategy of internal fixation. From January 2008 to January 2013, 100 patients with dorsal Barton's fracture were randomly divided into two groups. In treatment group, there were 30 males and 20 females with an average age of (33.8±3.6) years old;30 cases were type B, 20 cases were type C;and treated with T-shaped locking internal fixation. In control group, there were 32 male and 18 females with an average age of (32.9±3.4) years old; 29 cases were type B, 21 cases were type C; and treated with external fixation. Volar tilt, ulnar deviation and radial height at 3 months after operation were detected and compared between two groups. Mechara functional evaluation were used to evaluate postoperative clinical effects. Clinical cure time, postoperative complications,joint mobility and function score were recorded and compared between two groups. In treatment group,volar tilt was (11.9±2.7)°, ulnar deviation was (20.8+ 2.9)°,and radial height was (10.9±1.8) mm; while volar tilt was (9.1±1.6)°, ulnar deviation was (17.1±2.9)°, and radial height was (8.1±1.5) mm in control group. Treatment group was better than control group in volar tilt, ulnar deviation and radial height. Clinical cure time in treatment group was(12.0±2.3) weeks, shorter than control group (18.0±4.1) weeks. The incidence of complications in treatment group was lower than control group. According to Mehara functional evaluation,20 cases got excellent results, 25 good, 3 moderate and 2 poor in treatment group; 16 cases got excellent results, 14 good, 10 moderate and 10 poor in control group. Treatment group was better than control group in clinical effects. T-shaped locking internal fixation with postoperative functional exercise for the treatment of dorsal Barton's fracture fits for biomechanics demands,and has advantages of stable fixation

  3. Distal tibial fracture treated by minimally invasive plate osteosynthesis after external fixation Retrospective clinical and radiographic assessment

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    Al. Șerban


    Full Text Available Fractures of the horizontal surface of the distal tibia are known commonly as pylon or plafond fractures, and represent 1-5% of lower extremity fractures, 7-10% of all tibial fractures. The protocol consisted of immediate (within eight to 24 hours open reduction and internal fixation of the fibula, using a fibular plate or one third tubular plate and application of an external fixator spanning the ankle joint. In the second stage, the treatment of proximal and distal tibial fractures with close reduction and MIPPO technique can preserve soft tissue, simplify operative procedure and decrease wound, obtain rigid internal fixation and guarantee early function exercises of ankle joint. In this study we evaluated 22 patients treated in Clinical Emergency Hospital Constanta between April 2012 - July 2013 diagnosed with multifragmentary fractures of the distal tibia. This study evaluates the treatment of complex fractures of distal tibia with locked plate after external fixation. There were 17 males and 5 females of mean age 51,7 years (31-68. The mean follow-up period was 14 weeks. (Ranging from 9-16 weeks. All patients were fully weight bearing at 16 weeks (ranging 9-16 weeks showing radiological union. There were no cases of failures of fixation, or rotational misalignment. No significant complication was observed in our patients. MIPO is an effective method of treatment for distal tibial fractures, reduce surgical trauma and maintain a more biologically favorable environment for fracture healing, reducing risks of infection and nonunion.

  4. A Novel Technique Using Customized Headgear for Fixation of Rigid External Distraction Device in an Infant With Crouzon Syndrome. (United States)

    Hariri, Firdaus; Rahman, Zainal Ariff Abdul; Mahdah, Saridah; Mathaneswaran, Vickneswaran; Ganesan, Dharmendra


    Rigid external distraction device is often indicated for superior midfacial advancement in pediatric syndromic craniosynostosis patients. Even though the technique is proven reliable to treat the functional issues related to the craniofacial deformity, major complications associated with its fixation, such as intracranial pin perforation and migration have been reported. We report a novel technique of using a customized headgear to prevent intracranial pin perforation over a very thin temporal bone region in an 8-month-old infant with Crouzon syndrome who underwent monobloc Le Fort III distraction osteogenesis using a combination of bilateral internal and a rigid external distraction device. The customized headgear provides a protective platform at the temporal region thus preventing intracranial pin perforation and allows stable fixation during the early phase of consolidation period to prevent central component relapse. The headgear can be used short term when rigid external distractor is indicated in infant patient but requires close monitoring because of risks of skin necrosis and temporal region indentation.

  5. [Nylon fixation at the internal and external canthus combined with skin graft for recurrent lower eyelids ectropion]. (United States)

    Yu, Li; Wang, Jiaqi


    To investigate the long-time effects of nylon fixation at the internal and external canthus combined with skin graft for recurrent lower eyelids ectropion. Under local anesthesia, the cicatricial contraction was released to repostion the lower eyelid. Then nylon thread was implanted in the fascial tissue at the upper margin of tarsus and was fixed on the periosteum at the internal and external canthus. The skin graft was applied on the wound of lower eyelids. 12 patients with lower eyelids ectropion at 19 sides were treated with primary healing. The patients were followed up for 6-24 months. All cases were satisfied with functional and cosmetic results. No complication and no recurrence happened. The technique of nylon fixation at the internal and external canthus combined with skin graft is an effective method for recurrent lower eyelids ectropion.

  6. No Higher Risk of CRPS After External Fixation of Distal Radial Fractures - Subgroup Analysis Under Randomised Vitamin C Prophylaxis. (United States)

    Zollinger, Paul E; Kreis, Robert W; van der Meulen, Hub G; van der Elst, Maarten; Breederveld, Roelf S; Tuinebreijer, Wim E


    Operative and conservative treatment of wrist fractures might lead to complex regional pain syndrome (CRPS) type I.In our multicenter dose response study in which patients with distal radial fractures were randomly allocated to placebo or vitamin C in a daily dose of 200mg, 500mg or 1500mg during 50 days, an operated subgroup was analyzed.48 (of 427) fractures) were operated (11.2%). Twenty-nine patients (60%) were treated with external fixation, 14 patients (29%) with K-wiring according to Kapandji and five patients (10%) with internal plate fixation. The 379 remaining patients were treated with a plaster.In the operated group of patients who received vitamin C no CRPS (0/37) was seen in comparison with one case of CRPS (Kapandji technique) in the operated group who received placebo (1/11 = 9%, p=.23). There was no CRPS after external fixation.In the conservatively treated group 17 cases of CRPS (17/379 = 4.5%) occurred in comparison with one in case of CRPS in the operated group (1/48 = 2.1%, p=.71).External fixation doesn't necessarily lead to a higher incidence of CRPS in distal radial fractures. Vitamin C may also play a role in this. This subgroup analysis in operated distal radial fractures showed no CRPS occurrence with vitamin C prophylaxis.


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    Full Text Available INTRODUCTION Fractures of the tibial plateau are the result of high energy trauma. Because of the nature of the trauma and the relative high frequency of soft tissue injuries, the rate of complications is high. Complications include joint stiffness, compartment syndrome, malunion, skin loss, osteomyelitis, and possible amputation. The Ilizarov external fixator helps in minimizing these complications by allowing early mobilization and weight bearing, minimal soft tissue injury and blood loss along with a stable fixation MATERIAL AND METHODS In our prospective study of 20 patients which included adults with open/closed Schatzker type 5 and 6 tibial plateau fractures, we studied the outcome following surgery with Ilizarov external fixation using the modified Hohl and Luck criteria which includes functional (extensor lag, valgus or varus instability, knee range of movement, walking distance and pain and radiological parameters (valgus/varus deformity, depression of articular surface and osteoarthritis. RESULTS All patients (n = 20 started weight bearing the day after the surgery. Functionally, 55% (n=11 had a excellent result, 40% (n=8 had a good result. 75% (n=15 had an excellent result radiologically. 3 patients out of 20 had a pin tract infection and one patient had an early implant removal due to non-compliance. CONCLUSION Treatment of open/ closed tibial plateau fractures with Ilizarov circular external ring fixator has proven to be advantageous in terms of early weight bearing and minimal soft tissue compromise. Excellent Radiological outcome is not necessarily associated with similar functional outcome.

  8. Comparison of external fixation versus the trauma pelvic orthotic device on unstable pelvic injuries: a cadaveric study of stability. (United States)

    Prasarn, Mark L; Horodyski, MaryBeth; Conrad, Bryan; Rubery, Paul T; Dubose, Dewayne; Small, John; Rechtine, Glenn R


    Most institutions treating pelvic fractures use some method of acute mechanical stabilization. This typically involves use of pelvic binders or circumferential sheeting, and/or external fixation. The comparative value of these different modalities is controversial. We hypothesized that an external fixator would provide more stability to an unstable pelvic injury than a commercially available binder device (trauma pelvic orthotic device [T-POD]). Unstable pelvic injuries (Tile C) were surgically created in five fresh whole human cadavers. Electromagnetic sensors were placed on the same position of each hemipelvis. The amount of angular motion during testing was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device. Maximum displacements were recorded during application of the stabilizing devices, bed transfer, logrolling, and head-of-bed elevation. External fixation frames were constructed by placing two 5.0-mm half pins into the iliac crest and then connected them with a 10-mm curved bar. The T-POD device was placed at the level of the greater trochanters as per manufacturer's recommendations. While logrolling the patient and performing bed transfers, the T-POD conferred more stability in all planes of motion, although this did not reach statistical significance. During elevation of the head of the bed, the T-POD allowed less motion in the sagittal and coronal planes but permitted equivalent motion in axial rotation. These differences were not statistically significant. There were no significant differences in stability conferred by an external fixator or a T-POD for unstable pelvic injuries. We advocate acute, temporary stabilization of pelvic injuries with a binder device and early conversion to internal fixation when the patient's medical condition allows. Copyright © 2012 by Lippincott Williams & Wilkins.

  9. A biomechanic comparison of an internal radiocarpal-spanning 2.4-mm locking plate and external fixation in a model of distal radius fractures. (United States)

    Wolf, Jonathon C; Weil, Wayne M; Hanel, Douglas P; Trumble, Thomas E


    To compare the biomechanic stability of distal radius fracture fixation with a new internal radiocarpal-spanning 2.4-mm locking plate, which acts as an internal distal radius fixator, versus a standard distal radius external fixator. The number of locking screws necessary for adequate fracture fixation was also assessed. Ten cadaveric specimens were mounted in a loading fixture with cables attached to the 2 flexor and 3 extensor wrist tendons. A 1-cm osteotomy was created to simulate an unstable distal radius fracture. The radiocarpal-spanning locking plate was fixed to the radius and index metacarpal with 4 screws proximally and 4 distally. The specimen was incrementally loaded through the tendons. Motion at the fracture site was determined. Screws were sequentially removed from the construct, the specimen was again incrementally loaded, and fracture motion was measured. The fixation was then changed to an external fixator, and the loading tests were repeated. Fracture fixation with the radiocarpal-spanning 2.4-mm locking plate was significantly more stable with 4 screws proximally and 4 screws distally (4 x 4) and with the 3 x 3 configuration than with the external fixator in both flexion and extension. The 4 x 4 screw configuration was not significantly different from the 3 x 3 screw configuration. The 4 x 4 screw configuration was significantly more stable than the 2 x 2 and 1 x 1 screw configurations in both flexion and extension. All internal fixator configurations and the external fixator showed more fracture displacement at increasingly higher loads. Fracture fixation with the new internal radiocarpal-spanning 2.4-mm locking plate is more stable than with a standard distal radius external fixator. Only three 2.4-mm locking screws proximally and three 2.4-mm locking screws distally are required for adequate fixation of the locking spanning plate.

  10. Treatment of Gustilo grade III B supracondylar fractures of the femur with Ilizarov external fixation. (United States)

    Kumar, Pankaj; Singh, Girish K; Singh, Mahipal; Bajraacharya, Suraj


    Twenty patients who had been treated with Ilizarov external fixation for a Gustilo grade IIIB supracondylar fracture of the femur were functionally assessed 12 to 52 months after treatment. Fourteen fractures were type C3 and 6 were type C2 according to the AO classification. Fractures were united at an average of 39 +/- 9 weeks. There was a final knee extension deficit of 5 degrees to 10 degrees (12.2 degrees +/- 3.5 degrees) and flexion reached 110 degrees +/- 10 degrees in type C2 and 73 degrees +/- 36 degrees in C3 supracondylar fractures. Forty percent of the supracondylar fractures had 4cm shortening and 40% had 1.5 cm. Pin-track infection occurred in 21%. Half of the C3 fracture cases had problems with pain on walking, needed support and had pain at rest, whereas no patients had difficulty getting out of a chair, going up and down stairs. However, all C2 type fractures had problems with all types of function.

  11. Evaluation of a nontoxic rigid polymer as connecting bar in external skeletal fixators. (United States)

    Störk, Christoph K; Canivet, Philippe; Baidak, Alexandre A; Balligand, Marc H


    To investigate the mechanical characteristics of a nontoxic, low-cost, rigid polymer (RP) and to compare the structural and mechanical properties of a full-frame external skeletal fixator (ESF) with either RP connecting bars, polymethylmethacrylate (PMMA) connecting bars, or stainless-steel (SS) clamps and connecting bars. In vitro mechanical evaluation. Mechanical properties were assessed using an in vitro bone fracture model with a bilateral uniplanar ESF (type II). Identical ESF were built with connecting bars using RP (n = 8), PMMA (n = 8), and SS connecting bars and clamps (System Meynard; n = 3). Nondestructive mechanical tests were performed in uniaxial compression (AC) and craniocaudal (CC) 4-point bending, as well as fatigue AC. Composite stiffness for each specimen and for each loading mode was calculated from 6 replicate measures using the slope of the load displacement curve at small displacements. RP, PMMA, and SS ESF constructs yielded mean +/- SD composite stiffness values of 227 +/- 15, 381 +/- 30, and 394 +/- 9 N/mm in AC and of 35 +/- 2, 24 +/- 2, and 15 +/- 0 N/mm in CC, respectively. Structural and mechanical properties of RP are satisfactorily rigid and fatigue resistant for its use as a connecting bar in ESF. RP connecting bars in an ESF are a reliable, versatile, nontoxic and inexpensive option for the veterinary surgeon. Copyright 2003 by The American College of Veterinary Surgeons

  12. Clinical results of resection arthrodesis by triangular external fixation for posttraumatic arthrosis of the ankle joint in 89 cases

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    Kiene J


    Full Text Available Abstract The methods for ankle arthrodesis differ significantly, probably a sign that no method is clearly superior to others. In the last ten years there is a clear favour toward internal fixation. We retrospectively evaluate the technique and evaluate the clinical long term results of external fixation in a triangular frame. Patients and Methods From 1994 to 2001 a consecutive series of 95 patients with end stage arthritis of the ankle joint were treated. Retrospectively the case notes were evaluated regarding trauma history, medical complaints, further injuries and illnesses, walking and pain status and occupational issues and the clinical examination before arthrodesis. Mean age at the index procedure was 45.4 years (18-82, 67 patients were male (70.5%. Via a bilateral approach the malleoli and the joint surfaces were resected. An AO fixator was applied with two Steinmann-nails inserted with approximately 8 cm distance in the distal tibia, one in the neck of the talus and one in the dorsal calcaneus. The fixator was removed after approximately 12 weeks. Follow up examination at mean 4.4 years included a standardised questionnaire and a clinical examination including the criteria of the AOFAS-Score and radiographs. Results: Due to different complications, 8 (8.9% further surgical procedures were necessary including 1 below knee amputation. In 4 patients a non-union of the ankle arthrodesis developed (4.5%. The mean AOFAS score improved from 20.8 to 69.3 points. Conclusion Non-union rates and clinical results of arthrodesis by triangular external fixation of the ankle joint do not differ to internal fixation methods. The complication rate and the reduced patient comfort reserve this method mainly for infected arthritis and complicated soft tissue situations.

  13. Immediate interlocking nailing versus external fixation followed by delayed interlocking nailing for Gustilo type IIIB open tibial fractures. (United States)

    Park, H J; Uchino, M; Nakamura, M; Ueno, M; Kojima, Y; Itoman, M; Yokoyama, K; Suzuki, T; Nemoto, M


    To compare immediate interlocking nailing with external fixation followed by delayed interlocking nailing, for Gustilo type IIIB open tibial fractures. 23 patients with Gustilo IIIB open tibial fractures were treated with either immediate unreamed interlocking nailing (n=9) or external fixation followed by delayed unreamed interlocking nailing (n=14). Patient age, sex ratio, fracture site, fracture type, and severity were similar in both groups. The time to union, deep infection rate, and nonunion rate in the 2 groups were compared. In the immediate and delayed nailing groups, respective mean times to union were 21 (standard deviation [SD], 14) months and 14 (SD, 8) months; nonunion rates were 44% (4/9) and 36% (5/14), and deep infection rates were 22% (2/9) and 7% (1/14). All corresponding differences were not statistically significant. Prospective, randomised, multicentre studies are needed to assess whether there are significant differences between the 2 treatment methods.

  14. Locking plate external fixation and negative pressure wound therapy for treatment of a primary infection in a closed clavicle fracture. (United States)

    Kenyon, Robert M; Morrissey, David I; Molony, Diarmuid C; Quinlan, John Francis


    Infection in a clavicle fracture is uncommon, but remains a challenging problem. A paucity of soft tissue coverage often combined with significant displacement and interfragmentary movement add complexity to an already difficult situation for effective infection treatment. External fixation in principle offers a means of achieving fracture stability, while the infection is being eradicated. We present the case of a closed clavicle fracture, initially treated conservatively, that presented 5 weeks later with infection. The fracture was definitively treated with external fixation using a locking plate positioned superficially to the skin, plus negative pressure wound therapy and subsequent secondary closure and antibiotic therapy. This case illustrates a novel method of treatment in this unusual presentation that was well tolerated by the patient and resulted in a good clinical outcome. 2016 BMJ Publishing Group Ltd.

  15. Complications after use of extracortical clamp device in combined and consecutive external and internal fixation of femoral bone

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    L. N. Solomin


    Full Text Available Introduction. Extracortical Clamp Device (ECD is a tool that, unlike conventional wires and pins, does not perforate long bone cortex. Therefore, its use simplifies methods of combined and consequtive use of internal and external fixation, osteosynthesis in periprosthetic fractures and deformities. Purpose of the study - to compare the rate of complications and their structure depending on extracortical clamp device application and conventional transosseous elements in combined external fixation of femur. Materials and methods. We analyzed the complications arising in treatment of 66 patients with frames where ECD were used (group «ECD». The results were compared with the results of treatment 29 patients, when utilizing combination of external and internal fixation, external fixation device included conventional transosseous elements only (group «W-P». Results. In the group «ECD» inflammation of the soft tissues around fixing elements was identified in 14.8% of cases. In these patients complication arisen at 45.5% of the all used fixing elements; of them - 18.2% around ECD. In the group «W-P» pin-tract infection occurred in 29.2% cases. ECD breaking was in one case (3.7% breaking of wires or pins in «W-P» group was diagnosed in 3 cases (13.6%. In the treatment of periprosthetic fractures and deformities with ECD soft tissues around fixing elements was in 16.7% of cases. In the treatment of similar fractures and deformities without prosthesis pin-tract infection were diagnosed in 21.5% cases. All of these complications did not affect the outcome. Other complications (neuropathy, contracture of the knee were not depending on the application of ECD.

  16. Stiffness Analysis of the Sarafix External Fixator based on Stainless Steel and Composite Material

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    Nedim Pervan


    Full Text Available This paper describes a structural analysis of the CAD model three versions fixators Sarafix which is to explore the possibility of introducing composite materials in the construction of the connecting rod fixators comparing values of displacement and stiffness at characteristic structure points. Namely, we have investigated the constructional performance of fixators Sarafix with a connecting rod formed from three different composite materials, the same matrix (epoxy resin with three different types of fibers (E glass, kevlar 49 and carbonM55J. The results of the structural analysis fixators Sarafix with a connecting rod made of composite materials are compared with the results of tubular connecting rod fixators made of stainless steel. After comparing the results, from the aspect of stiffness, we gave the final considerations about composite material which provides an adequate substitution for the existing material.

  17. Repeatability of goniometer measurements of the knee in patients wearing an Ilizarov external fixator: a clinic-based study. (United States)

    Barker, K L; Lamb, S E; Burns, M; Simpson, A H


    To examine the intra-tester and inter-tester reliability of three different methods of measurement of knee range of motion in patients undergoing limb reconstruction with the Ilizarov external fixator. Twenty-five patients had the passive range of motion of their knee measured by 13 physiotherapists who were experienced in the use of goniometry. The testers were assigned into random pairs, each tester measured three or four patients who were allocated to them using the three different methods. These were: (1) a universal goniometer aligned against anatomical landmarks, (2) a universal goniometer aligned against the Ilizarov frame and (3) a modified universal goniometer. Orthopaedic limb reconstruction outpatient clinics. Twenty-five patients undergoing limb reconstruction using an Ilizarov external fixator on both the femur and tibia. Comparison of the three different goniometry methods showed that using a modified goniometer there was enhanced reliability compared with other methods. This method demonstrated good repeatability for both intra-tester and inter-tester measurements. When serial measurements of knee range of motion are taken in patients wearing an Ilizarov external fixator the modified model of goniometer should be used.

  18. Open tibial shaft fractures. Treatment with intramedullary nailing after provisional stabilization with non penetrating external fixator

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    Jose Octavio Soares Hungri


    Full Text Available Objective: To evaluate the incidence of union, nonunion, deep infection and factors influencing the time of bone healing in the treatment of open tibial shaft fractures Gustilo and Anderson types I and II initially treated with a non penetrating external fixator (Pinless(r followed by an unreamed intramedullary locked nail (UTN(r. Methods: It is a prospective study of 39 open tibial shaft fractures. According to the AO classification, 16 patients (41.0% were type A, 17 (43.6% were type B and six (15.4% were type C. According to the Gustilo and Anderson classification, 14 patients (35.9% were type I and 25 (64.1% were type II. For the definitive stabilization of the fracture were used an unreamed intramedulary locked nail (UTN(r. Results: Bone healing was achieved in 97.4% of the cases, with a mean time of 21.2 weeks, ranging from 12 to 104 weeks. Deep infection was seen in 2.6% patients and malunion were seen in 5.1%. Only the presence of complications were statistically significant to the time of bone healing, with a risk of faster healing in patients without complications of 4.29 times (CI 95%: 1.25 -14.71 comparing to patients with complications. Conclusion: The treatment of open tibial shaft fractures with unreamed intramedullary locked nail allows high rates of bone healing, low rates of nonunion and deep infection, and only the presence of complications is statistically significant to the time of bone healing.

  19. Stability at the half pin–frame interface on external fixation constructs

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    Alexios Dimitrios Iliadis


    Full Text Available Abstract A mechanical study investigating the use of two different methods (grub and bolt screws to secure external fixation half pins to circular frames. A four part experiment: (1 Grub and bolt screws were used to secure half pins in Taylor Spatial frames. Loosening torques were measured using a calibrated torque wrench. (2 Using universal testing machine (UTM, axial loading was applied to establish thresholds for loosening in grub and bolt screw constructs. (3 We established the application torque to produce failure at the head–driver interface using these two methods. (4 Grub and bolt screw constructs were created controlling torque. Using UTM, axial loading was applied to establish thresholds for loosening. Statistical analysis was conducted using SPSS v20.0.0. (1 Higher torque is employed when bolt rather than grub screws is used to secure half pins on Rancho cubes (p < 0.05. (2 Loading threshold for loosening is higher in bolt screw constructs when the torque applied to secure the constructs is not controlled (p < 0.05. (3 Torque required for failure at the head–driver interface was 5.3 Nm for grub screws and 9.9 Nm for bolts. (4 Loading threshold for loosening is higher in grub screw constructs when the same torque was applied to secure them (p < 0.05. Bolt screws can be employed to secure the half pin–frame interface. They offer good stability and reduce failure at the head–driver interface. Further research is needed to determine the mechanical properties of such constructs in vivo.

  20. A prospective study of dynamic treatment of fracture phalanx and metacarpals of the hand with Kirschner-wire fixation/external fixator and finger splint: Daycare management (30 cases

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    Rahul Madhukar Salunkhe


    Full Text Available Introduction: Fractures of the phalanx and metacarpals are some of the most frequently encountered orthopedics injuries and constitute between 14-28% of all visits to emergency department which comprises 46% of the hand fracture and out of that mostly involved are the proximal phalanx and metacarpal neck fracture are most common and then the middle and distal phalanx and the base of metacarpal. The commonest complication with surgical treatment were stiff painful joints due to prolonged immobilization at fracture sites. This prospective study was undertaken to evaluate the functional outcome after surgical stabilization of metacarpal and phalanx fracture on day care basis. Materials And Methods: In our study we treated 30 patients who came to our hospital by fixation either with K wire or external fixation or hybrid fixation under local anaesthesia depending on the type of fracture between 2013 to 2014 with the average age 28 years with the youngest being 18 years and the oldest being 41 years with transverse, spiral, oblique closed fracture, grade 1 compound fracture, intraarticular, extraarticular, comminuted and non comminuted fracture of phalanx and metacarpals.These were day care treatment. Patient was allowed to begin his daily routine work from post operative day l. During this course the operated site was protected with splinting. Results: Clinical Outcomes were assessed as Excellent, Good, Satisfactory and Poor. Radiological assessment was done by taking x-ray to check radiological union.There were 24 cases had excellent outcome, 5 cases had good outcome and only 1 case had satisfactory outcome which occurred due to mal-union. There were 3 cases of pin-tract infection which subsided with oral antibiotics, and 3 cases of malunion. Conclusion: This was a day care procedure, patient were admitted, treated and discharged on the same day & encouraged to begin mobilization of the joints of hands from day 1.

  1. Distal tibial pilon fractures (AO/OTA type B, and C treated with the external skeletal and minimal internal fixation method

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    Milenković Saša


    Full Text Available Background/Aim. Distal tibial pilon fractures include extra-articular fractures of the tibial metaphysis and the more severe intra-articular tibial pilon fractures. There is no universal method for treating distal tibial pilon fractures. These fractures are treated by means of open reduction, internal fixation (ORIF and external skeletal fixation. The high rate of soft-tissue complications associated with primary ORIF of pilon fractures led to the use of external skeletal fixation, with limited internal fixation as an alternative technique for definitive management. The aim of this study was to estimate efficacy of distal tibial pilon fratures treatment using the external skeletal and minimal internal fixation method. Methods. We presented a series of 31 operated patients with tibial pilon fractures. The patients were operated on using the method of external skeletal fixation with a minimal internal fixation. According to the AO/OTA classification, 17 patients had type B fracture and 14 patients type C fractures. The rigid external skeletal fixation was transformed into a dynamic external skeletal fixation 6 weeks post-surgery. Results. This retrospective study involved 31 patients with tibial pilon fractures, average age 41.81 (from 21 to 60 years. The average follow-up was 21.86 (from 12 to 48 months. The percentage of union was 90.32%, nonunion 3.22% and malunion 6.45%. The mean to fracture union was 14 (range 12-20 weeks. There were 4 (12.19% infections around the pins of the external skeletal fixator and one (3.22% deep infections. The ankle joint arthrosis as a late complication appeared in 4 (12.90% patients. All arthroses appeared in patients who had type C fractures. The final functional results based on the AOFAS score were excellent in 51.61%, good in 32.25%, average in 12.90% and bad in 3.22% of the patients. Conclusion. External skeletal fixation and minimal internal fixation of distal tibial pilon fractures is a good method for

  2. Incidence of infection after early intramedullary nailing of open tibial shaft fractures stabilized with pinless external fixators

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    Kulshrestha Vikas


    Full Text Available Background: A major drawback of conventional fixator system is the penetration of fixator pins into the medullary canal. The pins create a direct link between the medullary cavity and outer environment, leading to higher infection rates on conversion to intramedullary nailing. This disadvantage is overcome by the AO pinless fixator, in which the trocar points are clamped onto the outer cortex without penetrating it. This study was designed to evaluate the role of AO pinless fixators in primary stabilization of open diaphyseal tibial fractures that received staged treatment because of delayed presentation or poor general condition. We also analyzed the rate of infection on early conversion to intramedullary nail. Materials and Methods: This study is a retrospective review of 30 open diaphyseal fractures of tibia, which were managed with primary stabilization with pinless fixator and early exchange nailing. Outcome was evaluated in terms of fracture union and rate of residual infection. The data were compared with that available in the literature. Results: All the cases were followed up for a period of 2 years. The study includes Gustilo type 1 (n=10, 14 Gustilo type 2 (n=14, and type3 (n=6 cases. 6 cases (20% had clamp site infection, 2 cases (6.7% had deep infection, and in 28 cases (93% the fracture healed and consolidated well. Conclusion: This study has highlighted the valuable role of pinless external fixator in the management of open tibial fractures in terms of safety and ease of application as well as the advantage of early conversion to intramedullary implant without the risk of deep infection.

  3. A Technique for Reduction of Edentulous Fractures Using Dentures and SMARTLock Hybrid Fixation System

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    Anna Rose Carlson, MD


    Full Text Available Summary:. Establishing anatomic reduction of an edentulous mandible fracture is a frequently acknowledged challenge in craniomaxillofacial trauma surgery. In this study, we report a novel method for the reduction of the edentulous mandible fracture, via fabrication of modified Gunning splints using existing dentures and SMARTLock hybrid arch bars. This technique dramatically simplifies the application of an arch bar to dentures, obviates the need for the fabrication of impressions and custom splints, and eliminates the lag time associated with the creation of splints. Furthermore, this method may be used with or without adjunctive rigid internal fixation. The technique described herein of creating Gunning splints with SMARTLock hybrid arch bars provides surgeons with a simple, rapid, single-stage solution for reduction of mandibular fractures in the edentulous patient.

  4. The Use Of External Fixator In The Management Of Gunshot Related ...

    African Journals Online (AJOL)

    the one who developed tetanus). Conclusions: ... degree of infection. For these reasons internal fixation devices cannot be applied. Basic, simple, cheap methods of fracture stabilization such as POPs, window POPs, bridge-. POPs, skeletal ...

  5. External fixation of femoral shaft fractures in children: enhanced stability with the use of an auxiliary pin. (United States)

    Sola, J; Schoenecker, P L; Gordon, J E


    From 1989 through 1994, we used a monolateral external fixator (Orthofix) to treat 39 femur fractures in 37 patients. The average age of the patients was 9.5 years (range, 5+11 to 18+8 years); 38 fractures were closed, and one was a grade I (Gustillo-Anderson classification) open fracture. Twenty-two fractures were treated by using the standard Orthofix pin configuration with two or three pins held in the pin clamps both above and below the fracture. We treated the remaining 16 fractures identically, except for the addition of an auxiliary pin, which was secured to the body of the fixator by using wire and methylmethacrylate. All patients were followed up to union and fixator removal at a mean of 97 days after fixator placement (range, 50-175 days). Thirty-one (84%) patients were followed up for 1 year after injury. Six of 22 femurs without an auxiliary pin required remanipulation for loss of reduction. Only one of 16 femurs treated with an auxiliary pin required remanipulation. Four of 22 femurs without an auxiliary pin went on to malunion. No femur with an auxiliary pin went on to malunion.

  6. The effect of HIV on early wound healing in open fractures treated with internal and external fixation. (United States)

    Aird, J; Noor, S; Lavy, C; Rollinson, P


    There are 33 million people worldwide currently infected with human immunodeficiency virus (HIV). This complex disease affects many of the processes involved in wound and fracture healing, and there is little evidence available to guide the management of open fractures in these patients. Fears of acute and delayed infection often inhibit the use of fixation, which may be the most effective way of achieving union. This study compared fixation of open fractures in HIV-positive and -negative patients in South Africa, a country with very high rates of both HIV and high-energy trauma. A total of 133 patients (33 HIV-positive) with 135 open fractures fulfilled the inclusion criteria. This cohort is three times larger than in any similar previously published study. The results suggest that HIV is not a contraindication to internal or external fixation of open fractures in this population, as HIV is not a significant risk factor for acute wound/implant infection. However, subgroup analysis of grade I open fractures in patients with advanced HIV and a low CD4 count (HIV should be treated by early debridement followed by fixation at an appropriate time.

  7. Femoral bone transport by a monolateral external fixator with or without the use of intramedullary nail: a single-department retrospective study. (United States)

    Wan, Jun; Ling, Lin; Zhang, Xiang-sheng; Li, Zhi-hong


    Treatment for bone defect remains a challenge for orthopedists. Bone transport gives an effective alternative, which can be performed with an external fixator alone or combined with an intramedullary nail. Each has its advantages and disadvantages. We present a retrospective study to find out the optimal choice by evaluating the outcomes of treatment for femoral bone defect with two methods. Two groups of patients, the monolateral external fixator alone (group A, n = 13) and the monolateral external fixator combined with intramedullary nail (group B, n = 15), were compared. Duration of the external fixator, external fixator index, radiographic consolidation index, complication, and total cost for treatment was also recorded. A modified classification of the Association for the Study and Application of the Method of Ilizarov (ASAMI) was used to assess results in two groups of patients; another SF-36 health survey questionnaire was used to assess the life qualities patients of two groups. Healing was achieved in 13/13 and 13/15 of the two groups, respectively. The rates of complications were significantly higher in the group A. Two patients performed amputations because of persistent deep infections in group B. Statistically significant difference was found when comparing ASAMI scores and categories of the SF-36 health survey. Bone transport by monolateral external fixator with the use of intramedullary nail reduces the incidence of complication and the duration of external fixator time that give patients a better life quality in both physical and emotional. However, if chronic osteitis exists, bone transport should be treated with monolateral external fixator alone due to a lower rate of amputations.

  8. [Minimal invasive elastic intramedullary nails and external fixation for treatment of comminuted closed fracture of tibia-fibula shaft]. (United States)

    Yu, Yang; Chen, Wei-kai; Cui, Wei; Zhou, Yi-fei; Chen, Hua; Yang, Lei


    To investigate the clinical results of external fixation and AO titanium elastic intramedullary nailing for treatment of tibia-fibula comminuted closed fractures. From June 2010 to June 2012,58 patients with tibia-fibula comminuted closed fractures were treated with external fixation and AO titanium elastic intramedullary nailing, including 31 males and 27 females with an average age of 38.5 years old ranging from 21 to 57 years old. According to the system of AO Classification, the fractures were classified as type B1 in 9 cases,type B2 in 7 cases, type B3 in 10 cases, type Cl in 14 cases, type C2 in 12 cases,and type C3 in 6 cases. According to the system of Winquist-Hanson,the fractures' comminuted were classified as grade 1 in 23 cases, grade 2 in 17 cases, grade 3 in 12 cases, and grade 4 in 6 cases. According to the system of Johner-Wruhs, clinical results were compared between different type and grade groups by the time of last followed-up. All 58 patients were followed up with an average time of 6.8 months (ranged from 18 to 36 weeks). All fractures had clinical healing with an average time of 28 weeks (ranged from 24 to 32 weeks). The total rate of good to excellent results was 91.4%. The rate of good to excellent in the group of grade 1 was higher than that of other grades. The complication rates and fracture healing time would increase respectively with higher Winquist-Hanson's grade. The complication rates in the group of type C3 was higher than that of other types, but the rate of good to excellent was lower than that of other types. The complication rates in the group of type B1 was lower than that of other types,but the rate of good to excellent was higher than that of other types. Minimal invasiveusing AO titanium elastic intramedullary nailing combined with external fixation for treatment of tibia-fibula fractures especially for the multiple-segment,long spiral mild-to-moderate comminuted with hidden fracture can get satisfactory reduction and

  9. Pin site care for preventing infections associated with external bone fixators and pins. (United States)

    Lethaby, Anne; Temple, Jenny; Santy-Tomlinson, Julie


    Metal pins are used to apply skeletal traction or external fixation devices in the management of orthopaedic fractures. These percutaneous pins protrude through the skin, and the way in which they are treated after insertion may affect the incidence of pin site infection. This review set out to summarise the evidence of pin site care on infection rates. To assess the effect on infection rates of different methods of cleansing and dressing orthopaedic percutaneous pin sites. In September 2013, for this third update, we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We evaluated all randomised controlled trials (RCTs) that compared the effect on infection and other complication rates of different methods of cleansing or dressing orthopaedic percutaneous pin sites. Two review authors independently assessed the citations retrieved by the search strategies for reports of relevant RCTs, then independently selected trials that satisfied the inclusion criteria, extracted data and undertook quality assessment. A total of eleven trials (572 participants) were eligible for inclusion in the review but not all participants contributed data to each comparison. Three trials compared a cleansing regimen (saline, alcohol, hydrogen peroxide or antibacterial soap) with no cleansing (application of a dry dressing), three trials compared alternative sterile cleansing solutions (saline, alcohol, peroxide, povidone iodine), three trials compared methods of cleansing (one trial compared identical pin site care performed daily or weekly and the two others compared sterile with non sterile techniques), one trial compared daily pin site care with no care and six trials compared different dressings (using different solutions/ointments and dry and impregnated gauze or sponges). One small blinded

  10. Combined circular external fixation and open reduction internal fixation with pro-syndesmotic screws for repair of a diabetic ankle fracture

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    Zacharia Facaros


    Full Text Available The surgical management of ankle fractures among the diabetic population is associated with higher complication rates compared to the general population. Efforts toward development of better methods in prevention and treatment are continuously evolving for these injuries. The presence of peripheral neuropathy and the possible development of Charcot neuroarthropathy in this high risk patient population have stimulated much surgical interest to create more stable osseous constructs when open reduction of an ankle fracture/dislocation is required. The utilization of multiple syndesmotic screws (pro-syndesmotic screws to further stabilize the ankle mortise has been reported by many foot and ankle surgeons. In addition, transarticular Steinmann pins have been described as an adjunct to traditional open reduction with internal fixation (ORIF of the ankle to better stabilize the talus, thus minimizing risk of further displacement, malunion, and Charcot neuroarthropathy. The authors present a unique technique of ORIF with pro-syndesmotic screws and the application of a multi-plane circular external fixator for management of a neglected diabetic ankle fracture that prevented further deformity while allowing a weight-bearing status. This technique may be utilized for the management of complex diabetic ankle fractures that are prone to future complications and possible limb loss.

  11. Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection in a goat model.

    Energy Technology Data Exchange (ETDEWEB)

    Dejong, E. Schuyler; Deberardino, T. M.; Brooks, D. E.; Nelson, B. J.; Campbell, Allison A.; Bottoni, Craig R.; Pusateri, A. E.; Walton, R. S.; Guymon, C. H.; Mcmanus, Albert T.


    Background: Pin tract infection is a common complication of external fixation. An antiinfective external fixator pin might help to reduce the incidence of pin tract infection and improve pin fixation. Methods: Stainless steel and titanium external fixator pins, with and without a lipid stabilized hydroxyapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites were examined daily. On day 14, the animals were killed, and the pin tips cultured. Insertion and extraction torques were measured. Results: Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation torque over uncoated pins (p = 0.04). Conclusion: These results demonstrate that the lipid stabilized hydroxyapatite/chlorhexidine coating was successful in decreasing infection and improving fixation of external fixator pins.

  12. Non-bridging external fixation employing multiplanar K-wires versus volar locked plating for dorsally displaced fractures of the distal radius. (United States)

    Gradl, Georg; Gradl, Gertraud; Wendt, Martina; Mittlmeier, Thomas; Kundt, Guenther; Jupiter, Jesse B


    The aim of this study was to compare non-bridging external fixation to palmar angular stable plating with respect to radiological outcome, wrist function, and quality of life. One hundred and two consecutive patients (mean age: 63 years) were enrolled in the study. Fifty-two patients were randomized for plate osteosynthesis (2.4 mm, Synthes), 50 patients received non-bridging external fixation (AO small fixator). Objective (range of motion, grip strength), patient rated outcomes (quality of life, pain), and radiological outcome were assessed 8 weeks, 6 months, and 1 year after surgery. Loss of radial length of more than 3 mm was not detected in any group. Volar tilt was better restored by external fixation (7.2°) than by volar plating (0.1°). Wrist function was good in both groups. The external fixator was tolerated very well, and the quality of life assessment revealed comparable results in both groups. Osteoporosis was found in 54 % of patients and had no influence on radiological and functional outcome. Non-bridging external fixation employing multiplanar K-wires is a suitable treatment option in intra- and extra-articular fractures of the distal radius even in osteoporotic bone.

  13. A new tool fixation for external 3D head tracking using the Polaris Vicra system with the HRRT PET scanner

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Andersen, Flemming; Holm, Søren

    Objectives: The Polaris Vicra system (Northern Digital Inc.) is used for external 3D head registration with the Siemens HRRT brain PET. Our new tool fixation using a standard bandaid with a velcro-strap implies an improved frame repositioning. Methods: Head movements during serial PET 15O......-water studies for up to 75 min (3-8 injections) were registered by the Polaris system in 4 volunteers. The tracking tool was fixed. Scans were divided into subframes based on the registered movements and reconstructed using the 3D-OSEM PSF method. The reconstructed subframes were repositioned to a reference...

  14. Treatment of unstable distal radius fractures: non-invasive dynamic external fixator versus volar locking plate - functional and radiological outcome in a prospective case-controlled series. (United States)

    Bajwa, Ali S; Rammappa, Manju; Lee, Ling; Nanda, Rajesh


    Distal radius fracture (DRF) is a common injury and various treatment modalities including open reduction and internal fixation (ORIF) with volar locking plate are available. More recently, a non-invasive external fixator has been used. To prospectively compare the use of a non-invasive external fixator with early dynamisation for DRF against ORIF with volar locking plate control group. Consecutive patients with closed DRF were included in a prospective case-controlled study. Patients were assigned to non-invasive external fixator or ORIF. Minimum follow-up was two years. Follow-up was at weeks 2, 4, 6, 8, 12, 26 and at one and two-year post-operatively. The outcome measures included demographic details, injury mechanism, AO fracture type, risk factors, body mass index (BMI), ulnar styloid fracture and dorsal comminution, radiographs, grip strength and DASH score. Consecutive 50 patients were treated either with non-invasive external fixator (25/50) or with ORIF (25/50) and the mean age of the two groups was 53 years (SD 17.1) and 49 years (SD 19.5), respectively. Demographics were matched in two groups. In the non-invasive external fixator group, there were 10 AO Type-A, 5 Type-B and 10 Type-C fractures. The ORIF group included 8 Type-A, 6 Type-B and 11 Type-C fractures. The mean DASH score at three-months and one-year post-injury in non-invasive fixator group was 12.2 (SD 3.1) and 3.5 (SD 0.7), respectively, significantly greater than those of ORIF group 14.5 (SD 5.6) and 11.2 (SD 4.4), respectively (p invasive external fixator can give functional results superior to ORIF at three-months and the trend is maintained at one and two-year post-operatively.


    Directory of Open Access Journals (Sweden)

    K.K. Levchenko


    Full Text Available The authors of article suggest methods of surgical correction of pathology by means of fixation of the first metatarsal bone with specialconstruction ofmini-apparatus for externalfixation. This approach provides decrease of recovery period, reduces complications riskas well as deformation relapse.

  16. Intramedullary Nailing and External Ring Fixation for Tibiotalocalcaneal Arthrodesis in Charcot Arthropathy. (United States)

    Richman, James; Cota, Adam; Weinfeld, Steven


    Surgical strategies to address deformities of the ankle and hindfoot in patients with Charcot arthropathy include the use of retrograde intramedullary nails and ring fixators. The literature has not shown superiority of one technique over the other. This study presents a single surgeon's case series of Charcot arthropathy patients treated with either a ring fixator or retrograde intramedullary nail to achieve tibiotalocalcaneal arthrodesis. We performed a retrospective analysis of 27 consecutive patients with Charcot arthropathy who underwent a tibiotalocalcaneal arthrodesis using either a retrograde intramedullary (IM) nail (n = 16 patients) or a ring fixator (RF) (n = 11 patients) by a single surgeon. We report the rates of limb salvage complications requiring secondary surgery and fusion in both groups. The patient demographics and presence of medical comorbidities known to increase the risk of surgical complications were similar between groups. The mean duration of follow-up for the retrograde nail group was 3.6 years and 2.2 years for the ring fixator group. The mean time to discharge from the hospital after the index surgical procedure was 2.7 days for the IM group and 4.6 days for the RF group. For the patients treated with a ring fixator, the mean time to removal of the frame after the initial application was 13.3 ± 1.8 weeks. The limb salvage rate for the RF group was 9 of 11 patients whereas it was 15 of 16 in the IM group. Complications including deep infection, hardware failure, and symptomatic nonunion requiring revision surgery were common in the IM group, with 11 of 16 patients requiring further surgery. Seven patients in the IM group required removal of the implant at a mean of 117.2 weeks after the index procedure because of the development of deep infection or nail cutout. In the RF group, only 1 patient required revision surgery. Fusion rates were similar between both groups, with 10 of 16 patients fusing in the IM group and 7 of 11 in the RF

  17. Percutaneous iliosacral fixation in external rotational pelvic fractures. A biomechanical analysis. (United States)

    Giráldez-Sánchez, Miguel A; Lázaro-Gonzálvez, Ángel; Martínez-Reina, Javier; Serrano-Toledano, David; Navarro-Robles, Alfredo; Cano-Luis, Pedro; Fragkakis, Evangelos M; Giannoudis, Peter V


    Although the gold standard in open book pelvic fractures remains the pubic symphysis (PS) plate fixation, the clinical outcomes are not satisfactory, despite the excellent anatomical reduction assessed radiologically. Some authors suggest that residual instability of the posterior pelvic elements may be responsible for the chronic pain and the early osteoarthritic changes in the sacroiliac joint (SIJ). To evaluate whether the isolated posterior fixation with one or two iliosacral screws (ISSs) is sufficient to provide adequate stability for the treatment of Burgess Young APC-II (YB APC-II) type of pelvic ring injuries. Biomechanical experimental study using 7 fresh human pelvises, where an YB APC-II pelvic injury was previously implemented. The isolated posterior fixation of the pelvic ring with 1 or 2 ISSs directed in the S1 vertebra body was analysed in each specimen following an axial load of 300N. The different displacement of the SIJ and of the PS were analysed in all three spatial axes, using the validated optical measurement system 3D PONTOS 5M. A multivariate version of Friedman test (non-parametric ANOVA for repeated measures) was performed. The isolated fixation of the SIJ with 1 ISS did not show any differences with respect to the intact pelvis (p=0.851). Regarding the PS, both type of fixations (with 1 or 2 ISSs) confirmed an acceptable correction and adequate control of the PS even though with some differences compared to the intact pelvis (p=0.01). The presence of the second ISS found not to offer any significant additional benefit. The three-dimensional analysis of the behaviour of the pelvic elements, in these two different types of fixation, did not show any statistical significant differences (p=0.645). The posterior fixation with ISS can represent an alternative option for treatment of pelvic injuries associated with rotational instability. Further prospective clinical studies are necessary to determine, the influence of the residual pubic

  18. Distal femoral derotational osteotomy with external fixation for correction of excessive femoral anteversion in patients with cerebral palsy. (United States)

    Skiak, Eyad; Karakasli, Ahmet; Basci, Onur; Satoglu, Ismail S; Ertem, Fatih; Havitcioglu, Hasan


    Patients with cerebral palsy (CP) disorder often develop rotational hip deformity. Increasing deformities impair already diminished walking abilities; femoral osteotomies are often performed to maintain and improve walking abilities. Fixation of osteotomies with condylar plates has been used successfully, but does not often enable immediate postoperative full weight-bearing. To avoid considerable postoperative rehabilitation deficit and additional bone loss because of inactivity, a postoperative treatment with full weight-bearing, is therefore, desirable. Self-tapping Schanz screws with a unilateral external fixator crossing the knee joint providing stronger anchoring in osteopenic bone might fulfill these demands. A retrospective study was carried out on 27 ambulatory CP patients, mean age 17.5 years (range 9-22 years); 11 patients with bilateral severe intoeing deformities underwent a supracondylar femoral osteotomy between September 2008 and April 2012. All patients were allowed to bear their full weight postoperatively. The aim of this study was to describe the technique, the results of this technique, to evaluate the time required for bone healing, and the type of complications associated with a distal derotational femoral osteotomy fixed with a uniaxial external fixator crossing the knee joint. A total of 27 patients were studied [mean weight 48.8 kg (range 29.8-75 kg)]. The mean preoperative rotation included internal rotation of 69° and external rotation of 17°. All patients were evaluated clinically and radiographically for a minimum of 1 year after surgery. There was a significant decrease in the mean medial rotation from 69° to 32° (P=0.00034). The lateral rotation increased significantly from preoperative 17° to postoperative 45° (P=0.0011). The femoral anteversion decreased significantly from a mean of 55° preoperatively to a mean 17° postoperatively (P=0.030). All patients, except one, achieved solid fusion uneventfully. One patient was a

  19. Results of deformity correction in children with X-linked hereditary hypophosphatemic rickets by external fixation or combined technique. (United States)

    Popkov, Arnold; Aranovich, Anna; Popkov, Dmitry


    The operative procedures to correct multiplanar bone deformities may be indicated for prevention of secondary orthopaedic complications in children with X-linked hereditary hypophosphatemic rickets (XHPR). Different problems related to surgical correction were reported: increased rate of non-union, delayed union, recurrent deformity, deep intramedullary infection, refracture, nerve palsy, and pin tract infection. The aim of this retrospective study was comparison of results of correction in children with XHPR who underwent the treatment with either the Ilizarov device alone or a combined technique: the Ilizarov fixator with flexible intramedullary nailing (FIN) with hydroxyapatite bioactive coating and FIN. We retrospectively analysed 47 cases (children of age under 14 years) affected by XHPR. Simultaneous deformity correction in femur and tibia was performed with the Ilizarov device (group I) or the combined method (group II). This article is based on the results of a historical comparative retrospective study from the same institution. The duration of external fixation is noted to be shorter applying the combined technique: 124.7 days (group I) vs 87.4 days (group II). In both groups deformity correction was achieved with a proper alignment. Nevertheless, while a child continues to grow during long-term follow-up, deviations of the mechanic axis from the centre of the knee joint have been developing again and values of mLDFA, mMPTA have become pathologic in the most of the cases. In group I location of a newly developed deformity resembled a pre-operative one, whereby both diaphyseal and metaphyseal parts were deformed. In group II in all the cases an apex of deformity was located in distal metadiaphyseal zone of the femur and proximal metadiaphyseal zone of the tibia. It is important to note that all of those in group II were out of the zone of the intramedullary nail. Simultaneous correction of femoral and tibial deformities by means of circular external

  20. Prospective intraoperative syndesmotic evaluation during ankle fracture fixation: stress external rotation versus lateral fibular stress. (United States)

    Matuszewski, Paul E; Dombroski, Derek; Lawrence, J Todd R; Esterhai, John L; Mehta, Samir


    We hypothesized that the method of stress external rotation more accurately reproduces the mechanism of injury, and therefore this diagnostic method more likely detects ankle instability than the fibular stress examination. Prospective cohort comparison study. Level 1 trauma center. Twenty-eight consecutive patients with unstable ankle fractures presenting within 7 days from the time of injury. Previous ankle surgical history or age younger than 18 years was excluded. Stress external rotation and lateral fibular stress examination was performed intraoperatively. Radiographic measurement of the tibiofibular clear space, tibiofibular overlap, and medial clear space were recorded. After normalization of the fluoroscopic measurements, there was no difference in detecting changes in tibiofibular clear space or tibiofibular overlap. However, there was a significant difference in detecting medial clear space widening with stress external rotation. Compared with lateral fibular stress, stress external rotation demonstrated a 35% increase (P stress external rotation. Untreated instability impacts patient outcomes. The difference in widening with stress external rotation was significantly greater than lateral fibular stress and appreciable on standard fluoroscopic views. Stress external rotation radiographs are a more reliable indicator of mortise instability than traditional lateral fibular stress. Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

  1. Reconstruction after external hemipelvectomy using tibia-hindfoot rotationplasty with calcaneo-sacral fixation


    Kong, G Y; Rudiger, H A; Ek, E T; Morrison, W A; Choong, P.F.


    BACKGROUND: External hemipelvectomy is associated with high post operative morbidity and a poor functional outcome. We aim to explore a reconstruction technique to improve function and post operative appearance for patients who undergo external hemipelvectomy. CASE PRESENTATION: We present a Case where extensive cancer involvement of pelvis and femur was managed with a novel surgical technique, which involved a calf sparing modified anterior flap hemipelvectomy combined with rotationplast...

  2. Mechanical evaluation of external skeletal fixator-intramedullary pin tie-in configurations applied to cadaveral humeri from red-tailed hawks (Buteo jamaicensis). (United States)

    Van Wettere, Arnaud J; Redig, Patrick T; Wallace, Larry J; Bourgeault, Craig A; Bechtold, Joan E


    Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: (1) varying the fixation pin position in the proximal bone segment and (2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n=24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.

  3. Decreasing Complications of Quadricepsplasty for Knee Contracture after Femoral Fracture Treatment with an External Fixator: Report of Four Cases

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    Naoya Kashiwagi


    Full Text Available Introduction: In performing quadricepsplasty for contracture that develops after application of an external fixator for femoral fractures, surgeons must be aware of the potential risk for re-fracture and pin-related problems. The purpose of this report is to highlight these not well-detailed complications and to discuss specific findings and treatment suggestions.Case Report: 4 men (mean age, 40 years presenting with secondary to contracture that developed after application of an external fixator for femoral fractures were included in this study. The radiographs showed union across the fracture site however two of these patients couldn't stand on one leg raising suspicion about the union status. A computed tomographic image indeed demonstrated limited continuity of the cortex. Bone grafting was performed prior to quadricepsplasty. The mean extension and flexion before the quadricepsplasty were 0o and 570 , respectively. At the final follow-up examination, the mean active flexion of the knee had increased to 98o.Results: The incidence of re-fracture during and after quadricepsplasty has been reported to be between 10 and 25%. There are 2 preoperative features that may mislead surgeons into believing that complete union of the fractures has been attained: one is the patient's ability to stand on a single leg, and the other is the fact that plain radiographs may lend themselves to different interpretations. In such cases, computed tomography will provide evidence of the continuity of the cortical bone. Bone grafting in 2 of our patients is thought to have prevented the postoperative complications of re-fracture. Complications at pin sites induce contracture at surrounding structures. When extreme tightness of the skin is noted, a tension-releasing procedure such as a skin graft should be performed.Conclusion: In conclusion, re-fracture or pin-site contracture should be carefully managed before quadricepsplasty, because the patients who need a

  4. Open unstable metaphyseo-diaphyseal fractures of the tibia in adolescents: treatment by flexible intramedullary nails augmented by external fixator. (United States)

    Atef, Ashraf; El Tantawy, Ahmad


    The treatment of open and unstable metaphyseo-diaphyseal fractures of the tibia in adolescents is challenging. It is important to choose a fixation method that can maintain alignment, allow wound care and not violate the growth plate. The aim of this work was to evaluate the efficacy of using flexible intramedullary nails (FIN) augmented by external fixator (EF) in the management of such fractures. A total of 26 males, with a mean age of 14.08 years and average body weight of 49.8 kg, presented with open metaphyseo-diaphyseal tibial fractures. All cases were treated using FIN augmented by mono-lateral EF. The fractures were located at the upper third in 17 cases and at the lower third in nine cases. The fracture pattern was spiral in eight cases, oblique in seven and multi-fragmentary in 11. The results were evaluated according to the scoring system for femoral TENs. All fractures united primarily after an average eight to 12 weeks with no evident angular deformity or limb-length discrepancy. None of the cases required cast immobilization or revision procedure. Twenty patients had excellent results, six patients showed good results and none had poor results. Fracture characteristics as well as patients' characteristics had no statistically significant effect (p > 0.005) on the final end results. The use of FIN augmented by EF is a good alternative in the management of open metaphyseo-diaphyseal tibial fractures in adolescents. This fixation provides more stability, allows easy access to the wound and early patients' ambulation.

  5. Bilateral humeral lengthening in achondroplasia with unilateral external fixators: is it safe and does it improve daily life? (United States)

    Balci, H I; Kocaoglu, M; Sen, C; Eralp, L; Batibay, S G; Bilsel, K


    A retrospective study was performed in 18 patients with achondroplasia, who underwent bilateral humeral lengthening between 2001 and 2013, using monorail external fixators. The mean age was ten years (six to 15) and the mean follow-up was 40 months (12 to 104). The mean disabilities of the arm, shoulder and hand (DASH) score fell from 32.3 (20 to 40) pre-operatively to 9.4 (6 to 14) post-operatively (p = 0.037). A mean lengthening of 60% (40% to 95%) was required to reach the goal of independent perineal hygiene. One patient developed early consolidation, and fractures occurred in the regenerate bone of four humeri in three patients. There were three transient radial nerve palsies. Humeral lengthening increases the independence of people with achondroplasia and is not just a cosmetic procedure. ©2015 The British Editorial Society of Bone & Joint Surgery.

  6. Investigation of the mechanical properties and failure modes of hybrid natural fiber composites for potential bone fracture fixation plates. (United States)

    Manteghi, Saeed; Mahboob, Zia; Fawaz, Zouheir; Bougherara, Habiba


    The purpose of this study is to investigate the mechanical feasibility of a hybrid Glass/Flax/Epoxy composite material for bone fracture fixation such as fracture plates. These hybrid composite plates have a sandwich structure in which the outer layers are made of Glass/Epoxy and the core from Flax/Epoxy. This configuration resulted in a unique structure compared to prior composites proposed for similar clinical applications. In order to evaluate the mechanical properties of this hybrid composite, uniaxial tension, compression, three-point bending and Rockwell Hardness tests were conducted. In addition, water absorption tests were performed to investigate the rate of water absorption for the specimens. This study confirms that the proposed hybrid composite plates are significantly more flexible axially compared to conventional metallic plates. Furthermore, they have considerably higher ultimate strength in tension, compression and flexion. Such high strength will ensure good stability of bone-implant construct at the fracture site, immobilize adjacent bone fragments and carry clinical-type forces experienced during daily normal activities. Moreover, this sandwich structure with stronger and stiffer face sheets and more flexible core can result in a higher stiffness and strength in bending compared to tension and compression. These qualities make the proposed hybrid composite an ideal candidate for the design of an optimized fracture fixation system with much closer mechanical properties to human cortical bone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Functional Rehabilitation With a Foot Plate Modification for Circular External Fixation (United States)


    neurologic injury,3,5,6,16,19 multiple studies3,5 have suggested that weight bearing in an ankle-spanning circular external fix - ator must be delayed to run short distances in an IDEO 2 Underwent a transtibial amputation for refractory nerve pain, able to run in prosthesis 3 Back on active...essentially unlimited access to very specialized health care , world-class rehabilitation, and social work support. This is in stark contrast to the average

  8. Skeletal traction versus external fixation in the initial temporization of femoral shaft fractures in severely injured patients. (United States)

    Scannell, Brian P; Waldrop, Norman E; Sasser, Howell C; Sing, Ronald F; Bosse, Michael J


    : Damage control with external fixation (DC-EF) of femoral shaft fractures in polytrauma patients is becoming standard treatment in many trauma centers. However, skeletal traction (ST) has long been used in the temporization of fractures. The purpose of this study was to compare the major physiologic clinical outcomes of provisional ST with DC-EF of femoral shaft fractures in severely injured patients. : We retrospectively reviewed 205 patients sustaining blunt trauma, a femoral shaft fracture, and an Injury Severity Score > or =17 from 2001 to 2007 at a level I trauma center. Patients underwent definitive fixation in the first 24 hours with intramedullary nailing (IMN) (N = 126), initial DC-EF with delayed definitive treatment (N = 19), or initial ST with delayed definitive treatment (N = 60). Incidences of adult respiratory distress syndrome, multiple organ failure, sepsis, pneumonia, pulmonary embolism, and deep vein thrombosis were evaluated. Length of stay (LOS), intensive care unit LOS, days of mechanical ventilation, and mortality were also compared. : There were no significant differences between ST and DC-EF groups in age, mechanism of injury, Injury Severity Score, Glasgow Coma Scale score on arrival, mean time to definitive fixation (4.1 days versus 5.0 days, respectively), or Abbreviated Injury Scale for chest. However, the ST group had a higher Abbreviated Injury Scale-head (2.5 versus 1.0, p = 0.0026). There were no significant differences in subsequent rates of adult respiratory distress syndrome, multiple organ failure, pulmonary embolism, deep vein thrombosis, pneumonia, mechanical ventilation days, intensive care unit LOS, and death. However, the ST group had a lower rate of sepsis (8.3% versus 31.6%, p = 0.0194) and a shorter LOS (26.5 days versus 36.2 days, p = 0.0237) than the EF group. : DC-EF of femur fractures in severely injured patients offers no significant advantage in clinical outcomes compared with ST. Unless initially subjected to

  9. Internal and external hybrids and the nature of joint ventures

    NARCIS (Netherlands)

    Hennart, J.M.A.; Grandori, A.


    This chapter attempts to bring some clarity and consistency to the literature on hybrids, networks, and joint ventures. That literature is now a thicket of ambiguous concepts and mutually inconsistent theories. I use the tools of transaction cost theory to develop a comprehensive framework that

  10. [Manipulative reduction and external fixation with cardboard splint for the treatment of calcaneal fractures: a 60-case report]. (United States)

    Hao, Bo-Chuan; Xie, Ke-Bo


    To investigate the therapeutic effects of manipulative reduction for calcaneal fractures. From January 2009 to June 2012, 53 cases (60 affected feet) of Sanders type I-IV calcaneal fractures were treated by manipulative reduction and external fixation with cardboard splint,including 45 males and 8 females with an average age of (33.5 +/- 1.54) years old ranging from 18 to 65. The course of disease ranged 0.5 h to 7 d. Before treatment the feet were swelling, ache and activity limitation in evidence, some feet were wide flat deformity, the cortical bone was broken in the imaging examination. All selected cases were evaluated using Creighton-Nebraska health foundation assessment scale for fractures of calcaneus. All cases were followed up at 12 months after treatment, 13 feet got excellent curative effect, 34 good, 11 moderate and 2 poor. Manipulative reduction for Sanders type I-IV calcaneal fractures could get excellent curative effect. Manipulative reduction for calcaneal fractures could avoid surgical trauma while assure high curative effects. Manipulative reduction is not only economical and easy therapy, but also can restore maximum function of the calcaneus with few complications and facilitate early rehabilitation of ankle and joint function.

  11. Dynamic and functional gait analysis of severely displaced intra-articular calcaneus fractures treated with a hinged external fixator or internal stabilization. (United States)

    Besch, Lutz; Radke, Birgit; Mueller, Michael; Daniels-Wredenhagen, Mark; Varoga, Deike; Hilgert, Ralf-Erik; Mathiak, Guenther; Oehlert, Katharina; Seekamp, Andreas


    The purpose of this article was to assess functional gait outcome. Fifty-five patients with severely displaced intra-articular calcaneus fractures and soft tissue damage were evaluated prospectively with computerized dynamic pedography and a clinical scoring scale. The treatment protocol assigned 30 patients to open reduction and internal fixation (ORIF) and 25 to closed reduction and stabilization with a biomechanically tested hinged external fixator. Gait parameter was evaluated by measuring plantar pressure distribution, length of a double-step, double-step duration, standing duration, effective foot length, and width of gait. Pedographic measurements were performed with a custom-made gait analysis system (medilogic Gangas, Berlin, Germany). Results were graded by an extended protocol of questionnaires and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot scales. Radiographs were reviewed according to the Sanders classification at the time of follow-up (7.3 years). All measurements were statistically analyzed (t test; Mann-Whitney U test). Aberrations were associated with all calcaneal fractures in both groups. Dynamic gait analysis showed gait asymmetry in all patients. The type of treatment (ORIF or a hinged fixator) of severely displaced calcaneus fractures did not affect gait analysis nor result in significantly different (P > .05) patient outcome scores. The gait analysis system allows a valid dynamic pedographic measurement. The hinged external fixator can be recommended in displaced intra-articular calcaneal fractures with severe soft tissue damage to reduce complications associated with ORIF. ACFAS Level of Clinical Evidence: 2c.

  12. Early Conversion of External Fixation to Interlocked Nailing in Open Fractures of Both Bone Leg Assisted with Vacuum Closure (VAC) - Final Outcome. (United States)

    Gill, Simrat Pal Singh; Raj, Manish; Kumar, Sunil; Singh, Pulkesh; Kumar, Dinesh; Singh, Jasveer; Deep, Akash


    Management of compound grade III fractures of both bone leg includes external stabilization for long period, followed by various soft tissue coverage procedures. Primary interlocking of tibia had been also done with variable results. External fixation for long time without any bone loss often leads to infected nonunion, loss of reduction, pin tract infection and failure of fixation, primary interlocking in compound grade III fractures had shown high medullary infection rate. We managed all cases of compound grade III A/B fractures with primary external fixation, simultaneous wound management using vacuum assisted closure (VAC) followed by early conversion to interlocking within 2 weeks of fixator application. To determine the effectiveness of vacuum assisted closure (VAC) for the early conversion of external fixator to definitive interlocking in open fractures of the both bone leg. In current study we selected 84 cases of compound grade IIIA/B diaphyseal fractures of both bone leg during period of May 2010 to September 2013. We managed these cases by immediate debridement and application of external fixation followed by repeated debridement, application of vacuum assisted closure (VAC) and conversion to interlocking within two weeks. Out of 84 cases union was achieved in 80(95%) of cases with definitive tibial interlocking. Excellent to good result were obtained in 77(91.8%) of cases and fair to poor result seen in rest of 7(8.2%) of cases according to modified Ketenjian's criteria. 5 out of these 7 poor result group cases were from Compound Grade III B group to start with. Deep infection rate in our series were 7% i.e. total 6 cases and 4 out of these were from compound Grade III B group to start with. Vacuum assisted closure (VAC) give a good help for rapid closure of the wound and help in early conversion to definitive intramedullary nailing. Reamed nail could well be used in compound grade IIIA/B fractures without increasing the risk of infection. It gives

  13. Rapid fixation of non-native alleles revealed by genome-wide SNP analysis of hybrid tiger salamanders

    Directory of Open Access Journals (Sweden)

    Shaffer H Bradley


    Full Text Available Abstract Background Hybrid zones represent valuable opportunities to observe evolution in systems that are unusually dynamic and where the potential for the origin of novelty and rapid adaptation co-occur with the potential for dysfunction. Recently initiated hybrid zones are particularly exciting evolutionary experiments because ongoing natural selection on novel genetic combinations can be studied in ecological time. Moreover, when hybrid zones involve native and introduced species, complex genetic patterns present important challenges for conservation policy. To assess variation of admixture dynamics, we scored a large panel of markers in five wild hybrid populations formed when Barred Tiger Salamanders were introduced into the range of California Tiger Salamanders. Results At three of 64 markers, introduced alleles have largely displaced native alleles within the hybrid populations. Another marker (GNAT1 showed consistent heterozygote deficits in the wild, and this marker was associated with embryonic mortality in laboratory F2's. Other deviations from equilibrium expectations were idiosyncratic among breeding ponds, consistent with highly stochastic demographic effects. Conclusion While most markers retain native and introduced alleles in expected proportions, strong selection appears to be eliminating native alleles at a smaller set of loci. Such rapid fixation of alleles is detectable only in recently formed hybrid zones, though it might be representative of dynamics that frequently occur in nature. These results underscore the variable and mosaic nature of hybrid genomes and illustrate the potency of recombination and selection in promoting variable, and often unpredictable genetic outcomes. Introgression of a few, strongly selected introduced alleles should not necessarily affect the conservation status of California Tiger Salamanders, but suggests that genetically pure populations of this endangered species will be difficult to

  14. Surgical correction of bilateral metacarpophalangeal valgus with curved osteotomies and type II external skeletal fixation in a seven-month-old alpaca. (United States)

    Schoonover, Mike J; Whitfield, Chase T; Rochat, Mark C; Streeter, Robert N; Sippel, Kate


    To report the successful surgical correction of severe bilateral metacarpophalangeal valgus angular limb deformities in a seven-month-old intact male alpaca cria using curved osteotomies stabilized with type II external skeletal fixation. Using a 21 mm crescentic shaped oscillating saw blade, bilateral osteotomies were performed in the distal metaphyses of the fused third and fourth metacarpal bones to correct valgus angular limb deformity of the metacarpophalangeal joints. Axial alignment of each limb was achieved by medially rotating the distal metacarpus in the frontal plane along the curved osteotomies. The osteotomies were stabilized using type II external skeletal fixators. The alpaca was immediately weight-bearing following the surgical procedure and no to minimal lameness was observed during healing of the osteotomies. Evaluation at five and 10 months following the surgery demonstrated acceptable axial alignment in the left forelimb while moderate to severe varus deformity (overcorrection) was observed in the right. Curved osteotomy of the distal metacarpus stabilized with type II external skeletal fixation can provide a favourable outcome in older alpaca crias affected with metacarpophalangeal angular limb deformities. Placement of the distal transfixation pins relative to the metacarpal physes should be carefully evaluated as overcorrection is possible, especially if growthpotential remains in only one physis of the fused third and fourth metacarpal bones.

  15. Initial experience of use of an articulated external fixator in treating Legg-Calvé-Perthes disease by means of arthrodiastasis during the active phase of the disease

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    Carlos Augusto Malheiros Luzo


    Full Text Available ABSTRACT OBJECTIVE: To present the preliminary results from treating patients with Legg-Calvé-Perthes Disease (LCPD by means of hip arthrodiastasis using a monolateral external fixator applied to the hip and to succinctly describe the surgical technique used, in a prospective study. METHODS: Prospective study on 18 patients with LCPD who underwent surgical treatment by means of the hip arthrodiastasis technique using a monolateral external fixator. There were 13 male and five female patients of mean age 8.5 years, ranging from five to 13 years. All the patients presented unilateral hip impairment: nine on the right side and nine on the left. The results were evaluated at maturity using clinical and radiological criteria. RESULTS: All the patients evolved with improvement of joint mobility, and pain relief was achieved in 88.9% of them. Reossification of the femoral epiphysis occurred within the first three months of the treatment. The hips operated at the necrosis stage of the disease did not passed through the fragmentation stage, thus shortening the evolution of the disease. The results were 77.8% satisfactory and 22.2% unsatisfactory. CONCLUSION: Hip arthrodiastasis with a monolateral external fixator during the active phase of LCPD improved the degree of joint mobility. Use of the arthrodiastasis technique at the necrosis stage or at the fragmentation stage (active phase of the disease presented satisfactory results from treatment of LCPD.

  16. Operative management of high-grade dysplastic L5 spondylolisthesis with the use of external transpedicular fixation: advantages and drawbacks. (United States)

    Prudnikova, Oksana G; Shchurova, Elena N


    The aim of our study was to analyze clinical and radiographic outcomes of operative management of L5 high-grade dysplastic spondylolisthesis with the apparatus for external transpedicular fixation (AETF), and to compare the results of its use for reduction and spondylodesis. There were 13 patients with L5 dysplastic spondylolisthesis of grade 4 (Meyerding grading) and having a mean age of 25.0 ± 3.6 years. The management included two stages: gradual reduction with the AETF, followed by either isolated anterior spondylodesis with the same AETF (group 1, n = 8), or by spondylodesis using a combined method (internal transpedicular instrumentation and posterior lumbar interbody fusion [PLIF]) (group 2, n = 5). Clinical evaluation included pain (VAS scale) and functional status (Oswestry questionnaire [ODI]). Reduction and fusion completeness were assessed radiographically after treatment and at a mean follow-up of 2.1 ± 0.4 years. Initial slippage was reduced by 51.6 % with AETF and was of grade 1 or 2. Reduction made up 31.1 % at follow-ups (grade 2 or 3). Pain decreased by 57.6 % (p spondylolisthesis provides gradual controlled reduction of the slipped vertebra, decompression of cauda equine roots, and recovery of the local sagittal spinal column balance. It creates conditions for achieving stability of lumbosacral segments with combined spondylodesis (internal transpedicular instrumentation and PLIF). AETF is not suitable for spondylodesis due to a high rate of pseudarthrosis.

  17. Development of an external readout electronics for a hybrid photon detector

    CERN Document Server

    Uyttenhove, Simon; Tichon, Jacques; Garcia, Salvador

    The pixel hybrid photon detectors currently installed in the LHCb Cherenkov system encapsulate readout electronics in the vacuum tube envelope. The LHCb upgrade and the new trigger system will require their replacement with new photon detectors. The baseline photon detector candidate is the multi-anode photomultiplier. A hybrid photon detector with external readout electronics has been proposed as a backup option. This master thesis covers a R & D phase to investigate this latter concept. Extensive studies of the initial electronics system underlined the noise contributions from the Beetle chip used as front-end readout ASIC and from the ceramic carrier of the photon detector. New front-end electronic boards have been developed and made fully compatible with the existing LHCb-RICH infrastructure. With this compact readout system, Cherenkov photons have been successfully detected in a real particle beam environment. The proof-of-concept of a hybrid photon detector with external readout electronics was val...

  18. Secondary nailing after external fixation for tibial shaft fracture: risk factors for union and infection. A 55 case series. (United States)

    Roussignol, X; Sigonney, G; Potage, D; Etienne, M; Duparc, F; Dujardin, F


    Secondary intramedullary nailing (SIN) following external fixation (EF) of tibial shaft fracture is controversial, notably due to the infection risk, which is not precisely known. The present study therefore analysed a continuous series of tibial shaft SIN, to determine (1) infection and union rates, and (2) whether 1-stage SIN associated to EF ablation increased the risk of infection. Factors exist for union and onset of infection following tibial shaft SIN. A retrospective series of SIN performed between 1998 and 2012 in over 16-year-old patients with non-pathologic tibial shaft fracture was analysed. EF pin site infection was an exclusion criterion. Fractures were graded according to AO and Gustilo classifications. Study parameters were: time to SIN, 1- versus 2-stage procedure, bacteriologic results on reaming product, post-nailing onset of infection, and time to union. Fifty-five patients (55 fractures) were included. There were 16 closed and 39 open fractures: 7 Gustilo type I, 26 type II and 6 type IIIA; 33 AO type A, 14 type B and 8 type C. Mean time to SIN was 9 ± 9.6 weeks (range, 4 days to 12 months). There were 23 1-stage procedures, and 32 two-stage procedures with a mean 12-day interval (range, 4-30 days). Twelve reaming samples were biologically positive without secondary infection. There were 4 septic complications (3 abscesses, 1 osteomyelitis), and 1 aseptic non-union required re-nailing. The union rate was 96%. The sole factor of poor prognosis was severity of fracture opening. One-stage SIN did not increase infection risk. The present results were better than reported in the literature, where the rates of Gustilo IIIA and IIIB fracture and pin site infection are, however, higher. Tibial shaft SIN is a reliable procedure, with infection risk correlating with Gustilo type and time to surgery. Surgery should be early, before onset of EF pin site infection. A 1-stage attitude appears feasible in early SIN. Level IV. Retrospective study type

  19. Outcomes of anterolateral thigh-free flaps and conversion from external to internal fixation with bone grafting in gustilo type IIIB open tibial fractures. (United States)

    Lee, Jae Hoon; Chung, Duke Whan; Han, Chung Soo


    The purpose of this study was to analyze the utility and the clinical outcomes of anterolateral thigh (ALT)-free flaps and conversion from external to internal fixation with plating and bone grafting in Gustilo type IIIB open tibial fractures. A total of 21 patients were analyzed retrospectively. The mean follow-up period was 18 months and the mean age was 46.7 years. There were 18 men and three women. The mean time from injury to flap coverage was 11.6 days. The mean size of flaps used was 15.3 × 8.2 cm. The mean size of bone defects was 2.26 cm. Segmental bone defects were observed in 5 five cases, for which bone transport or vascularized fibular graft were performed. When flaps were successful and the fracture sites did not have any evidence of infection, internal fixation with plates and bone grafting were performed. Flaps survived in 20 cases. In the 20 cases with successful flaps, two cases developed osteomyelitis, but the 20 cases achieved solid bone union at a mean of 8.6 months after the injury, salvaging the lower extremity in 100% of the cases. At the last follow-up, 9 nine cases were measured excellent or good; 6, fair; and 6, poor in the functional assessment based on the method developed by Puno et al. ALT- free flaps to cover soft tissue defects in Gustilo type IIIB open tibial fractures are considered as useful option for the treatment of composite defects. In addition, conversion to internal fixation and bone grafting can be an alternative method in order to reduce the risk of complications and inconvenience of external fixators. Copyright © 2012 Wiley Periodicals, Inc.

  20. Bone grafting via reamer-irrigator-aspirator for nonunion of open Gustilo-Anderson type III tibial fractures treated with multiplanar external fixator. (United States)

    Kusnezov, Nicholas; Prabhakar, Gautham; Dallo, Matthew; Thabet, Ahmed M; Abdelgawad, Amr A


    The purpose of this investigation was to evaluate the outcomes following reamer-irrigator-aspirator (RIA) autogenous bone grafting (ABG) of high-grade open tibia fracture nonunions stabilized via multiplanar external fixation. We retrospectively reviewed all patients with Gustilo-Anderson type III open tibia fractures treated with multiplanar external fixation and who underwent RIA ABG for nonunion at our institutional Level 1 Trauma Center between 2008 and 2015. All patients between 15 and 65 years of age with a minimum of six-month follow-up were included. The primary outcomes of interest were achievement of union, time to union, and incidence of revision surgery. Complications and all-cause reoperation were recorded as secondary endpoints. Fifteen patients met the inclusion criteria with a mean age of 41.1 ± 14.0 years. RIA ABG was harvested from the femur in all cases, with a mean volume of 34 ± 15 mL. At an average follow-up of 13.3 ± 6.8 months, all patients achieved union, including two who required repeat RIA ABG. One patient experienced a femoral shaft fracture four months following RIA that required intramedullary fixation. The average time to union was 6.0 ± 6.3 months. Twelve patients (80%) went on to union within six months and 13 (86.7%) within one year. Five patients experienced a total of six post-operative complications including three deep infections, one refracture through the nonunion site, and one gradual varus deformity. Two patients in this series required a subsequent RIA autografting procedure secondary to persistent nonunion despite initial RIA. We found that RIA ABG offered a reliable solution to nonunion of Gustilo-Anderson type III open tibial fractures treated with multiplanar external fixation, circumventing the need to change the method of fixation. © The Authors, published by EDP Sciences, 2017.

  1. Bone grafting via reamer-irrigator-aspirator for nonunion of open Gustilo-Anderson type III tibial fractures treated with multiplanar external fixator

    Directory of Open Access Journals (Sweden)

    Kusnezov Nicholas


    Full Text Available Introduction: The purpose of this investigation was to evaluate the outcomes following reamer-irrigator-aspirator (RIA autogenous bone grafting (ABG of high-grade open tibia fracture nonunions stabilized via multiplanar external fixation. Methods: We retrospectively reviewed all patients with Gustilo-Anderson type III open tibia fractures treated with multiplanar external fixation and who underwent RIA ABG for nonunion at our institutional Level 1 Trauma Center between 2008 and 2015. All patients between 15 and 65 years of age with a minimum of six-month follow-up were included. The primary outcomes of interest were achievement of union, time to union, and incidence of revision surgery. Complications and all-cause reoperation were recorded as secondary endpoints. Results: Fifteen patients met the inclusion criteria with a mean age of 41.1 ± 14.0 years. RIA ABG was harvested from the femur in all cases, with a mean volume of 34 ± 15 mL. At an average follow-up of 13.3 ± 6.8 months, all patients achieved union, including two who required repeat RIA ABG. One patient experienced a femoral shaft fracture four months following RIA that required intramedullary fixation. The average time to union was 6.0 ± 6.3 months. Twelve patients (80% went on to union within six months and 13 (86.7% within one year. Five patients experienced a total of six post-operative complications including three deep infections, one refracture through the nonunion site, and one gradual varus deformity. Two patients in this series required a subsequent RIA autografting procedure secondary to persistent nonunion despite initial RIA. Conclusion: We found that RIA ABG offered a reliable solution to nonunion of Gustilo-Anderson type III open tibial fractures treated with multiplanar external fixation, circumventing the need to change the method of fixation.

  2. [Case-control study on close reduction and plaster slab fixation combined with plaster external traction for the treatment of pediatric Gartland type III supracondylar humerus fractures]. (United States)

    Kang, Yu-Xiang; Wei, Xiao-Chun; Li, Hai-Ming


    To compare the therapeutic effects between close reduction and plaster slab fixation combined with plaster external traction and operation for the treatment of pediatric closed Gartland type III supracondylar humerus fractures without neurovascular injury complications. From June 2009 to June 2012, 151 children with closed Gartland III supracondylar humerus fractures were retrospectively studied and divided into two groups, including 87 boys and 64 girls, ranging in age from 1 to 12 years old with an average of 5.3 years old. Among them, 76 children (conservative group) were treated with close reduction and plaster slab fixation combined with plaster external traction; 75 children (operation group) underwent surgical operation. The time of elbow joint function exercise, the healing time of fracture, the function recovery of elbow joint and carrying angle was recorded and analyzed. The therapeutic effects were evaluated by the Flynn criteria system. All patients were followed up from 6 to 36 months (18.3 months on average). The average time of fracture healing and elbow joint functional exercise of the conservative group was shorter than those of operation group (P 0.05). According to Flynn criteria system, in conservative group, the result was excellent in 31 cases, good in 35, fair in 7, and poor in 3; in operation group, 27 in excellent, 30 in good, 17 in fair and 1 in poor; there was no significant difference between two groups in therapeutic effects (P > 0.05). Close reduction and plaster slab fixation combined with plaster external traction in treatment of pediatric closed Gartland type III supracondylar humerus fractures without neurovascular injury complications,which has similar effect to surgical treatment, and the time of fracture healing and elbow joint function exercise are significantly shorter.

  3. Reduction and temporary stabilization of Tile C pelvic ring injuries using a posteriorly based external fixation system. (United States)

    Martin, Murphy P; Rojas, David; Mauffrey, Cyril


    Tile C pelvic ring injuries are challenging to manage even in the most experienced hands. The majority of such injuries can be managed using percutaneous reduction techniques, and the posterior ring can be stabilized using percutaneous transiliac-transsacral screw fixation. However, a subgroup of patients present with inadequate bony corridors, significant sacral zone 2 comminution or significant lateral/vertical displacement of the hemipelvis through a complete sacral fracture. Percutaneous strategies in such circumstances can be dangerous. Those patients may benefit from prone positioning and open reduction of the sacral fracture with fixation through tension band plating or lumbo-pelvic fixation. Soft tissue handling is critical, and direct reduction techniques around the sacrum can be difficult due to the complex anatomy and the fragile nature of the sacrum making clamp placement and tightening a challenge. In this paper, we propose a mini-invasive technique of indirect reduction and temporary stabilization, which is soft tissue friendly and permits maintenance of reduction during definitive fixation surgical.

  4. Induction of apomixis and fixation of heterosis in Egyptian rice Hybrid1 line using colchicine mutagenesis


    Reda M. Gaafar; Adel R. El Shanshoury; Ahmad A. El Hisseiwy; Mahmoud A. AbdAlhak; Aimn F. Omar; Mohammad M. Abd El Wahab; Randa S. Nofal


    It is known that hybrid rice yields 15–20% over inbred varieties in first generation because of heterosis. However, heterosis is normally broken due to segregation. Applying apomixis produces plants as a clone of mother plant and overcomes the problem of breaking heterosis. In order to fix heterosis in the Egyptian rice Hybrid1, their seeds were mutagenized in 0.2% colchicine for two time periods 24 and 50 h. After colchicine mutagenesis, rice seedlings were grown in the field till maturation...

  5. A cost analysis of three methods of treating femoral shaft fractures in children: a comparison of traction in hospital, traction in hospital/home and external fixation. (United States)

    Hedin, Hanne; Borgquist, Lars; Larsson, Sune


    There is no consensus as to which is best treatment of femoral fractures in children. We performed a cost analysis comparing three treatments of femoral shaft fractures in children aged 3-15 years at 3 hospitals during the same period (1993-2000). The analysis included total medical costs and costs for the care provider and were calculated from the time of injury up to 1 year. At hospital 1, treatment consisted of external fixation and early mobilization. At hospital 2, the treatment was skin or skeletal traction in hospital for 1-2 weeks, followed by home traction. At hospital 3, treatment was skin or skeletal traction in hospital until the fracture healed. The average total costs per patient were EUR 10,000 at hospital 1, EUR 23,000 at hospital 2, and EUR 38,000 at hospital 3. The main factor for determining the cost of treatment was the number of days in hospital, which was lower in children treated with external fixation.

  6. Nanofabrication Yields. Hybridization and Click-Fixation of Polycyclic DNA Nanoassemblies

    KAUST Repository

    Lundberg, Erik P.


    We demonstrate the stepwise assembly of a fully addressable polycyclic DNA hexagon nanonetwork for the preparation of a four-ring system, one of the biggest networks yet constructed from tripodal building blocks. We find that the yield exhibits a distinct upper level <100%, a fundamental problem of thermodynamic DNA assembly that appears to have been overlooked in the DNA nanotechnology literature. A simplistic model based on a single step-yield parameter y can quantitatively describe the total yield of DNA assemblies in one-pot reactions as Y = yduplex n, with n the number of hybridization steps. Experimental errors introducing deviations from perfect stoichiometry and the thermodynamics of hybridization equilibria contribute to decreasing the value of yduplex (on average y = 0.96 for our 10 base pair hybridization). For the four-ring system (n = 31), the total yield is thus less than 30%, which is clearly unsatisfactory if bigger nanoconstructs of this class are to be designed. Therefore, we introduced site-specific click chemistry for making and purifying robust building blocks for future modular constructs of larger assemblies. Although the present yield of this robust module was only about 10%, it demonstrates a first step toward a general fabrication approach. Interestingly, we find that the click yields follow quantitatively a binomial distribution, the predictability of which indicates the usefulness of preparing pools of pure and robust building blocks in this way. The binomial behavior indicates that there is no interference between the six simultaneous click reactions but that step-yield limiting factors such as topological constraints and Cu(I) catalyst concentration are local and independent. © 2011 American Chemical Society.

  7. Induction of apomixis and fixation of heterosis in Egyptian rice Hybrid1 line using colchicine mutagenesis

    Directory of Open Access Journals (Sweden)

    Reda M. Gaafar


    Full Text Available It is known that hybrid rice yields 15–20% over inbred varieties in first generation because of heterosis. However, heterosis is normally broken due to segregation. Applying apomixis produces plants as a clone of mother plant and overcomes the problem of breaking heterosis. In order to fix heterosis in the Egyptian rice Hybrid1, their seeds were mutagenized in 0.2% colchicine for two time periods 24 and 50 h. After colchicine mutagenesis, rice seedlings were grown in the field till maturation and the resulted M1 seeds were sown in season 2 and plants were selected based on yield and homogeneity. Then, seeds were sown to be evaluated in season 3. Pollen fertility test, esterase isozyme analysis, and flow cytometry seed screening were performed to confirm the results of field selection of populations identical to control. Pollen fertility examination was performed on the populations of the third season. Pollens of populations 304, 298, 292, 284, 281, 154 and 149 were found to be completely sterile. However, these plants had high seed set percentage. The flow cytometry screening of the six yield-based identical populations and the control seeds showed that populations 220, 339, 351 and 298 have higher nuclear DNA content (C2 than untreated hybrid (C2 & C3. Results of flow cytometry clearly showed that population 298 has one peak (C2 and its endosperm was formed autonomously without fertilization. Although its pollen grains were sterile, it showed high seed set percentage. This indicates that heterosis was completely fixed by apomixis in this population.

  8. Hip- and knee-strength assessments using a hand-held dynamometer with external belt-fixation are inter-tester reliable. (United States)

    Thorborg, Kristian; Bandholm, Thomas; Hölmich, Per


    In football, ice-hockey, and track and field, injuries have been predicted, and hip- and knee-strength deficits quantified using hand-held dynamometry (HHD). However, systematic bias exists when testers of different sex and strength perform the measurements. Belt-fixation of the dynamometer may resolve this. The aim of the present study was therefore to examine the inter-tester reliability concerning strength assessments of isometric hip abduction, adduction, flexion, extension and knee-flexion strength, using HHD with external belt-fixation. Twenty-one healthy athletes (6 women), 30 (8.6) (mean (SD)) years of age, were included. Two physiotherapy students (1 female and 1 male) performed all the measurements after careful instruction and procedure training. Isometric hip abduction, adduction, flexion, extension, and knee-flexion strength were tested. The tester-order and hip-action order were randomised. No systematic between-tester differences (bias) were observed for any of the hip or knee actions. The intra-class correlation coefficients (ICC 2.1) ranged from 0.76 to 0.95. Furthermore, standard errors of measurement in per cent (SEM %) ranged from 5 to 11 %, and minimal detectable change in per cent (MDC %) from 14 to 29 % for the different hip and knee actions. The present study shows that isometric hip- and knee-strength measurements have acceptable inter-tester reliability at the group level, when testing strong individuals, using HHD with belt-fixation. This procedure is therefore perfectly suited for the evaluation and monitoring of strong athletes with hip, groin and hamstring injuries, some of the most common and troublesome injuries in sports. Diagnostic, Level III.

  9. Unreamed Intramedullary Nailing is a better alternative than External Fixator for Gustilo grade IIIB Tibial Fractures based on a meta-analysis. (United States)

    Zhang, F; Zhu, Y; Li, W; Chen, W; Tian, Y; Zhang, Y


    There remains a controversy between unreamed intramedullary nailing and external fixation to treat Gustilo grade IIIB tibial fractures. To evaluate the comparative effectiveness and safeness of both methods for this type of fracture, we performed this meta-analysis. Relevant original studies were searched in MEDLINE, EMBASE, China National Knowledge Infrastructure, and Cochrane Central Database (all through February 2014). Studies included in this meta-analysis had to compare the effectiveness or complications and provided sufficient data of interest. The patients treated by both methods were similar statistically in demography and injury mechanism. The Stata 11.0 was used to analyze all data. Six studies involving 163 participants were included. Unreamed intramedullary nailing was associated with reduced time to union (standardized mean difference, -1.14; 95% confidence interval, -2.04 to -0.24) and lower rates of superficial infection (odds ratio: 0.39; 95% confidence interval: 0.17-0.87) and malunion (odds ratio: 0.27; 95% confidence interval: 0.09-0.78). However, there were no significant differences in other adverse events including delayed union, non-union, deep infection, and fixation failure. The existing evidence supports unreamed intramedullary nailing to be a better method for treating Gustilo grade IIIB tibial fractures, and this might aid in the management of this sever injury. © The Finnish Surgical Society 2015.

  10. Treament of Tibial Plateau Schatzker Type VI Fractures with the Ilizarov Technique Using Ring External Fixators Across the Knee: A Retrospective Review

    Directory of Open Access Journals (Sweden)

    IR Ranatunga


    Full Text Available This is a retrospective review of 18 patients with tibial plateau fractures Schatzker type VI. These cases were performed in our medical centre from January 2003 to December 2004. The Ilizarov technique (Russian technique using the ring external fixator was the technique performed. Articular reconstruction and joint alignment were achieved with traction and olive wires with washers. One case required percutaneous elevation of the articular surface and bone grafting through a cortical window. Average clinical union was achieved within 4 months of trauma. Mean final knee flexion was 85°, which is compatible with walking. All patients successfully returned to their previous occupations. In conclusion, the Ilizarov technique has been shown to be a good option and a viable tool in the management of these complex and unstable injuries.

  11. Simultaneous anterior and posterior compression of the pelvic ring with external fixation using a pre-tensed curved bar: A biomechanical study. (United States)

    Queipo-de-Llano, Alfonso; Perez-Blanca, Ana; Ezquerro, Francisco; Luna-González, Felipe


    External fixators continue to be essential tools in the urgent treatment of pelvic fractures for compression and stabilization of the pelvic ring. Current systems fail to produce simultaneous anterior and posterior compression. A modified application of an existing curved bar fixator is proposed using a specifically designed tensioner to pre-tense the bar prior to its connection to Schanz screws. Subsequent pre-tension release and elastic recovery of the bar could potentially compress the pelvis. The aim of this work was to determine if the modified application could produce greater simultaneous compression across the sacroiliac joint and the symphysis of an unstable fractured pelvis than the standard application without pretension. Six synthetic pelvis models with symphyseal and unilateral sacroiliac joints disruptions, simulating a Tile type C pelvic ring fracture, were used. Each specimen was stabilized using two 5mm×250mm supra-acetabular Schanz pins, a couple of open adjustable clamps and a semicircular carbon fibre rod applied without and with pre-tension. Two distances from bar to bone and three levels of pretension were compared. Each pelvis was tested with the six possible parameter combinations. Compressive forces at the disrupted joints were measured using pressure sensitive film sensors. The modified application produced forces significantly higher than the minimal compression achieved with standard application. At the sacroiliac joint, after pre-tension release, mean compressive forces measured ranged from 28.7 to 85.6N. The closest bar-to-bone distance always produced a significantly higher force; similarly, a significant increase in compression was found as the pre-tension level rose. At the symphysis, mean compressive forces between 35.3N and 49.0N were determined. No significant variations were seen with changes of any of the two factors analyzed To pre-tense a semi-circular bar before its use for external fixation of the fractured pelvis, is an

  12. Flexible fixation and fracture healing

    DEFF Research Database (Denmark)

    Schmal, Hagen; Strohm, Peter C; Jaeger, Martin


    , noncomminuted fractures. External fixation uses external bars for stabilization, whereas internal fixation is realized by subcutaneous placement of locking plates. Both of these "biologic" osteosynthesis methods allow a minimally invasive approach and do not compromise fracture hematoma and periosteal blood...... of articular fractures. They allow for subchondral stabilization using small-diameter angular stable screws as well as buttressing of the joint and the metaphyseal component of a fracture. Biomechanically, they can be far stiffer than external fixators, because subcutaneous plates are located much closer...... to the bone surface than external fixator bars. External fixators have the advantage of being less expensive, highly flexible, and technically less demanding. They remain an integral part of orthopaedic surgery for emergent stabilization, for pediatric fractures, for definitive osteosynthesis in certain...

  13. Endochondral fracture healing with external fixation in the Sost knockout mouse results in earlier fibrocartilage callus removal and increased bone volume fraction and strength. (United States)

    Morse, A; Yu, N Y C; Peacock, L; Mikulec, K; Kramer, I; Kneissel, M; McDonald, M M; Little, D G


    Sclerostin deficiency, via genetic knockout or anti-Sclerostin antibody treatment, has been shown to cause increased bone volume, density and strength of calluses following endochondral bone healing. However, there is limited data on the effect of Sclerostin deficiency on the formative early stage of fibrocartilage (non-bony tissue) formation and removal. In this study we extensively investigate the early fibrocartilage callus. Closed tibial fractures were performed on Sost(-/-) mice and age-matched wild type (C57Bl/6J) controls and assessed at multiple early time points (7, 10 and 14days), as well as at 28days post-fracture after bony union. External fixation was utilized, avoiding internal pinning and minimizing differences in stability stiffness, a variable that has confounded previous research in this area. Normal endochondral ossification progressed in wild type and Sost(-/-) mice with equivalent volumes of fibrocartilage formed at early day 7 and day 10 time points, and bony union in both genotypes by day 28. There were no significant differences in rate of bony union; however there were significant increases in fibrocartilage removal from the Sost(-/-) fracture calluses at day 14 suggesting earlier progression of endochondral healing. Earlier bone formation was seen in Sost(-/-) calluses over wild type with greater bone volume at day 10 (221%, pfractured Sost(-/-) tibiae was greater than that that of wild type fractured tibiae. In summary, bony union was not altered by Sclerostin deficiency in externally-fixed closed tibial fractures, but fibrocartilage removal was enhanced and the resultant united bony calluses had increased bone fraction and increased strength. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  14. Intramedullary nailing versus external fixation in Gustilo type III open tibial shaft fractures: a meta-analysis of randomised controlled trials. (United States)

    Giovannini, Francesca; de Palma, Luigi; Panfighi, Andrea; Marinelli, Mario


    Open tibial shaft fractures are the most common of long-bone open fractures. Management of the fracture is either by intramedullary nailing (IMN) or by external fixation (EF). Since the literature does not indicate clearly which is more effective, a meta-analysis was conducted to establish which approach is more suitable to treat Gustilo type III fractures. MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE and CINAHL databases were searched for randomised controlled trials (RCT) describing IMN and EF treatment of Gustilo type III fractures. As of 15 November 2012, five RCT involving 239 patients had been published; the outcomes examined in this study are their surgical complications. Data analysis led complications to be grouped into infection, fracture healing problems (non-union, malunion) and "other complications" (vascular injury, revision surgery, soft tissue damage, mechanical failure and tibial malalignment). IMN was associated with lower rates of infection and fracture healing problems; the differences between the two approaches for "other complications" were not significant. The data indicate that IMN is the treatment of choice for Gustilo type III fractures.

  15. Fixação externa em fratura completa de metacarpo em potros External fixation in complete metacarpal fracture in foals

    Directory of Open Access Journals (Sweden)

    Marcelo Jorge Cavalcanti de Sá


    Full Text Available A regeneração de fraturas nos membros de eqüinos é complexa pelas características da espécie. Baseado em estudo biomecânico prévio, dez potros com fratura iatrogênica experimental do metacarpo tiveram redução pelo método de transfixação óssea. Cada animal foi avaliado mediante exames clínico, laboratorial e radiográfico até a recuperação. As complicações não foram significativas, exceto em um potro que requereu eutanásia. O método mostrou-se adequado e oferece estabilidade suficiente para cicatrização.The fracture healing in equine legs is a complex process due to species characteristics. Based in previous biomechanical study ten horses had iatrogenic metacarpal fractures reduced by external bone fixation. Each animal was evaluated by clinical, laboratorial and radiografic examination till complete recovery. No significant complication were observed, except one animal which was submitted to euthanasia. The method offers appropriate stability for bone healing.

  16. External skeletal fixator intramedullary pin tie-in for the repair of tibiotarsal fractures in raptors: 37 cases (1995-2011). (United States)

    Bueno, Irene; Redig, Patrick T; Rendahl, Aaron K


    To evaluate the outcome of the application of an external skeletal fixator intramedullary pin tie-in (TIF) to tibiotarsal fractures in raptors. Retrospective case series. Thirty-four raptors with 37 tibiotarsal fractures. Medical records and radiographs for raptors with tibiotarsal fractures that were treated at The Raptor Center at the University of Minnesota between 1995 and 2011 were reviewed. Descriptive statistics were generated and univariate logistic regression analyses were used to assess whether age, sex, body weight, location and nature of the fracture, and type of surgical reduction were significantly associated with whether the fracture healed following surgical reduction and TIF application. 31 of 37 (84%) tibiotarsal fractures successfully healed following surgical reduction and TIF application. The mean healing time was 38 days (range, 15 to 70 days). None of the variables assessed were significantly associated with whether the tibiotarsal fracture healed. Twenty of the 34 (59%) raptors were eventually rehabilitated and released. Results indicated that most tibiotarsal fractures were successfully managed by surgical reduction and stabilization with a TIF. However, other comorbidities (eg, systemic infections and visual deficits) negatively affected the rehabilitation of raptors and sometimes resulted in euthanasia despite the fact that the tibiotarsal fracture had healed, and those comorbidities, along with the variables evaluated (eg, age, sex, and nature of the fracture), should be used as triage criteria and prognostic indicators.

  17. ADHD and the externalizing spectrum: direct comparison of categorical, continuous, and hybrid models of liability in a nationally representative sample. (United States)

    Carragher, Natacha; Krueger, Robert F; Eaton, Nicholas R; Markon, Kristian E; Keyes, Katherine M; Blanco, Carlos; Saha, Tulshi D; Hasin, Deborah S


    Alcohol use disorders, substance use disorders, and antisocial personality disorder share a common externalizing liability, which may also include attention-deficit hyperactivity disorder (ADHD). However, few studies have compared formal quantitative models of externalizing liability, with the aim of delineating the categorical and/or continuous nature of this liability in the community. This study compares categorical, continuous, and hybrid models of externalizing liability. Data were derived from the 2004-2005 National Epidemiologic Survey on Alcohol and Related Conditions (N = 34,653). Seven disorders were modeled: childhood ADHD and lifetime diagnoses of antisocial personality disorder (ASPD), nicotine dependence, alcohol dependence, marijuana dependence, cocaine dependence, and other substance dependence. The continuous latent trait model provided the best fit to the data. Measurement invariance analyses supported the fit of the model across genders, with females displaying a significantly lower probability of experiencing externalizing disorders. Cocaine dependence, marijuana dependence, other substance dependence, alcohol dependence, ASPD, nicotine dependence, and ADHD provided the greatest information, respectively, about the underlying externalizing continuum. Liability to externalizing disorders is continuous and dimensional in severity. The findings have important implications for the organizational structure of externalizing psychopathology in psychiatric nomenclatures.

  18. Is there a connection between the clinical response after an external fixation test or a subsequent lumbar fusion and the pre-test intervertebral kinematics? (United States)

    Lund, Teija; Oxland, Thomas R; Nydegger, Thomas; Schlenzka, Dietrich; Laine, Timo; Heini, Paul


    Evaluation of a possible correlation of clinical symptoms of chronic low back pain (LBP) patients before and after application of external spinal fixation (ESF) with three-dimensional motion patterns. To determine whether the intervertebral kinematics in chronic LBP patients correlate with pain relief after stabilization of the suspected painful segments. Chronic LBP is a complex clinical entity with mechanical, biochemical, and psychosocial components. Although clinically controversial, ESF has been shown to reduce intervertebral motion, and thus, it provides a mechanism to investigate the mechanical aspect of LBP. Thirty-four chronic LBP patients were tested with ESF of the suspected painful segments. The subjective pain relief experienced by the patients during the test and 2 years after spinal fusion surgery was determined, along with the Oswestry Disability Index. Before removal of ESF, the three-dimensional intervertebral kinematics of the painful segments (specifically range of motion, coupling patterns, and motion asymmetries) were analyzed with a precision optoelectronic camera system during active trunk motions. A series of linear correlations were performed between the clinical measures and the motion parameters. The subjective pain relief during the ESF test was nominally, but not significantly, associated with lateral bending asymmetry ( = 0.22) and "abnormal" axial rotation-lateral bending coupling ( = 0.13). The improvement in the Oswestry Disability Index both post-test and at 2 years after lumbar fusion surgery was significantly correlated with the extension range of motion ( = 0.049 and = 0.036, respectively) and the extension-to-flexion range of motion ratio ( = 0.035 and = 0.044, respectively). The "abnormal" motion patterns of chronic LBP patients did not correlate with subjective pain relief after ESF of the suspected symptomatic levels or with the midterm outcome of subsequent lumbar fusion surgery. The results suggest that preserved motion

  19. High-Power Hybrid Mode-Locked External Cavity Semiconductor Laser Using Tapered Amplifier with Large Tunability

    Directory of Open Access Journals (Sweden)

    Andreas Schmitt-Sody


    Full Text Available We report on hybrid mode-locked laser operation of a tapered semiconductor amplifier in an external ring cavity, generating pulses as short as 0.5 ps at 88.1 MHz with an average power of 60 mW. The mode locking is achieved through a combination of a multiple quantum well saturable absorber (>10% modulation depth and an RF current modulation. This designed laser has 20 nm tuning bandwidth in continuous wave and 10 nm tuning bandwidth in mode locking around 786 nm center wavelength at constant temperature.

  20. Comparison of fatigue strength of C2 pedicle screws, C2 pars screws, and a hybrid construct in C1-C2 fixation. (United States)

    Su, Brian W; Shimer, Adam L; Chinthakunta, Suresh; Salloum, Kanaan; Ames, Christopher P; Vaccaro, Alexander R; Bucklen, Brandon


    A biomechanical study comparing the fatigue strength of different types of C2 fixation in a C1-C2 construct. To determine the pullout strength of a C2 pedicle screw and C2 pars screw after cyclical testing and differentiate differences in stiffness pre- and post-cyclical loading of 3 different C1-C2 fixations. Some surgeons use a short C2 pars screw in a C1-C2 construct, because it is less technically demanding and/or when the vertebral artery is high riding. Difference in construct stiffness between use of bilateral C2 pedicle screws, bilateral C2 pars screws, or a hybrid construct is unknown. Biomechanical testing was performed on 15 specimens. A bicortical C1 lateral mass screw was used in combination with 1 of 3 methods of C2 fixation: (1) bilateral long C2 pedicle screws (LL), (2) bilateral 14-mm C2 pars screws (SS), and (3) unilateral long C2 pedicle screw with a contralateral 14-mm C2 pars screw (LS). Each construct was subject to 16,000 cycles to simulate the immediate postoperative period. Changes in motion in flexion-extension, lateral bending, and axial rotation were calculated. This was followed by pullout testing. The ability to limit range of motion significantly decreased after cyclical testing in flexion-extension, lateral bending, and axial rotation for all 3 groups. After loading, the LL and LS groups had less percentage of increase in motion in flexion-extension and lateral bending than the SS group. Overall, the average pullout strength of a pedicle screw was 92% stronger than a pars screw. C2 pedicle screws have twice the pullout strength of C2 pars screws after cyclical loading. In cases in which the anatomy limits placement of bilateral C2 pedicle screws, a construct using a unilateral C2 pedicle screw with a contralateral short pars screw is a viable option and compares favorably with a bilateral C2 pedicle screw construct. N/A.

  1. Hip- and knee-strength assessments using a hand-held dynamometer with external belt-fixation are inter-tester reliable

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Bandholm, Thomas; Hölmich, Per


    PURPOSE: In football, ice-hockey, and track and field, injuries have been predicted, and hip- and knee-strength deficits quantified using hand-held dynamometry (HHD). However, systematic bias exists when testers of different sex and strength perform the measurements. Belt-fixation of the dynamome......PURPOSE: In football, ice-hockey, and track and field, injuries have been predicted, and hip- and knee-strength deficits quantified using hand-held dynamometry (HHD). However, systematic bias exists when testers of different sex and strength perform the measurements. Belt......-fixation. This procedure is therefore perfectly suited for the evaluation and monitoring of strong athletes with hip, groin and hamstring injuries, some of the most common and troublesome injuries in sports. LEVELS OF EVIDENCE: Diagnostic, Level III....

  2. Design Fixation (United States)

    Kelley, Todd R.; Sung, Euisuk


    The purpose of this article is to provide awareness of the danger of design fixation and promote the uses of brainstorming early in the design process--before fixation limits creative ideas. The authors challenged technology teachers to carefully limit the use of design examples too early in the process and provided suggestions for facilitating…

  3. Simulation of external flows using a hybrid particle mesh vortex method

    DEFF Research Database (Denmark)

    Spietz, Henrik; Hejlesen, Mads Mølholm; Walther, Jens Honore

    The long-term goal of this project is to develop and apply state-of-the-art simulation software to enable accurate prediction of fluid structure interaction, specifically vortex-induced-vibration and flutter of long-span suspension bridges to avoid error-prone structural designs. In the following...... a hybrid particle mesh vortex method is applied for the simulation of uniform flow past stationary solid obstacles of arbitrary shapes....

  4. Treatment of fractures of the tibial diaphysis using external fixator compared with locked intramedullary nails Tratamento das fraturas diafisárias da tíbia com fixador externo comparado com a haste intramedular bloqueada

    Directory of Open Access Journals (Sweden)

    Rodrigo Tavares Cardozo


    Full Text Available OBJECTIVE: To compare efficiency of external fixator in modular form with unilateral and uniplanar intramedullary locked seeking definitive treatment of fractures of the tibia diaphysis. METHODS: Orthopedic surgical treatments were compared to 50 patients with definite diafisária fracture of the tibia, through the use of the external fixator, modular and intramedullary locked. The fractures were treated at emergency hospital school of Orthopedics and Traumatology service in the period from January 2007 to January 2011, with a variation of 15 to 48 weeks. RESULTS: this study has proven functional results and excellent consolidation when locked intramedullary rods were used and the versatility and speed of application of external fixator reaching the necessary stabilization of bony fragments. Consolidation of fractures was obtained in 95 cases when using the intramedullary locked and 90 cases undergoing external fixation. CONCLUSIONS: the definitive treatment of tibial diaphysis fractures by external fixator modular presented themselves as valid alternative treatment in patients who could not be submitted for early conversion to internal osteosynthesis or when the intramedullary nails are not available to the surgeon. OBJETIVO: Comparar a eficiência de fixador externo modular na forma uniplanar e unilateral com haste intramedular bloqueada (HIB buscando tratamento definitivo das fraturas diafisárias da tíbia. MÉTODOS: Foram comparados os tratamentos cirúrgicos ortopédicos definitivos de 50 pacientes com fratura diafisária da tíbia, por meio do uso do fixador externo modular e da haste intramedular bloqueada. As fraturas foram tratadas no setor de emergência de um hospital-escola pelo serviço de ortopedia e traumatologia de janeiro de 2007 a janeiro de 2011, com variação de 15 a 48 semanas. RESULTADOS: Este estudo comprovou resultados funcionais e de consolidação excelentes quando usada a haste intramedular bloqueada e a

  5. Generation of maximally entangled states in hybrid two quantum dots mediated by a spherical metal nanoparticle driven by external laser field


    Blekos, Kostas; Stasinou, Maria-Eftaxia; Terzis, Andreas F.; Paspalakis, Emmanuel


    We theoretically study the generation of quantum correlations in a hybrid system composed by two interacting semiconductor quantum dots mediated by a metal nanoparticle and coupled to an external laser field. Interactions present in the hybrid system are treated using a semiclassical approximation except for the direct dipole-dipole interaction. We report the entanglement of formation, which gives information about entanglement quantum correlations, for continuous wave and pulsed driving appl...

  6. Evaluation of External Memory Access Performance on a High-End FPGA Hybrid Computer

    Directory of Open Access Journals (Sweden)

    Konstantinos Kalaitzis


    Full Text Available The motivation of this research was to evaluate the main memory performance of a hybrid super computer such as the Convey HC-x, and ascertain how the controller performs in several access scenarios, vis-à-vis hand-coded memory prefetches. Such memory patterns are very useful in stencil computations. The theoretical bandwidth of the memory of the Convey is compared with the results of our measurements. The accurate study of the memory subsystem is particularly useful for users when they are developing their application-specific personality. Experiments were performed to measure the bandwidth between the coprocessor and the memory subsystem. The experiments aimed mainly at measuring the reading access speed of the memory from Application Engines (FPGAs. Different ways of accessing data were used in order to find the most efficient way to access memory. This way was proposed for future work in the Convey HC-x. When performing a series of accesses to memory, non-uniform latencies occur. The Memory Controller of the Convey HC-x in the coprocessor attempts to cover this latency. We measure memory efficiency as a ratio of the number of memory accesses and the number of execution cycles. The result of this measurement converges to one in most cases. In addition, we performed experiments with hand-coded memory accesses. The analysis of the experimental results shows how the memory subsystem and Memory Controllers work. From this work we conclude that the memory controllers do an excellent job, largely because (transparently to the user they seem to cache large amounts of data, and hence hand-coding is not needed in most situations.

  7. A clinical study of ligamentoaxis using an external fixator, modified frame in the management of a neglected, relapsed, resistant older congenital Talipes Equino varus child

    Directory of Open Access Journals (Sweden)

    Ajit Shinde


    Full Text Available Background: In an older, relapsed, recurrent, resistant Congenital Talipes Equino Varus (CTEV child with previous surgical scar, soft tissue release alone is often not sufficient for full correction, particularly at above 2 years of age. Here controlled, fractional differential distraction with Joshi′s external stabilization system is a useful option to correct all the deformities. It is a well-established modality but with complication rate of 30%, mainly related to pin loosening and infection leading to instability of frame. We aimed to study a method to increase stability of frame to reduce incidence of pin loosening, infection and to evaluate clinical and functional outcome of the modality along with modification. Materials and Methods: 117 children underwent Joshi′s external stabilization system procedure. The principle of correction applied in this study was fractional distraction. Patients were evaluated by Catteral and Simons criteria. Results: Excellent results were obtained in 68.50% of cases, good results in 23.90%, and poor results in 7.60% of the cases. The complication rate reduced to 3% pin tract infections, which eventually healed with outpatient treatment. Conclusion: Fractional distraction method by using Joshi′s External Stabilization System is an easy, simple, less invasive method, which corrects all the deformities in resistant, neglected, and relapsed cases of CTEV and modification of the frame we used proved to be beneficial. Teaching and awareness of parents regarding distraction schedule, stability of frame postoperative importance of wearing of corrected footwear for long period are important.

  8. Simultaneous Quantification of Active Carbon- and Nitrogen-Fixing Communities and Estimation of Fixation Rates Using Fluorescence In Situ Hybridization and Flow Cytometry


    Allison S. McInnes; Shepard, Alicia K.; Raes, Eric J.; Waite, Anya M.; Quigg, Antonietta


    Understanding the interconnectivity of oceanic carbon and nitrogen cycles, specifically carbon and nitrogen fixation, is essential in elucidating the fate and distribution of carbon in the ocean. Traditional techniques measure either organism abundance or biochemical rates. As such, measurements are performed on separate samples and on different time scales. Here, we developed a method to simultaneously quantify organisms while estimating rates of fixation across time and space for b...

  9. Distinguishing between incomplete lineage sorting and genomic introgressions: complete fixation of allospecific mitochondrial DNA in a sexually reproducing fish (Cobitis; Teleostei, despite clonal reproduction of hybrids.

    Directory of Open Access Journals (Sweden)

    Lukas Choleva

    Full Text Available Distinguishing between hybrid introgression and incomplete lineage sorting causing incongruence among gene trees in that they exhibit topological differences requires application of statistical approaches that are based on biologically relevant models. Such study is especially challenging in hybrid systems, where usual vectors mediating interspecific gene transfers--hybrids with Mendelian heredity--are absent or unknown. Here we study a complex of hybridizing species, which are known to produce clonal hybrids, to discover how one of the species, Cobitis tanaitica, has achieved a pattern of mito-nuclear mosaic genome over the whole geographic range. We appplied three distinct methods, including the method using solely the information on gene tree topologies, and found that the contrasting mito-nuclear signal might not have resulted from the retention of ancestral polymorphism. Instead, we found two signs of hybridization events related to C. tanaitica; one concerning nuclear gene flow and the other suggested mitochondrial capture. Interestingly, clonal inheritance (gynogenesis of contemporary hybrids prevents genomic introgressions and non-clonal hybrids are either absent or too rare to be detected among European Cobitis. Our analyses therefore suggest that introgressive hybridizations are rather old episodes, mediated by previously existing hybrids whose inheritance was not entirely clonal. Cobitis complex thus supports the view that the type of resulting hybrids depends on a level of genomic divergence between sexual species.

  10. Fixação esquelética externa em fratura tarsometatársica de seriema (Cariama cristata: relato de caso External skeletal fixation in tarsumetatarsus fracture of red-legged seriema (Cariama cristata: a case report

    Directory of Open Access Journals (Sweden)

    B.B.J. Torres


    Full Text Available Uma seriema (Cariama cristata adulta foi atendida com histórico de traumatismo por tentativa de captura. A ave apresentava dificuldade de apoio do membro pélvico direito, dor à manipulação e fratura exposta do osso tarsometatarso. Optou-se pelo tratamento cirúrgico com redução fechada, utilizando-se fixador esquelético externo tipo II, com barra de conexão acrílica. A técnica cirúrgica utilizada foi satisfatória para o tratamento da fratura, possibilitando reparação óssea e retorno funcional do membro 60 dias após a cirurgia.An adult red-legged seriema (Cariama cristata was referred for examination with history of trauma by capture. The physical examination revealed lameness in the right pelvic limb, sensibility to touch and open fracture of tarsumetatarsus. The treatment was done with surgical closed reduction using a external skeletal fixator type II with acrylic connecting bar. The surgical technique applied was satisfactory for the treatment of the fracture of tarsumetatarsus, since there was bone healing and functional return of the limb at 60 days after surgery.

  11. VAC® for external fixation of flail chest

    DEFF Research Database (Denmark)

    Winge, Rikke; Berg, Jais O; Albret, Rikke


    A large aterior chest wall defect following tumor resection was reconstructed with a Gore-Tex® membrane and a combined musculocutaneous rectus femoris and tensor fasciae latae free flap. Subsequent paradoxical respiration impeded weaning from the ventilator. Appliance of Vacuum Assisted Closure...

  12. Fixation methods for implantable port chamber: comparative study using glue, self-stabilizing leg and suture fixations in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Na, Hyoung Il; Shim, Hyung Jin; Kwak, Byung Kook; Kim, Hyeon Joo; Lee, Yong Cheol [Chung-Ang University College of Medicine, Seoul (Korea, Republic of)


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

  13. Avaliação radiográfica e de função de vôo após fixação de osteotomias distais do úmero em pombas (Columba livia, com modelo de fixador externo articulado Radiologic and flight function evaluation after fixation of distal humeral osteotomies in pigeons, with model of articulated external fixator

    Directory of Open Access Journals (Sweden)

    Vanessa C.M. Ferraz


    viabilidade de músculos e tendões, e assim, garantindo a capacidade de vôo das aves tratadas, sendo um método adequado para a reparação de fraturas distais de úmero em aves quando se pretende a reabilitação destes animais.The treatment of distal humeral fractures in birds is very difficult, technically and for consolidation and maintenance of normal function of the wing, because theses bones are pneumatic, and its cortices very thin. The ankylosis of the humerus-radius-ulnar joint with external fixator is unviable for birds intended for rehabilitation and release. In all animals, the experimental fixator was placed over the humerus, with its articulation over the humerus-radial-ulnar joint e the extension of the fixator was placed over the ulna. The animals were divided in two groups: bilateral surgeries with ankylosis in one wing (static wing and maintenance of the joint function in the other (dynamic wing (Group 1, and unilateral surgery, with maintenance of the joint function (dynamic wing (Group 2. The bonny callus was evaluated with radiographs: post-surgical, at 3, 6 and 9 weeks. The birds in Group 2 were evaluated as of their flight abilities between 11 and 15 weeks after surgery. The wing amplitude and humeral length was evaluated in all animals, after euthanasia. At 6 weeks, all the animals in Group 2, that underwent unilateral surgery, without ankylosis, and four animals in Group 1, that underwent bilateral surgeries: ankylosis of one elbow (static wing and not of the other (dynamic wing, presented radiographic and clinical consolidation of the fractures. Two animals in Group 1 only presented consolidation of the dynamic wing at 9 weeks and of the static wing at 12 weeks. All the animals in Group 2 presented adequate flight capacity, in at least 13 weeks after surgery. There are few published papers on bird osteosynthesis, and therefore we studied the use of articulated external fixator for the stabilization of distal humeral fractures, avoiding ankylosis

  14. reoperation rates following intramedullary nailing versus external

    African Journals Online (AJOL)

    hardware failure or malrotation. Conclusion: Treatment of Gustilo Type 3A open tibia shaft fractures with interlocking intramedullary nailing results in lower reoperation rate in the early stages of treatment compared to uniplanar external fixation. Keywords: Orthopaedic surgery, Tanzania, Intramedullary nail, External fixation, ...

  15. Latarjet Fixation (United States)

    Alvi, Hasham M.; Monroe, Emily J.; Muriuki, Muturi; Verma, Rajat N.; Marra, Guido; Saltzman, Matthew D.


    Background: Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. Purpose: To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws. Results: All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144). Conclusion: There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws. Clinical Relevance: Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option. PMID:27158630

  16. Avaliação pós-operatória da fixação esquelética externa em 29 cães: estudo retrospectivo Post surgical evaluation of external skeletal fixation in 29 dogs: a retrospective study

    Directory of Open Access Journals (Sweden)

    C.M.F. Rezende


    Full Text Available In this retrospective study 29 dogs of both sexes of several breeds, were evaluated. Complications of external skeletal fixation were common. The most frequent post-surgical complications were chronic pin track drainage or pin loosing (11; 37.9%, followed by dry crust at the skin-to-pin interface (5; 17.1%. In five cases (17.1% occurred the healing of the fracture without complications. In three dogs (10.4% occurred nonunion and it was used another fixation method. It was observed individual cases of poor limb use (3.5% or breakage of the pin (3.5% or of the acrylic column (3.5%. Pin track drainage or loosing was related to the owners care. The most did not come back to the hospital as was demanded or did not follow the instructions to inspect the apparatus daily. This behaviour contributed to increase the rate of post-surgical complications. The external fixation has the advantage to be less invasive and can be used to treat closed and open fractures, limb deformities, nonunion and infected fractures.

  17. Fixational saccades alter the gap effect. (United States)

    Watanabe, Masayuki; Matsuo, Yuka; Zha, Ling; MacAskill, Michael R; Kobayashi, Yasushi


    The reaction times of saccadic eye movements have been studied extensively as a probe for cognitive behavior controlled by large-scale cortical and subcortical neural networks. Recent studies have shown that the reaction times of targeting saccades toward peripheral visual stimuli are prolonged by fixational saccades, the largest miniature eye movements including microsaccades. We have shown previously that the frequency of fixational saccades is decreased by volitional action preparation controlled internally during the antisaccade paradigm (look away from a stimulus). Instead, here we examined whether fixational saccade modulation induced externally by sensory events could also account for targeting saccade facilitation by the same sensory events. When targeting saccades were facilitated by prior fixation stimulus disappearance (gap effect), fixational saccade occurrence was reduced, which could theoretically facilitate targeting saccades. However, such reduction was followed immediately by the rebound of fixational saccade occurrence in some subjects, which could eliminate potential benefits from the previous fixational saccade reduction. These results do not mean that fixational saccades were unrelated to the gap effect because they indeed altered that effect by delaying targeting saccade initiation on trials without the fixation gap more strongly than trials with it. Such changes might be attributed to the disruption of volitional saccade preparation because the frequency of fixational saccades observed in this study was associated with the ability of volitional control over antisaccade behavior. These results suggest that fixational saccades alter the gap effect on targeting saccade reaction times, presumably by disrupting volitional saccade commands. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  18. proximal femoral periprosthetic fracture fixation with a hooked ...

    African Journals Online (AJOL)

    viii) The wound was closed over a drain. Adjuvant medical and supportive therapy included: (i) Prophylactic antibiotics- intraoperative followed by postop. for three days .... The hybrid fixation of this particular fracture with a locked hooking plate ...

  19. Distal tibial fractures: evaluation of different fixation techniques. (United States)

    Jöstl, Julian; Tiefenböck, Thomas Manfred; Hofbauer, Marcus; Winnisch, Markus; Lang, Nikolaus; Hajdu, Stefan; Sarahrudi, Kambiz


    The purpose of this study was the comparison of the most commonly used surgical techniques (external fixation, intramedullary nailing, and plate fixation) for the treatment of distal tibial fractures (AO/OTA classification 42-A, B, C or 43-A, B1). A retrospective cohort study of patients who underwent surgical treatment for distal tibial fractures between 1992 and 2011 was performed. A total of 93 patients (52 male/41 female) met inclusion criteria. Statistically significant differences were found regarding the consolidation time of the intramedullary-nailing (147.32 ± 91.16 days) and the plate-fixation group (135.75 ± 110.75 days) versus the external-fixation group (163.12 ± 96.79 days; P = 0.001; P = 0.01). Significant differences were also observed in the range of motion (ROM) of the ankle joint in the intramedullary-nailing and plate-fixation group versus the ROM in the external-fixation group (P = 0.044; P = 0.025). The overall complication rate was 13/93 (14 %). Out of 66 patients treated with intramedullary nailing, 8 (12 %) suffered from complications. Out of the 15 patients treated with plate and 12 patients with external fixation, 2 (13 %) and 3 (25 %) showed complications, respectively. Our results demonstrate advantages in terms of shorter mobilization time and a better ROM of the ankle joint for intramedullary nailing and plate fixation compared with external fixation. Due to our results, we suggest internal fixation (intramedullary nailing or plate fixation) whenever patient's condition and the local fracture situation allow it.

  20. The Role of External Features in Face Recognition with Central Vision Loss. (United States)

    Bernard, Jean-Baptiste; Chung, Susana T L


    We evaluated how the performance of recognizing familiar face images depends on the internal (eyebrows, eyes, nose, mouth) and external face features (chin, outline of face, hairline) in individuals with central vision loss. In experiment 1, we measured eye movements for four observers with central vision loss to determine whether they fixated more often on the internal or the external features of face images while attempting to recognize the images. We then measured the accuracy for recognizing face images that contained only the internal, only the external, or both internal and external features (experiment 2) and for hybrid images where the internal and external features came from two different source images (experiment 3) for five observers with central vision loss and four age-matched control observers. When recognizing familiar face images, approximately 40% of the fixations of observers with central vision loss was centered on the external features of faces. The recognition accuracy was higher for images containing only external features (66.8 ± 3.3% correct) than for images containing only internal features (35.8 ± 15.0%), a finding contradicting that of control observers. For hybrid face images, observers with central vision loss responded more accurately to the external features (50.4 ± 17.8%) than to the internal features (9.3 ± 4.9%), whereas control observers did not show the same bias toward responding to the external features. Contrary to people with normal vision who rely more on the internal features of face images for recognizing familiar faces, individuals with central vision loss show a higher dependence on using external features of face images.

  1. Ipsilateral Femoral Fracture Non-Union and Delayed Union Treated By Hybrid Plate Nail Fixation and Vascularized Fibula Bone Grafting: A Case Report

    Directory of Open Access Journals (Sweden)

    CK Chan


    Full Text Available Non-union is a well recognized complication of femoral neck fractures. The decision whether to attempt fracture fixation or to resort to hip replacement is particularly difficult in patients in the borderline age group in whom complex attempts at gaining union may fail and later present a difficult revision. On the other hand the patient may be young enough that arthroplasty best be avoided . Besides, presence of ipsilateral femoral shaft fracture with delayed union in addition to the femoral neck non-union will pose major problems at operation. We share our experience in treating a femoral neck fracture non-union with ipsilateral femoral shaft delayed union in the shaft and in the distal femur in a fifty years old patient. The fracture was treated with an angle blade plate and supracondylar nail supplemented with a free vascularised fibular bone grafting and autologous cancellous graft. There was radiological union at fourth month. At sixth months, the patient was free of pain and able to walk without support. Thus, we would like to suggest that vascularised fibula bone grafting with supracondylar nailing is a viable option for this pattern of fracture.

  2. Radiological evaluation of ankle arthrodesis with Ilizarov fixation compared to internal fixation. (United States)

    Morasiewicz, Piotr; Dejnek, Maciej; Urbański, Wiktor; Dragan, Szymon Łukasz; Kulej, Mirosław; Dragan, Szymon Feliks


    We asked whether the type of ankle joint arthrodesis stabilization will affect: (1) rate of union, (2) rate of adjacted-joint arthritis, (3) malalignment of the ankle joint. We retrospectively radiological studied 62 patients who underwent ankle arthrodesis with Ilizarov external fixator stabilization (group 1,n=29) or internal stabilization (group 2,n=33) from 2006 to 2015. Radiologic outcomes were mesure by: (1) rate of union, (2) rate of adjacent-joint arthritis, (3) malalignment of the ankle joint. The Levene's test,Mann-Whitney U test and Students t-test were used to the statistical analyses. Ankle fusion was achieved in 100% of patients treated with external fixation and in 88% with internal stabilization. Desired frontal plane alignment was achieved in 100% of patients with external fixation and 76% with internal stabilization. Desired sagittal plane alignment was achieved in 100% of external fixation and 85% of internal stabilization. A total of 14 (48.3%) patients from group 1 showed a radiographic evidence of pre-existing adjacent-joint OA. The radiographic evidence of pre-existing adjacent-joint OA was also found in 27(81.8%) subjects from group 2. Alterations of adjacent joints were also found on postoperative radiograms of 19 (65.5%) patients subjected to Ilizarov fixation and in all 33 patients from group 2. Ilizarov fixation of ankle arthrodesis is associated with lower prevalence of adjacent-joint OA and ankle joint misalignment,and with higher fusion rates than after internal fixation.Although achieving a complex ankle fusion is generally challenging,radiological outcomes after fixation with the Ilizarov apparatus are better than after internal stabilization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Osteossíntese provisória das fraturas expostas da diáfise da tíbia com fixador externo não transfixante Provisional osteosynthesis of open diaphyseal fractures of the tibia with pinless external fixator

    Directory of Open Access Journals (Sweden)

    José Octavio Soares Hungria


    Full Text Available OBJETIVO: Avaliar a eficácia do fixador externo não transfixante como tratamento provisório das fraturas expostas Gustilo e Anderson graus I e II. MÉTODOS: Em estudo prospectivo, 36 fraturas expostas da diáfise da tíbia foram tratadas seqüencialmente com fixador não transfixante seguido por haste intramedular maciça bloqueada não fresada. A média de idade foi de 28 anos e 88,9% dos pacientes eram do sexo masculino. O mecanismo de trauma foi: acidente motociclístico em 47,1%, atropelamento em 36,1%. Entre os pacientes, nove (25,0% apresentaram lesões associadas. Segundo a classificação AO, 12 pacientes (33,3% haviam sofrido fraturas do tipo A, 18 (50,0% do tipo B e seis (16,6% fraturas tipo C. Segundo a classificação de Gustilo e Anderson, 13 pacientes (36,1% eram portadores de fraturas expostas grau I e 23 (63,9%, de fraturas grau II. O tempo médio de fixação externa foi de seis dias, variando de três a 22 dias. RESULTADOS: Entre os pacientes, 32 evoluíram satisfatoriamente. As complicações relacionadas ao fixador existiram em quatro pacientes: em três houve impossibilidade de conversão com o fixador instalado e em um ocorreu neurapraxia do fibular superficial. CONCLUSÃO: O fixador externo não transfixante é útil como fixação provisória das fraturas expostas da diáfise da tíbia quando se visa a conversão para osteossíntese intramedular.OBJECTIVE: To evaluate the effectiveness of the pinless external fixator for the provisional treatment of Gustilo and Anderson grade I and II open fractures. METHODS: In a prospective study, 36 open diaphyseal fractures of the tibia were sequentially treated with a pinless fixator followed by massive, blocked, non-edged intramedullary nail. Mean age was 28 years, and 88.9% of the patients were male. The mechanism of trauma was: motorcycle accident in 47.1%, being run over by vehicle in 36.1%. Among the patients, 9 (25.0% had associated lesions. According to the AO

  4. 2.5-Gb/s hybridly-integrated tunable external cavity laser using a superluminescent diode and a polymer Bragg reflector. (United States)

    Yoon, Ki-Hong; Oh, Su Hwan; Kim, Ki Soo; Kwon, O-Kyun; Oh, Dae Kon; Noh, Young-Ouk; Lee, Hyung-Jong


    We presented a hybridly-integrated tunable external cavity laser with 0.8 nm mode spacing 16 channels operating in the direct modulation of 2.5-Gbps for a low-cost source of a WDM-PON system. The tunable laser was fabricated by using a superluminescent diode (SLD) and a polymer Bragg reflector. The maximum output power and the power slope efficiency of the tunable laser were 10.3 mW and 0.132 mW/mA, respectively, at the SLD current of 100 mA and the temperature of 25 degrees C. The directly-modulated tunable laser successfully provided 2.5-Gbps transmissions through 20-km standard single mode fiber. The power penalty of the tunable laser was less than 0.8 dB for 16 channels after a 20-km transmission. The power penalty variation was less than 1.4 dB during the blue-shifted wavelength tuning.

  5. Tibial Lengthening Using a Fixator-Assisted Lengthening Plate: A New Technique (United States)

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


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

  6. Regional Externalities

    NARCIS (Netherlands)

    Heijman, W.J.M.


    The book offers practical and theoretical insights in regional externalities. Regional externalities are a specific subset of externalities that can be defined as externalities where space plays a dominant role. This class of externalities can be divided into three categories: (1) externalities

  7. Photographic fixative poisoning (United States)

    Photographic fixatives are chemicals used to develop photographs. This article discusses poisoning from swallowing such chemicals. This article is for information only. DO NOT use it to treat or manage an ...

  8. Controversies in ankle fracture treatment. Indications for fixation of stable Weber type B fractures and indications for syndesmosis stabilization. (United States)

    Miller, S D


    Although the treatment of ankle fractures is often straightforward, several controversies remain. This article reviews the need for open reduction and internal fixation of the displaced supination-external rotation fracture, and contrasts the studies that mandate anatomic reduction with clinical results. The many issues surrounding syndesmosis fixation are also reviewed, including the need for fixation of distal fractures and the timing of screw fixation.

  9. Goniometria da articulação tíbio-tarsal após imobilização temporária com fixador esquelético externo em cães Tarsocrural joint goniometry after temporary immobilization with external skeletal fixation in dogs

    Directory of Open Access Journals (Sweden)

    Marcelo Meller Alievi


    Full Text Available Neste experimento, foram utilizados 10 cães clinicamente sadios, submetidos à imobilização temporária das articulações tíbio-tarsal, intertarsal e tarso-metatarsiana direita com fixador esquelético externo, tendo por objetivo avaliar através da mensuração da flexão, da extensão e da amplitude articular os danos provocados por esta imobilização. O aparelho de fixação esquelética externa manteve a articulação em um ângulo aproximado de 135º e permaneceu por 45 dias. Os animais apresentaram desconforto à manipulação articular para a realização do exame goniométrico no dia da retirada do aparelho, demonstrando dor na flexão e na extensão passiva do membro imobilizado, sendo que tal dificuldade desapareceu após três dias. Foi observado que a imobilização articular temporária obtida pela fixação esquelética externa promove perda estatisticamente significativa nos graus de flexão, de extensão e de amplitude articular tíbio-tarsal imediatamente após a remoção do fixador externo. Porém, após sete dias desta remoção para extensão e quinze dias para flexão e amplitude articular, esta perda não é mais verificada.In this study, 10 clinically healthy adult mongrel dogs were submitted to the temporary immobilization of the hock with external skeletal fixation. The aim of this procedure was to evaluate, using a manual goniometer, the flexion, the extension and the range of motion of the tarsocrural joint after immobilization in a functional angle of 135º for 45 days. The animals presented discomfort in relation to the articular manipulation for the goniometric exam on the day of the removal of the apparatus, demonstrating pain in the passive flexion and extension of the limb, and such difficulty disappeared after three days. It was observed that the temporary immobilization of the articulation obtained by the external skeletal fixation promotes statistically significant loss in the degree of flexion

  10. Update: Biological Nitrogen Fixation. (United States)

    Wiseman, Alan; And Others


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

  11. Sacroiliac Screw Fixation

    NARCIS (Netherlands)

    E.W. van den Bosch


    textabstractThe aim of this thesis is to evaluate three major aspects of the use of sacroiliac screws in patients with unstable pelvic ring fractures: the optimal technique for sacroiliac screw fixation, the reliability of peroperative fluoroscopy and the late results. We focused on the questions

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

    Directory of Open Access Journals (Sweden)

    Kadir Kotil


    Full Text Available 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

  13. Avaliação da resistência mecânica de três diferentes pinos de Schanz às forças de torção em montagens do fixador externo monolateral Mechanical resistance evaluation of three different Schanz screws to torsion forces in monolateral external fixation assemblies

    Directory of Open Access Journals (Sweden)

    Marcelo Mercadante


    Full Text Available OBJETIVO: O objetivo deste estudo é avaliar a resistência mecânica de três montagens de fixador externo linear utilizando pinos de 4,5 mm e de 5,5 mm com alma 3,2mm, e de 5,5 mm com alma de 4,5 mm no setor rosqueado dos pinos. MATERIAL E MÉTODOS: Foram montados fixadores externos lineares em tubos de polipropileno de 500 mm, com um corte obliquo a 45º no seu centro, com dois pinos de Schanz em cada segmento. Foram estudados 18 corpos de prova, divididos em três grupos de seis peças cada. No grupo 1 foram utilizados pinos de Schanz de 4,5 mm, no grupo 2 pinos de 5,5 mm ambos com alma de 3,2 mm e no grupo 3 pinos de 5,5 mm com alma de 4,5 mm de diâmetro. Os testes mecânicos foram realizadas em máquina de torção MT-100, e as medidas de resistência realizadas com 4,5º, 9,0º, 13,5º e 18,0º de torção. RESULTADOS: Os pinos de Schanz de 4,5 mm e alma de 3,2 mm mostraram como média de resistência para as torções de 4,5º, 9,0º, 13,5º e 18,0º, respectivamente: 12,0 N/mm, 21,0 N/mm, 33,0 N/mm e 46,0 N/mm. Os pinos de 5,5 com alma de 3,2 mm mostraram como resistência média: 13,2 N/mm, 25,3 N/mm, 40,0 N/mm e 51,2 N/mm, respectivamente. Os testes com os pinos de Schanz de 5,5 mm com alma de 4,5 mm mostraram resistência média de: 15,2 N/mm, 33,5 N/mm, 53,0 N/mm e 70,0 N/mm. Estudo estatístico com o teste da Análise de Variância e o teste de Bonferroni mostraram ausência de diferença estatisticamente significante entre os grupos com pinos com diâmetro da alma da parte roscada de 3,2mm (de 4,5 mm e 5,5 mm. Houve diferença estatisticamente significante (alfa OBJECTIVE: The objective of this study was to evaluate the mechanical force of three different assemblies of a linear external fixator using 4.5 mm and 5.5 mm Schanz screws with a 3.2 mm-diameter root, and another screw with 5.5 mm diameter with a 4,5mm root. MATERIAL AND METHODS: The linear external fixator was assembled in a 500 mm-long polypropylene tube, with a 45

  14. Novel posterior fixation keratoprosthesis (United States)

    Lacombe, Emmanuel


    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.

  15. Emprego de fixador externo circular no tratamento de complicações de fraturas do rádio e ulna em cães de raças pequenas Use of circular external fixator in the treatment of fracture complications of radius and ulna in small breed dogs

    Directory of Open Access Journals (Sweden)

    Sheila Canevese Rahal


    s fixator constructed using aluminum rings and steel rods was used in three Miniature Poodles (cases 1, 2 and 3 and in one Pinscher (case 4. Because of previous treatment with splints, cases 1 and 4 showed delayed union of the mid-distal and distal aspect of the radius-ulna shaft, respectively. The frame was assembled using two proximal rings and one distal ring. Fractures in cases 1 and 4 healed completely. However, case 1 showed a slight cranial deviation of the segments in the fractured site. The other two cases (2 and 3 had complications because of surgically-treated fractures. Case 2 showed forelimb lateral rotation and nonunion of the distal aspect of the radial diaphysis associated with an intramedullary pin and two cerclage wires. The intramedullary pin and one of the cerclage wires were then removed and fracture-derotation was done. The frame was assembled as in cases 1 and 4. Fracture healing was achieved with moderate caudal deviation of the bone shaft. In case 3, bone reabsorption in diaphysis was observed due to inadequate use of pin-resin external fixator. Bone transport with the Ilizarov´s fixator was used to induce bone regeneration. However, this treatment option was interrupted due to lack of response. The Ilizarov´s fixator was maintained and the bone defect was treated using autogenous cancellous bone graft and biomaterials. Ulna filled out part of bone defect of the radius. It was possible to conclude that the Ilizarov´s method may be used in the treatment of delayed union and nonunion, but the circular external fixator is difficult to apply in small breed dogs.

  16. Biomechanical effect of interspinous process distraction height after lumbar fixation surgery: An in vitro model. (United States)

    Fu, Lin; Ma, Jianxiong; Lu, Bin; Jia, Haobo; Zhao, Jie; Kuang, Mingjie; Feng, Rui; Xu, Liyan; Bai, Haohao; Sun, Lei; Wang, Ying; Ma, Xinlong


    Pedicle screw fixation may induce abnormal activity at adjacent segment and accelerate the degeneration of lumbar vertebrae. Dynamic stabilizers could provide an intermediate solution between conservative treatment and fusion surgery. Lumbar vertebral segment cephalad to instrumented fixation was the most common localization of adjacent segment degeneration. The aim of this study is to explore the use of interspinous process devices in the lumbar vertebral segment cephalad to fixation segment in changing the mechanical distribution and limiting abnormal activity of the spine. Eight specimens were tested in the following groups: intact group, instability group (bilateral facetectomy at L3-L4), fixation group (bilateral facetectomy and pedicle screw fixation at L3-L4), and hybrid fixation group (fixation at L3-L4 and simulating interspinous device implantation of 6, 8, 10, 12, 14, 16, and 18 mm at L2-L3). Range of motion, motion of vertebral body, and strain distribution change were recorded. The range of motion in extension with 16- and 18-mm hybrid constructs was significantly lower than intact, instability, and fixation groups. In flexion and lateral bending, the strain values of L4 inferior articular process with 18-mm hybrid construct have a significant difference compared with other groups. In axial rotation, under the condition of a contralateral state, the strain values of L2 superior articular process with 18-mm hybrid construct have a significant difference compared with intact and fixation groups. The strain value of the L4 inferior articular process had negative correlation with height distraction in three dimensions, except extension. A negative correlation between the strain value of the L2 superior articular process and distraction height was found in contralateral bending and contralateral axial rotation. Interspinous process devices above the fixation segment can change the mechanical distribution of the spine and limit activity in some of the

  17. Fixador esquelético pino-resina acrílica e enxerto ósseo esponjoso no tratamento de complicações secundárias à imobilização inadequada de fratura do rádio e ulna em cães Acrylic-pin external fixator and cancellous bone graft in the treatment of complications caused by inadequate immobilization of radius and ulna fracture in dogs

    Directory of Open Access Journals (Sweden)

    Sheila Canevese Rahal


    Full Text Available O objetivo do estudo foi avaliar a eficácia do fixador esquelético pino-resina, configuração tipo II, coadjuvado pelo enxerto ósseo esponjoso autólogo, no tratamento das complicações secundárias à imobilização inadequada de fraturas do rádio e ulna em 10 cães, com peso entre 1,8 e 33,6 kg. Detectou-se não-união (n=4, osteomielite (n=1, má-união (n=1, falência ou quebra de implante (n=4, sendo 60% das lesões referente ao uso prévio de pino intramedular no rádio. A montagem do fixador foi realizada com transfixação de pinos lisos em sua maioria angulados, cujas extremidades excedentes foram dobradas e estabilizadas com resina acrílica. Em todos os casos, utilizou-se enxerto esponjoso autólogo fresco, após debridamento do foco de fratura. O tempo de permanência do aparelho variou entre 45 dias e 5 meses e a maior complicação foi o afrouxamento dos pinos transfixantes. A consolidação das fraturas ocorreu por formação de calo periosteal de mínimo a moderado, indicando boa rigidez da montagem.The aim of this study was to evaluate the acrylic-pin external fixator, type II-configuration, and cancellous bone autograft for treating complications of radius and ulna fractures in 10 dogs weighing between 1.8 and 33.6 kg. Nonunion (n=4, osteomyelitis (n=1, malunion (n=1, failure or breakage of implant (n=4 were detected, and 60 % of them were associated with previous intramedullary pin placement in the radius. The fixator frame was constructed using most of the smooth transfixation pins angled. The fixation rods were constructed by placing acrylic resin over the ends of the transfixation pins that were previously bent. In all cases fresh cancellous bone autograft was used after cleaning of the fracture site. The permanence time of the external fixator ranged from 45 days to 5 months, and the most important complication was pin loosening. Fracture healing was by minimal to moderate periosteal callus, suggesting good rigidity

  18. [Treatment of sternoclavicular joint dislocation with sternoclavicular hook plate fixation]. (United States)

    Liu, Pan; Yuan, Jia-bin; Liu, Zhong-qian; Lu, Bing; Wang, Yue


    To evaluate the technique and therapeutic effect of sternoclavicular hook plate fixation in treating sternoclavicular joint (SCJ) dislocation. From January 2010 to March 2014,6 patients with SCJ dislocation were treated with sternoclavicular hook plate fixation in our hospital. Among the 6 patients, 5 patients were male and 1 patient was female, and the average age was 34 years, ranging from 26 to 48 years. The course of the disease ranged from 3 to 20 days. All the SCJ dislocations were caused by external injury and accompanied with the symptoms of swelling pain and obvious shoulder joint activity restricted in affected side. All SCJ dislocations were anterior dislocation by the diagnosis of X-ray and CT scan. The postoperative curative effect was evaluated according to Rockwood score. All the patients' operative incision were healed well and in good appearance. X-ray showed that the dislocated SCJ was well reduced and the plate was on right position. All the 6 patients were followed up for 4 to 18 months, with an average of 12 months. The results were evaluated according to Rockwood score, 4 got excellent results, 1 good and 1 fair. No fixation loosening, redislocation or side injury such as vessel, nerve or pleura injury were found. With sternoclavicular hook plate fixation, SCJ dislocation could be reduced while keeping its amphiarthrodial function and the completeness of the cartilage surface. Sternoclavicular hook plate fixation has advantages of safety and stabilization in fixation, and patients can begin function exercises earlier.

  19. How I improvised an external fixator to manage open fractures

    African Journals Online (AJOL)

    also reduces the heat generated by friction. The more the heat generated during drilling of holes in bones the more the necrosis along the pin tracts and the ... This improvisation consists of a long threaded metal rod that passes through two pieces of metal pipe. A small piece of metal plate is welded at an angle to each pipe.

  20. How I improvised an external fixator to manage open fractures

    African Journals Online (AJOL)

    Orthopaedic surgery is a technical specialty. In Nigeria, as in most developing countries, insufficient funding is available for technological advancement [1]. Indigenous hospital technology can reduce cost of managing injuries needing surgery, many of which are caused by an epidemic of road traffic accidents [2]. This paper.

  1. Pin Tract Infection after Uniplanar External Fixation of Open ...

    African Journals Online (AJOL)


    Afr. J. surg. COSECSA/ASEA Publication --East & Central African Journal of Surgery 2017; Vol. 22 (1) ... Tursky in their study of femur fractures involving 42 children found an incidence of 85%3. Regionally, a study by ... liver failure, renal failure, tumours and smoking were excluded – these conditions were thought that they ...

  2. The Safe Zone for External Fixator Pins in the Femur (United States)


    anatomy to avoid inad- vertent neurovascular injury and intra-articular pin penetra- tion.7,8 Pins placed into the shaft of the femur can be in a lateral...trochanter (LT), perpendicular to the femoral shaft. The final step involved palpation of the superior border of the patella, which was marked. Using a...with SAS 9.1 (Cary, NC). RESULTS Description of Nerve Anatomy The first branch crossed the femur at an average distance from the ASIS of 107 ± 22 mm

  3. Eighth international congress on nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)


    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.


    Directory of Open Access Journals (Sweden)

    M. A. Stepanov


    Full Text Available Elimination of congenital shortening of lower limb still remains a complex and unsolved orthopaedic task which requires an improved fixation technique as well as adjusted tactics of treatment and rehabilitation procedures.Purpose of the study — experimental approval of femur lengthening technique by external fixation with Ilizarov apparatus and internal fixation by plate.Materials and methods. Femur lengthening was performed in 6 mongrel dogs. Average animal age was 1,5±0,3 years, average weight — 20±5 kg, femur length — 22±2 sm. External apparatus with two supports and a titanium plate of an original design were applied under general anesthesia on the right femur of animals. Lengthening was performed manually at a rate of1 mm per day in 4 stages at a distance of 10% from initial segment length. External apparatus was removed on the last day of distraction after locking the plate. X-ray examination was done on the day of surgery, in 7, 14 and 25 days from the onset of distraction as well as in 14, 30, 60 and 90 days after completion of distraction and removal of external apparatus. Three animals were taken out of experiment in 30 days of fixation, remaining three animals — in 90 days. After euthanasia the authors performed autopsy of the organic femur complex and tissues contacting the plate.Results. The use of operated limb was not restricted during the whole distraction period. The authors observed first roentgenological signs of distraction osteogenesis on 7th day of lengthening. By the end of distraction period, at 25th day, shadows of regenerates demonstrated longitudinal striated structures in all cases. Median lucency area of 1–5 mm was located diagonally and across the regenerate or was intermittent. In 60 days of fixation X-rays demonstrated homogeneous regenerate. External fixation index was 13,9±1,5 days/sm (p≤0,05. The authors observed no cases of implants fracture or deformity during the experiment

  5. Internal fixation vs. conventional therapy in midface fractures. (United States)

    Klotch, D W; Gilliland, R


    The purpose of this review is to evaluate internal fixation by means of AO miniplates compared to conventional therapy for the treatment of complicated midface fractures. A more precise division of midface fractures into functional units than that afforded by the Le Fort classification was employed to categorize the complexity of injury. The criteria of evaluation were ease of functional rehabilitation, incidence of complications, and results of surgery. The classification system was helpful in surgical planning and in subsequent analysis of results. Forty-nine of the 92 midface fractures treated by open repair between July 1980 and January 1986 were malar fractures, and 41 of these had associated orbital fractures. The remaining 43 had Le Fort II or more complicated midface fractures, only 15 of which could be adequately categorized by the Le Fort classification. Twenty-two of the 43 patients with complicated midface fractures were surgically treated with internal fixation utilizing 67 AO miniplates. The remaining 21 patients were treated with conventional therapy utilizing a combination of intermaxillary fixation (IMF), and/or interosseous wiring, and/or primary bone grafting. Among the problems encountered were a nonunion of the midface in a delayed repair of a severely comminuted midface fracture, which required secondary split rib grafting. Three plates were removed because of intraoral extrusion. There were no plate-related infections. One of the advantages of internal fixation is that the need for primary bone grafting and external fixation is eliminated. Another is that intermaxillary fixation is needed less frequently, allowing immediate access to the oral cavity for control of airway, care of intraoral wounds, and rapid return to normal alimentation with full mandibular function. Most patients with no associated GI problems tolerated a soft diet within 6 days. Tracheostomy tubes were removed within 3 days if no pulmonary failure was present. We can


    Directory of Open Access Journals (Sweden)

    Sendhilvelan Rajagopalan


    Full Text Available BACKGROUND Syndesmotic disruptions are often seen in ankle fractures. Malreduction of these fractures can result in arthritis and instability. A proportion of these patients with malreduction require revision fixation. This study presents the results of revision fixation in such patients, using the Ankle TightRope ® (Arthrex system. METHODS Between January 2000 to December 2009, 124 patients who underwent ankle fracture fixations with syndesmotic stabilisation were analysed. Out of 124 patients, 8 patients were diagnosed with failure of primary stabilisation (based on radiological and clinical criteria and subjected to revision fixation using the Ankle TightRope ® (Arthrex system. Followup was done at periodic time intervals of 3, 6 and 12 months. Both clinical and radiological assessment was performed. Complications and duration of hospital stay was recorded. Functional evaluation was performed using the American Orthopaedic Foot and Ankle Society (AOFAS scoring system. RESULTS Five patients had good results, one satisfactory and two had poor outcomes. CONCLUSIONS Ankle TightRope ® fixation is an alternative method of stabilisation in patients who require revision syndesmosis fixation. Further studies are required to evaluate this method of revision stabilisation as compared to screws.

  7. Neuronal control of fixation and fixational eye movements (United States)


    Ocular fixation is a dynamic process that is actively controlled by many of the same brain structures involved in the control of eye movements, including the superior colliculus, cerebellum and reticular formation. In this article, we review several aspects of this active control. First, the decision to move the eyes not only depends on target-related signals from the peripheral visual field, but also on signals from the currently fixated target at the fovea, and involves mechanisms that are shared between saccades and smooth pursuit. Second, eye position during fixation is actively controlled and depends on bilateral activity in the superior colliculi and medio-posterior cerebellum; disruption of activity in these circuits causes systematic deviations in eye position during both fixation and smooth pursuit eye movements. Third, the eyes are not completely still during fixation but make continuous miniature movements, including ocular drift and microsaccades, which are controlled by the same neuronal mechanisms that generate larger saccades. Finally, fixational eye movements have large effects on visual perception. Ocular drift transforms the visual input in ways that increase spatial acuity; microsaccades not only improve vision by relocating the fovea but also cause momentary changes in vision analogous to those caused by larger saccades. This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’. PMID:28242738

  8. Neuronal control of fixation and fixational eye movements. (United States)

    Krauzlis, Richard J; Goffart, Laurent; Hafed, Ziad M


    Ocular fixation is a dynamic process that is actively controlled by many of the same brain structures involved in the control of eye movements, including the superior colliculus, cerebellum and reticular formation. In this article, we review several aspects of this active control. First, the decision to move the eyes not only depends on target-related signals from the peripheral visual field, but also on signals from the currently fixated target at the fovea, and involves mechanisms that are shared between saccades and smooth pursuit. Second, eye position during fixation is actively controlled and depends on bilateral activity in the superior colliculi and medio-posterior cerebellum; disruption of activity in these circuits causes systematic deviations in eye position during both fixation and smooth pursuit eye movements. Third, the eyes are not completely still during fixation but make continuous miniature movements, including ocular drift and microsaccades, which are controlled by the same neuronal mechanisms that generate larger saccades. Finally, fixational eye movements have large effects on visual perception. Ocular drift transforms the visual input in ways that increase spatial acuity; microsaccades not only improve vision by relocating the fovea but also cause momentary changes in vision analogous to those caused by larger saccades.This article is part of the themed issue 'Movement suppression: brain mechanisms for stopping and stillness'. © 2017 The Authors.

  9. Elevated CO2 concentration around alfalfa nodules increases N2 fixation (United States)

    Fischinger, Stephanie A.; Hristozkova, Marieta; Mainassara, Zaman-Allah; Schulze, Joachim


    Nodule CO2 fixation via PEPC provides malate for bacteroids and oxaloacetate for N assimilation. The process is therefore of central importance for efficient nitrogen fixation. Nodule CO2 fixation is known to depend on external CO2 concentration. The hypothesis of the present paper was that nitrogen fixation in alfalfa plants is enhanced when the nodules are exposed to elevated CO2 concentrations. Therefore nodulated plants of alfalfa were grown in a hydroponic system that allowed separate aeration of the root/nodule compartment that avoided any gas leakage to the shoots. The root/nodule compartments were aerated either with a 2500 μl l−1 (+CO2) or zero μl l−1 (–CO2) CO2-containing N2/O2 gas flow (80/20, v/v). Nodule CO2 fixation, nitrogen fixation, and growth were strongly increased in the +CO2 treatment in a 3-week experimental period. More intensive CO2 and nitrogen fixation coincided with higher per plant amounts of amino acids and organic acids in the nodules. Moreover, the concentration of asparagine was increased in both the nodules and the xylem sap. Plants in the +CO2 treatment tended to develop nodules with higher %N concentration and individual activity. In a parallel experiment on plants with inefficient nodules (fix–) the +CO2 treatment remained without effect. Our data support the thesis that nodule CO2 fixation is pivotal for efficient nitrogen fixation. It is concluded that strategies which enhance nodule CO2 fixation will improve nitrogen fixation and nodule formation. Moreover, sufficient CO2 application to roots and nodules is necessary for growth and efficient nitrogen fixation in hydroponic and aeroponic growth systems. PMID:19815686

  10. Arthroscopy-assisted fracture fixation. (United States)

    Atesok, Kivanc; Doral, M Nedim; Whipple, Terry; Mann, Gideon; Mei-Dan, Omer; Atay, O Ahmet; Beer, Yiftah; Lowe, Joseph; Soudry, Michael; Schemitsch, Emil H


    the purpose of this article was to systematically analyze the results of published studies in the literature which evaluated the use of arthroscopically assisted techniques in intra-articular fracture fixation. published investigations to date were analyzed by classifying them according to joints that were involved with intra-articular fractures including: knee, ankle, hip, shoulder, elbow, and wrist joints. The results were studied to assess the feasibility, efficiency, and outcomes of arthroscopy-assisted fracture fixation. arthroscopy-assisted techniques have been used successfully for the treatment of fractures of the tibial plateau, tibial eminence, malleoli, pilon, calcaneus, femoral head, glenoid, greater tuberosity, distal clavicle, radial head, coronoid, distal radius, and scaphoid. The major advantages of arthroscopic fracture fixation over open methods are direct visualization of the intra-articular space, decreased invasiveness, and the possibility for multitask interventions through which fixation of the fracture, and repair of the soft tissues and the cartilage can be performed simultaneously. The time-consuming and technically demanding nature of the procedures with a prolonged learning curve and limited fixation alternatives are the main disadvantages of this technique. arthroscopic fixation is increasingly utilized for certain intra-articular fracture types due to the minimally invasive nature of the procedures and high accuracy. Randomized controlled trials are needed to justify wider use of arthroscopy-assisted techniques for treatment of intra-articular fractures.

  11. Componente tibial na revisão da artroplastia do joelho: comparação entre fixação cimentada e híbrida Tibial component in revision of total knee arthroplasty: comparison between cemented and hybrid fixation

    Directory of Open Access Journals (Sweden)

    Francisco Fontes Cintra


    Full Text Available OBJETIVO: Comparar os resultados clínicos, radiográficos e de seguimento a médio prazo de dois métodos de fixação do componente tibial nas cirurgias de revisão de prótese total do joelho: cimentada (bandeja e haste e híbrida (bandeja cimentada e haste que preenche o canal não cimentada e não porosa. MÉTODOS: Entre agosto de 1999 e novembro de 2005, 30 cirurgias de revisão de artroplastia total do joelho foram realizadas em 26 pacientes, sendo divididas em: grupo I: fixação cimentada (N = 21; grupo II: híbrida (N = 9. O tempo médio de acompanhamento foi de 52 meses, e não houve perda de seguimento pós-operatório. RESULTADOS: Não foram observadas diferenças nos resultados dos valores dos questionários da Womac e do Knee Society Score entre os dois grupos. Um paciente do grupo I apresentou sinais radiográficos de soltura. Dois pacientes (um de cada grupo referiram dor na região diafisária, compatível com o local da ponta das hastes. O sinal radiográfico de "pedestal" esteve presente em 89% dos joelhos com hastes não cimentadas e em nenhum com haste cimentada. CONCLUSÃO: A análise comparativa entre os dois métodos não mostrou diferenças nos parâmetros clínico, radiográfico e de sobrevida da artroplastia.OBJECTIVE: To compare the clinical, radiographic and medium-term follow-up results from two fixation methods for the tibial component in revision procedures on total knee prostheses: cemented (tray and stem and hybrid (cemented tray and uncemented, nonporous canal-filling stem. METHODS: Between August 1999 and November 2005, 30 revision procedures on total knee arthroplasties were performed on 26 patients, who were divided between group I (cemented fixation; 21 knees and group II (hybrid fixation; nine knees. The mean follow-up was 52 months and no patients were lost from the follow-up. RESULTS: No differences in the scores from the WOMAC and Knee Society questionnaires were observed between the two groups. One

  12. [Internal fixation in the treatment of Gustilo IIIb open fractures of the leg]. (United States)

    Schlemmer, B; Giraud, P; Jenny, G


    Gustilo type IIIb open fractures are most often associated with high energy trauma and cannot be closed by simple suture because of the high risk of infection and non-union. As an alternative to the external fixator, fixation by reamed locked intermedullary nailing was done according to the standard technique. The fixation allowed immediate partial or complete weightbearing and mobilisation of the neighbouring joints. In addition, it allows simple and rapid skin cover by flaps. This immediate skin cover allows one to diminish the risk of infection.

  13. Hybrid instrument applied to human reliability study in event of loss of external electric power in a nuclear power plant; Instrumento hibrido aplicado ao estudo da confiabilidade humana em evento de perda de energia eletrica externa em usina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Eduardo Ferraz


    The study projects in highly complex installations involves robust modeling, supported by conceptual and mathematical tools, to carry out systematic research and structured the different risk scenarios that can lead to unwanted events from occurring equipment failures or human errors. In the context of classical modeling, the Probabilistic Safety Analysis (PSA) seeks to provide qualitative and quantitative information about the project particularity and their operational facilities, including the identification of factors or scenarios that contribute to the risk and consequent comparison options for increasing safety. In this context, the aim of the thesis is to develop a hybrid instrument (CPP-HI) innovative, from the integrated modeling techniques of Failure Mode and Effect Analysis (FMEA), concepts of Human Reliability Analysis and Probabilistic Composition of Preferences (PCP). In support of modeling and validation of the CPP-HI, a simulation was performed on a triggering event 'Loss of External Electric Power' - PEEE, in a Nuclear Power plant. The results were simulated in a virtual environment (sensitivity analysis) and are robust to the study of Human Reliability Analysis (HRA) in the context of the PSA. (author)

  14. Comparison of routine fixation of tissues with rapid tissue fixation. (United States)

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


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

  15. [External otitis]. (United States)

    Olina, Massimo; Cametti, Massimiliano; Guglielmetti, Chiara; Gattoni, Massimo; Leigheb, Giorgio; Pia, Francesco


    Otitis externa is one of the most common diseases in ORL practice, during summer; the treatment of otitis externa may be simple and easy or protracted and frustrating, also with fatal outcome. Many local factors may interfere with the normal defences against infections in the external auditory canal. Removing or dissolving the cerumen by water or other instruments eliminates an important barrier to infections: its acids inhibit the growth of bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) and fungi (Aspergillus). Also skin abrasions or irritation, allergic diseases and many systemic condition like anaemia, vitamin deficiency, endocrine disorders (diabetes) and various forms of dermatitis cause a lower resistance to infections in external auditory canal. Even if the prognosis remains benign in the majority of cases, important complications could appear like: malignant otitis externa, facial nerve paralysis, tympanic bone osteomyelitis, pericondrytis. Successful treatment depends on a proper diagnosis and therapy: the most important factor in the treatment is repeated debridement of the external auditory canal by the physician. The use of Castellani' Tintura rubra, hydroalcoholic solution of phenic fuchsin, can be very effective for bacteria and mycotic eradication. Culturing of ear canal infection could be performed on the second or third visit if the otitis externa is not responding to therapy. Complication are not frequent, but malignant otitis externa can be mortal. Dermatological consultation is often necessary for correct diagnosis.

  16. Treatment of acute proximal humeral fractures in children with modular exter nal fixator

    Directory of Open Access Journals (Sweden)

    Michele Bisaccia


    Full Text Available Objective: To evaluate the follow-up of the fractures treated by external fixator. Methods: A total of 31 children aged 6–15 years with proximal humeral fractures Grade IV according to Neer–Horowitz classification were treated. The medium follow-up was 24 months. Results: In all cases, a good stability of the fracture and a quick healing process were obtained. The mean time of follow-up was 24 months. The external fixation was removed after 6 weeks (5–8 weeks on average. Constant shoulder score was proposed to all patients and the average result was 97.5 (84–100. Conclusions: Advantages of the external fixation are rapid mobilization of the joint, low invasiveness, a single surgery and the possibility to correct any secondary displacement. It is important to underline that the positioning of external fixator should be implanted by expert surgeons and that the patients must cooperate during the entire process up to the time of the removal of the fixator.

  17. Arthroscopic-assisted plate fixation for displaced large-sized comminuted greater tuberosity fractures of proximal humerus: a novel surgical technique. (United States)

    Park, Sang-Eun; Jeong, Jae-Jung; Panchal, Karnav; Lee, Jong-Yun; Min, Hyung-Ki; Ji, Jong-Hun


    The purpose of the present study was to describe the use of a novel hybrid surgical technique-arthroscopic-assisted plate fixation-and evaluate its clinical and anatomical outcomes in the management of large, displaced greater tuberosity (GT) fractures with comminution. From 2009 to 2011, this novel technique was performed in 11 patients [2 men and 9 women; median age, 64 years (range 41-83 years)] with large, comminuted GT fractures, with fragment displacements of >5 mm. The preoperative mean posterior and superior migration of the fractured fragment, as measured on computed tomography (CT), was 19.5 and 5.5 mm, respectively. Two patients had shoulder fracture-dislocation, and three had associated undisplaced surgical neck fracture. The mean duration between injury and surgery was 4 days. The mean follow-up duration was 26 months. At the final follow-up, the mean postoperative ASES, UCLA and SST scores were 84, 29, and 8, respectively. The mean range of motion was as follows: forward flexion, 138°; abduction, 135°; external rotation at the side, 19°; and internal rotation, up to the L2 level. The mean posterior and superior displacements of fracture fragments on postoperative CT scan [0.7 ± 0.8 mm (range 0-2.1 mm) and 2.8 ± 0.5 mm (range 3.4-5.3 mm), respectively] were significantly improved (p fracture fragment was noted in 1 patient at 4 weeks, after corrective reduction and fixation surgery. The novel arthroscopic-assisted anatomical plate fixation technique was found to be effective in reducing large-sized, displaced, comminuted GT fractures and in allowing concurrent management of intra-articular pathologies and early functional rehabilitation. Compared with the conventional plate fixation or arthroscopic suture anchor fixation technique, arthroscopic-assisted plate fixation enabled accurate restoration of the medial footprint of the GT fracture and provided an effective buttress to the large-sized GT fracture fragments. Retrospective

  18. [Complex reconstruction with internal locking plate fixation for Charcot arthropathy]. (United States)

    Ramadani, F; Härägus, H; Radu, P; Trieb, K; Hofstaetter, S


    Osteosynthesis and reposition of the Charcot foot is challenging with respect to choice of a proper implant. There is currently no international consensus regarding the optimal implant. Locking plates seem to be an innovative and stable method for reconstruction. The aim of this work is to analyze bone fusion, complications, pseudoarthrosis, and patient satisfaction. This paper presents a retrospective analysis of 63 consecutive Charcot feet treated between 2004 and 2014. The mean follow-up time was 2.4 years. All Charcot feet treated between 2004 and 2014 were Sanders type II or III. A bony fusion was achieved in 50 % of the cases, 26 % had a functional pseudoarthrosis with intact implants and pain-free mobility, and 22 % showed no healing with broken implants. Conclusion Internal fixation with locking plates is superior to screw fixation only with regard to biomechanics. We prefer internal fixation plates to external fixation because of stability even in the case of pseudoathrosis and because of the learning curve.

  19. Single-suture scleral fixation of subluxated foldable intraocular lenses. (United States)

    Yarangumeli, Alper; Alp, Mehmet Numan; Kural, Gulcan


    To evaluate the results of single-suture scleral fixation of subluxated foldable intraocular lenses (IOL) in eyes with sufficient residual capsular support. The results of IOL repositioning by single-suture scleral fixation in 6 eyes of 6 patients with IOL subluxation were included. All subluxated IOLs were single-piece hydrophilic acrylic. Subluxation resulted from posterior capsule tears in 3 eyes, zonular dialyses in 2 eyes, and zonular dialysis with a capsulorhexis tear in 1 eye. A similar technique was used in all eyes in which one haptic was externalized through a superior clear corneal incision and tied with a Pair-PAK 10-0 polypropylene suture, and was finally retracted and fixated behind the iris close to the ciliary sulcus at the 12:00 meridian. All patients were followed up for at least 6 months. Best-corrected visual acuities ranged between finger counting and 20/70 (mean logMAR 1.02±0.64) preoperatively, and between 20/100 and 20/20 (mean logMAR 0.22±0.26) at the final postoperative visit. All IOLs remained centered and no significant postoperative complications were encountered except for an IOL tilt which resulted in a considerable oblique astigmatism in one eye. Subluxated foldable IOLs may safely be repositioned and secured with a single scleral fixation suture in selected cases with adequate amount of capsular remnants.

  20. A Review of Current Fixation Use and Registry Outcomes in Total Hip Arthroplasty

    DEFF Research Database (Denmark)

    Troelsen, Anders; Malchau, Erik; Sillesen, Nanna Hylleholt


    and to analyze age-stratified risk of revision comparing cemented, hybrid, and uncemented fixation as reported by national hip arthroplasty registries. METHODS: Data were extracted from the annual reports of seven national hip arthroplasty registries; we included all national registries for which annual reports...... were available in English or a Scandinavian language, if the registry had a history of more than 5 years of data collection. RESULTS: Current use of uncemented fixation in primary THAs varies between 15% in Sweden and 82% in Canada. From 2006 to 2010 the registries of all countries reported overall...... increases in the use of uncemented fixation; Sweden reported the smallest absolute increase (from 10% to 15%), and Denmark reported the greatest absolute increase (from 47% to 68%). Looking only at the oldest age groups, use of uncemented fixation also was increasing during the period. In the oldest age...

  1. Understanding Nitrogen Fixation

    Energy Technology Data Exchange (ETDEWEB)

    Paul J. Chirik


    synthesis of ammonia, NH{sub 3}, from its elements, H{sub 2} and N{sub 2}, via the venerable Haber-Bosch process is one of the most significant technological achievements of the past century. Our research program seeks to discover new transition metal reagents and catalysts to disrupt the strong N {triple_bond} N bond in N{sub 2} and create new, fundamental chemical linkages for the construction of molecules with application as fuels, fertilizers and fine chemicals. With DOE support, our group has discovered a mild method for ammonia synthesis in solution as well as new methods for the construction of nitrogen-carbon bonds directly from N{sub 2}. Ideally these achievements will evolve into more efficient nitrogen fixation schemes that circumvent the high energy demands of industrial ammonia synthesis. Industrially, atmospheric nitrogen enters the synthetic cycle by the well-established Haber-Bosch process whereby N{sub 2} is hydrogenated to ammonia at high temperature and pressure. The commercialization of this reaction represents one of the greatest technological achievements of the 20th century as Haber-Bosch ammonia is responsible for supporting approximately 50% of the world's population and serves as the source of half of the nitrogen in the human body. The extreme reaction conditions required for an economical process have significant energy consequences, consuming 1% of the world's energy supply mostly in the form of pollution-intensive coal. Moreover, industrial H{sub 2} synthesis via the water gas shift reaction and the steam reforming of methane is fossil fuel intensive and produces CO{sub 2} as a byproduct. New synthetic methods that promote this thermodynamically favored transformation ({Delta}G{sup o} = -4.1 kcal/mol) under milder conditions or completely obviate it are therefore desirable. Most nitrogen-containing organic molecules are derived from ammonia (and hence rely on the Haber-Bosch and H{sub 2} synthesis processes) and direct synthesis from

  2. A new fixation strategy for addressable nano-network building blocks

    KAUST Repository

    Lundberg, Erik P.


    Rapid controlled self-assembly makes DNA ideal for building nanostructures. A problem using hybridized intermediates in hierarchic assembly is their thermodynamic lability. We demonstrate a click-fixation technology by which robust hexagonal DNA modules can be made. This principle is applicable to a wide variety of DNA nanoconstructs. © 2010 The Royal Society of Chemistry.

  3. Analysis and an overview of fixators in medicine and the methods of processing materials for producing fixators

    Directory of Open Access Journals (Sweden)

    Dalibor Milojko Đenadić


    Full Text Available The fixator is a medical device that provides support to fractured biological structures. Metal biomaterials are mainly used for replacing broken or damaged hard tissues such as bones because of their high strenght, toughness and corrosion resistance. Materials such as stainless steel, titanium and aluminium alloys (Ti-6Al-4V, cobalt and chromium alloys, composite materials and other biocompatible materials are used in orthopedy for the stabilization of connective tissue injuries or as a substitute for the bone tissues. Fixators are classified according to the place of installation to external and internal fixators. Widely used medical fixators are pins, rods plates, screws, pipes, wires, nails and external fixators. Conventional and non-conventional methods of processing are used in the production process for all types of fixators. Introduction Fixators are medical devices manufactured to support damaged biological structures. In the field of orthopedic surgery that deals with skeletal disorders such as bone, spine, joints, muscles and tendons injuries and diseases, various metals, titanium and cobalt alloys etc. are used to stabilize the supporting tissue injuries or as a substitute for bone tissues. Metallic implants are frequently used in orthopedic surgery as joint prosthesis (hip, knee and elbow fracture fixation devices (plates, screws, external fixators and devices for the fixation of the spine. In principle, fixators are devided into external and internal ones, depending on the place of installation (outside or inside the body. The most common types of medical fixators are pins, rods and plates. This paper presents some of the most common materials used for the production of fixators, their processing and possibilties of use in medicine for various purposes. Types of fixators and materials used for their production Nowadays, biocompatible materials are usually used for the production of fixators and implants. These materials show good

  4. Correção da cifose de Scheuermann: estudo comparativo da fixação híbrida com ganchos e parafusos versus fixação apenas com parafusos Corrección de la cifosis de Scheuermann: estudio comparativo de la fijación híbrida con ganchos y tornillos versus fijación solo con tornillos Correction of Scheuermann kyphosis: comparative study of hybrid fixation using hooks and screws versus screw-only fixation

    Directory of Open Access Journals (Sweden)

    Enguer Beraldo Garcia


    fijación solo con tornillos.OBJECTIVE: to evaluate the degree of correction of Sheuermann kyphosis, in 6 patients who were submitted to surgery using hybrid instrumentation comprised of hooks and screws (H, and 17 patients undergoing screw-only fixation (P. METHODS: 23 patients with Scheuermann kyphosis were submitted to surgical treatment using anterior and posterior approach. In the present study, we indicated surgical treatment for rigid kyphosis, varying between 60º and 105º. All patients presented a Risser signal above 4. Liberation and Fusion were realized through anterior approach, followed by fixation, deformity correction, and arthrodesis through posterior approach. RESULTS: in Group H, a preoperative kyphosis of 84.17º and a postoperative of 47.5º were observed. In Group P, a preoperative kyphosis of 80.35º and postoperative of 33.53º were observed. CONCLUSION: it was concluded that both types of fixation presented very satisfactory results, with screw only fixation being superior.

  5. Design and research of a new kind of minimally invasive fixation ...

    African Journals Online (AJOL)

    A new kind of external fixation for orthopaedics was designed in order to overcome the shortcomings of high weight, difficult operation and high degree of injury for ... In order to verify the feasibility of the designed structure, FEM (finite element method) was used to simulate the real condition of the load when the device was ...

  6. The Effect of Formaldehyde Fixation on RNA (United States)

    Evers, David L.; Fowler, Carol B.; Cunningham, Brady R.; Mason, Jeffrey T.; O'Leary, Timothy J.


    Formalin-fixed, paraffin-embedded tissues generally provide low yields of extractable RNA that exhibit both covalent modification of nucleic acid bases and strand cleavage. This frustrates efforts to perform retrospective analyses of gene expression using archival tissue specimens. A variety of conditions have been reported to demodify formaldehyde-fixed RNA in different model systems. We studied the reversal of formaldehyde fixation of RNA using a 50 base RNA oligonucleotide and total cellular RNA. Formaldehyde-adducted, native, and hydrolyzed RNA species were identified by their bioanalyzer electrophoretic migration patterns and RT–quantitative PCR. Demodification conditions included temperature, time, buffer, and pH. The reversal of formaldehyde-fixed RNA to native species without apparent RNA hydrolysis was most successfully performed in dilute Tris, phosphate, or similar buffers (pH 8) at 70°C for 30 minutes. Amines were not required for efficient formaldehyde demodification. Formaldehyde-fixed RNA was more labile than native RNA to treatment with heat and buffer, suggesting that antigen retrieval methods for proteins may impede RNA hybridization or RNA extraction. Taken together, the data indicate that reliable conditions may be used to remove formaldehyde adducts from RNA to improve the quality of RNA available for molecular studies. PMID:21497290

  7. Robot Motion Vision by Fixation (United States)


    These are 8 - bit images but the last two digits are usually too noisy to be reliable. The true motion between these frames is a combination of...Brightness Gradients 2nd ImageN Ist Image yk t k+) Sti+ l Figure B-i: The first brightness derivatives required in the direct methods can be estimated...individual time varying frames, the above algorithms compensate for part of the tessellation errors involved in discrete digitized images. Depth at Fixation

  8. On Fixation of Hip Prostheses


    Palm, Lars


    This thesis, comprising 5 separate studies, is concerned with fixation of prosthetic components in total hip arthroplasty. The results and conclusions of the studies fol-low; The initial stability of femoral revision components, the long cementless PCA stem and the Exeter standard stem cemented in a bed of impacted bone graft, was com-pared in an experimental study. The PCA stem was more stable than the Exeter stem. However, for both stems initial stability may not be sufficient to allow bone...

  9. External noise distinguishes attention mechanisms. (United States)

    Lu, Z L; Dosher, B A


    We developed and tested a powerful method for identifying and characterizing the effect of attention on performance in visual tasks as due to signal enhancement, distractor exclusion, or internal noise suppression. Based on a noisy Perceptual Template Model (PTM) of a human observer, the method adds increasing amounts of external noise (white gaussian random noise) to the visual stimulus and observes the effect on performance of a perceptual task for attended and unattended stimuli. The three mechanisms of attention yield three "signature" patterns of performance. The general framework for characterizing the mechanisms of attention is used here to investigate the attentional mechanisms in a concurrent location-cued orientation discrimination task. Test stimuli--Gabor patches tilted slightly to the right or left--always appeared on both the left and the right of fixation, and varied independently. Observers were cued on each trial to attend to the left, the right, or evenly to both stimuli, and decide the direction of tilt of both test stimuli. For eight levels of added external noise and three attention conditions (attended, unattended, and equal), subjects' contrast threshold levels were determined. At low levels of external noise, attention affected threshold contrast: threshold contrasts for non-attended stimuli were systematically higher than for equal attention stimuli, which were, in turn, higher than for attended stimuli. Specifically, when the rms contrast of the external noise is below 10%, there is a consistent 17% elevation of contrast threshold from attended to unattended condition across all three subjects. For higher levels of external noise, attention conditions did not affect threshold contrast values at all. These strong results are characteristic of a signal enhancement, or equivalently, an internal additive noise reduction mechanism of attention.

  10. [Mechanobiology of fracture healing part 2 : Relevance for internal fixation of fractures]. (United States)

    Claes, L


    Clinical studies do not allow a quantitative correlation between stability of fracture fixation and outcome of bone healing. This limits the biomechanical improvement of fracture fixation techniques. The most practical quantitative parameter to describe the stability of a fracture fixation is the stiffness. This can be determined for several types of fixation through biomechanical methods and in some clinical studies in vivo. By using numerical fracture healing models, it is now possible to use the tissue differentiation rules found in basic research to calculate optimal stiffness parameters for various fixation techniques. For a tibial fracture as an example the possibilities of a numerical fracture healing simulation have been demonstrated. The effects of the diameter of an intramedullary nail, type of fracture, fracture gap size and nail material on healing could be demonstrated. To circumvent complex and time consuming calculations for several fixations a map was calculated which shows the expected bone healing quality as a function of the axial stiffness and the shear stiffness of the fixation device. By comparing the stiffness of various fixation techniques with the stiffness map it becomes evident that the methods most often used (e.g. unreamed nail, plate and external fixator) have a low shear and/or rotational stiffness that is too low to achieve the optimal healing outcome. The high axial stiffness of plates next to the plate surface can lead to very low tissue strain directly adjacent to the plate and can delay the bone healing process at this location.

  11. Smaller Fixation Target Size Is Associated with More Stable Fixation and Less Variance in Threshold Sensitivity.

    Directory of Open Access Journals (Sweden)

    Kazunori Hirasawa

    Full Text Available The aims of this randomized observational case control study were to quantify fixation behavior during standard automated perimetry (SAP with different fixation targets and to evaluate the relationship between fixation behavior and threshold variability at each test point in healthy young participants experienced with perimetry. SAP was performed on the right eyes of 29 participants using the Octopus 900 perimeter, program 32, dynamic strategy. The fixation targets of Point, Cross, and Ring were used for SAP. Fixation behavior was recorded using a wearable eye-tracking glass. All participants underwent SAP twice with each fixation target in a random fashion. Fixation behavior was quantified by calculating the bivariate contour ellipse area (BCEA and the frequency of deviation from the fixation target. The BCEAs (deg2 of Point, Cross, and Ring targets were 1.11, 1.46, and 2.02, respectively. In all cases, BCEA increased significantly with increasing fixation target size (p < 0.05. The logarithmic value of BCEA demonstrated the same tendency (p < 0.05. A positive correlation was identified between fixation behavior and threshold variability for the Point and Cross targets (ρ = 0.413-0.534, p < 0.05. Fixation behavior increased with increasing fixation target size. Moreover, a larger fixation behavior tended to be associated with a higher threshold variability. A small fixation target is recommended during the visual field test.

  12. Abnormal Fixational Eye Movements in Amblyopia. (United States)

    Shaikh, Aasef G; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F


    Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity.

  13. Fixational eye movements and binocular vision. (United States)

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


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

  14. Comparison of fixation disparity curve parameters obtained with the Wesson and Saladin fixation disparity cards

    National Research Council Canada - National Science Library

    Ngan, Janice; Goss, David A; Despirito, Joseph


    This study compared fixation curve parameters with two commercially available fixation disparity cards, one that has been available for several years, the Wesson card, and a new one, the Saladin card...

  15. Percutaneous Fixation of Displaced Calcaneal Fracture

    Directory of Open Access Journals (Sweden)

    Yeung Yip-Kan


    Conclusion: Percutaneous fixation of displaced tongue-type calcaneal fractures is an effective treatment with acceptable clinical outcome, short hospital stay, minimal skin complications, and quick recovery.

  16. Suppressive interactions underlying visually evoked fixational saccades. (United States)

    Wang, Helena X; Yuval-Greenberg, Shlomit; Heeger, David J


    Small saccades occur frequently during fixation, and are coupled to changes in visual stimulation and cognitive state. Neurophysiologically, fixational saccades reflect neural activity near the foveal region of a continuous visuomotor map. It is well known that competitive interactions between neurons within visuomotor maps contribute to target selection for large saccades. Here we asked how such interactions in visuomotor maps shape the rate and direction of small fixational saccades. We measured fixational saccades during periods of prolonged fixation while presenting pairs of visual stimuli (parafoveal: 0.8° eccentricity; peripheral: 5° eccentricity) of various contrasts. Fixational saccade direction was biased toward locations of parafoveal stimuli but not peripheral stimuli, ∼100-250ms following stimulus onset. The rate of fixational saccades toward parafoveal stimuli (congruent saccades) increased systematically with parafoveal stimulus contrast, and was suppressed by the simultaneous presentation of a peripheral stimulus. The suppression was best characterized as a combination of two processes: a subtractive suppression of the overall fixational saccade rate and a divisive suppression of the direction bias. These results reveal the nature of suppressive interactions within visuomotor maps and constrain models of the population code for fixational saccades. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Iliosacral screw fixation of the unstable pelvic ring injuries. (United States)

    Rysavý, M; Pavelka, T; Khayarin, M; Dzupa, V


    To report on the early results and possible complications of iliosacral screw fixation in the management of unstable pelvic ring injuries. One hundred and two unstable pelvic ring injuries were treated using iliosacral screw fixation for posterior pelvic ring disruptions. Closed manipulative reductions of the posterior lesion were attempted for all patients. Open reductions were used in the minority of patients with unsatisfactory closed reductions as assessed fluoroscopically at the time of surgery. Anterior fixations were by means of open reduction in 62 patients and by external fixation in 14 patients, and by screws in 7 patients. Twenty patients had no anterior fixation. Plain anteroposterior, inlet and outlet radiographs of the pelvis were obtained postoperatively at six weeks, three months, six months and one year. A pelvic computed tomography scan was performed postoperatively in those patients where residual displacement or screw misplacement was suspected. Complications were recorded. One patient died 31 days after the trauma due to pneumonia and one died 9 months after the surgery after a fall from a height in a second suicidal attempt. There were two posterior pelvic infections and one anterior pelvic infection. Screw misplacement occurred in seven cases. In six cases a misplaced screw produced transient L5 neuroapraxia. There was no fixation failure requiring revision surgery. There was one case of injury to the superior gluteal artery. Unstable pelvic ring disruptions are severe injuries, associated with a high rate of morbidity and mortality. Pelvic fractures can be treated by variety of methods. Treatment with traction and pelvic slings does not offer accurate reduction and confines the patient to prolong bed rest with all potential complications. Several authors documented lower morbidity and mortality rates and shorter hospital stay in patients treated by early operative stabilization of pelvic injuries. The timing of the surgery is still

  18. Models of Fixation and Tissue Processing (United States)

    Grizzle, William E.


    Fixation and processing of tissue to paraffin blocks are used to permit tissues to be cut thinly (4 to 5 µm); cutting thin sections of tissue and staining them histochemically or immunohistochemically are necessary to permit tissues to be viewed adequately as to their structures (e.g., subcellular components and surrounding stroma) using a bright field microscope. Over the last century, anatomists and pathologists have used fixation in 10% neutral buffered formalin (10% NBF) as the fixative of choice. Also, both human and veterinary pathologists have trained using fixation in 10% NBF so these professionals have been and are reluctant to change the microscopic appearance of diagnostic tissues by using a different type of fixation; in addition, the effects of tissue processing on the microscopic appearance of tissue has essentially been ignored in most studies. Because of the use of 10% NBF by pathologists, archives of paraffin blocks contain essentially paraffin blocks only fixed in 10% NBF. Thus, if retrospective studies use archival paraffin blocks to correlate the molecular features of diseases with the outcomes of diseases, the studies must be based upon using tissue fixed in 10% NBF. Studies of how fixation in 10% NBF interacts with histochemical and immunohistochemical staining are very limited in number and most are based upon relatively long times of fixation in 10% NBF (≥ 36 hours). Current times of fixation in 10% NBF have been reduced to fixation in 10% NBF and its interaction with tissue processing at any time of fixation, especially short times of fixation. Even less is known about how fixation of tissues in 10% NBF interact with more modern assays using immunohistochemistry, real time quantitative PCR, and techniques which depend upon the analysis of proteins extracted from paraffin blocks such as analysis by multiplex immunoassays or by mass spectrometry. In general, multiple antibody-antigen combinations are reported not to work in tissues fixed

  19. Biomechanical analysis and design of a dynamic spinal fixator using topology optimization: a finite element analysis. (United States)

    Lin, Hung-Ming; Liu, Chien-Lin; Pan, Yung-Ning; Huang, Chang-Hung; Shih, Shih-Liang; Wei, Shun-Hwa; Chen, Chen-Sheng


    Surgeons often use spinal fixators to manage spinal instability. Dynesys (DY) is a type of dynamic fixator that is designed to restore spinal stability and to provide flexibility. The aim of this study was to design a new spinal fixator using topology optimization [the topology design (TD) system]. Here, we constructed finite element (FE) models of degenerative disc disease, DY, and the TD system. A hybrid-controlled analysis was applied to each of the three FE models. The rod structure of the topology optimization was modelled at a 39 % reduced volume compared with the rigid rod. The TD system was similar to the DY system in terms of stiffness. In contrast, the TD system reduced the cranial adjacent disc stress and facet contact force at the adjacent level. The TD system also reduced pedicle screw stresses in flexion, extension, and lateral bending.

  20. Assessment of the externalities of biomass energy for electricity production

    Energy Technology Data Exchange (ETDEWEB)

    Linares, P.; Leal, J.; Saez, R.M.


    This study presents a methodology for the quantification of the socioeconomic and environmental externalities of the biomass fuel cycle. It is based on the one developed by the ExternE Project of the European Commission, based in turn in the damage function approach, and which has been extended and modified for a better adaptation to biomass energy systems. The methodology has been applied to a 20 MW biomass power plant, fueled by Cynara cardunculus, in southern Spain. The externalities addressed have been macroeconomic effects, employment, CO{sub 2}, fixation, erosion, and non-point source pollution. The results obtained should be considered only as subtotals, since there are still other externalities to be quantified. anyway, and in spite of the uncertainty existing, these results suggest that total cost (those including internal and external costs) of biomass energy are lower than those of conventional energy sources, what, if taken into account, would make biomass more competitive than it is now. (Author)

  1. Tips and Tricks in Mallet Fracture Fixation. (United States)

    Chin, Yuin Cheng; Foo, Tun-Lin


    We describe three steps to aid fracture assessment and fixation in the extensor block pin technique for mallet fractures. The first step is the use of fluoroscopy in the initial assessment to determine indication for fixation. Next is the use of supplementary extension block pin to control larger dorsal fragments. The third technique described details the steps of open reduction of nascently malunited fractures.

  2. Outcome of rail fixator system in reconstructing bone gap

    Directory of Open Access Journals (Sweden)

    Amit Lakhani


    Conclusion: All patients well tolerated rail fixator with good functional results and gap reconstruction. Easy application of rail fixator and comfortable distraction procedure suggest rail fixator a good alternative for gap reconstruction of limbs.

  3. Rapid eye-fixation training without eyetracking. (United States)

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


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

  4. Comparison of fixation disparity curve parameters obtained with the Wesson and Saladin fixation disparity cards. (United States)

    Ngan, Janice; Goss, David A; Despirito, Joseph


    This study compared fixation curve parameters with two commercially available fixation disparity cards, one that has been available for several years, the Wesson card, and a new one, the Saladin card. Fixation disparity curves were measured on 50 subjects with the Wesson fixation disparity card and the Saladin fixation disparity card. The x intercepts were on average more in the base-in direction with the Wesson card than with the Saladin card. The y intercepts were shifted in the exo direction with the Wesson card compared with the Saladin card. The slope with the Wesson card was steeper than the slope obtained with the Saladin card. The distribution of curve types was also different with the two different instruments. Fixation disparity curves measured with these two instruments are different, and separate norms should be used for each fixation disparity measurement method.

  5. Eighth international congress on nitrogen fixation. Final program

    Energy Technology Data Exchange (ETDEWEB)


    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.

  6. The hybrid BCI. (United States)

    Pfurtscheller, Gert; Allison, Brendan Z; Brunner, Clemens; Bauernfeind, Gunther; Solis-Escalante, Teodoro; Scherer, Reinhold; Zander, Thorsten O; Mueller-Putz, Gernot; Neuper, Christa; Birbaumer, Niels


    Nowadays, everybody knows what a hybrid car is. A hybrid car normally has two engines to enhance energy efficiency and reduce CO2 output. Similarly, a hybrid brain-computer interface (BCI) is composed of two BCIs, or at least one BCI and another system. A hybrid BCI, like any BCI, must fulfill the following four criteria: (i) the device must rely on signals recorded directly from the brain; (ii) there must be at least one recordable brain signal that the user can intentionally modulate to effect goal-directed behaviour; (iii) real time processing; and (iv) the user must obtain feedback. This paper introduces hybrid BCIs that have already been published or are in development. We also introduce concepts for future work. We describe BCIs that classify two EEG patterns: one is the event-related (de)synchronisation (ERD, ERS) of sensorimotor rhythms, and the other is the steady-state visual evoked potential (SSVEP). Hybrid BCIs can either process their inputs simultaneously, or operate two systems sequentially, where the first system can act as a "brain switch". For example, we describe a hybrid BCI that simultaneously combines ERD and SSVEP BCIs. We also describe a sequential hybrid BCI, in which subjects could use a brain switch to control an SSVEP-based hand orthosis. Subjects who used this hybrid BCI exhibited about half the false positives encountered while using the SSVEP BCI alone. A brain switch can also rely on hemodynamic changes measured through near-infrared spectroscopy (NIRS). Hybrid BCIs can also use one brain signal and a different type of input. This additional input can be an electrophysiological signal such as the heart rate, or a signal from an external device such as an eye tracking system.

  7. Research on Transverse Acetabular Fracture Fixation Using Different Plate Attachment Methods

    Directory of Open Access Journals (Sweden)

    Gediminas Gaidulis


    Full Text Available The article deals with the problem of transverse acetabular fracture fixation using different plate attachment methods. A 3D model of pelvis and hip joint structure was created and the design of three different fixation plates using SolidWorks was made. The plates were fixed at distances of 10, 20 and 30 mm from the acetabulum. The model was meshed into finite elements, a static external load of 2500 N was added and the analysis of stress distribution in plates and fracture displacement was performed. The obtained results showed that fracture displacement was quite similar in all fixation methods. However, the maximal stress in the nearest from the acetabulum plate was higher than yield strength. Thus, this placement is not eligible. The plate fixed at a distance of 30 mm from the acetabulum appeared the most suitable because of the smallest and symmetrical stress distribution in the plate.

  8. Indications and limitations of the fixator TGF "Gex-Fix" in proximal end humeral fractures. (United States)

    Parlato, A; D'Arienzo, A; Ferruzza, M; Galvano, N; D'Arienzo, M


    The incidence of fractures of the humerus has increased exponentially in recent years. The most used classifications for humerus fracture are morphological (Neer), biological (AO/ASIF) and descriptive (Hertel). The types of surgical treatment for humerus fracture include prosthetic replacement and synthesis using different devices, including the Tension Guide Fixator (TGF), Gex-Fix. External fixation for displaced proximal humeral fractures avoids dissection and soft tissue stripping and has been reported by some authors to be associated with higher union rates, a lower incidence of avascular necrosis, less scarring of the scapulohumeral interface, and faster rehabilitation compared with open reduction and internal fixation. Other authors have reported that external fixation does not ensure acceptable reduction and fracture stability, particularly in patients with osteoporosis. The external fixation technique involves the introduction of Steinmann's pin to keep manual reduction, the introduction of two K-wires in the humeral head, the removal of the Steinmann's pin, and the introduction of two fiches on the humeral shaft. Hub connectors are mounted on the wires and on the chips to connect the outer bar and tensioning system. A total of 84 patients aged 42-84 years with proximal end humeral fractures (66% had two-part fractures) were treated with Fixator TGF in this study from December 2007 to June 2012. The postoperative recovery was earlier and the active-assisted motion was less painful than has been reported with other surgical techniques. The TGF was removed without anaesthesia at the outpatient clinic at a mean of 7 weeks (range 5-8 weeks) after surgery, and there was no loss of reduction or secondary displacement after removal. These results, after five years of experience, confirm that the best indication for this fixator is two- or three-part fractures because the device enables early active mobilisation. The limitations of this fixator are evident in

  9. Dinitrogen fixation in aphotic oxygenated marine environments

    Directory of Open Access Journals (Sweden)

    Eyal eRahav


    Full Text Available We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO3--rich, waters of the oligotrophic Levantine Basin (LB and the Gulf of Aqaba (GA. N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L-1 d-1 to 0.38 nmol N L-1 d-1. N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as photic depths. Dissolved free amino acid amendments to whole water from the GA enhanced bacterial productivity by 2to 3.5 and N2 fixation rates by ~ 2 fold in samples collected from aphotic depths while in amendments to water from photic depths bacterial productivity increased 2 to 6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP an heterotrophic N2 fixation are carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particles (TEP concentration and N2 fixation rates. This suggests that sinking organic material and high carbon (C: nitrogen (N micro-environments (such as TEP-based aggregates or marine snow could support high heterotrophic N2 fixation rates in oxygenated surface waters and in the aphotic zones. Indeed, our calculations show that aphotic N2 fixation accounted for 37 to 75 % of the total daily integrated N2 fixation rates at both locations in the Mediterranean and Red Seas with rates equal or greater to those measured from the photic layers. Moreover, our results indicate that that while N2 fixation may be limited in the surface waters, aphotic, pelagic N2 fixation may contribute significantly to new N inputs in other oligotrophic basins, yet it is currently not included in regional or global N budgets.

  10. Successful treatment of nonunion with an Ilizarov ring fixator after ankle fracture for Charcot arthropathy: a case report. (United States)

    Nozaka, Koji; Shimada, Yoichi; Kimura, Yoshiaki; Yamada, Shin; Kashiwagura, Takeshi; Sakuraba, Tsutomu; Wakabayashi, Ikuko


    Ankle fractures in patients with diabetes mellitus have long been recognized as a challenge to orthopedic surgeons. Nonunion and lengthy wound healing in high-risk patients with diabetes, particularly patients with peripheral arterial disease and renal failure, occur secondary to several clinical conditions and are often fraught with complications. Whether diabetic ankle fractures are best treated noninvasively or surgically is controversial. A 53-year-old Japanese man fractured his right ankle. The fractured ankle was treated nonsurgically with a plaster cast. Although he remained non-weight-bearing for 3 months, radiography at 3 months showed nonunion. The nonunion was treated by Ilizarov external fixation of the ankle. The external fixator was removed 99 days postoperatively, at which time the patient exhibited anatomical and functional recovery and was able to walk without severe complications. In patients with diabetes mellitus, severe nonunion of ankle fractures with Charcot arthropathy in which the fracture fragment diameter is very small and the use of internal fixation is difficult is a clinical challenge. Ilizarov external fixation allows suitable fixation to be achieved using multiple Ilizarov wires.

  11. Fixational saccades reflect volitional action preparation. (United States)

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


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

  12. Immaturity of Visual Fixations in Dyslexic Children.

    Directory of Open Access Journals (Sweden)

    TIADI eBi Kuyami Guy Aimé


    Full Text Available To our knowledge, behavioral studies recording visual fixations abilities in dyslexic children are scarce. The object of this paper is to explore further the visual fixation ability in dyslexics compared to chronological age-matched and reading age-matched non-dyslexic children. Fifty-five dyslexic children from 7 to 14 years old, fifty-five chronological age-matched non-dyslexic children and fifty-five reading age-matched non-dyslexic children participated to this study. Eye movements from both eyes were recorded horizontally and vertically by a video-oculography system (EyeBrain® T2. The fixation task consisted in fixating a white-filled circle appearing in the centre of the screen for 30 seconds. Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. Furthermore, dyslexics made more saccades during the last 15 sec of fixation period with respect to both groups of non-dyslexic children. Such poor visual fixation capability in dyslexic children could be due to impaired attention abilities, as well as to an immaturity of the cortical areas controlling the fixation system.

  13. Biomechanical Analysis of Latarjet Screw Fixation: Comparison of Screw Types and Fixation Methods. (United States)

    Shin, Jason J; Hamamoto, Jason T; Leroux, Timothy S; Saccomanno, Maristella F; Jain, Akshay; Khair, Mahmoud M; Mellano, Christen R; Shewman, Elizabeth F; Nicholson, Gregory P; Romeo, Anthony A; Cole, Brian J; Verma, Nikhil N


    To compare the initial fixation stability, failure strength, and mode of failure of 5 different screw types and fixation methods commonly used for the classic Latarjet procedure. Thirty-five fresh-frozen cadaveric shoulder specimens were allocated into 5 groups. A 25% anteroinferior glenoid defect was created, and a classic Latarjet coracoid transfer procedure was performed. All grafts were fixed with 2 screws, differing by screw type and/or fixation method. The groups included partially threaded solid 4.0-mm cancellous screws with bicortical fixation, partially threaded solid 4.0-mm cancellous screws with unicortical fixation, fully threaded solid 3.5-mm cortical screws with bicortical fixation, partially threaded cannulated 4.0-mm cancellous screws with bicortical fixation, and partially threaded cannulated 4.0-mm captured screws with bicortical fixation. All screws were stainless steel. Outcomes included cyclic creep and secant stiffness during cyclic loading, as well as load and work to failure during the failure test. Intergroup comparisons were made by a 1-way analysis of variance. There were no significant differences among different screw types or fixation methods in cyclic creep or secant stiffness after cyclic loading or in load to failure or work to failure during the failure test. Post-failure radiographs showed evidence of screw bending in only 1 specimen that underwent the Latarjet procedure with partially threaded solid cancellous screws with bicortical fixation. The mode of failure for all specimens analyzed was screw cutout. In this biomechanical study, screw type and fixation method did not significantly influence biomechanical performance in a classic Latarjet procedure. When performing this procedure, surgeons may continue to select the screw type and method of fixation (unicortical or bicortical) based on preference; however, further studies are required to determine the optimal method of treatment. Surgeons may choose the screw type and

  14. Glutaraldehyde fixation preserves the trend of elasticity alterations for endothelial cells exposed to TNF-α. (United States)

    Targosz-Korecka, Marta; Brzezinka, Grzegorz Daniel; Danilkiewicz, Joanna; Rajfur, Zenon; Szymonski, Marek


    Among the users of atomic force microscopy based techniques, there is an ongoing discussion, whether cell elasticity measurements performed on fixed cells could be used for determination of the relative elasticity changes of the native (unfixed) cells subjected to physiologically active external agents. In this article, we present a case, for which the legitimacy of cell fixation for elasticity measurements is justified. We provide an evidence that the alterations of cell elasticity triggered by tumor necrosis factor alpha (TNF-α) in EA.hy926 endothelial cells are preserved after glutaraldehyde (GA) fixation. The value of post-fixation elasticity parameter is a product of the elasticity parameter obtained for living cells and a constant value, dependent on the GA concentration. The modification of the initial value of elasticity parameter caused by remodeling of the cortical actin cytoskeleton is reflected in the elasticity measurements performed on fixed cells. Thus, such fixation procedure may be particularly helpful for experiments, where the influence of an external agent on the cell cortex should be assessed and AFM measurements of living cells are problematic or better statistics is needed. © 2015 Wiley Periodicals, Inc.

  15. Beaming in Charcot Arthropathy-Intramedullary Fixation for Complicated Reconstructions: A Cadaveric Study. (United States)

    Fidler, Corey M; Watson, Benjamin C; Reb, Christopher W; Hyer, Christopher F

    In the modern treatment of Charcot neuroarthropathy, beam screw fixation is an alternative to plate and screw fixation. Exposure is minimized for implantation, and this technique supports the longitudinal columns of the foot as a rigid load-sharing construct. A published data review identified a paucity of data regarding metatarsal intramedullary canal morphology relevant to beam screw fixation. The purpose of the present study was to describe metatarsal diaphyseal morphology qualitatively and quantitatively in an effort to provide data that can be used by surgeons when selecting axially based intramedullary fixation. Twenty fresh-frozen cadaveric below-the-knee specimens were obtained. The metatarsals were exposed, cleaned of soft tissue, and axially transected at the point of the narrowest external diameter. Next, a digital caliper was used to measure the size and shape of the diaphysis of the first through fourth metatarsals. The diaphyseal canal shape was categorized as round, oval, triangular, or pear. The widest distance between the endosteal cortical surfaces was measured. Triangular endosteal canals were only found in the first metatarsal, and the remainder of the metatarsal canals were largely round or oval. These data help to approximate the size of fixation needed to achieve maximal screw-endosteal purchase. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Vacuum suction fixation versus staple fixation in TAPP laparoscopic hernia repair: introduction of a new technique for mesh fixation. (United States)

    Zhang, Guangyong; Zhang, Xiang; Zhan, Hanxiang; Hu, Sanyuan


    Proper mesh fixation is critical for successful TAPP laparoscopic hernia repair. Conventional mesh fixation may cause chronic neuralgia, groin paresthesia or other complications. This study aimed at introducing a new vacuum suction technique for mesh fixation and evaluating its efficacy and safety compared with traditional staple fixation way. Clinical data of 242 patients undergoing TAPP from July 2011 to March 2014 were retrospectively analyzed. Patients were divided into vacuum suction fixation group and staple fixation group. The operation time, hospital stay, complications, recurrence, visual analogue scale pain score and cost were evaluated. All surgeries were successful. The operation time of staple group was (42.34 ± 10.15) min for unilateral hernia and (64.08 ± 16.01) min for bilateral hernias. The postoperative hospital stay was (2.76 ± 0.84) days. One recurrence was observed (0.90%). For vacuum group, the operation time was (42.66 ± 7.76) min and (63.92 ± 10.49) min, and hospital stay was (2.60 ± 0.74) days. No recurrence was observed. There was no significant difference in recurrence, operation time, postoperative pain and hospital stay between two groups (P > 0.05). Average cost were (11,714 ± 726) RMB for vacuum group which was lower than staple group (14,837 ± 1568) RMB (P 0.05). Both techniques for mesh fixation are safe and effective. There is no significant difference in recurrence, operation time, postoperative pain or hospital stay. The vacuum suction fixation technique is more economical with lower incidence of scrotal emphysema.

  17. Regulating multiple externalities

    DEFF Research Database (Denmark)

    Waldo, Staffan; Jensen, Frank; Nielsen, Max


    Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

  18. The Stability of Double Jaw Surgery: A Comparison of Rigid Fixation versus Skeletal Wire Fixation (United States)


    C. Moody Alexander and Dr. Robert Gaylord. It has been a wonderful and rewarding experience. Thanks to Dr. Warren Parker for his support and guidance...postoperative range of motion when compared to wire fixation with its associated four to six weeks of intermaxillary fixation ( Aragon and Van Sickels 1987...REFERENCES Aragon , Steven B., and Van Sickels, Joseph E. 1987. "Mandibular Range of Motion with Rigid/Nonrigid Fixation." Oral Surg. 63: 408-411. Araujo

  19. ExternE National Implementation Finland

    Energy Technology Data Exchange (ETDEWEB)

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)


    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  20. Fixation probability on clique-based graphs (United States)

    Choi, Jeong-Ok; Yu, Unjong


    The fixation probability of a mutant in the evolutionary dynamics of Moran process is calculated by the Monte-Carlo method on a few families of clique-based graphs. It is shown that the complete suppression of fixation can be realized with the generalized clique-wheel graph in the limit of small wheel-clique ratio and infinite size. The family of clique-star is an amplifier, and clique-arms graph changes from amplifier to suppressor as the fitness of the mutant increases. We demonstrate that the overall structure of a graph can be more important to determine the fixation probability than the degree or the heat heterogeneity. The dependence of the fixation probability on the position of the first mutant is discussed.

  1. Maxwellian Eye Fixation during Natural Scene Perception

    Directory of Open Access Journals (Sweden)

    Jean Duchesne


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

  2. Tension band fixation of medial malleolus fractures. (United States)

    Ostrum, R F; Litsky, A S


    A prospective study on tension band fixation of medial malleolus fractures was performed on 30 consecutive patients with 31 fractures from October 1987 until December 1990. All patients had at least a displaced medial malleolus fracture unreduced by closed methods. The fractures were classified into small, medium and large using a modified Lauge-Hansen classification. There were no nonunions or movements of wires postoperatively and only two patients had subjective complaints with reference to the wires that required hardware removal. There was one 2-mm malreduction and one patient with a wound slough and subsequent osteomyelitis. One fragment had 2 mm of displacement after fixation but went on to union. A biomechanical study was undertaken to compare fixation of the medial malleolus with K wires alone, K wires plus a tension band, and two cancellous screws. The tension band fixation provided the greatest resistance to pronation forces: for times stiffer than the two screws and 62% of the intact specimen. Tension band fixation of the medial malleolus is a biomechanically strong and clinically acceptable method of treatment for displaced medial malleolus fractures. This method of fixation may be especially useful for small fragments and in osteoporotic bone.

  3. Variable Nitrogen Fixation in Wild Populus.

    Directory of Open Access Journals (Sweden)

    Sharon L Doty

    Full Text Available The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees.

  4. Absolute Versus Relative Fracture Fixation: Impact on Fracture Healing. (United States)

    Norris, Brent L; Lang, Gerald; Russell, Thomas A Toney; Rothberg, David L; Ricci, William M; Borrelli, Joseph


    The goals of all orthopaedic surgeons treating fractures are, and will remain, obtaining union of the fracture with a well-aligned and functional limb while minimizing the risk of complications. This requires us to understand how the biomechanical environment of the fracture affects healing and to be able to discern which mechanical environment is preferred over another. Understanding the spectrum of stability imparted by our current surgical devices is paramount to giving our patients the best opportunity to heal and recover from their injury. Gone are the simplistic views of plates and screws being applied for absolute stability and nails and external fixators being applied for relative stability. This review sheds new light on how the use of different implants provides the appropriate stability to encourage fracture healing and limit the risk of complication and loss of function.

  5. Arthrography and its value in comparison with fixation radiography in the diagnosis of lesions to the capsular ligament of the ankle joint

    Energy Technology Data Exchange (ETDEWEB)

    Franke, D.; Weiher, U.; Sossinka, N.P.; Fenn, K.


    From May 1981 till May 1982, we consistently performed arthography of the injured joint and fixation radiography according to Scheuba (pressure: 15 kp) of both ankle joints for reasons of comparison in all patients with a distorsion trauma of the ankle joint and with suspected lesions to the ligaments. 259 cases were used for the assessment. Fixation radiography should not be used any more. Mere clinical examination combined with the case history can be assumed to be superior to fixation radiography still. Arthrography clearly is the more sensitive method for the diagnosis of injuries to the external capsular ligament of the ankle joint. (orig./SHA).

  6. Nitrogen fixation in trees - 1

    Energy Technology Data Exchange (ETDEWEB)

    Dobereiner, J.; Gauthier, D.L.; Diem, H.G.; Dommergues, Y.R.; Bonetti, R.; Oliveira, L.A.; Magalhaes, F.M.M.; Faria, S.M. de; Franco, A.A.; Menandro, M.S.


    Six papers are presented from the symposium. Dobereiner, J.; Nodulation and nitrogen fixation in leguminous trees, 83-90, (15 ref.), reviews studies on Brazilian species. Gauthier, D.L., Diem, H.G., Dommergues, Y.R., Tropical and subtropical actinorhizal plants, 119-136, (Refs. 50), reports on studies on Casuarinaceae. Bonetti, R., Oliveira, L.A., Magalhaes, F.M.M.; Rhizobium populations and occurrence of VA mycorrhizae in plantations of forest trees, 137-142, (Refs. 15), studies Amazonia stands of Cedrelinga catenaeformis, Calophyllum brasiliense, Dipteryx odorata, D. potiphylla, Carapa guianensis, Goupia glabra, Tabebuia serratifolia, Clarisia racemosa, Pithecellobium racemosum, Vouacapoua pallidior, Eperua bijuga, and Diplotropis species. Nodulation was observed in Cedrelinga catenaeformis and V. pallidior. Faria, S.M. de, Franco, A.A., Menandro, M.S., Jesus, R.M. de, Baitello, J.B.; Aguiar, O.T. de, Doebereiner, J; survey of nodulation in leguminous tree species native to southeastern Brazil, 143-153, (Refs. 7), reports on 119 species, with first reports of nodulation in the genera Bowdichia, Poecilanthe, Melanoxylon, Moldenhaurea (Moldenhawera), and Pseudosamanea. Gaiad, S., Carpanezzi, A.A.; Occurrence of Rhizobium in Leguminosae of silvicultural interest for south Brazil, 155-158, (Refs. 2). Nodulation is reported in Mimosa scabrella, Acacia mearnsii, A. longifolia various trinervis, Enterolobium contortisiliquum, and Erythrina falcata. Magalhaes, L.M.S., Blum, W.E.H., Nodulation and growth of Cedrelinga catanaeformis in experimental stands in the Manaus region - Amazonas, 159-164, (Refs. 5). Results indicate that C. catenaeformis can be used in degraded areas of very low soil fertility.

  7. Linked linear mixed models: A joint analysis of fixation locations and fixation durations in natural reading. (United States)

    Hohenstein, Sven; Matuschek, Hannes; Kliegl, Reinhold


    The complexity of eye-movement control during reading allows measurement of many dependent variables, the most prominent ones being fixation durations and their locations in words. In current practice, either variable may serve as dependent variable or covariate for the other in linear mixed models (LMMs) featuring also psycholinguistic covariates of word recognition and sentence comprehension. Rather than analyzing fixation location and duration with separate LMMs, we propose linking the two according to their sequential dependency. Specifically, we include predicted fixation location (estimated in the first LMM from psycholinguistic covariates) and its associated residual fixation location as covariates in the second, fixation-duration LMM. This linked LMM affords a distinction between direct and indirect effects (mediated through fixation location) of psycholinguistic covariates on fixation durations. Results confirm the robustness of distributed processing in the perceptual span. They also offer a resolution of the paradox of the inverted optimal viewing position (IOVP) effect (i.e., longer fixation durations in the center than at the beginning and end of words) although the opposite (i.e., an OVP effect) is predicted from default assumptions of psycholinguistic processing efficiency: The IOVP effect in fixation durations is due to the residual fixation-location covariate, presumably driven primarily by saccadic error, and the OVP effect (at least the left part of it) is uncovered with the predicted fixation-location covariate, capturing the indirect effects of psycholinguistic covariates. We expect that linked LMMs will be useful for the analysis of other dynamically related multiple outcomes, a conundrum of most psychonomic research.

  8. Posterior atlantoaxial fixation: a review of all techniques. (United States)

    Huang, Da-Geng; Hao, Ding-Jun; He, Bao-Rong; Wu, Qi-Ning; Liu, Tuan-Jiang; Wang, Xiao-Dong; Guo, Hua; Fang, Xiang-Yi


    Posterior atlantoaxial fixation is an effective treatment for atlantoaxial instability. Great advancements on posterior atlantoaxial fixation techniques have been made in the past decades. However, there is no article reviewing all the posterior atlantoaxial fixation techniques yet. The aim was to review the evolution and advancements of posterior atlantoaxial fixation. This was a literature review. The application of all posterior fixation techniques in atlantoaxial stabilization, including wiring techniques, interlaminar clamp fixation, transarticular fixation, screw-plate systems, screw-rod systems, and hook-screw systems, are reviewed and discussed. Recent advancements on the novel technique of atlantoaxial fixation are described. The combination of the C1 and C2 screws in screw-rod systems are described in detail. All fixation techniques are useful. The screw-rod system appears to be the most popular approach. However, many novel or modified fixation methods have been introduced in recent years. Great advancements on posterior atlantoaxial fixation techniques have been made in the past decades. The wiring technique and interlaminar clamps technique have fallen out of favor because of the development of newer and superior fixation techniques. The C1-C2 transarticular screw technique may remain the gold standard for atlantoaxial fusion, whereas screw-rod systems, especially the C1 pedicle screw combined with C2 pedicle/pars screw fixation, have become the most popular fixation techniques. Hook-screw systems are alternatives for atlantoaxial fixation. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Design Fixation in the Wild: Design Environments and Their Influence on Fixation (United States)

    Youmans, Robert J.


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

  10. Fixational Saccades and Their Relation to Fixation Instability in Strabismic Monkeys. (United States)

    Upadhyaya, Suraj; Pullela, Mythri; Ramachandran, Santoshi; Adade, Samuel; Joshi, Anand C; Das, Vallabh E


    To evaluate the contribution of fixational saccades toward fixation instability in strabismic monkeys. Binocular eye movements were measured as six experimental monkeys (five strabismic monkeys and one monkey with downbeat nystagmus) and one normal monkey fixated targets of two shapes (Optotype, Disk) and two sizes (0.5°, 2°) during monocular and binocular viewing. Fixational saccades were detected using an unsupervised clustering algorithm. When compared with the normal monkey, amplitude and frequency of fixational saccades in both the viewing and nonviewing eye were greater in 3 of 5 strabismic monkeys (1-way ANOVA on ranks P saccades was largely due to quick phases of ongoing nystagmus. Fixational saccade amplitude was increased significantly (3-way ANOVA; P saccade amplitude and the Bivariate Contour Ellipse Area (BCEA) was nonlinear, showing saturation of saccade amplitude. Fixation instability in depth was significantly greater in strabismic monkeys (vergence BCEA: 0.63 deg2-2.15 deg2) compared with the normal animal (vergence BCEA: 0.15 deg2; P saccades. Target parameter effects on fixational saccades are similar to previous findings of target effects on BCEA.

  11. Recurrent dislocations of the atlantooccipital and atlantoaxial joints in a halo vest fixator are resolved by backrest elevation in an elevation angle-dependent manner. (United States)

    Kato, Go; Kawaguchi, Kenichi; Tsukamoto, Nobuaki; Komiyama, Keisuke; Mizuta, Kazutaka; Onohara, Takayuki; Okano, Hirofumi; Hotokezaka, Shunsuke; Mae, Takao


    atlantoaxial joints as well as possible secondary damage to the upper cervical spinal cord during the external fixation period. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Effect of graft fixation sequence on knee joint biomechanics in double-bundle anterior cruciate ligament reconstruction. (United States)

    Shi, Dongliang; Zhou, Jingbin; Yapici, Can; Linde-Rosen, Monica; Smolinski, Patrick; Fu, Freddie H


    To investigate the effect of graft fixation sequence in double-bundle anterior cruciate ligament (ACL) reconstruction on knee biomechanics. Twelve mature porcine knees underwent double-bundle ACL reconstruction with a randomized fixation order of the two graft bundles. The knees were subjected to external loadings of (1) an 89 N anterior tibial load at 30°, 60° and 90° of knee flexion and (2) 4 N-m internal and external tibial torques at 30° and 60° of knee flexion for ACL intact, deficient and reconstructed states. Knee kinematics and in situ graft forces were measured under the applied loads. The anterior tibial translation of the two reconstructions was not different from each other but was significantly different from the intact ACL. There was no difference in internal and external rotations between the intact knees and the reconstructions. At lower flexion angles, the graft that was fixed last (whether anteromedial or posterolateral) tended to carry significantly higher in situ load under anterior tibial loading and tibial torques. While a difference in knee kinematics may not be observable with different graft fixation sequences, fixation sequence can alter the in situ forces that the grafts bear under knee loading.

  13. High-quality lung fixation by controlled closed loop perfusion for stereological analysis in a large animal model. (United States)

    Trachsel, Sebastien; Purkabiri, Kurosch; Loup, Ophelie; Jenni, Hansjörg; Eberle, Balthasar; Ochs, Matthias; Kadner, Alexander


    Stereology is an essential method for quantitative analysis of lung structure. Adequate fixation is a prerequisite for stereological analysis to avoid bias in pulmonary tissue, dimensions and structural details. We present a technique for in situ fixation of large animal lungs for stereological analysis, based on closed loop perfusion fixation. Twenty anesthetized ventilated pigs (30 ± 3 kg) underwent cannulation of the pulmonary artery and ligation of the right hilus. Following circulatory arrest a continuous positive pressure of 12 mbar was applied to the airways and lung perfusion started with the fixative solution (1.5% paraformaldehyde; 1.5% glutaraldehyde in 0.15 M HEPES). In five animals, a single-pass perfusion technique was performed, in 15 subsequent animals, the closed-loop technique was applied. Afterwards, lungs were removed, externally postfixed in the recycled fixative solution, and stored at 4 °C. Fifteen lung specimens underwent stereological analysis with volume estimation and subsequent systematic uniform random sampling for light and electron microscopic analysis. Singlepass perfusion did not result in satisfactory fixation. Left lung closed loop perfusion rate was 0.5-0.7 L/min with total median [min-max] perfusion time of 15 min (11-19). Perfusion pressure was 15 mm Hg (9-33). Subsequent lung analysis revealed well-preserved cell and tissue ultrastructure. The closed loop perfusion technique represents a valuable and reproducible fixation method in large animal models. Pressure controlled fixation perfusion results in high-quality preservation of in situ parenchymal architecture of lungs with or without injury, which is ideally suited for quantitative assessment of lung structure by stereology. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. External Costs of Transport




    This study is an update of a former UIC study on external effects (IFRAS / IWW 2000). It aims at improving the empirical basis of external costs of transport based on the actual state of the art of cost estimation methodologies reflecting also recent studies on external costs of transport on a European level (especially UNITE).The following dimensions are considered:- cost categories- contries- base year- differentiation by means of transport 

  15. External radiation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.


    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  16. Biomechanical comparison of lumbosacral fixation using Luque-Galveston and Colorado II sacropelvic fixation: advantage of using locked proximal fixation. (United States)

    Early, Sean; Mahar, Andrew; Oka, Richard; Newton, Peter


    Biomechanical evaluation of sacropelvic fixation strategies as they apply to neuromuscular scoliosis. The primary objective was to compare the rigidity of 2 methods of sacropelvic fixation (Galveston vs. Colorado II). The secondary objective was to evaluate the effect on construct rigidity by adding a pair of L1 pedicle screws to a Luque wire construct. The Galveston modification to the Luque rodding system has become standard for treating childhood and adolescent neuromuscular scoliosis. The Galveston method provides reasonable lumbo-pelvic fixation with a relatively simple method of insertion. Clinical reviews of sagittal plane stability in neuromuscular patients with Galveston fixations performed at our institution have led to concerns regarding the technique's ability to maintain proper lumbar lordosis. This concern has generated interest in evaluating biomechanical stability of more rigid fixation methods in these long spino-pelvic constructs. As such, the following biomechanical study evaluated lumbosacral stability of 2 sacropelvic fixation methods: the standard Luque-Galveston method and the Colorado II sacropelvic fixation method using the Chopin plate-screw block. As a secondary interest, evaluations of the rigidity of the proximal construct when using pedicle screw fixation were completed. It was hypothesized that one additional point of rigid fixation at the thoracolumbar junction may make substantial improvement in rigidity to the otherwise Luque construct. Lumbo-pelvic segments of human cadaveric specimens were instrumented with L1 pedicle screws, sublaminar wires between L2 and L5, and sacropelvic fixation with either Galveston rods or Colorado II sacropelvic plates using S1 screws, S2 alar screws, and iliac screws. Tests were conducted for physiologic flexion-extension and torsional loading. Construct stiffness between L1-S1 was determined for each specimen. Motion measurement data were collected between L1-L5 and L5-S1 using a noncontact marker

  17. Complications of Scleral-Fixated Intraocular Lenses. (United States)

    Davies, Emma C; Pineda, Roberto


    Understanding the evolution of complications after scleral-fixated lens placement demonstrates advantageous surgical techniques and suitable candidates. A literature search in PubMed for several terms, including "scleral intraocular lens complication," yielded 17 relevant articles. Reviewing complication trends over time, lens tilt and suture erosion have decreased, cystoid macular edema has increased, and retinal detachment has remained the same after scleral-fixated lens placement. The successful reduction in complications are attributed to several alterations in technique, including positioning sclerotomy sites 180 degrees apart and using scleral flaps or pockets to bury sutures. Possible reduction in retinal risks have been proposed by performing an anterior vitrectomy prior to lens placement in certain settings. Complications after scleral-fixated lens placement should assist patient selection. Elderly patients with a history of hypertension should be counseled regarding risk of suprachoroidal hemorrhage, while young patients and postocular trauma patients should be considered for concurrent anterior vitrectomy.

  18. The development of internal fixation - historical overview. (United States)

    Lesić, Aleksandar R; Zagorac, Slavisa; Bumbasirević, Vesna; Bumbasirević, Marko Z


    Since the ancient times, man was faced with the problem of fracture treatment, which is first described in the records from ancient Egypt. Ever since, many treatment methods have been developed, but the real revolution in the fracture treatment was achieved by internal fixation. Since it was described for the first time, at the end of the 18th century, this method has continuously developed, but sterilization, radiographies, anaesthesiology, antibiotics made this surgery modern and safe. The great ideas and practical solutions of the new methods were done by Albin Lambotte, William Arbuthnot Lane, Robert Danis, William Hey Groves. They lead to the expansion of this method and truly made the principles for the future AO school. New methods, biological internal fixation, minimally invasive procedures, new technologies and devices for internal fixation are introduced in the surgical practice daily.

  19. Dinitrogen fixation of rice-Klebsiella associations

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, I.D.; Fujii, T.; Sano, Y.; Komagata, K.; Yoneyama, T.; Iyama, S.; Hirota, Y.

    N/sub 2/ fixation by Klebsiella oxytoca strain NG13, isolated from the rhizosphere of a rice (Oryza sativa L.) plant, in association with Indica type rice strain, C5444 is reported. The C/sub 2/H/sub 2/-reduction assays, biomass measurements, N content determinations, and /sup 15/N isotopic dilution assays indicated that inoculation of C5444 with NG13 resulted in a 6% increase of total plant+soil N content, and a 19% /sup 15/N isotopic dilution of plant N after 120 days of cultivation. Our results demonstrated significant levels of N/sub 2/ fixation by K. oxytoca when associated with rice. By optimizing such rice plant-bacterial N/sub 2/ fixation capacity, the N uptake by rice could be enhanced.

  20. Breast specimen shrinkage following formalin fixation

    Directory of Open Access Journals (Sweden)

    Horn CL


    Full Text Available Christopher L Horn, Christopher Naugler Department of Pathology and Laboratory Medicine, University of Calgary, and Calgary Laboratory Services, Calgary, AB, Canada Abstract: Accurate measurement of primary breast tumors and subsequent surgical margin assessment is critical for pathology reporting and resulting patient therapy. Anecdotal observations from pathology laboratory staff indicate possible shrinkage of breast cancer specimens due to the formalin fixation process. As a result, we conducted a prospective study to investigate the possible shrinkage effects of formalin fixation on breast cancer specimens. The results revealed no significant changes in tumor size, but there were significant changes in the distance to all surgical resection margins from the unfixed to fixed state. This shrinkage effect could interfere with the accuracy of determining distance to margin assessment and tumor-free margin assessment. Thus, changes in these measurements due to the formalin fixation process have the potential to alter treatment options for the patient. Keywords: breast margins, formalin, shrinkage, cancer

  1. Interrami intraoral fixation technique for severe mandibular rifle fragmented bullet injury management. (United States)

    Shuker, Sabri T


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

  2. Automated classification and scoring of smooth pursuit eye movements in the presence of fixations and saccades. (United States)

    Komogortsev, Oleg V; Karpov, Alex


    Ternary eye movement classification, which separates fixations, saccades, and smooth pursuit from the raw eye positional data, is extremely challenging. This article develops new and modifies existing eye-tracking algorithms for the purpose of conducting meaningful ternary classification. To this end, a set of qualitative and quantitative behavior scores is introduced to facilitate the assessment of classification performance and to provide means for automated threshold selection. Experimental evaluation of the proposed methods is conducted using eye movement records obtained from 11 subjects at 1000 Hz in response to a step-ramp stimulus eliciting fixations, saccades, and smooth pursuits. Results indicate that a simple hybrid method that incorporates velocity and dispersion thresholding allows producing robust classification performance. It is concluded that behavior scores are able to aid automated threshold selection for the algorithms capable of successful classification.

  3. Checklists for external validity

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke


    RATIONALE, AIMS AND OBJECTIVES: The quality of the current literature on external validity varies considerably. An improved checklist with validated items on external validity would aid decision-makers in judging similarities among circumstances when transferring evidence from a study setting to ...

  4. Social Agglomeration Externalities


    Borck, Rainald


    This paper examines social agglomeration externalities. Using survey data from the German Socio-Economic Panel, I examine the link between city size and different measures of consumption, social interaction and social capital. Further, using responses to satisfaction questions, I analyse whether individuals are compensated for diseconomies of agglomeration by positive agglomeration externalities in other areas. This equilibrium hypothesis cannot be rejected.

  5. External approach to rhinoplasty. (United States)

    Goodman, Wilfred S; Charbonneau, Paul A


    The technique of external rhinoplasty is outlined. Having reviewed 74 cases, its advantages and disadvantages are discussed. Reluctance to use this external approach seems to be based on emotional rather than radical grounds, for its seems to be the procedure of choice for many problems.

  6. The External Mind

    DEFF Research Database (Denmark)

    The External Mind: an Introduction by Riccardo Fusaroli, Claudio Paolucci pp. 3-31 The sign of the Hand: Symbolic Practices and the Extended Mind by Massimiliano Cappuccio, Michael Wheeler pp. 33-55 The Overextended Mind by Shaun Gallagher pp. 57-68 The "External Mind": Semiotics, Pragmatism...

  7. Osteomyelitis in burn patients requiring skeletal fixation

    NARCIS (Netherlands)

    Barret, JP; Desai, MH; Herndon, DN

    Deep and severe burns often present with the exposure of musculoskeletal structures and severe deformities. Skeletal fixation, suspension and/or traction are part of their comprehensive treatment. Several factors put burn patients at risk for osteomyelitis, osteosynthesis material being one of them.

  8. Heterotrophic fixation of CO2 in soil

    Czech Academy of Sciences Publication Activity Database

    Šantrůčková, Hana; Bird, M. I.; Elhottová, Dana; Novák, Jaroslav; Picek, T.; Šimek, Miloslav; Tykva, Richard


    Roč. 49, č. 2 (2005), s. 218-225 ISSN 0095-3628 R&D Projects: GA ČR(CZ) GA206/02/1036; GA AV ČR(CZ) IAA6066901 Institutional research plan: CEZ:AV0Z60660521 Keywords : heterotrophic fixation * CO2 * soil Subject RIV: EH - Ecology, Behaviour Impact factor: 2.674, year: 2005

  9. biological nitrogen fixation by inoculated soya beans

    African Journals Online (AJOL)

    Biological Nitrogen Fixation (BNF) by soya beans (Glycine max) was estimated using the acetylene reduction assay (ARA) for varieties Davis, Kudu, Impala, Hardee, Geduld, and an unidentified variety, grown in pure and mixed cultures with maize (Zea mays) over two seasons. All varieties had higher levels of BNF when ...

  10. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G


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

  11. Nitrogen fixation in the phyllosphere of Gramineae

    NARCIS (Netherlands)

    Bessems, E.P.M.


    The investigation was carried out with Zea mays , grown under temperate conditions, and with Tripsacum laxum Nash, grown in the tropics. The conditions for nitrogen fixation were found to be unfavourable in the leachate, obtained by spray irrigation of the aerial plant

  12. Headspace analysis of foams and fixatives

    Energy Technology Data Exchange (ETDEWEB)

    Harper, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Truong, Thanh-Tam [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Magwood, Leroy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, Brent [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nicholson, James [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    In the process of decontaminating and decommissioning (D&D) older nuclear facilities, special precautions must be taken with removable or airborne contamination. One possible strategy utilizes foams and fixatives to affix these loose contaminants. Many foams and fixatives are already commercially available, either generically or sold specifically for D&D. However, due to a lack of revelant testing in a radioactive environment, additional verification is needed to confirm that these products not only affix contamination to their surfaces, but also will function in a D&D environment. Several significant safety factors, including flammability and worker safety, can be analyzed through the process of headspace analysis, a technique that analyzes the off gas formed before or during the curing process of the foam/fixative, usually using gas chromatography-mass spectrometry (GC-MS). This process focuses on the volatile components of a chemical, which move freely between the solid/liquid form within the sample and the gaseous form in the area above the sample (the headspace). Between possibly hot conditions in a D&D situation and heat created in a foaming reaction, the volatility of many chemicals can change, and thus different gasses can be released at different times throughout the reaction. This project focused on analysis of volatile chemicals involved in the process of using foams and fixatives to identify any potential hazardous or flammable compounds.

  13. Biodegradable interlocking nails for fracture fixation

    NARCIS (Netherlands)

    van der Elst, M.; Bramer, J. A.; Klein, C. P.; de Lange, E. S.; Patka, P.; Haarman, H. J.


    Serious problems such as stress shielding, allergic reactions, and corrosion are associated with the use of metallic fracture fixation devices in fractured long bones. Metal implants often are removed during a second retrieval operation after fracture healing has completed. A biocompatible implant

  14. Biological nitrogen fixation, forms and regulating factors

    NARCIS (Netherlands)

    Giller, K.E.; Mapfumo, P.


    Nitrogen fixation is the basis of the global N cycle. Therefore it is not surprising that the ability to fix atmospheric N2 evolved in the "primeval soup" and is deeply rooted in the evolutionary tree of life. Despite this, nitrogenase remains an enzyme exclusive to prokaryotes; no eukaryote has

  15. Rigid internal fixation of infected mandibular fractures. (United States)

    Mehra, Pushkar; Van Heukelom, Emily; Cottrell, David A


    To evaluate the treatment outcomes of rigid internal fixation for the management of infected mandible fractures. A retrospective chart review of infected mandible fractures managed by a single oral and maxillofacial surgeon at a level I trauma center during a 7-year period was accomplished by independent examiners. All patients were treated with incision and drainage, culture and sensitivity testing, extraction of nonsalvageable teeth, placement of maxillomandibular fixation when possible, fracture reduction with bone debridement and decortication, rigid internal fixation of the mandible by an extraoral approach, and antibiotic therapy. The medical and social history was contributory in most patients. The analysis was stratified by the differentiation of the fractures into 2 groups: those with soft tissue infections in the fracture region versus those with hard tissue-infected fractures (biopsy-proven osteomyelitis). A total of 44 patients were included in this study, with an average follow-up of 18.2 months from the date of surgery (range 3 to 48). The treatment protocol was successful in all 18 patients (100%) with soft tissue infected mandibular fractures and 24 (92%) of 26 patients with hard tissue-infected fractures. A protocol consisting of concomitant incision and drainage, mandibular debridement, fracture reduction, and stabilization with rigid internal fixation can be effectively used for single-stage management of infected mandible fractures.

  16. Fixational saccades during grating detection and discrimination. (United States)

    Spotorno, Sara; Masson, Guillaume S; Montagnini, Anna


    We investigated the patterns of fixational saccades in human observers performing two classical perceptual tasks: grating detection and discrimination. First, participants were asked to detect a vertical or tilted grating with one of three spatial frequencies and one of four luminance contrast levels. In the second experiment, participants had to discriminate the spatial frequency of two supra-threshold gratings. The gratings were always embedded in additive, high- or low-contrast pink noise. We observed that the patterns of fixational saccades were highly idiosyncratic among participants. Moreover, during the grating detection task, the amplitude and the number of saccades were inversely correlated with stimulus visibility. We did not find a systematic relationship between saccade parameters and grating frequency, apart from a slight decrease of saccade amplitude during grating discrimination with higher spatial frequencies. No consistent changes in the number and amplitude of fixational saccades with performance accuracy were reported. Surprisingly, during grating detection, saccade number and amplitude were similar in grating-with-noise and noise-only displays. Grating orientation did not affect substantially saccade direction in either task. The results challenge the idea that, when analyzing low-level spatial properties of visual stimuli, fixational saccades can be adapted in order to extract task-relevant information optimally. Rather, saccadic patterns seem to be overall modulated by task context, stimulus visibility and individual variability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Fibrin sealant for mesh fixation in laparoscopic umbilical hernia repair

    DEFF Research Database (Denmark)

    Eriksen, J R; Bisgaard, T; Assaadzadeh, S


    Fibrin sealant for mesh fixation has significant positive effects on early outcome after laparoscopic ventral hernia repair (LVHR) compared with titanium tacks. Whether fibrin sealant fixation also results in better long-term outcome is unknown.......Fibrin sealant for mesh fixation has significant positive effects on early outcome after laparoscopic ventral hernia repair (LVHR) compared with titanium tacks. Whether fibrin sealant fixation also results in better long-term outcome is unknown....

  18. Determination of Optimum Formalin Fixation Duration for Prostate Needle Biopsies for Immunohistochemistry and Quantum Dot FISH Analysis. (United States)

    Sathyanarayana, Ubaradka G; Birch, Chandler; Nagle, Raymond B; Tomlins, Scott A; Palanisamy, Nallasivam; Zhang, Wenjun; Hubbard, Antony; Brunhoeber, Patrick; Wang, Yixin; Tang, Lei


    Prostate biopsy is the key clinical specimen for disease diagnosis. However, various conditions used during biopsy processing for histologic analysis may affect the performance of diagnostic tests, such as hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), or in situ hybridization (ISH). One such condition that may affect diagnostic test performance is fixation duration in 10% neutral buffered formalin (NBF). For example, prostate needle biopsies are often tissue fixation duration on diagnostic test performance to enable optimized assay procedures. This study was designed to study the effect of 10% NBF fixation duration of prostate needle biopsy on multiplexed quantum dot (QD) ISH assay of ERG and PTEN, 2 genes commonly altered in prostate cancer. The samples were also evaluated for H&E staining and ERG and PTEN IHC. H&E staining and ERG and PTEN IHC were acceptable for all the durations of fixation tested. For QD ISH, we observed good signals with biopsy samples fixed from 4 to 120 hours. Biopsy specimens fixed between 8 and 72 hours gave the best signal as scored by the study pathologist. In a separate cohort of 18 routinely processed prostate biopsy cores, all cores were stained successfully with the QD ISH assay, and results were 100% concordant to ERG and PTEN IHC. We conclude that 8 to 72 hours duration of fixation for prostate needle biopsies in 10% NBF results in optimal QD ISH assay performance.

  19. A physiological perspective on fixational eye movements (United States)

    Snodderly, D. Max


    For a behavioral neuroscientist, fixational eye movements are a double-edged sword. On one edge, they make control of visual stimuli difficult, but on the other edge they provide insight into the ways the visual system acquires information from the environment. We have studied macaque monkeys as models for human visual systems. Fixational eye movements of monkeys are similar to those of humans but they are more often vertically biased and spatially more dispersed. Eye movements scatter stimuli from their intended retinal locations, increase variability of neuronal responses, inflate estimates of receptive field size, and decrease measures of response amplitude. They also bias against successful stimulation of extremely selective cells. Compensating for eye movements reduced these errors and revealed a fine-grained motion pathway from V1 feeding the cortical ventral stream. Compensation is a useful tool for the experimenter, but rather than compensating for eye movements, the brain utilizes them as part of its input. The saccades and drifts that occur during fixation selectively activate different types of V1 neurons. Cells that prefer slower speeds respond during the drift periods with maintained discharges and tend to have smaller receptive fields that are selective for sign of contrast. They are well suited to code small details of the image and to enable our fine detailed vision. Cells that prefer higher speeds fire transient bursts of spikes when the receptive field leaves, crosses, or lands on a stimulus, but only the most transient ones (about one-third of our sample) failed to respond during drifts. Voluntary and fixational saccades had very similar effects, including the presence of a biphasic extraretinal modulation that interacted with stimulus-driven responses. Saccades evoke synchronous bursts that can enhance visibility but these bursts may also participate in the visual masking that contributes to saccadic suppression. Study of the small eye movements

  20. Theory and practice of combining coagulant fixation and microwave histoprocessing

    NARCIS (Netherlands)

    Boon, M. E.; Kok, L. P.


    The German, F. Blum, introduced formalin as a fixative in 1893. Formalin rapidly became popular for hardening and preserving gross human and animal specimens. As a result, microscopy for diagnostic pathology by combining paraffin embedding and formalin fixation was developed. Alcohol-based fixatives

  1. The cyanobacterial nitrogen fixation paradox in natural waters [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Hans Paerl


    Full Text Available Nitrogen fixation, the enzymatic conversion of atmospheric N (N2 to ammonia (NH3, is a microbially mediated process by which “new” N is supplied to N-deficient water bodies. Certain bloom-forming cyanobacterial species are capable of conducting N2 fixation; hence, they are able to circumvent N limitation in these waters. However, this anaerobic process is highly sensitive to oxygen, and since cyanobacteria produce oxygen in photosynthesis, they are faced with a paradoxical situation, where one critically important (for supporting growth biochemical process is inhibited by another. N2-fixing cyanobacterial taxa have developed an array of biochemical, morphological, and ecological adaptations to minimize the “oxygen problem”; however, none of these allows N2 fixation to function at a high enough efficiency so that it can supply N needs at the ecosystem scale, where N losses via denitrification, burial, and advection often exceed the inputs of “new” N by N2 fixation. As a result, most marine and freshwater ecosystems exhibit chronic N limitation of primary production. Under conditions of perpetual N limitation, external inputs of N from human sources (agricultural, urban, and industrial play a central role in determining ecosystem fertility and, in the case of N overenrichment, excessive primary production or eutrophication. This points to the importance of controlling external N inputs (in addition to traditional phosphorus controls as a means of ensuring acceptable water quality and safe water supplies. Nitrogen fixation, the enzymatic conversion of atmospheric N2 to ammonia (NH3 is a  microbially-mediated process by which “new” nitrogen is supplied to N-deficient water bodies.  Certain bloom-forming cyanobacterial species are capable of conducting N2 fixation; hence they are able to circumvent nitrogen limitation in these waters. However, this anaerobic process is highly sensitive to oxygen, and since cyanobacteria produce

  2. Complications of lateral plate fixation compared with tension band wiring and pin or lag screw fixation for calcaneoquartal arthrodesis. Treatment of proximal intertarsal subluxation occurring secondary to non-traumatic plantar tarsal ligament disruption in dogs. (United States)

    Barnes, D C; Knudsen, C S; Gosling, M; McKee, M; Whitelock, R G; Arthurs, G I; Ness, M G; Radke, H; Langley-Hobbs, S J


    To compare complication rates and the outcomes of these complications after lateral plate fixation with figure-of-eight tension-band-wire and pin or lag screw fixation for arthrodesis of the calcaneoquartal joint, following non-traumatic disruption of the plantar tarsal ligament in dogs. Data were collected retrospectively from five UK referral centres. Diplomate specialists and their residents performed all procedures. Referring veterinarians were contacted for long-term follow-up. Seventy-four procedures were undertaken in 61 dogs. There were 58 arthrodeses in the lateral plate group (Plate), nine in the pin and tension-band-wire group (Pin), and seven in the lag screw and tension-band wire-group (Screw). Compared to Plate (17%), further surgical intervention was required more frequently following Pin (56%, OR = 3.2) or Screw (43%, OR = 2.5) fixation. Clinical failure of arthrodesis occurred less frequently with Plate (5%) compared with Screw (43%, OR = 8.6) and Pin fixation (22%, OR = 4.4). Cases managed with external coaptation postoperatively were more likely to suffer from postoperative complications (OR = 2.2). Lateral plating was associated with fewer postoperative complications than pin and tension-band-wire fixation for arthrodesis of the calcaneoquartal joint in dogs with non-traumatic disruption of the plantar tarsal ligament.

  3. Solid bolt fixation of the medial column in Charcot midfoot arthropathy. (United States)

    Wiewiorski, Martin; Yasui, Tetsuro; Miska, Matthias; Frigg, Arno; Valderrabano, Victor


    Charcot medial column and midfoot deformities are associated with rocker bottom foot, recurrent plantar ulceration, and consequent infection. The primary goal of surgical intervention is to realign and stabilize the plantar arch in a shoe-able, plantigrade alignment. Different fixation devices, including screws, plates, and external fixators, can be used to stabilize the Charcot foot; however, each of these methods has substantial disadvantages. To assess the effectiveness of rigid, minimally invasive fixation of the medial column and midfoot, 8 cases of solid intramedullary bolt fixation for symptomatic Charcot neuroarthropathy were reviewed. The patients included 6 males (75%) and 2 females (25%), with a mean age of 63 (range 46 to 80) years. The Charcot foot deformity was caused by diabetic neuropathy in 7 cases (87.5%) and alcoholic neuropathy in 1 (12.5%). The mean duration of postoperative follow-up period was 27 (range 12 to 44) months. The mean radiographic correction of the lateral talar-first metatarsal angle was 15° (range 3° to 19°), and the mean radiographic correction of the dorsal midfoot dislocation was 9 (range -4 to 23) mm. The mean loss of correction of the lateral talar-first metatarsal angle and midfoot dislocation after surgery was 7° (range 0° to 26°) and 1 (range 0 to 7) mm, respectively. No bolt breakage was observed, and no cases of recurrent or residual ulceration occurred during the observation period. Bolt removal was performed in 3 cases (37.5%), 2 (25%) because of axial migration of the bolt into the ankle joint and 1 (12.5%) because of infection. The results of the present review suggest that a solid intramedullary bolt provides reasonable fixation for realignment of the medial column in cases of Charcot neuroarthropathy. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Implantation of posterior chamber foldable intraocular lens in the absence of adequate capsular support: iris fixation versus scleral fixation

    Directory of Open Access Journals (Sweden)

    Tamer Gamal Elsayed


    In the absence of adequate capsular support, fixation of posterior chamber foldable IOL by iris suturing is associated with significantly less IOL malposition and consumes a shorter operative time compared with scleral fixation. However, iris suture fixation is associated with a higher incidence of postoperative iridocyclitis in the early postoperative period.

  5. External incontinence devices (United States)

    ... enable JavaScript. External incontinence devices are products (or appliances). These are worn on the outside of the ... us Disclaimers Copyright Privacy Accessibility Quality Guidelines Viewers & Players MedlinePlus Connect for EHRs For Developers U.S. National ...

  6. Externally Verifiable Oblivious RAM

    Directory of Open Access Journals (Sweden)

    Gancher Joshua


    Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

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

    Directory of Open Access Journals (Sweden)

    John Mukhopadhaya


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

  8. Mechanical evaluation of fourth-generation composite femur hybrid locking plate constructs. (United States)

    Goswami, Tarun; Patel, Vinit; Dalstrom, David J; Prayson, Michael J


    Locking compression plates are routinely used for open reduction and internal fixation of fractures. Such plates allow for locking or non-locking screw placement in each hole. A combined use of both types of screw application for stabilization of a fracture is commonly applied and referred to as hybrid internal fixation. Locking screws improve the stability of the fixation construct but at the expense of significant additional cost. This study experimentally analyzes various combinations of locking and non-locking screws under simultaneous axial and torsional loading to determine the optimal hybrid locking plate-screw construct in a fourth generation composite femur. Clinically it is necessary to ensure adequate fixation stability in a worse case fracture-bone quality scenario. A locking screw near the fracture gap increased the axial and torsional strength of the locked plate system. Greater removal torque remained in non-locked screws adjacent to locked screws compared to an all non-locking screws control group.

  9. ADE Guide for External Reviewers. (United States)

    ADE Bulletin, 2002


    Helps external reviewers of academic departments draw on the experience of those who have learned by trial and error. Outlines the steps taken by an external reviewer. Considers the particular task for an external reviewer and presents some notes on self-preservation for the external reviewer. Discusses the external reviewer's responsibility of…

  10. External trade development in 2010


    Český statistický úřad


    Analysis of the external trade development of the CR in total (turnover, export, import, trade balance). Main factors, which influence the external trade development. Territorial structure (by main blocks and selected countries) and commodity structure (by SITC, rev. 4) of the external trade. Comparisons of the CR external trade development with the external trade development of the other member states of the EU.

  11. Optimized breeding strategies for multiple trait integration: II. Process efficiency in event pyramiding and trait fixation. (United States)

    Peng, Ting; Sun, Xiaochun; Mumm, Rita H


    Multiple trait integration (MTI) is a multi-step process of converting an elite variety/hybrid for value-added traits (e.g. transgenic events) through backcross breeding. From a breeding standpoint, MTI involves four steps: single event introgression, event pyramiding, trait fixation, and version testing. This study explores the feasibility of marker-aided backcross conversion of a target maize hybrid for 15 transgenic events in the light of the overall goal of MTI of recovering equivalent performance in the finished hybrid conversion along with reliable expression of the value-added traits. Using the results to optimize single event introgression (Peng et al. Optimized breeding strategies for multiple trait integration: I. Minimizing linkage drag in single event introgression. Mol Breed, 2013) which produced single event conversions of recurrent parents (RPs) with ≤8 cM of residual non-recurrent parent (NRP) germplasm with ~1 cM of NRP germplasm in the 20 cM regions flanking the event, this study focused on optimizing process efficiency in the second and third steps in MTI: event pyramiding and trait fixation. Using computer simulation and probability theory, we aimed to (1) fit an optimal breeding strategy for pyramiding of eight events into the female RP and seven in the male RP, and (2) identify optimal breeding strategies for trait fixation to create a 'finished' conversion of each RP homozygous for all events. In addition, next-generation seed needs were taken into account for a practical approach to process efficiency. Building on work by Ishii and Yonezawa (Optimization of the marker-based procedures for pyramiding genes from multiple donor lines: I. Schedule of crossing between the donor lines. Crop Sci 47:537-546, 2007a), a symmetric crossing schedule for event pyramiding was devised for stacking eight (seven) events in a given RP. Options for trait fixation breeding strategies considered selfing and doubled haploid approaches to achieve homozygosity

  12. Nutrient feedbacks to soil heterotrophic nitrogen fixation in forests (United States)

    Perakis, Steven; Pett-Ridge, Julie C.; Catricala, Christina E.


    Multiple nutrient cycles regulate biological nitrogen (N) fixation in forests, yet long-term feedbacks between N-fixation and coupled element cycles remain largely unexplored. We examined soil nutrients and heterotrophic N-fixation across a gradient of 24 temperate conifer forests shaped by legacies of symbiotic N-fixing trees. We observed positive relationships among mineral soil pools of N, carbon (C), organic molybdenum (Mo), and organic phosphorus (P) across sites, evidence that legacies of symbiotic N-fixing trees can increase the abundance of multiple elements important to heterotrophic N-fixation. Soil N accumulation lowered rates of heterotrophic N-fixation in organic horizons due to both N inhibition of nitrogenase enzymes and declines in soil organic matter quality. Experimental fertilization of organic horizon soil revealed widespread Mo limitation of heterotrophic N-fixation, especially at sites where soil Mo was scarce relative to C. Fertilization also revealed widespread absence of P limitation, consistent with high soil P:Mo ratios. Responses of heterotrophic N-fixation to added Mo (positive) and N (negative) were correlated across sites, evidence that multiple nutrient controls of heterotrophic N-fixation were more common than single-nutrient effects. We propose a conceptual model where symbiotic N-fixation promotes coupled N, C, P, and Mo accumulation in soil, leading to positive feedback that relaxes nutrient limitation of overall N-fixation, though heterotrophic N-fixation is primarily suppressed by strong negative feedback from long-term soil N accumulation.

  13. Reverse Anterior Cruciate Ligament Reconstruction Fixation: A Biomechanical Comparison Study of Tibial Cross-Pin and Femoral Interference Screw Fixation. (United States)

    Lawley, Richard J; Klein, Samuel E; Chudik, Steven C


    To evaluate the biomechanical performance of tibial cross-pin (TCP) fixation relative to femoral cross-pin (FCP), femoral interference screw (FIS), and tibial interference screw (TIS) fixation. We randomized 40 porcine specimens (20 tibias and 20 femurs) to TIS fixation (group 1, n = 10), FIS fixation (group 2, n = 10), TCP fixation (group 3, n = 10), or FCP fixation (group 4, n = 10) and performed biomechanical testing to compare ultimate load, stiffness, yield load, cyclic displacement, and load at 5-mm displacement. We performed cross-pin fixation of the looped end and interference screw fixation of the free ends of 9-mm-diameter bovine extensor digitorum communis tendon grafts. Graft fixation constructs were cyclically loaded and then loaded to failure in line with the tunnels. Regarding yield load, FIS was superior to TIS (704 ± 125 N vs 504 ± 118 N, P = .002), TCP was superior to TIS (1,449 ± 265 N vs 504 ± 118 N, P link, and combined TCP-FIS fixation theoretically would be biomechanically superior relative to combined FCP-TIS fixation with regard to yield load. Cyclic displacement showed a small difference in favor of FCP over TCP fixation and no difference between TIS and FIS. Time-zero biomechanics of TCP fixation paired with FIS fixation show that this method of fixation can be considered a potential alternative to current practice and may pose clinical benefits in different clinical scenarios of anterior cruciate ligament reconstruction. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  14. The hybrid BCI

    Directory of Open Access Journals (Sweden)

    Gert Pfurtscheller


    Full Text Available Nowadays, everybody knows what a hybrid car is. A hybrid car normally has 2 engines, its main purpose being to enhance energy efficiency and reduce CO2 output. Similarly, a typical hybrid brain-computer interface (BCI is also composed of 2 BCIs or at least one BCI and another system. Such a hybrid BCI, like any BCI, must fulfil the following four criteria: (i the device must rely on signals recorded directly from the brain; (ii there must be at least one recordable brain signal that the user can intentionally modulate to effect goal-directed behaviour; (iii real time processing; and (iv the user must obtain feedback. This paper introduces some hybrid BCIs which have already been published or are currently in development or validation, and some concepts for future work. The BCIs described classify 2 EEG patterns: One is the event-related (desynchronisation (ERD, ERS of sensorimotor rhythms, and the other is the steady-state visual evoked potential (SSVEP. The hybrid BCI can either have more than one input whereby the inputs are typically processed simultaneously or operate 2 systems sequentially, whereby the first system can act as a “brain switch”. In the case of self-paced operation of a SSVEP-based hand orthosis control with an motor imagery-based switch it was possible to reduce the rate of false positives during resting periods by about 50% compared to the SSVEP BCI alone. It is shown that such a brain switch can also rely on hemodynamic changes measured through near-infrared spectroscopy (NIRS. Another interesting approach is a hybrid BCI with simultaneous operations of ERD- and SSVEP-based BCIs. Here it is important to prove the existing promising offline simulation results with online experiments. Hybrid BCIs can also use one brain signal and another input. Such an additional input can be a physiological signal like the heart rate but also a signal from an external device like, an eye gaze control system.

  15. Evaluating Internal Fixation Skills Using Surgical Simulation. (United States)

    Burns, Geoffrey T; King, Brandon W; Holmes, James R; Irwin, Todd A


    Open reduction and internal fixation (ORIF) is an essential skill for an orthopaedic surgeon, yet teaching its components to surgical residents poses challenges in both complexity and cost. Surgical simulation has demonstrated efficacy and is now a mandated component of residency programs, but the techniques and resources required for effective simulation vary greatly. We hypothesized that simulation of ORIF skills could be accomplished in a cost-effective, quantifiable, and reproducible manner and that this experience coupled with didactic learning would increase skill proficiency and enhance ORIF performance. Sixteen postgraduate-year-1 orthopaedic surgery interns were assessed on performance of ORIF simulation tasks before and after attending a module designed to introduce and practice internal fixation techniques. Simulation tasks addressed drilling accuracy via oblique drilling through polyvinyl chloride (PVC) cylinders and bisecting wooden dowels and plunge control via drilling through layered boards of varying densities. Fracture fixation simulation involved fixing oblique fractures on synthetic ulnae. Task performance was assessed at 3 time points: immediately before the module, 1 week after the module, and 3 months after the module. Fracture fixation was assessed before and after the module via load-to-failure testing. Success rates for the tasks were analyzed using a repeated-measures analysis of variance, and mechanical properties of the fixed ulnar constructs were compared using paired t tests. In all ORIF simulation tasks, pre-module to post-module improvement in success rates was significant (p drill) can be significantly augmented and retained in the short term in surgical residents after exposure to faculty-led lecture and hands-on skills practice using low-cost materials. This study provides evidence for an effective, accessible method of enhancing and assessing surgical skills in training.

  16. Hybrid Metaheuristics

    CERN Document Server


    The main goal of this book is to provide a state of the art of hybrid metaheuristics. The book provides a complete background that enables readers to design and implement hybrid metaheuristics to solve complex optimization problems (continuous/discrete, mono-objective/multi-objective, optimization under uncertainty) in a diverse range of application domains. Readers learn to solve large scale problems quickly and efficiently combining metaheuristics with complementary metaheuristics, mathematical programming, constraint programming and machine learning. Numerous real-world examples of problems and solutions demonstrate how hybrid metaheuristics are applied in such fields as networks, logistics and transportation, bio-medical, engineering design, scheduling.

  17. Mechanical evaluation of aluminum alloy ring fixator. (United States)

    Tosborvorn, Somboon; Cheechareon, Sukrom; Ruttanuchun, Kittiput; Sirivedin, Suparerk; Rhienumporn, Chaitawat


    To test the homemade ring fixator as a tool for correction of bony deformity. The authors developed an aluminum alloy ring fixator and tested it to find out the accuracy of manufacturing and strength of the ring systems under axial load with the Roundness Testing Machine and Lloyd Universal Testing Machine. The mean diameter of the twenty five-drill holes was 6.5843872 +/- 0.0521594 mm (mean +/- SD). Distance between particular drill holes, which reflected the precision of drilling, had a high accuracy with standard deviation from 0.1138 to 0.1870 mm. The roundness of the rings was 0.2421376 +/- 0.12437977 mm (mean +/- SD). The system structure had minimal permanent deformity at breaking point, mean yield strength of the system was 4786.9 +/- 14.353 N (mean +/- SD). This was caused by the failure of the wire. Mean stiffness of the system was 127 N./mm. The aluminum alloy ring fixator was strong enough and well tolerated for clinical usage

  18. Nitrogen fixation in Red Sea seagrass meadows

    KAUST Repository

    Abdallah, Malak


    Seagrasses are key coastal ecosystems, providing many ecosystem services. Seagrasses increase biodiversity as they provide habitat for a large set of organisms. In addition, their structure provides hiding places to avoid predation. Seagrasses can grow in shallow marine coastal areas, but several factors regulate their growth and distribution. Seagrasses can uptake different kinds of organic and inorganic nutrients through their leaves and roots. Nitrogen and phosphorous are the most important nutrients for seagrass growth. Biological nitrogen fixation is the conversion of atmospheric nitrogen into ammonia by diazotrophic bacteria. This process provides a significant source of nitrogen for seagrass growth. The nitrogen fixation is controlled by the nif genes which are found in diazotrophs. The main goal of the project is to measure nitrogen fixation rates on seagrass sediments, in order to compare among various seagrass species from the Red Sea. Moreover, we will compare the fixing rates of the Vegetated areas with the bare sediments. This project will help to ascertain the role of nitrogen fixing bacteria in the development of seagrass meadows.

  19. Surgeon perception of cancellous screw fixation. (United States)

    Stoesz, Michael J; Gustafson, Peter A; Patel, Bipinchandra V; Jastifer, James R; Chess, Joseph L


    The ability of surgeons to optimize screw insertion torque in nonlocking fixation constructs is important for stability, particularly in osteoporotic and cancellous bone. This study evaluated screw torque applied by surgeons during synthetic cancellous fixation. It evaluated the frequency with which screws were stripped by surgeons, factors associated with screw stripping, and ability of surgeons to recognize it. Ten surgeons assembled screw and plate fixation constructs into 3 densities of synthetic cancellous bone while screw insertion torque and axial force were measured. For each screw, the surgeon recorded a subjective rating as to whether or not the screw had been stripped. Screws were then advanced past stripping, and stripped screws were identified by comparing the insertion torque applied by the surgeon to the measured stripping torque. Surgeons stripped 109 (45.4%) of 240 screws and did not recognize stripping 90.8% of the time when it occurred. The tendency to strip screws was highly variable among individual surgeons (stripping ranging from 16.7% to 83.3%, P perception is not reliable at preventing and detecting screw stripping at clinical torque levels in synthetic cancellous bone. Less aggressive insertion or standardized methods of insertion may improve the stability of nonlocking screw and plate constructs.

  20. Femoral neck shortening after internal fixation. (United States)

    Liu, Yue; Ai, Zi Sheng; Shao, Jin; Yang, Tieyi


    The aim of this study was to assess the factors affecting femoral neck shortening after internal fixation of femoral neck fractures. Eighty-six patients with femoral neck fractures were treated using three parallel cannulated screws between May 2004 and January 2011. The shortening of the femoral neck in the horizontal (X), vertical (Y), and along the resultant along the (Z) vector (X➝, Y➝, Z➝) was measured on anteroposterior radiographs corrected by screw diameter and analyzed using TraumaCad software. Age, gender, Garden classification, Garden's alignment index, Pauwels angle, Singh index, body mass index and weight-bearing time were also analyzed. Follow-up duration was 8 to 36 months. Significant femoral neck shortening of the abductor lever arm (greater than 5 mm) was present in 33 of 86 (38.4%) patients. Average Harris score (HSS) was 90.05 ± 7.04 (range: 71 to 100). The 5 predictors for shortening greater than 5 mm in the multivariate logistic regression model were age, Singh index, Pauwels classification, Garden's alignment index and body mass index. Femoral neck shortening associated with three parallel cannulated screws for fixation of femoral neck fractures is a common phenomenon. Femoral neck shortening after internal fixation is affected by multiple cofactors.


    Directory of Open Access Journals (Sweden)

    A. N. Erokhin


    Full Text Available Based on the literature data analysis a hypothesis was made that specific features of humeral diaphyseal fractures consolidation process in result of Ilizarov method treatment depend on their quantitative characteristics.Purpose of the study – to develop quantitative characteristics of diaphyseal humerus fractures and to analyze their correlation to the terms of bone fragments healing.Materials and methods. The authors studied X-rays of forty one patient with diaphyseal humerus fractures; age of patients ranged from 21 to 60 years (median – 37 years, there were 19 male and 22 female patients. The authors worked out the formulas using Weasis software for quantitative characteristics of diaphyseal humerus fractures: distance of the fracture site from proximal metaphysis of the humerus, extension of the fracture line and degree of bone fragments displacement. During statistical analysis of the recorded data the average standard deviation, median, minimum, maximum, 25th percentile and 75th percentile were calculated. The Shapiro-Wilk test was used to check consistency of recorded data with normal distribution of characteristics. Correlation analysis was performed by calculation of Kendall and Pearson coefficients. Statistical processing of reported data was done by means of unpaired criteria: non-parametric Wilcoxon test and parametric Student t-test. When comparing two samples a null hypothesis was rejected at the level of test significance p≤0.05. The authors utilized Microsoft Office Excel 2007 and AtteStat, version 13.1.Results. Statistical analysis of the samples including comminuted and spiral fractures of humeral diaphysis demonstrated that the level of the fracture was within 40.9±19.9% and distributed from 11.6% to 72.4% along the diaphysis. Correlation analysis demonstrated statistically valid moderate negative relation between the level of fracture site and consolidation period (Pearson correlation coefficient r = -0.46; р = 0.0091. There is a statistically valid positive moderate relation between extension of the fracture line and consolidation period (Pearson correlation coefficient r = 0.43; р = 0.015. Statistically valid positive and weak relation was observed between the value of “post-reduction displacement” of bone fragments and consolidation period (Kendall correlation coefficient τ = 0.25; p = 0.045. Within the group of comminuted and spiral diaphyseal fractures of the humerus the authors observed a statistically valid longer consolidation period in the sample with diaphyseal fractures, located up to 48.4% away from the proximal end of the humerus as compared to the sample of fractures, located below the indicated border. Conclusions. Consolidation period of the diaphyseal humerus fractures demonstrated statistically valid correlation with the following characteristics of the fracture: 1 fracture location: the closer to the distal end of the humerus the shorter is consolidation term; 2 extension of the fracture site: the longer is the fracture line the longer is consolidation period; 3 post-reduction degree of bone fragments displacement: the larger is the degree of displacement the longer is consolidation period. The correlations observed during the study are true for diaphyseal humerus fractures located within 11 to 72% away from the proximal end of the humerus. 

  2. Impact of the nursing consultation in the External Fixatives Clinic of National Children Hospital

    Directory of Open Access Journals (Sweden)

    Virginia Salas Cerdas


    Full Text Available This article presents the results of a study which analyzed 10 cases (8 female and 2 male aged betweentwo and 17 years, with a number of bone defects, and conducted over a period of three months in the externalfixator Clinic National Children's Hospital. Aimed to provide a clear vision about the need of this pediatricpopulation to have a consultation with Clinical Nursing. The exploratory study was conducted using anobservation guide and interviews with users, parents and interdisciplinary team, and implemented the nursingsegmented into three stages: pre-consultation, consultation and post-consultation, evaluating each the problemsand needs of each user (a, as well as the achievements of the children in this research and the role played by thenurse in the consultations. The results show specifically the educational aspects in physical and emotional healthnurse that gave the users and their families and at-hospital benefits through the implementation of the nursing. Weconclude that children participating in the study achieve proper assimilation and implementation of healtheducation regarding: skin healing fixer, signs and symptoms of infection, operation keys, administration ofantibiotics, plaster care and healthy food choices. In addition, awareness was achieved in children and theirparents in monitoring medical indications allowing satisfactory results in treatment.

  3. A hinged external fixator for complex elbow dislocations: A multicenter prospective cohort study

    NARCIS (Netherlands)

    N.W.L. Schep (Niels); J. de Haan (Jeroen); G.I.T. Iordens (Gijs); W.E. Tuinebreijer (Wim); M.W.G.A. Bronkhorst (Maarten); M.R. de Vries (Mark); J.C. Goslings (Carel); S.J. Ham (John); S. Rhemrev (Steven); G.R. Roukema (Gert); I.B. Schipper (Inger); J.B. Sintenie (Jan Bernard); H.G.W.M. Meulen (Hub); T.P.H. Thiel (Tom); A.B. van Vugt (Arie); E.J.M.M. Verleisdonk (Egbert); J.P.A.M. Vroemen (Jos); P. Wittich (Philippe); P. Patka (Peter); E.M.M. van Lieshout (Esther); D. den Hartog (Dennis)


    textabstractBackground: Elbow dislocations can be classified as simple or complex. Simple dislocations are characterized by the absence of fractures, while complex dislocations are associated with fractures of the radial head, olecranon, or coronoid process. The majority of patients with these

  4. A hinged external fixator for complex elbow dislocations: a multicenter prospective cohort study

    NARCIS (Netherlands)

    Schep, N.W.L.; den Haan, J.; Iordens, G.I.T.; Tuinebreijer, W.E.; Bronkhorst, M.W.G.A.; de Vries, M.R.; Goslings, J.C.; Ham, S.J.; Rhemrev, S.; Roukema, G.R.; Schipper, I.B.; Sintenie, J.B.; van der Meulen, H.G.W.M.; van Thiel, T.P.H.; van Vugt, A.B.; Verleisdonk, E.J.M.M.; Vroemen, J.P.A.M.; Wittich, P.; Patka, P.; van Lieshout, E.M.M.; den Hartog, D.


    Elbow dislocations can be classified as simple or complex. Simple dislocations are characterized by the absence of fractures, while complex dislocations are associated with fractures of the radial head, olecranon, or coronoid process. The majority of patients with these complex dislocations are

  5. Rapid pre-tension loss in the Ilizarov external fixator: an in vitro study.

    NARCIS (Netherlands)

    Aquarius, R.J.M.; Kampen, A. van; Verdonschot, N.J.J.


    BACKGROUND AND PURPOSE: Wire pre-tension in the Ilizarov frame is considered to be important in order to reduce movements that can impair fracture healing. Wires will eventually lose part of their pre-tension, however. In order to gain more insight into the need for wire pre-tension, we

  6. Comparison of the axial stiffness of carbon composite and aluminium alloy circular external skeletal fixator rings. (United States)

    Gauthier, C M; Kowaleski, M P; Gerard, P D; Rovesti, G L


    The purpose of this study was to compare the axial stiffness of aluminium alloy and carbon composite single-ring constructs. Single-ring constructs were made with rings of different material compositions (aluminium alloy and carbon composite), diameters (55 mm, 85 mm, and 115 mm), and thicknesses (6 mm for the single-ring, 12 mm for the double-ring) with all other components remaining constant. Stiffness of each construct was determined under loading in axial compression with a materials testing machine. The axial stiffness of each group was compared using a three-factor factorial analysis of variance investigating all main effects and interactions between ring diameter, ring thickness, and ring material composition; p <0.05 was considered significant. Carbon composite constructs were 16-55% as stiff as corresponding aluminium alloy constructs. Within each combination of ring material composition and ring diameter, stiffness did not significantly increase when the ring thickness was doubled. Within each combination of ring material composition and ring thickness, stiffness significantly decreased with increased ring diameter. Aluminium alloy rings were found to be significantly stiffer than carbon composite rings. Although the carbon composite rings were considerably less stiff, clinical recommendations cannot be made from a single-ring in vitro analysis. Further studies are needed to evaluate the behaviour of these rings in vivo.

  7. Tarsocrural joint goniometry after temporary immobilization with external skeletal fixation in dogs


    Alievi, Marcelo Meller; Schossler, J. E.; Teixeira, Marcelo Weinsten


    Neste experimento, foram utilizados 10 cães clinicamente sadios, submetidos à imobilização temporária das articulações tíbio-tarsal, intertarsal e tarso-metatarsiana direita com fixador esquelético externo, tendo por objetivo avaliar através da mensuração da flexão, da extensão e da amplitude articular os danos provocados por esta imobilização. O aparelho de fixação esquelética externa manteve a articulação em um ângulo aproximado de 135º e permaneceu por 45 dias. Os animais apresentaram...

  8. A novel fixation system for sacroiliac dislocation fracture: internal fixation system design and biomechanics analysis. (United States)

    Dawei, Tian; Na, Liu; Jun, Lei; Wei, Jin; Lin, Cai


    Although there were many different types of fixation techniques for sacroiliac dislocation fracture, the treat remained challenging in posterior pelvic ring injury. The purpose of this study was to evaluate the biomechanical effects of a novel fixation system we designed. 12 human cadavers (L3-pelvic-femora) were used to compare biomechanical stability after reconstruction on the same specimens in four conditions: (1) intact, (2) cable system, (3) plate-pedicle screw system, and (4) cable system and plate-pedicle screw combination system (combination system). Biomechanical testing was performed on a material testing machine for evaluating the stiffness of the pelvic fixation construct in compression and torsion. The cable system and plate-pedicle screw system alone may be insufficient to resist vertical shearing and rotational loads; however the combination system for unstable sacroiliac dislocation fractures provided significantly greater stability than single plate-pedicle or cable fixation system. The novel fixation system for unstable sacroiliac dislocation fractures produced sufficient stability in axial compression and axial rotation test in type C pelvic ring injuries. It may also offer a better solution for sacroiliac dislocation fractures. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Rapid induction of neutrophil-endothelial adhesion by endothelial complement fixation. (United States)

    Marks, R M; Todd, R F; Ward, P A


    The adhesion of neutrophils to vascular endothelium is an early event in their recruitment into acute inflammatory lesions. In evaluating potential neutrophil-endothelial adhesive mechanisms in acute inflammation, important considerations are that adhesion in vivo may occur very rapidly following injury and that the specificity of the reaction resides in altered endothelium. That is, neutrophils adhere only to altered endothelium adjacent to an inflammatory focus, rather than at random as would be expected if activation of neutrophils were the initiator of adhesion. We have explored a possible bridging role for complement in causing early neutrophil-endothelial cell adhesion. The complement system is involved in inflammatory processes, is capable of rapid amplification, and endothelial complement fixation at sites of inflammation could generate an endothelium-restricted signal for neutrophil adhesion. We have now developed a model in which this can be investigated without complicating factors such as immunoglobulin deposition, by constructing a novel molecule, a hybrid of the endothelial binding lectin Ulex europaeus I and of the complement activator cobra venom factor. This molecule has the capacity to cause fixation of complement on human umbilical vein endothelial cells. We show that complement fixation is a potent and rapid stimulus for neutrophil adhesion. Neutrophil adhesion requires only endothelial deposition of C3, and is mediated through the type 3 complement receptor.

  10. Comminuted long bone fractures in children. Could combined fixation improve the results? (United States)

    El-Alfy, Barakat; Ali, Ayman M; Fawzy, Sallam I


    Comminuted diaphyseal fractures in the pediatric age group represent a major orthopedic problem. It is associated with a high incidence of complications and poor outcomes because of the instability and difficulty in treatment. The aim of this study was to evaluate the efficacy of combined external skeletal fixation and flexible intramedullary nails in reconstruction of comminuted diaphyseal fracture in skeletally immature patients. Combined external fixator and elastic stable intramedullary nails were used in the management of 27 pediatric patients (15 males and 12 females) with unstable comminuted diaphyseal fractures of the tibia and femur. There were 19 fractures of the femur and eight fractures of the tibia. The average age of the patients was 8.7 years (range 7-14 years) for the femur and 10.8 years (range 6-15 years) for the tibia. Fractures were classified according to the system of Winquist and Hansen as grade II (five cases), grade III (nine cases), and grade IV (13 cases). All cases were operated within 6 days (range 0-6 days) after injury. The mean follow-up period was 2.8 years (range 2-3.5 years). The average duration of the external fixation was 1.6 months for fractures of the tibia, whereas it was 1.4 months for fractures of the femur. The average time for tibia fracture union was 2.8 months for fractures of the tibia, whereas it was 1.9 months for fractures of the femur. Malalignment in varus less than 5° was noted in one patient. One patient had a limb-length discrepancy of 1.5 cms. There were five cases (18.5%) with pin-tract infection. According to the Association for the Study and Application of the Methods of Ilizarov evaluation system, bone results were excellent in 23 cases (85.2%), good in three cases (11.1%), and poor in one case (3.7%). Functional results were excellent in 22 (81.5%) cases and good in five (18.5%) cases. Combined use of external fixators and elastic intramedullary nails is a good method for the treatment of comminuted

  11. Displaced Anterior Column Acetabular Fracture: Closed Reduction and Percutaneous CT-Navigated Fixation

    Energy Technology Data Exchange (ETDEWEB)

    Huegli, R.W.; Staedele, H.; Messmer, P.; Regazzoni, P.; Steinbrich, W.; Gross, T. [Univ. Hospital of Basel (Switzerland). Dept. of Radiology


    The purpose of this study is to demonstrate the feasibility of computer-tomography-navigated closed reduction and percutaneous fixation (CRPF) in a patient with an externally rotated left acetabular fracture. After a follow-up of 18 months the patient was pain-free and had a normal range of motion in both hip joints. Radiologically, the fracture was fully consolidated, remodelled, and there were no signs of osteoarthritis. To our knowledge, CT-navigated CRPF of a rotated acetabular fracture has not been reported before. Further studies regarding the feasibility of the method are warranted(CRPF)

  12. Fixator-Assisted Lengthening and Deformity Correction Over an Intramedullary Nail in a Patient with Achondroplasia

    Directory of Open Access Journals (Sweden)

    Erdal Uzun


    Full Text Available Achondroplasia is the most frequently encountered form of nonlethal skeletal dysplasia and a type of rhizomelic dwarfism. It results in considerable physical and psychologic handicaps owing to the disproportionate stature of the body and difficulty in performing routine activities of daily living. They also have major musculoskeletal problems including symptomatic malalignment of the lower limbs. Limb lengthening has been used in patients with achondroplasia by different techniques (Intramedullar nailing, monolateral or circular external fixator. We report our treatment of a patient 17 years of age with achondroplasia for bilateral lower limb length discrepancy and bilateral tibial varus deformity.

  13. Hybrid virtues


    Prijić – Samaržija, Snježana


    The controversies about cases such us of epistemic injustice, epistemic paternalism and epistocracy indicate that knowledge needs to be considered as socially situated phenomena and, consequently, that epistemic attitudes, social practices and institutions require evaluation from both an epistemic and an ethical/political perspective. The project titled as ethics of knowing and, especially, promising concept of hybrid virtues or corresponding hybrid view provides a desirable framework for the...

  14. Hybrid intermediaries


    Cetorelli, Nicola


    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  15. Nutrient limitation of terrestrial free-living nitrogen fixation. (United States)

    Dynarski, Katherine A; Houlton, Benjamin Z


    Nitrogen (N) fixation by free-living bacteria is a primary N input pathway in many ecosystems and sustains global plant productivity. Uncertainty exists over the importance of N, phosphorus (P) and molybdenum (Mo) availability in controlling free-living N fixation rates. Here, we investigate the geographic occurrence and variability of nutrient constraints to free-living N fixation in the terrestrial biosphere. We compiled data from studies measuring free-living N fixation in response to N, P and Mo fertilizers. We used meta-analysis to quantitatively determine the extent to which N, P and Mo stimulate or suppress N fixation, and if environmental variables influence the degree of nutrient limitation of N fixation. Across our compiled dataset, free-living N fixation is suppressed by N fertilization and stimulated by Mo fertilization. Additionally, free-living N fixation is stimulated by P additions in tropical forests. These findings suggest that nutrient limitation is an intrinsic property of the biochemical demands of N fixation, constraining free-living N fixation in the terrestrial biosphere. These findings have implications for understanding the causes and consequences of N limitation in coupled nutrient cycles, as well as modeling and forecasting nutrient controls over carbon-climate feedbacks. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  16. Productivity Change and Externalities

    DEFF Research Database (Denmark)

    Kravtsova, Victoria


    on Hungary. While the country leads the group of post-socialist countries in the amount of attracted foreign direct investments (FDI) the effect of this policy on the economy remains unclear. The research finds that different externalities play a different role in productivity, technological and efficiency...... firms and the economy as a whole. The approach used in the current research accounts for different internal as well as external factors that individual firms face and evaluates the effect on changes in productivity, technology as well as the efficiency of domestic firms. The empirical analysis focuses...

  17. Fixation of displaced subcapital femoral fractures. Compression screw fixation versus double divergent pins. (United States)

    Christie, J; Howie, C R; Armour, P C


    One hundred and twenty-seven consecutive patients with displaced subcapital fractures of the femoral neck (Garden Grade III or IV) all under 80 years of age and independently mobile, were randomly allocated to fixation with either double divergent pins or a single sliding screw-plate device. The incidence of non-union and infection in the sliding screw-plate group was significantly higher, and we believe that when internal fixation is considered appropriate multiple pinning should be used. Mobility after treatment was disappointing in about half of the patients, and we feel that internal fixation can only be justified in patients who are physiologically well preserved and who maintain a high level of activity.

  18. Hybrid BioMicromotors (United States)

    Schwarz, Lukas; Medina-Sánchez, Mariana; Schmidt, Oliver G.


    Micromotors are devices that operate at the microscale and convert energy to motion. Many micromotors are microswimmers, i.e., devices that can move freely in a liquid at a low Reynolds number, where viscous drag dominates over inertia. Hybrid biomicromotors are microswimmers that consist of both biological and artificial components, i.e., one or several living microorganisms combined with one or many synthetic attachments. Initially, living microbes were used as motor units to transport synthetic cargo at the microscale, but this simple allocation has been altered and extended gradually, especially considering hybrid biomicromotors for biomedical in vivo applications, i.e., for non-invasive microscale operations in the body. This review focuses on these applications, where other properties of the microbial component, for example, the capability of chemotaxis, biosensing, and cell-cell interactions, have been exploited in order to realize tasks like localized diagnosis, drug delivery, or assisted fertilization in vivo. In the biohybrid approach, biological and artificially imposed functionalities act jointly through a microrobotic device that can be controlled or supervised externally. We review the development and state-of-the-art of such systems and discuss the mastery of current and future challenges in order to evolve hybrid biomicromotors from apt swimmers to adapted in vivo operators.

  19. Genetic analysis of nitrogen fixation in a tropical fast-growing Rhizobium. (United States)

    Elmerich, C; Dreyfus, B L; Reysset, G; Aubert, J P


    The Rhizobium strain ORS571, which is associated with the tropical legume Sesbania rostrata, has the property of growing in the free-living state at the expense of ammonia or N(2) as sole nitrogen source. Five mutants, isolated as unable to form colonies on plates under conditions of nitrogen fixation, were studied. All of them, which appear as Fixin planta, are nif mutants. With mutant 5740, nitrogenase activity of the crude extract was restored by addition of pure Mo-Fe protein of Klebsiella pneumoniae. A 13-kb BamHI DNA fragment from the wild-type strain, which hybridized with a probe carrying the nifHDK genes of K. pneumoniae, was cloned in vector pRK290 to yield plasmid pRS1. The extent of homology between the probe and the BamHI fragment was estimated at 4 kb and hybridization with K. pneumoniae nifH, nifK, and possibly nifD was detected. The pRS1 plasmid was introduced into the sesbania rhizobium nif mutants. Genetic complementation was observed with strain 5740(pRS1) both in the free-living state and in planta. It thus appears that biochemistry and genetics of nitrogen fixation in this particular Rhizobium strain can be performed with bacteria grown under non-symbiotic conditions.

  20. A Subconscious Interaction between Fixation and Anticipatory Pursuit. (United States)

    Watamaniuk, Scott N J; Bal, Japjot; Heinen, Stephen J


    Ocular smooth pursuit and fixation are typically viewed as separate systems, yet there is evidence that the brainstem fixation system inhibits pursuit. Here we present behavioral evidence that the fixation system modulates pursuit behavior outside of conscious awareness. Human observers (male and female) either pursued a small spot that translated across a screen, or fixated it as it remained stationary. As shown previously, pursuit trials potentiated the oculomotor system, producing anticipatory eye velocity on the next trial before the target moved that mimicked the stimulus-driven velocity. Randomly interleaving fixation trials reduced anticipatory pursuit, suggesting that a potentiated fixation system interacted with pursuit to suppress eye velocity in upcoming pursuit trials. The reduction was not due to passive decay of the potentiated pursuit signal because interleaving "blank" trials in which no target appeared did not reduce anticipatory pursuit. Interspersed short fixation trials reduced anticipation on long pursuit trials, suggesting that fixation potentiation was stronger than pursuit potentiation. Furthermore, adding more pursuit trials to a block did not restore anticipatory pursuit, suggesting that fixation potentiation was not overridden by certainty of an imminent pursuit trial but rather was immune to conscious intervention. To directly test whether cognition can override fixation suppression, we alternated pursuit and fixation trials to perfectly specify trial identity. Still, anticipatory pursuit did not rise above that observed with an equal number of random fixation trials. The results suggest that potentiated fixation circuitry interacts with pursuit circuitry at a subconscious level to inhibit pursuit.SIGNIFICANCE STATEMENT When an object moves, we view it with smooth pursuit eye movements. When an object is stationary, we view it with fixational eye movements. Pursuit and fixation are historically regarded as controlled by different neural

  1. Network cities and externalities

    Directory of Open Access Journals (Sweden)

    Rafael Boix Domènech


    Full Text Available The concept of «agglomeration economies» explains the existence of advantages derived from the concentration of population and activity. However, it does not explain the existence of spatially dynamic external economies. Network economies generated in networks of cities correspond to this last type, since they are generated from the interaction between urban units, linked by a network relationship. The objective of this research is to advance in the study of the relationship between the networks of cities and the generation of external economies. The research is divided in four parts: first we expose the link between networks of cities and external economies. The second part outlines a model for the combined measuring of the concentration and network economies. The third part explains the results of applying the model to a case of study: the network of cities of Catalonia. The results suggest that there is a causal relationship between the organization of the urban units forming networks of cities and the generation of external economies that affect growth and economic development. Finally, conclusions and policy implications are drawn up.

  2. Stochastic Control - External Models

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad


    This note is devoted to control of stochastic systems described in discrete time. We are concerned with external descriptions or transfer function model, where we have a dynamic model for the input output relation only (i.e.. no direct internal information). The methods are based on LTI systems...... a section on that topic can be found in appendix....

  3. On parabolic external maps

    DEFF Research Database (Denmark)

    Lomonaco, Luna; Petersen, Carsten Lunde; Shen, Weixiao


    We prove that any C1+BV degree d ≥ 2 circle covering h having all periodic orbits weakly expanding, is conjugate by a C1+BV diffeomorphism to a metrically expanding map. We use this to connect the space of parabolic external maps (coming from the theory of parabolic-like maps) to metrically...

  4. Improving Saliency Models by Predicting Human Fixation Patches

    KAUST Repository

    Dubey, Rachit


    There is growing interest in studying the Human Visual System (HVS) to supplement and improve the performance of computer vision tasks. A major challenge for current visual saliency models is predicting saliency in cluttered scenes (i.e. high false positive rate). In this paper, we propose a fixation patch detector that predicts image patches that contain human fixations with high probability. Our proposed model detects sparse fixation patches with an accuracy of 84 % and eliminates non-fixation patches with an accuracy of 84 % demonstrating that low-level image features can indeed be used to short-list and identify human fixation patches. We then show how these detected fixation patches can be used as saliency priors for popular saliency models, thus, reducing false positives while maintaining true positives. Extensive experimental results show that our proposed approach allows state-of-the-art saliency methods to achieve better prediction performance on benchmark datasets.

  5. Overcoming Design Fixation Through Education and Creativity Methods

    DEFF Research Database (Denmark)

    Howard, Thomas J.; Maier, Anja; Onarheim, Balder


    This paper reports an experiment on the topic design fixation using 12 teams of masters students working on three design problems from (Jansson and Smith 1991). The objective of the experiment is to determine the effectiveness of two interventions to help overcome fixation on example solutions....... The first intervention consisted of educating each team on the phenomena and effects of design fixation. The results showed that this intervention reduced the number of fixation elements in comparison to the control group (p=0.025). The second intervention involved using Dix et als' (2006) 'Bad Ideas...... of ideas produced per group and the groups' fixation ratios, adding to the quantity breads novelty debate. Finally, the study also provided further evidence of the hypothesis by Agogué et al (2011) that example solutions constructed from restrictive partitions have a greater fixation affect....

  6. Individual Objective and Subjective Fixation Disparity in Near Vision (United States)

    Jaschinski, Wolfgang


    Binocular vision refers to the integration of images in the two eyes for improved visual performance and depth perception. One aspect of binocular vision is the fixation disparity, which is a suboptimal condition in individuals with respect to binocular eye movement control and subsequent neural processing. The objective fixation disparity refers to the vergence angle between the visual axes, which is measured with eye trackers. Subjective fixation disparity is tested with two monocular nonius lines which indicate the physical nonius separation required for perceived alignment. Subjective and objective fixation disparity represent the different physiological mechanisms of motor and sensory fusion, but the precise relation between these two is still unclear. This study measures both types of fixation disparity at viewing distances of 40, 30, and 24 cm while observers fixated a central stationary fusion target. 20 young adult subjects with normal binocular vision were tested repeatedly to investigate individual differences. For heterophoria and subjective fixation disparity, this study replicated that the binocular system does not properly adjust to near targets: outward (exo) deviations typically increase as the viewing distance is shortened. This exo proximity effect—however—was not found for objective fixation disparity, which–on the average–was zero. But individuals can have reliable outward (exo) or inward (eso) vergence errors. Cases with eso objective fixation disparity tend to have less exo states of subjective fixation disparity and heterophoria. In summary, the two types of fixation disparity seem to respond in a different way when the viewing distance is shortened. Motor and sensory fusion–as reflected by objective and subjective fixation disparity–exhibit complex interactions that may differ between individuals (eso versus exo) and vary with viewing distance (far versus near vision). PMID:28135308

  7. Individual Objective and Subjective Fixation Disparity in Near Vision.

    Directory of Open Access Journals (Sweden)

    Wolfgang Jaschinski

    Full Text Available Binocular vision refers to the integration of images in the two eyes for improved visual performance and depth perception. One aspect of binocular vision is the fixation disparity, which is a suboptimal condition in individuals with respect to binocular eye movement control and subsequent neural processing. The objective fixation disparity refers to the vergence angle between the visual axes, which is measured with eye trackers. Subjective fixation disparity is tested with two monocular nonius lines which indicate the physical nonius separation required for perceived alignment. Subjective and objective fixation disparity represent the different physiological mechanisms of motor and sensory fusion, but the precise relation between these two is still unclear. This study measures both types of fixation disparity at viewing distances of 40, 30, and 24 cm while observers fixated a central stationary fusion target. 20 young adult subjects with normal binocular vision were tested repeatedly to investigate individual differences. For heterophoria and subjective fixation disparity, this study replicated that the binocular system does not properly adjust to near targets: outward (exo deviations typically increase as the viewing distance is shortened. This exo proximity effect-however-was not found for objective fixation disparity, which-on the average-was zero. But individuals can have reliable outward (exo or inward (eso vergence errors. Cases with eso objective fixation disparity tend to have less exo states of subjective fixation disparity and heterophoria. In summary, the two types of fixation disparity seem to respond in a different way when the viewing distance is shortened. Motor and sensory fusion-as reflected by objective and subjective fixation disparity-exhibit complex interactions that may differ between individuals (eso versus exo and vary with viewing distance (far versus near vision.

  8. Incidence and risk factors for surgical site infection after open reduction and internal fixation of tibial plateau fracture: A systematic review and meta-analysis. (United States)

    Shao, Jiashen; Chang, Hengrui; Zhu, Yanbin; Chen, Wei; Zheng, Zhanle; Zhang, Huixin; Zhang, Yingze


    This study aimed to quantitatively summarize the risk factors associated with surgical site infection after open reduction and internal fixation of tibial plateau fracture. Medline, Embase, CNKI, Wanfang database and Cochrane central database were searched for relevant original studies from database inception to October 2016. Eligible studies had to meet quality assessment criteria according to the Newcastle-Ottawa Scale, and had to evaluate the risk factors for surgical site infection after open reduction and internal fixation of tibial plateau fracture. Stata 11.0 software was used for this meta-analysis. Eight studies involving 2214 cases of tibial plateau fracture treated by open reduction and internal fixation and 219 cases of surgical site infection were included in this meta-analysis. The following parameters were identified as significant risk factors for surgical site infection after open reduction and internal fixation of tibial plateau fracture (p external fixation (OR 2.07; 95% CI 1.05-4.09). Other factors, including male sex, were not identified as risk factors for surgical site infection. Patients with the abovementioned medical conditions are at risk of surgical site infection after open reduction and internal fixation of tibial plateau fracture. Surgeons should be cognizant of these risks and give relevant preoperative advice. Copyright © 2017. Published by Elsevier Ltd.

  9. Labyrinthine fenestration for tympanosclerotic stapes fixation. (United States)

    Querat, C; Richard, C; Martin, C


    To report the results obtained in patients with intact tympanic membrane tympanosclerotic stapes fixation treated by labyrinthine fenestration and to discuss the value of this operation. Retrospective study of 28 cases of tympanosclerotic stapes fixation operated between 1982 and 2010. Labyrinthine fenestration was performed using a CO(2) laser. In the first group of patients, the columellar effect was restored by stapedectomy with graft interposition and reconstruction was performed by TORP prosthesis and in the second group, stapedotomy was performed with reconstruction by a piston crimped onto the long process of incus (LPI) or the malleus handle (MH). Postoperatively (2 to 6 months), stapedectomy and reconstruction by TORP prosthesis allowed a gain of the mean Rinne by 18 dB and reconstruction by piston crimped onto the LPI or an MH placed in the stapedotomy orifice allowed a gain of 14 dB. With a follow-up of 3 years, this gain was maintained with the first technique. No case of cophosis or sensorineural hearing loss greater than 20 dB was observed. Labyrinthine fenestration provides an immediate hearing gain in patients with tympanosclerotic stapes fixation with the two techniques used. In the longer term, these good results were maintained with the stapedectomy and TORP prosthesis technique, but the hearing gain was no longer statistically significant in the long-term with the stapedotomy technique because of a limited number of cases. However, only a study based on a larger number of patients would be able to confirm the superiority of TORP compared to stapedotomy. Labyrinthine fenestration, which comprised only a low risk of deterioration of hearing and which did not induce any total hearing loss, must nevertheless be performed only in the case of severe bilateral conductive hearing loss, with an intact tympanic membrane, in patients refusing a hearing aid and informed about the risks of deterioration of hearing. Copyright © 2012 Elsevier Masson SAS. All

  10. Stability analysis of craniovertebral junction fixation techniques. (United States)

    Puttlitz, Christian M; Melcher, Robert P; Kleinstueck, Frank S; Harms, Juergen; Bradford, David S; Lotz, Jeffrey C


    Craniovertebral arthrodesis in the upper cervical spine is challenging because of the high degree of mobility afforded by this region. A novel method for achieving atlantoaxial fixation with use of polyaxial screws inserted bilaterally into the lateral masses of C1 and transpedicularly into C2 with longitudinal rod connection has recently been introduced. The question remains as to whether this technique provides adequate stability when extended cephalad to include the occiput. The purpose of this study was to determine the primary stability afforded by this novel construct and compare its stability with the current standard of bilateral longitudinal plates combined with C1-C2 transarticular screws. We used ten fresh-frozen human cadaveric cervical spines (C0-C4). Pure moment loads were applied to the occiput, and C4 was constrained during the testing protocol. We evaluated four conditions: (1) intact, (2) destabilized by means of complete odontoidectomy, (3) stabilization with longitudinal plates with C1-C2 transarticular screw fixation, and (4) stabilization with a posterior rod system with C1 lateral mass screws and C2 pedicle screws. Rigid-body three-dimensional rotations were detected by stereophotogrammetry by means of a three-camera system with use of marker triads. The range of motion data (C0-C2) for each fixation scenario was calculated, and a statistical analysis was performed. Destabilization of the specimen significantly increased C0-C2 motion in both flexion-extension and lateral bending (p motion in the destabilized spine by over 90% for all motions tested (p < 0.05). No significant differences were detected between the two constructs in any of the three rotational planes. Both hardware systems provide equivalent construct stability in the immediate postoperative period when it is critical for the eventual success of a craniovertebral arthrodesis. On the basis of this work, we believe that the decision to use either construct should be determined by

  11. Fractures and refractures after femoral locking compression plate fixation in children and adolescents. (United States)

    Becker, Tali; Weigl, Daniel; Mercado, Eyal; Katz, Kalman; Bar-On, Elhanan


    Locking compression plates (LCPs) are being increasingly utilized in fixation of fractures and osteotomies in the pediatric population. However, plate insertion or removal may pose a risk of femoral fractures or refractures. The goal of this study was to analyze failure patterns associated with LCPs and identify possible contributing factors. The sample included all patients who underwent fixation of femoral fractures or osteotomies utilizing straight LCPs at a tertiary pediatric medical center from 2004 to 2009. All were followed up until fracture union. The charts and radiographs were reviewed, and data on demographics, indications, surgical technique, and timing of plate removal were summarized. In cases of failure, the timing, circumstances, fracture location, and refixation method were recorded. Thirty-seven patients underwent 41 straight LCP fixations during the study period. The indication for surgery was acute femoral fracture in 25 procedures (25 patients) and elective osteotomy or limb lengthening in 16 procedures (12 patients). Thirty-five plates were removed after complete clinical and radiographic union. The time from plate fixation to removal averaged 13 months (range, 5 to 34 mo) in the fracture group and 17.6 months (range, 7.5 to 28 mo) in the osteotomy group. Five procedures (12%) were complicated by femoral fractures or refractures: 2 occurred after the index surgery-1 at the proximal screw and 1 through the original fracture site, with plate breakage. Three patients sustained refractures after plate removal, all at the original fracture or regenerate site: 1 after a fall and 2 spontaneously. The average time from plate removal to refracture was 18 days (range, 10 to 30). There were no differences in demographics, timing, or technique between patients with and without complications. Although LCPs are considered flexible fixators, they may carry the risk of overstiffness, similar to external fixators. Further clinical and biomechanical studies are

  12. The application of fluorescence in situ hybridization (FISH technique for studying the microbial communities in intestinal tissues of white shrimp (Penaeus vannamei

    Directory of Open Access Journals (Sweden)

    Supamattaya, K.


    Full Text Available Fluorescence in situ hybridization technique is very useful for the evaluation of microbial communities in various environments. It is possible to apply this technique to study the intestinal microflora in white shrimp (Penaeus vannamei. Different fixatives and storage temperature were tested in this technique. It was found that fixation with 10% buffered formalin for 12 hours and changed to 70% ethanol shown positive results when compared to the fixation with Davidson's fixative or RF fixative. The best signaling was obtainedfrom the samples which were stored in -20ºC. By using the DNA probe targeted to the Eubacteria domain (EUB338 probe, 5′-GCT GCC TCC CGT AGG AGT-3′ labeled with fluorescein as a hybridizing probe, it was found that most intestinal microflora were aggregated with the intestinal contents, or dispersed in the lumen. There was not evidence of the attachment of the microflora with the intestinal epithelium in this study.


    Directory of Open Access Journals (Sweden)



    Full Text Available INTRODUCTI ON: We studied the clinical and functional outcome of distal radius fractures managed by ligamentotaxis and/or percutaneous pinning versus open reduction & internal fixation by buttress plates. METHODS : This prospective study was conducted during Aug 2012 to October 2014. All skeletally matured patients were having both Intra articular and extra articular Closed Distal Radius fractures were studied. Treatment was done either external fixator supplemented with k wires or internal fixation with plate and screws. The radiographic evaluation included radial length, palmar tilt, any evidence of jointincongruity and radio ulnar joint instability and arthritis. The assessments that were made includes Subjective assessment – pain, numbness, weakness of hand, stiffness, OBJECTIVE : R ange of motion measured by hand held goniometer, Measurement of grip strength done by commercially available hand dynamometer. Unaffected hand served as control. RESULTS : Male patients (85.46% outnumbered female patients (14.54% in incidence. The incidence of distal ra dius fractures was common between the ages of 20 to 40 years. Left sided fractures were more common (52.73%. Type III was most common type of fracture (Frykman’s Classification, accounting for 29% of all fractures.25 cases were treated by external fixati on and 30 cases were treated by open reduction and buttress plating. The results were evaluated by using STEWART ET AL anatomical and functional scoring system. The average range of movement at the knee joint was Dorsiflexion 70*, Palmar Flexion 65*, Ulnar Deviation 25*, Radial Deviation 15*, Supination 70*, Pronation 65*. Most common early complication was pin tract infection. Based on the stewar et al scoring, 4(7.27% had excellent, 43(78.18% had good, 7(12.72% had fair, 1(1.81% had poor results. CONC LUSION : We observed that both fixations were equally same, there is no superiority with over the other. The incidence of complications in

  14. An improved perfusion fixation method for the testis. (United States)

    Forssmann, W G; Ito, S; Weihe, E; Aoki, A; Dym, M; Fawcett, D W


    A reliable and uniform vascular perfusion fixation method for the testis has been developed by using an initial washout solution containing a vasodilator and an anticoagulant. This is followed by a brief fixation with a sodium phosphate buffered formaldehyde-glutaraldehyde solution of conventional strenght, and then a second more concentrated aldehyde fixative solution containing picric acid. The method takes into account some of the unique features of the vascular supply of the male genital tract for its favorable perfusion and fixation. The advantages of this method are: (1) consistently favorable preservation of the testis; (2) simple and inexpensive apparatus; and (3) stable and relatively innocuous stock solutions.

  15. Alcohol-based solutions for bovine testicular tissue fixation. (United States)

    Cabrera, Nelson C; Espinoza, Jorge R; Vargas-Jentzsch, Paul; Sandoval, Patricio; Ramos, Luis A; Aponte, Pedro M


    Tissue fixation, a central element in histotechnology, is currently performed with chemical compounds potentially harmful for human health and the environment. Therefore, alternative fixatives are being developed, including alcohol-based solutions. We evaluated several ethanol-based mixtures with additives to study fixative penetration rate, tissue volume changes, and morphologic effects in the bovine testis. Fixatives used were Bouin solution, 4% formaldehyde (F4), 70% ethanol (E70), E70 with 1.5% glycerol (E70G), E70 with 5% acetic acid (E70A), E70 with 1.5% glycerol and 5% acetic acid (E70AG), and E70 with 1.5% glycerol, 5% acetic acid, and 1% dimethyl sulfoxide (DMSO; E70AGD). Five-millimeter bovine testicular tissue cubes could be completely penetrated by ethanol-based fixatives and Bouin solution in 2-3 h, whereas F4 required 21 h. Bouin solution produced general tissue shrinkage, whereas the other fixatives (alcohol-based and F4) caused tissue volume expansion. Although Bouin solution is an excellent fixative for testicular tissue, ethanol-based fixatives showed good penetration rates, low tissue shrinkage, and preserved sufficient morphology to allow identification of the stages of the seminiferous epithelium cycle, therefore representing a valid alternative for histotechnology laboratories. Common additives such as acetic acid, glycerol, and DMSO offered marginal benefits for the process of fixation; E70AG showed the best preservation of morphology with excellent nuclear detail, close to that of Bouin solution.

  16. Where have eye been? Observers can recognise their own fixations. (United States)

    Foulsham, Tom; Kingstone, Alan


    We are often not explicitly aware of the location of our spatial attention, despite its influence on our perception and cognition. During a picture memory task, we asked whether people could later recognise their eye fixations in a two-alternative test. In three separate experiments, participants performed above chance when discriminating their own fixation patterns from random locations or locations fixated in a different image. Recognition was much poorer when the task was to spot your own versus someone else's fixations on the same stimulus, but performance remained better than chance. That we are sensitive to our own scan patterns has implications for perception, memory, and meta-cognition.

  17. Biomechanical superiority of plate fixation for proximal tibial osteotomy. (United States)

    Hartford, James M; Hester, Peter; Watt, Phil M; Hamilton, Doris; Rohmiller, Michael; Pienkowski, David


    Proximal tibial osteotomies require secure and durable fixation to allow early range of motion; however, biomechanical data comparing commonly used fixation methods are lacking. The current study was done to quantify the dynamic biomechanical performance of blade staple fixation and plate fixation of simulated proximal tibial osteotomies. A 15 degrees proximal tibial osteotomy was done on each of 18 synthetic adult composite tibias. Blade staples were used as the means of fixation in nine tibias; plate fixation was used in the remaining nine tibias. The specimens were stressed cyclically in sinusoidal loading whose peak compression and tension loads imitate those measured during normal gait. Device performance was quantified by measuring displacement at the osteotomy site and the number of cycles to failure. Plate fixation had a greater fatigue life than staples (eight plates surviving past 200,000 cycles versus one blade staple) and showed a trend toward less displacement (0.69 mm versus 0.97 mm). Plate fixation of proximal tibial osteotomies offers better fixation and dynamic mechanical performance than blade staples.

  18. N2-fixation and residual N effect of four legume species and four companion grass species

    DEFF Research Database (Denmark)

    Rasmussen, Jim; Søegaard, Karen; Pirhofer-Walzl, Karin


    and climatic conditions. We conducted a field experiment on a sandy soil at two nitrogen levels with seven two-species forage mixtures: alfalfa, bird's-foot trefoil, red clover, or white clover in mixture with perennial ryegrass, and white clover in mixture with meadow fescue, timothy, or hybrid ryegrass. We...... found high N2-fixation of more than 300 kg N ha-1 from both red clover and alfalfa even when the two mixtures received 300 kg total-N ha-1 in cattle slurry. The addition of cattle slurry N fertilizer lowered N2-fixation for white clover and red clover as expected, but for bird's-foot trefoil and alfalfa...... no changes in the proportion of N derived from N2-fixation was observed. We conclude that the competition for available soil N from perennial ryegrass in mixture was an important factor for the proportion of N in alfalfa, white clover, and bird's-foot trefoil obtained from N2-fixation. White clover had...

  19. [Posterior fixation and fusion for treatment of Os odontoideum complicated by atlantoaxial dislocation]. (United States)

    Zhang, Hui; Jin, Anmin; Zhang, Li; Zhou, Zhilai; Duan, Yang; Min, Shaoxiong


    To summarize the techniques and evaluate the therapeutic effect of posterior fixation and fusion in the treatment of Os odontoideum complicated by atlantoaxial dislocation. From March, 2007 to October, 2010, 10 patients with Os odontoideum (including 6 male and 4 female patients aged from 20 to 65 years, mean 39.8 years) were treated in our hospital. Before and after the operation, the patients underwent X ray, CT and MRI examinations to measure and evaluate the degree of dislocation and neural compression. After preoperative traction for 1-2 weeks, all the 10 patients showed deductible atlantoaxial dislocation. Through a posterior approach, Atlantoaxial pedicle screws fixation were performed in 9 cases, and C2/3 pedicle-Occiput screw fixation was performed in 1 case. All the patients wore cervical collars as external support for 3 months after the operation. The mean operative time was 3 h in these patients with a mean intraoperative blood loss of 420 ml. The symptoms were relieved after the surgery in all the patients, who showed no neck pain or neurological defects. The patients were followed up for 6 to 52 months (mean 22 months), and bony fusion was observed in all the 10 cases within 6 to 8 months without such complications as internal fixation failure or redislocation of the atlas. Patients with Os odontoideum complicated by atlantoaxial dislocation should undergo surgical stabilization to avoid severe neurological injury. Pedicle screw instrument in the atlas allows restoration of the spinal stability, short-segment fusion, and maximal preservation of the mobility of the neck.

  20. Regulation of Development and Nitrogen Fixation in Anabaena

    Energy Technology Data Exchange (ETDEWEB)

    James W Golden


    The nitrogen-fixing filamentous cyanobacterium Anabaena sp. strain PCC 7120 is being used as a simple model of microbial development and pattern formation in a multicellular prokaryotic organism. Anabaena reduces atmospheric nitrogen to ammonia in highly specialized, terminally differentiated cells called heterocysts. Anabaena is an important model system because of the multicellular growth pattern, the suspected antiquity of heterocyst development, and the contribution of fixed nitrogen to the environment. We are especially interested in understanding the molecular signaling pathways and genetic regulation that control heterocyst development. In the presence of an external source of reduced nitrogen, the differentiation of heterocysts is inhibited. When Anabaena is grown on dinitrogen, a one-dimensional developmental pattern of single heterocysts separated by approximately ten vegetative cells is established to form a multicellular organism composed of two interdependent cell types. The goal of this project is to understand the signaling and regulatory pathways that commit a vegetative cell to terminally differentiate into a nitrogen-fixing heterocyst. Several genes identified by us and by others were chosen as entry points into the regulatory network. Our research, which was initially focused on transcriptional regulation by group 2 sigma factors, was expanded to include group 3 sigma factors and their regulators after the complete Anabaena genome sequence became available. Surprisingly, no individual sigma factor is essential for heterocyst development. We have used the isolation of extragenic suppressors to study genetic interactions between key regulatory genes such as patS, hetR, and hetC in signaling and developmental pathways. We identified a hetR R223W mutation as a bypass suppressor of patS overexpression. Strains containing the hetR R223W allele fail to respond to pattern formation signals and overexpression of this allele results in a lethal phenotype

  1. ExternE transport methodology for external cost evaluation of air pollution

    DEFF Research Database (Denmark)

    Jensen, S. S.; Berkowicz, R.; Brandt, J.

    The report describes how the human exposure estimates based on NERI's human exposure modelling system (AirGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Initially, a brief description of the ExternE Tranport methodology is given and it is summarised...


    Directory of Open Access Journals (Sweden)



    Full Text Available INTRODUCTION An inguinal hernia is a weakness in the wall of the abdominal cavity that is large enough to allow escape of soft body tissue or internal organ, especially a part of the intestine. It usually appears as a lump and for some peoples can cause pain and discomfort, limit daily activities and the ability to work. If the bowel strangulates or becomes obstructed it can be life-threatening. A hernia is repaired generally using a synthetic mesh either with open surgery or increasingly using less invasive laparoscopic procedures. AIMS AND OBJECTIVES To compare and evaluate Laparoscopic hernia repair (trans-abdominal pre-peritoneal and total extra peritoneal repair (TAPP & TEP using Prolene mesh with or without fixation. MATERIAL AND METHODS Our study was conducted in dept. of surgery, Government Medical College and associated Dr. Susheela Tiwari Hospital. A total sample of 100 patients who underwent inguinal hernia repair as an elective surgery. 50 of whom underwent fixation of mesh (fixation will be done either by tacker or suture. Rest 5o underwent non fixation of mesh. RESULTS In our study Statistically there was non-significant heterogeneity in operating time (p = 0.15, post-operative pain (p = 0.45, post-operative complications (p = 0.55 and length of hospital stay (p = 0.11 were statistically comparable between two techniques of mesh fixation in LIHR. The risk of developing chronic groin pain (p = 0.67 and risk of hernia recurrence (p = 0.77 was also similar. CONCLUSION NMF in LIHR does not increase the risk of hernia recurrence. It is comparable with TMF in terms of operation time, post-operative pain, post-operative complications, length of hospital stay and chronic groin pain. Therefore, based upon the results of our study NMF approach may be adopted routinely and safely in LIHR.

  3. [Wearable Automatic External Defibrillators]. (United States)

    Luo, Huajie; Luo, Zhangyuan; Jin, Xun; Zhang, Leilei; Wang, Changjin; Zhang, Wenzan; Tu, Quan


    Defibrillation is the most effective method of treating ventricular fibrillation(VF), this paper introduces wearable automatic external defibrillators based on embedded system which includes EGG measurements, bioelectrical impedance measurement, discharge defibrillation module, which can automatic identify VF signal, biphasic exponential waveform defibrillation discharge. After verified by animal tests, the device can realize EGG acquisition and automatic identification. After identifying the ventricular fibrillation signal, it can automatic defibrillate to abort ventricular fibrillation and to realize the cardiac electrical cardioversion.

  4. Externally triggered microcapsules (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)


    Disclosed are microcapsules comprising a polymer shell enclosing one or more immiscible liquid phases in which a drug or drug precursor are contained in a liquid phase. The microparticles also contain magnetic particles that can be heated by application of an external magnetic field and thus heated to a predetermined Curie temperature. Heating of the particles melts the polymer shell and releases the drug without causing heating of surrounding tissues.

  5. Agglomeration Externalities in Germany


    Bode, Eckhardt


    Several recent econometric investigations found externalities related to the density of economic activity to account for one fifth to one half of total regional variations in average labor productivity in the U.S. and big European countries, including Germany. The present paper shows for German NUTS 3 regions, first, that this result is not robust against a more extensive control for private returns that may be correlated with economic density. The paper presents, second, evidence of various ...

  6. Midtarsal Reconstructive Arthrodesis Using a Multi-Axial Correction Fixator in Charcot Midfoot Arthropathy. (United States)

    Matsumoto, Takumi; Parekh, Selene G


    Reconstructive surgeries for Charcot foot are challenging due to complicated conditions and comorbidities including poor bone quality, sensory abnormalities, poor vascularity, and immunity impairment. Although various fixation devices, including screws, plates, and external fixators, have been used in the surgical reconstruction of the Charcot midfoot, all of these devices are associated with some disadvantages. This study aims to evaluate the outcome of the Multi-Axial Correction (MAC) monolateral external fixation system for the reconstructive surgery of midfoot Charcot neuroarthropathy. A total of 11 feet with midfoot Charcot arthropathy were treated surgically using the MAC fixation system solely or accompanied with minimal internal fixation. The mean postoperative follow-up was 29 (range = 12-44) months. The mean postoperative timing of the MAC system removal was 8.7 (range = 5-14) weeks. No pin tract infections were observed. All patients went on to successful union and correction of a rocker bottom deformity. No cases resulted in limb amputation. All patients were able to ambulate with custom diabetic shoes and insoles in 9 patients (10 feet) and commercially available shoes in 1 patient (1 foot). This study suggests that the MAC system can be an acceptable, easy option for the surgical treatment of midfoot Charcot arthropathy. Therapeutic, Level IV: Case series. © 2015 The Author(s).

  7. Electrical potential-assisted DNA hybridization. How to mitigate electrostatics for surface DNA hybridization. (United States)

    Tymoczko, Jakub; Schuhmann, Wolfgang; Gebala, Magdalena


    Surface-confined DNA hybridization reactions are sensitive to the number and identity of DNA capture probes and experimental conditions such as the nature and the ionic strength of the electrolyte solution. When the surface probe density is high or the concentration of bulk ions is much lower than the concentration of ions within the DNA layer, hybridization is significantly slowed down or does not proceed at all. However, high-density DNA monolayers are attractive for designing high-sensitivity DNA sensors. Thus, circumventing sluggish DNA hybridization on such interfaces allows a high surface concentration of target DNA and improved signal/noise ratio. We present potential-assisted hybridization as a strategy in which an external voltage is applied to the ssDNA-modified interface during the hybridization process. Results show that a significant enhancement of hybridization can be achieved using this approach.

  8. Nitrogen Fixation and Hydrogen Metabolism in Cyanobacteria (United States)

    Bothe, Hermann; Schmitz, Oliver; Yates, M. Geoffrey; Newton, William E.


    Summary: This review summarizes recent aspects of (di)nitrogen fixation and (di)hydrogen metabolism, with emphasis on cyanobacteria. These organisms possess several types of the enzyme complexes catalyzing N2 fixation and/or H2 formation or oxidation, namely, two Mo nitrogenases, a V nitrogenase, and two hydrogenases. The two cyanobacterial Ni hydrogenases are differentiated as either uptake or bidirectional hydrogenases. The different forms of both the nitrogenases and hydrogenases are encoded by different sets of genes, and their organization on the chromosome can vary from one cyanobacterium to another. Factors regulating the expression of these genes are emerging from recent studies. New ideas on the potential physiological and ecological roles of nitrogenases and hydrogenases are presented. There is a renewed interest in exploiting cyanobacteria in solar energy conversion programs to generate H2 as a source of combustible energy. To enhance the rates of H2 production, the emphasis perhaps needs not to be on more efficient hydrogenases and nitrogenases or on the transfer of foreign enzymes into cyanobacteria. A likely better strategy is to exploit the use of radiant solar energy by the photosynthetic electron transport system to enhance the rates of H2 formation and so improve the chances of utilizing cyanobacteria as a source for the generation of clean energy. PMID:21119016

  9. Carbon Dioxide Fixation by Lupin Root Nodules (United States)

    Laing, William A.; Christeller, John T.; Sutton, William D.


    Labeling studies using detached lupin (Lupinus angustifolius) nodules showed that over times of less than 3 minutes, label from [3,4-14C]glucose was incorporated into amino acids, predominantly aspartic acid, to a much greater extent than into organic acids. Only a slight preferential incorporation was observed with [1-14C]- and [6-14C]glucose, while with [U-14C]-glucose more label was incorporated into organic acids than into amino acids at all labeling times. These results are consistent with a scheme whereby the “carbon skeletons” for amino acid synthesis are provided by the phosphoenolpyruvate carboxylase reaction. A comparison of 14CO2 release from nodules supplied with [1-14C]- and [6-14C]glucose indicated that the oxidative pentose phosphate pathway accounted for less than 6% of glucose metabolism. Several enzymes of the oxidative pentose phosphate and glycolytic pathways were assayed in vitro using the 12,000g supernatant fraction from nodule homogenates. In all cases, the specific activities were adequate to account for the calculated in vivo fluxes. Three out of four diverse treatments that inhibited nodule nitrogen fixation also inhibited nodule CO2 fixation, and in the case of the fourth treatment, replacement of N2 with He, it was shown that the normal entry of label from exogenous 14CO2 into the nodule amino acid pool was strongly inhibited. PMID:16660746

  10. Biological Nitrogen Fixation: Perspective and Limitation

    Directory of Open Access Journals (Sweden)

    N D Purwantari


    Full Text Available The demand of chemical fertilizer, N in particular will be increasing until 2020. In Indonesia, the demand of fertilizer from 1999 – 2002 increased 37.5 and 12.4% for urea and ammonium sulphate, respectively. At the same time, the price of this fertilizer is also increasing and it can not be afforded by the farmer. Other problem in using chemical fertilizer is damaging to the soil and environment. One of the problem solvings for this condition is to maximize biological nitrogen fixation (BNF. BNF is the fixation of N atmosphere by association between soil bacteria rhizobia and leguminous plant. BNF is sustainable and environmentally friendly in providing nitrogen fertilizer. Therefore, it would reduce the requirement of chemical nitrogen fertilizer for the plant. Gliricidia sepium fixes 170 kg N/ha/12 months, equivalent with 377 kg urea, Sesbania sesban 179 kg N/ha/10 months, equivalent 397 kg with urea, soybean 26 – 57 kg/2 months equivalent with 57 – 126 kg urea. The amount of N2- fixed varies, affected by species, environmental and biological factors. There are some limitations in applying this technology. The effect of N contribution is very slow at the beginning but in the long term, it would be beneficial for plant production and at the same time, maintain condition of physical and chemical of soil, soil microbes and therefore soil fertility.

  11. Plasticity of fixation in patients with central vision loss. (United States)

    Tarita-Nistor, Luminita; González, Esther G; Markowitz, Samuel N; Steinbach, Martin J


    The aim of this study was to explore the plasticity of fixation in patients with central vision loss. Most of these patients use preferred retinal loci (PRLs) in the healthy eccentric part of the retina to fixate, but fixation stability and retinal location are not always optimal for best visual performance. This study examined whether fixation stability and a new PRL location can be trained and whether these changes in ocular motor control transfer into better reading performance. Six patients with age-related macular degeneration participated in the study. Fixation stability measurements, microperimetry, and auditory biofeedback training were performed with the MP-1 microperimeter. The auditory biofeedback was used during five 1-h long training sessions to improve fixation and relocate the PRL. Fixation location and stability were recorded while viewing four different targets: a cross, a letter, a word, and a nine-cycle radial grating. Visual acuity was assessed with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart and reading performance with the MNRead test. The results showed that all patients developed a new PRL in an optimal location for reading, and they were able to use it consistently while viewing different targets. Fixation stability improved 53% after training. Learning transferred to the old PRL even though fixation stability at this location was not trained. All these improvements in ocular motor control translated into better reading performance: reading speed improved 38% and reading acuity and critical print size gained two lines. We conclude that the ability of the ocular motor system to fixate is flexible in patients with central vision loss: a new PRL can be trained, fixation stability can be improved, and learning transfers to an untrained location. These gains in ocular motor control result in better visual performance. This property can be successfully used to optimize the residual vision of patients with central vision loss.

  12. A new custom moldable external neck brace (ENB 2.0) to improve hands-free speech in laryngectomized patients

    NARCIS (Netherlands)

    Dirven, R.; Clark, J.R.; Wismans, J.G.; McGuiness, J.; Palme, C.E.; Blyth, K.; Baxter, C.; Stone, D.B.; Marres, H.A.M.


    OBJECTIVES/HYPOTHESIS: The majority of laryngectomy patients fail to use a hands-free valve on a daily basis, mainly due to fixation problems of the adhesive baseplate housing. To support adhesive housings during hands-free speech a new external neck brace (ENB 2.0) was developed. The effect of the

  13. External Auditors and Corporate Corruption: Implications for External Audit Regulators

    National Research Council Canada - National Science Library

    Kassem, Rasha; Higson, Andrew W


      The purpose of the current study is to examine the responsibility of external auditors in relation to corporate corruption and to highlight the implications of this for external audit regulators...

  14. Hybrid Warfare (United States)


    military vocabulary to describe these observed phenomena. After an intense focus on large-scale conventional conflicts during the Cold War, with episodic...requiring the mastery of both grammars.85 It follows that hybrid warfare requires the blending of both grammars. The Theoretical Lineage of

  15. Analysis of Glenoid Fixation with Anatomic Total Shoulder Arthroplasty in an Extreme Cyclic Loading Scenario. (United States)

    Roche, Christopher P; Staunch, Cameron; Hahn, William; Grey, Sean G; Flurin, Pierre-Henri; Wright, Thomas W; Zuckerman, Joseph D


    ASTM F2028-14 was adopted to recom mend a cyclic eccentric glenoid edge loading test that simulates the rocking horse loading mechanism beleived to cause aTSA glenoid loosening. While this method accurately simulates that failure mechanism, the recommended 750 N load may not be sufficient to simulate worst-case loading magnitudes, and the recommended 100,000 cycles may not be sufficient to simulate device fatigue-related failure modes. Finally, if greater loading magnitude or a larger number of cycles is performed, the recommended substrate density may not be sufficiently strong to support the elevated loads and cycles. To this end, a new test method is proposed to supplement ASTM F2028-14. A series of cyclic tests were performed to evaluate the long-term fixation strength of two different hybrid glenoid designs in both low (15 pcf) and high (30 pcf) density polyurethane blocks at elevated loads relative to ASTM F2028-14. To simulate a worst case clinical condition in which the humeral head is superiorly migrated, a cyclic load was applied to the superior glenoid rim to induce a maximum torque on the fixation pegs for three different cyclic loading tests: 1. 1,250 N load for 0.75 M cycles in a 15 pcf block, 2. 1,250 N load for 1.5 M cycles in a 30 pcf block, and 3. 2,000 N load for 0.65 M cycles in a 30 pcf block. All devices completed cyclic loading without failure, fracture, or loss of fixation regardless of glenoid design, polyurethane density, loading magnitude, or cycle length. No significant difference in post-cyclic displacement was noted between designs in any of the three tests. Post-cyclic radiographs demonstrated that each device maintained fixa - tion with the metal pegs within the bone-substitute blocks with no fatigue related failures. These results demonstrate that both cemented hybrid glenoids maintained fixation when tested according to each cyclic loading scenario, with no difference in post-cyclic displacement observed between designs. The lack

  16. Rib fracture fixation in a South African public trauma service ...

    African Journals Online (AJOL)

    Background: Rib fractures and flail chests have traditionally been treated nonoperatively. Current literature suggests that it is not only safe and feasible but also desirable to perform fixation of severe rib fractures. Our unit in the Pietermaritzburg public sector adopted rib fracture fixation in 2014 and in this audit we assess its ...

  17. Cultivar effects on nitrogen fixation in peas and lentils (United States)

    Increasing nitrogen fixation in legume crops could increase cropping productivity and reduce nitrogen fertilizer use. Studies have found that crop genotype, rhizobial strain, and occasionally genotype-specific interactions affect N fixation, but this knowledge has not yet been used to evaluate or br...

  18. Indications and outcome of Open Reduction and Internal Fixation of ...

    African Journals Online (AJOL)

    Background: Open reduction and internal fixation (ORIF) is a well-established surgical treatment of fractures worldwide. However, the indications and modes of stabilization of long bone fractures vary and are evolving .The general trend now is towards fixation with locked intramedullary nail (i.m nail) rather than plate and ...

  19. Evaluation of potassium release and fixation behaviour of some ...

    African Journals Online (AJOL)

    In this study, K fixation and release parameters estimated for 25 Nigerian soils both by the conventional fixation methods and the electro-ultrafiltration (EUF) technique were related to some soil physico-chemical properties. This was to ascertain the suitability of the EUF to comprehensively characterize K dynamics in the ...

  20. Nitrogen fixation of Acacia mangium Willd. from two seed sources ...

    African Journals Online (AJOL)

    Phosphorus (P) is required to facilitate the fixation of atmospheric nitrogen (N) by leguminous species such as Acacia mangium. We studied the N fixation of A. mangium trees grown from two seed sources. These consisted of bulk seedlots collected from seed orchards in Sumatra, one based on natural provenances from ...

  1. Nitrogen fixation rates in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ahmed, A.; Gauns, M.; Kurian, S.; Bardhan, P.; Pratihary, A.K.; Naik, H.; Shenoy, D.M.; Naqvi, S.W.A.

    fixation rates were low (0.9�1.5 ?mol N m-3 d-1). Due to episodic events of diazotroph bloom, contribution of N2 fixation to the total nitrogen pool may vary in space and time....

  2. Overcoming design fixation through education and creativity methods

    DEFF Research Database (Denmark)

    Howard, T. J.; Maier, A. M.; Onarheim, B.


    . The first intervention consisted of educating each team on the phenomena and effects of design fixation. The results showed that this intervention reduced the number of fixation elements in comparison to the control group (p=0.025). The second intervention involved using Dix et als' (2006) 'Bad Ideas...

  3. Sacroiliac screw fixation: A mini review of surgical technique

    Directory of Open Access Journals (Sweden)

    Hernando Raphael Alvis-Miranda


    Full Text Available The sacral percutaneous fixation has many advantages but can be associated with a significant exposure to X-ray radiation. Currently, sacroiliac screw fixation represents the only minimally invasive technique to stabilize the posterior pelvic ring. It is a technique that should be used by experienced surgeons. We present a practical review of important aspects of this technique.

  4. Overcoming Organizational Fixation: Creating and Sustaining an Innovation Culture (United States)

    Stempfle, Joachim


    Fixation on established paradigms and practices can severely limit the capability of organizations to change, thereby jeopardizing the ability of organizations to keep up with changes in their environment and new technological developments. Overcoming organizational fixation is therefore a requirement for any organization that strives to achieve…

  5. Modeling evolution using the probability of fixation: history and implications. (United States)

    McCandlish, David M; Stoltzfus, Arlin


    Many models of evolution calculate the rate of evolution by multiplying the rate at which new mutations originate within a population by a probability of fixation. Here we review the historical origins, contemporary applications, and evolutionary implications of these "origin-fixation" models, which are widely used in evolutionary genetics, molecular evolution, and phylogenetics. Origin-fixation models were first introduced in 1969, in association with an emerging view of "molecular" evolution. Early origin-fixation models were used to calculate an instantaneous rate of evolution across a large number of independently evolving loci; in the 1980s and 1990s, a second wave of origin-fixation models emerged to address a sequence of fixation events at a single locus. Although origin fixation models have been applied to a broad array of problems in contemporary evolutionary research, their rise in popularity has not been accompanied by an increased appreciation of their restrictive assumptions or their distinctive implications. We argue that origin-fixation models constitute a coherent theory of mutation-limited evolution that contrasts sharply with theories of evolution that rely on the presence of standing genetic variation. A major unsolved question in evolutionary biology is the degree to which these models provide an accurate approximation of evolution in natural populations.

  6. CRISP: A Computational Model of Fixation Durations in Scene Viewing (United States)

    Nuthmann, Antje; Smith, Tim J.; Engbert, Ralf; Henderson, John M.


    Eye-movement control during scene viewing can be represented as a series of individual decisions about where and when to move the eyes. While substantial behavioral and computational research has been devoted to investigating the placement of fixations in scenes, relatively little is known about the mechanisms that control fixation durations.…

  7. Narcotisation, fixation and preservation experiments with marine zooplankton

    NARCIS (Netherlands)

    Heyman, R.P.


    In this report narcotisation, fixation and preservation experiments with marine zooplankton are described. Narcotisation turns out to be useless for mixed plankton samples. M.S. 222 works well as narcotisation medium for organisms to be photographed. Fixation with 4% formalin proved to be a

  8. Effect of formalin tissue fixation and processing on immunohistochemistry. (United States)

    Werner, M; Chott, A; Fabiano, A; Battifora, H


    Although immunohistochemistry is routinely performed by many pathology laboratories, its standardization still lags behind. A major cause of variation in the reproducibility of immunohistochemical staining is induced by tissue fixation and, to a lesser degree, tissue processing. This report, stemming from the first meeting of the International Consensus Group on Standardization and Quality Control (ICGSQC) in Nice, France, summarizes the problem and suggests solutions to begin to achieve standardization of fixation and processing. Most laboratories use neutral-buffered formalin (10%) for tissue fixation which introduces cross-links, whereas coagulative fixatives are less popular. Problems with formalin fixation comprise delay of fixation and variations in the duration of the fixation mainly. Solutions to these problems could be to start fixation soon (tissue and to avoid overfixation (>24-48 hrs). For tissue processing, the most important problem is inadequate tissue dehydration prior to paraffin embedding. This can be prevented by preparing all solutions freshly every week, depending on the volume of tissue processed. If consistently applied, these procedures could eliminate some of the sources of variation in immunohistochemical stains.

  9. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    Objective: The aim of the study was to evaluate the mechanical behavior of three different fixation methods used in the bilateral sagittal split ramus osteotomy. Materials and Methods: Three different three-dimensional finite element models were created, each corresponding to three different fixation methods. The mandibles ...

  10. Sodium Carboxymethyl Chitosan as a Fixative for Eau de Cologne ...

    African Journals Online (AJOL)

    ... °C. However, products containing benzyl alcohol, ethyl acetoacetate and 94085 floral-fruity showed precipitation after 21 days. Conclusion: The results obtained indicate that SCM-chitosan could be used as a potential fixative for eau de cologne products. Keywords: Biopolymer, carboxymethyl chitosan, cologne, fixative, ...

  11. Tightrope fixation of ankle syndesmosis injuries: clinical outcome, complications and technique modification.

    LENUS (Irish Health Repository)

    Naqvi, Gohar A


    Ankle syndesmotic injuries are complex and require anatomic reduction and fixation. Tightrope fixation is a relatively new technique and we present the largest series of syndesmosis fixation using Arthrex Tightrope™ (Naples, FL, USA).

  12. Homoploid hybrid speciation and genome evolution via chromosome sorting (United States)

    Lukhtanov, Vladimir A.; Shapoval, Nazar A.; Anokhin, Boris A.; Saifitdinova, Alsu F.; Kuznetsova, Valentina G.


    Genomes of numerous diploid plant and animal species possess traces of interspecific crosses, and many researches consider them as support for homoploid hybrid speciation (HHS), a process by which a new reproductively isolated species arises through hybridization and combination of parts of the parental genomes, but without an increase in ploidy. However, convincing evidence for a creative role of hybridization in the origin of reproductive isolation between hybrid and parental forms is extremely limited. Here, through studying Agrodiaetus butterflies, we provide proof of a previously unknown mode of HHS based on the formation of post-zygotic reproductive isolation via hybridization of chromosomally divergent parental species and subsequent fixation of a novel combination of chromosome fusions/fissions in hybrid descendants. We show that meiotic segregation, operating in the hybrid lineage, resulted in the formation of a new diploid genome, drastically rearranged in terms of chromosome number. We also demonstrate that during the heterozygous stage of the hybrid species formation, recombination was limited between rearranged chromosomes of different parental origin, representing evidence that the reproductive isolation was a direct consequence of hybridization. PMID:25925097

  13. Regularization by External Variables

    DEFF Research Database (Denmark)

    Bossolini, Elena; Edwards, R.; Glendinning, P. A.


    Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind of regula...... of regularization, by external variables that shadow either the state or the switch of the original system. The shadow systems are derived from and inspired by various applications in electronic control, predator-prey preference, time delay, and genetic regulation....

  14. Chronic progressive external ophthalmoplegia. (United States)

    Lee, Andrew G; Brazis, Paul W


    Chronic progressive external ophthalmoplegia (CPEO) is a descriptive term for a heterogenous group of disorders characterized by chronic, progressive, bilateral, and usually symmetric ocular motility deficit and ptosis. Significant pain, proptosis, or pupil involvement are not features of CPEO and should prompt evaluation for alternative etiologies. Mitochondrial DNA mutations are increasingly being recognized as the etiology for CPEO syndromes. Clinicians should recognize the specific syndromes associated with CPEO, characterized by variable systemic, neurologic, or other findings. Treatment is limited, but newer therapies are being investigated.

  15. Effects of formalin fixation on tissue optical polarization properties

    Energy Technology Data Exchange (ETDEWEB)

    Wood, M F G; Vurgun, N; Wallenburg, M A; Vitkin, I A, E-mail: [Division of Biophysics and Bioimaging, Ontario Cancer Institute and Departments of Medical Biophysics (Canada)


    Formalin fixation is a preparation method widely used in handling tissue specimens, such as biopsies, specifically in optical studies such as microscopy. In this note, we examine how formalin fixation affects the polarization properties of porcine myocardium and liver as assessed by optical polarimetry. Spatial maps of linear retardance and depolarization were derived from four myocardial and four liver samples before and after formalin fixation. Overall, linear retardance and depolarization increased after fixation for both myocardium (15% and 23% increase, respectively) and liver (38% and 51%, respectively). The relative increase in retardance was greater in liver compared to myocardium, although the absolute increase in retardance was comparable for both. The effect of fixation on bulk optical properties was also investigated for myocardium where the scattering coefficient increased from 92 to 132 cm{sup -1} and the absorption coefficient remained constant at 1.1 cm{sup -1}. (note)

  16. Autistic symptomatology, face processing abilities, and eye fixation patterns. (United States)

    Kirchner, Jennifer C; Hatri, Alexander; Heekeren, Hauke R; Dziobek, Isabel


    Deviant gaze behavior is a defining characteristic of autism. Its relevance as a pathophysiological mechanism, however, remains unknown. In the present study, we compared eye fixations of 20 adults with autism and 21 controls while they were engaged in taking the Multifaceted Empathy Test (MET). Additional measures of face emotion and identity recognition were also obtained. While both groups fixated more on the face and mouth in the emotion recognition than in the face identity condition of the MET, individuals with autism fixated less on the face across MET conditions. Correlation analysis revealed associations between fixation time on the eyes and face processing abilities. Our results suggest that eye fixation patterns are an important characteristic of the social phenotype of autism.

  17. The importance of nodule CO2 fixation for the efficiency of symbiotic nitrogen fixation in pea at vegetative growth and during pod formation


    Fischinger, Stephanie Anastasia; Schulze, Joachim


    Nodule CO2 fixation is of pivotal importance for N2 fixation. The process provides malate for bacteroids and oxaloacetate for nitrogen assimilation. The hypothesis of the present paper was that grain legume nodules would adapt to higher plant N demand and more restricted carbon availability at pod formation through increased nodule CO2 fixation and a more efficient N2 fixation. Growth, N2 fixation, and nodule composition during vegetative growth and at pod formation were studied in pea plants...

  18. Fixational saccades are more disconjugate in adults than in children.

    Directory of Open Access Journals (Sweden)

    Aasef G Shaikh

    Full Text Available Fixational eye movements are of particular interest for three reasons. They are critical for preventing visual fading and enhancing visual perception; their disconjugacy allows scanning in three dimensions, and their neural correlates span through the cortico-striatal, striato-collicular and brainstem networks. Fixational eye movements are altered in various pediatric ophthalmologic and neurologic disorders. The goal of this study was to compare the dynamics of fixational eye movements in normal children and adults.We measured the fixational saccades and inter-saccadic drifts in eye positions using infrared video-oculography in children and adults. We assessed the frequency, amplitude, main-sequence, and disconjugacy of fixational saccades as well as the intra-saccadic drift velocity and variance between these two groups.We found a similar frequency but an increase in the amplitude of fixational saccades in children compared to adults. We also found that the fixational saccades were more conjugate in children than in adults. The inter-saccadic drifts were comparable between the two groups.This study provides normative values of dynamics of fixational eye movement in children and adults. The greater disconjugacy of fixational saccades in adults suggests the existence of neural mechanisms that can independently regulate the movements of two eyes. The differences between adult and pediatric populations could be due to completion of the development of binocularly independent regulation of fixational saccades nearing adulthood. The alternate possibility is that the increased disconjugacy between the two eyes may represent a deficiency in the eye movement performance as a function of increasing age.

  19. Hybrid Molten Salt Reactor (HMSR) System Study

    Energy Technology Data Exchange (ETDEWEB)

    Woolley, Robert D [PPPL; Miller, Laurence F [PPPL


    Can the hybrid system combination of (1) a critical fission Molten Salt Reactor (MSR) having a thermal spectrum and a high Conversion Ratio (CR) with (2) an external source of high energy neutrons provide an attractive solution to the world's expanding demand for energy? The present study indicates the answer is an emphatic yes.

  20. Les aciers inoxydables dans les fixations

    CERN Document Server



    Cet ouvrage, qui fait la synthèse de plusieurs travaux menés par le Cetim, propose une vue d'ensemble sur les aciers inoxydables utilisés pour les fixations. Au sommaire : les normes EN, ISO et ATSM qui s'y rapportent , les désignations symboliques , les nuances et caractéristiques mécaniques , les différentes formes de corrosion, les méthodes pour les détecter , les règles du métier , les mises en oeuvre. L'ouvrage comprend plusieurs fiches matériaux et des tableaux qui présentent les équivalences entre les désignations.

  1. Talar dome fracture repaired using bioabsorbable fixation. (United States)

    Zelent, Marek E; Neese, David J


    We describe a man with an acute osteochondral defect in the lateral talar dome associated with a supination-adduction-type ankle fracture. The osteochondral defect was readily visible on plain film radiographs, and magnetic resonance imaging was ordered to determine the full extent of soft-tissue and articular injury. It was discovered that the patient had a stage IV lesion of the talar dome, with complete inversion of the fragment, and rupture of the anterior talofibular and calcaneofibular lateral ankle ligaments. Furthermore, the patient experienced an oblique fracture of the medial malleolus with comminution. The talar dome lesion was surgically reduced and fixated using bioabsorbable pins. Nine months after surgery, the patient was fully recovered from his injury and had no functional limitations.

  2. Stress Modulation of Fracture Fixation Implants. (United States)

    Beltran, Michael J; Collinge, Cory A; Gardner, Michael J


    Stress modulation is the concept of manipulating bridge plate variables to provide a flexible fixation construct that allows callus formation through uneventful secondary bone healing. Obtaining absolute stability through the anatomic reduction of all fracture fragments comes at the expense of fracture biology, whereas intramedullary nailing, which is more advantageous for diaphyseal fractures of the lower extremity, is technically demanding and often may not be possible when stabilizing many metaphyseal fractures. Overly stiff plating constructs are associated with asymmetric callus formation, early implant failure, and fracture nonunion. Numerous surgeon-controlled variables can be manipulated to increase flexibility without sacrificing strength, including using longer plates with well-spaced screws, choosing titanium or stainless steel implants, and using locking or nonlocking screws. Axially dynamic emerging concepts, such as far cortical locking and near cortical overdrilling, provide further treatment options when bridge plating techniques are used.

  3. Posterior atlantal lateral mass fixation technique with polyaxial screw and rod fixation system. (United States)

    Calişaneller, Tarkan; Yilmaz, Cem; Ozdemir, Ozgür; Caner, Hakan


    Atlantoaxial instability may result from various pathologic conditions and operative treatment may be required to correct the deformity, provide stability and prevent neurological deficits. We presented our clinic's experience using C1-C2 fusion with polyaxial screw and rod fixation for C1 and C2 instability for various reasons. Four patients with atlantoaxial instability were operated using polyaxial C1 lateral mass and C2 lateral mass or pedicle screws. The mean age of the patients was 44+/-14,07 years. Satisfactory screw placement was achieved in all patients. There were no vertebral artery injuries, C2 nerve root injuries or spinal cord injuries. No per-operative or early postoperative instrumentation failure was observed. C1 lateral mass/C2 pedicle polyaxial screw fixation is a safe technique and can be used to achieve rigid and immediate atlantoaxial stabilization.

  4. Do you like what you see? The role of first fixation and total fixation duration in consumer choice

    NARCIS (Netherlands)

    Laan, van der L.N.; Hooge, I.T.C.; Ridder, de D.T.D.; Viergever, M.A.; Smeets, P.A.M.


    Although there has been recent growing interest in the associations between measures of visual attention and consumer choice, there is still uncertainty about the role of the first fixation in consumer choice and the factors that drive total fixation duration. The study aimed (1) to investigate the

  5. Phase-Contrast Hounsfield Units of Fixated and Non-Fixated Soft-Tissue Samples.

    Directory of Open Access Journals (Sweden)

    Marian Willner

    Full Text Available X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissue specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. Furthermore, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results.

  6. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya


    Full Text Available conventional glass reinforced plastics with biocomposites that exhibit structural and functional stability during storage and use and yet are susceptible to environmental degradation upon disposal. An interesting approach in fabricating biocomposites... natural fibre / biofibre in a matrix. Hybridization with glass fibre provides a method to improve the mechanical properties of natural fibre composites and its effect in different modes of stress depends on the design and construction of the composites...

  7. Hybrid microcircuit intraconnection processes

    Energy Technology Data Exchange (ETDEWEB)

    Bonham, H.B.


    Hybrid intraconnections join thin film networks and applique components into an electrically functional hybrid microcircuit (HMC). Applique components were intraconnected with thermocompression (TC) bonds to chromium/gold metallized thin film networks. The project determined critical processes, material parameters, quality criteria, and characterization techniques. The program began on July 1, 1970, and initial efforts consisted of organizing the development program and forecasting needed equipment and manpower. The total time schedule was then PERT-charted. Gold beam-lead devices, gold wire, and chromium/gold films had already been selected for these intraconnection technologies. Thermocompression bonding was developed to provide intraconnections between the HMC gold conductor metallization and gold beam-lead active devices, gold plated external leads, and gold terminated applique devices, such as capacitors. An optimum combination of bonding parameters based on the fundamental physics of the process was developed. This philosophy required bonding equipment to be thoroughly characterized so that the value of bonding parameters (such as force and temperature) indicated on the bonder could be translated into measurable values of the force and temperature within the bond zone.

  8. Comparison of three fixation methods in treatment of tibial fracture in adolescents. (United States)

    Lin, Lixiang; Liu, Yang; Lin, Chuanlu; Zhou, Yifei; Feng, Yongzeng; Shui, Xiaolong; Yu, Kehe; Lu, Xiaolang; Hong, Jianjun; Yu, Yang


    Tibial fractures are the most common musculoskeletal injury in adolescents. The optimal management of tibial fractures in adolescents is controversial. In this study, we compared the outcomes including complications of three fixation methods in tibial fractures of adolescents and explored the factors associated with the complications. A retrospective cohort study about 83 diaphyseal tibial fractures in 79 children and adolescents, who were treated with plate fixation (PF), elastic stable intramedullary nail fixation (ESINF), or external fixation (EF), was conducted. After adjustment for age, weight, energy of the injury, polytrauma, fracture level and pattern, and extent of comminution, treatment outcomes were compared in accordance with the length of the hospital stay, time to union, and complication rates including many factors. The mean age of the patients was 13.4 years, and their mean weight was 44.2 kg. There was a loss of reduction in two of 33 fractures treated with ESINF and four of 13 treated with EF (P < 0.001). At the time of final follow-up, three patients (two treated with EF and one treated with ESINF) had ≥2.0 cm of shortening. Four of the 32 patients (33 fractures) treated with ESINF underwent a reoperation (two due to loss of reduction and one each because of delayed union and nonunion). Six patients treated with EF required a reoperation (four due to loss of reduction, one for malunion and one for replacement of a pin complicated by infection). Two fracture treated with PF required refixation attributing to nonunion and malunion. A multivariate analysis with adjustment for baseline differences showed that EF was associated with a 7.56-times (95% confidence interval 3.74-29.87) greater risk of loss of reduction and/or malunion than ESINF. All three treatments had satisfactory outcomes, and EF was correlated with the highest rate of complications in our series of adolescents treated with a tibial fracture. However, we cannot currently

  9. Surgical treatment of zygomatic bone fracture using two points fixation versus three point fixation-a randomised prospective clinical trial (United States)


    Background The zygoma plays an important role in the facial contour for both cosmetic and functional reasons; therefore zygomatic bone injuries should be properly diagnosed and adequately treated. Comparison of various surgical approaches and their complications can only be done objectively using outcome measurements which in turn require protocol management and long-term follow up. The preference for open reduction and internal fixation of zygomatic fractures at three points has continued to grow in response to observations of inadequate results from two point and one point fixation techniques. The objectives of this study were to compare the efficacy of zygomatic bone after treatment with ORIF using 2 point fixation and ORIF using 3 point fixation and compare the outcome of two procedures. Methods 100 patients were randomly divided equally into two groups. In group A, 50 patients were treated by ORIF using two point fixation by miniplates and in group B, 50 patients were treated by ORIF using three point fixation by miniplates. They were evaluated for their complications during and after surgery with their advantages and disadvantages and the difference between the two groups was observed. Results A total of 100 fractures were sustained. We found that postoperative complication like decreased malar height and vertical dystopia was more common in those patients who were treated by two point fixation than those who were treated with three point fixation. Conclusions Based on this study open reduction and internal fixation using three point fixation by miniplates is the best available method for the treatment zygomatic bone fractures. PMID:22497773

  10. Eye Behavior Associated with Internally versus Externally Directed Cognition

    Directory of Open Access Journals (Sweden)

    Mathias Benedek


    Full Text Available What do our eyes do when we are focused on internal representations such as during imagination or planning? Evidence from mind wandering research suggests that spontaneous shifts from externally directed cognition (EDC to internally directed cognition (IDC involves oculomotor changes indicative of visual disengagement. In the present study, we investigated potential differences in eye behavior between goal-directed forms of IDC and EDC. To this end, we manipulated the focus of attention (internal versus external in two demanding cognitive tasks (anagram and sentence generation. IDC was associated with fewer and longer fixations and higher variability in pupil diameter and eye vergence compared to EDC, suggesting reduced visual scanning and higher spontaneous eye activity. IDC was further related to longer blinks, lower microsaccade frequency, and a lower angle of eye vergence. These latter changes appear conducive to attenuate visual input and thereby shield ongoing internal processes from external distraction. Together, these findings suggest that IDC is accompanied by characteristic eye behavior that reflects a decoupling of attention from external events and serves gating out visual input.

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

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


    Segmental bone defect animal models are often used for evaluating the bone regeneration performance of bone substituting biomaterials. Since bone regeneration is dependent on mechanical loading, it is important to determine mechanical load transfer after stabilization of the defect and to study the effects of biomaterial stiffness on the transmitted load. In this study, we assess the mechanical load transmitted over a 6mm femur defect that is stabilized with an internal PEEK fixation plate. Subsequently, three types of selective laser melted porous titanium implants with different stiffness values were used to graft the defect (five specimens per group). In one additional group, the defect was left empty. Micro strain gauges were used to measure strain values at four different locations of the fixation plate during external loading on the femoral head. The load sharing between the fixation plate and titanium implant was highly variable with standard deviations of measured strain values between 31 and 93% of the mean values. As a consequence, no significant differences were measured between the forces transmitted through the titanium implants with different elastic moduli. Only some non-significant trends were observed in the mean strain values that, consistent with the results of a previous finite element study, implied the force transmitted through the implant increases with the implant stiffness. The applied internal fixation method does not standardize mechanical loading over the defect to enable detecting small differences in bone regeneration performances of bone substituting biomaterials. In conclusion, the fixation method requires further optimization to reduce the effects of the operative procedure and make the mechanical loading more consistent and improve the overall sensitivity of this rat femur defect model. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Analysis of the stress and displacement distribution of inferior tibiofibular syndesmosis injuries repaired with screw fixation: a finite element study.

    Directory of Open Access Journals (Sweden)

    Qinghua Liu

    Full Text Available BACKGROUND: Studies of syndesmosis injuries have concentrated on cadaver models. However, they are unable to obtain exact data regarding the stress and displacement distribution of various tissues, and it is difficult to compare models. We investigated the biomechanical effects of inferior tibiofibular syndesmosis injuries (ITSIs and screw fixation on the ankle using the finite element (FE method. METHODOLOGY/PRINCIPAL FINDINGS: A three-dimensional model of a healthy ankle complex was developed using computed tomography (CT images. We established models of an ITSI and of screw fixation at the plane 2.5 cm above and parallel to the tibiotalar joint surface of the injured syndesmosis. Simulated loads were applied under three conditions: neutral position with single-foot standing and internal and external rotation of the ankle. ITSI reduced contact forces between the talus and fibula, helped periarticular ankle ligaments withstand more load-resisting movement, and increased the magnitude of displacement at the lower extreme of the tibia and fibula. ITSI fixation with a syndesmotic screw reduced contact forces in all joints, decreased the magnitude of displacement at the lower extreme of the tibia and fibula, and increased crural interosseous membrane stress. CONCLUSIONS/SIGNIFICANCE: Severe syndesmosis injuries cause stress and displacement distribution of the ankle to change multidirectional ankle instability and should be treated by internal fixation. Though the transverse syndesmotic screw effectively stabilizes syndesmotic diastasis, it also changes stress distribution around the ankle and decreases the joint's range of motion (ROM. Therefore, fixation should not be performed for a long period of time because it is not physiologically suitable for the ankle joint.

  13. Clinical and radiological outcome after mini-open Latarjet technique with fixation of coracoid with Arthrex wedge mini-plate. (United States)

    Chaudhary, Deepak; Goyal, Ankit; Joshi, Deepak; Jain, Vineet; Mohindra, Mukul; Mehta, Nitin


    Technical faults leading to coracoid fractures during screw insertion and coracoid graft osteolysis are concerns with standard screw fixation techniques in Latarjet procedure. The purpose of this study is to share our experience using Arthrex wedge profile plate with mini-open technique for graft fixation, that ensures better load distribution between coracoid graft and glenoid. We did retrospective analysis of 24 patients with recurrent anterior shoulder instability after failed arthroscopic Bankart's repair. Arthroscopic examination of affected shoulder was done in lateral position before making patient supine for open Latarjet. A low profile wedge plate (Arthrex) with two screws was used for the procedure. CT analysis was performed post-operatively at 6 months to see graft union and results were evaluated using the Rowe and Walch Duplay score. Mean follow-up time was 26 months. Postoperatively, mean forward elevation was 170.6 + 4.6° (loss of average 5.9°) and mean external rotation was 42.5 + 5.3° (loss of average 3.1°). All patients returned to their previous occupation. None reported to be having any recurrent subluxation. Functional assessment done using Rowe score and Walch Duplay score showed statistically significant improvement (p value 0.034). There were no implant-related complications and no case of coracoid graft osteolysis. Mini-open Latarjet with graft fixation with Arthrex mini-plate provides satisfactory outcome in patients who require reoperation due to dramatic bone loss and failed soft tissue reconstruction. The modified incision improves exposure enabling plate fixation and the secure fixation accelerates rehabilitation.

  14. Review of techniques for monitoring the healing fracture of bones for implementation in an internally fixated pelvis. (United States)

    Wong, Lydia Chwang Yuh; Chiu, Wing Kong; Russ, Matthias; Liew, Susan


    Sacral fractures from high-impact trauma often cause instability in the pelvic ring structure. Treatment is by internal fixation which clamps the fractured edges together to promote healing. Healing could take up to 12 weeks whereby patients are bedridden to avoid hindrances to the fracture from movement or weight bearing activities. Immobility can lead to muscle degradation and longer periods of rehabilitation. The ability to determine the time at which the fracture is stable enough to allow partial weight-bearing is important to reduce hospitalisation time. This review looks into different techniques used for monitoring the fracture healing of bones which could lead to possible methods for in situ and non-invasive assessment of healing fracture in a fixated pelvis. Traditional techniques being used include radiology and CT scans but were found to be unreliable at times and very subjective in addition to being non in situ. Strain gauges have proven to be very effective for accurate assessment of fracture healing as well as stability for long bones with external fixators but may not be suitable for an internally fixated pelvis. Ultrasound provides in situ monitoring of stiffness recovery but only assesses local fracture sites close to the skin surface and has only been tested on long bones. Vibration analysis can detect non-uniform healing due to its assessment of the overall structure but may suffer from low signal-to-noise ratio due to damping. Impedance techniques have been used to assess properties of non-long bones but recent studies have only been conducted on non-biological materials and more research needs to be done before it can be applicable for monitoring healing in the fixated pelvis. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

  15. Pysical fixation of carbon dioxide. Butsuritekina nisanka tanso no kotei

    Energy Technology Data Exchange (ETDEWEB)

    Akai, M. (Mechanical Engineering Laboratory, Tsukuba (Japen))


    Together with the introduction of physical fixation technology of carbon dioxide, possibility and problem are to be explained of carbon dioxide fixation by utilizing the deep-sea water in the ocean. The physical fixation methods comprise, among others, the oceanic fixation method, high pressure storage method in the exhausted oil or gas field and high pressure storage method into the rock salt piles. The oceanic fixation method has recently come to be studied in Japan also as having utilizable environments therearound. The oceanographic fixation technology of carbon dioxide is of an engineeringwise developed method. Particularly among others, the fixation technology to utilize deep-sea water, deeper than several hundreds of meters, heightens the carbon dioxide in solubility by availing of a condition of low temperature by high pressure. The liquefaction pressure of carbon dioxide being approx. 70atm at ordinary temperature, the liquefied carbon dioxide is higher in density than the sea water under a higher pressure than about 3000m in head. Due to the existence of temperature lamination, the absorbed carbon dioxide hardly circulates into the atmosphere. Apart from the above two points of advantage, it is advantageous also in other points. However, there remain many problems, inclusive of those ot basic mechanism, to be elucidated. 16 refs., 3 figs.

  16. Use of tightrope fixation in ankle syndesmotic injuries

    Directory of Open Access Journals (Sweden)

    Maempel Julian


    Full Text Available 【Abstract】Objective: Conventional fixation of syndesmotic injuries with screws remains problematic. A novel fibrewire device (Tightrope® has suggested advantages. However, small case series have reported high soft tissue complication rates. The purpose of our study was to quantify complication rates and further procedures in patients treated with Tightropes. A secondary objective was to determine incidence of complications and further procedures in those treated with syndesmotic screws over the same period. Methods: All patients undergoing syndesmotic fixation for ankle fracture between May 2008 and October 2009 were retrospectively reviewed. Incidence of complications, secondary procedures, maintenance of syndesmotic reduc- tion and time spent on non-weight bearing were recorded. Family doctors were contacted for those treated with Tight- ropes to check for any complications managed elsewhere. Results: Thirty-five patients required syndesmotic fixation, in which 12 were treated with Tightropes. They were followed up in clinic for a mean of 12.4 weeks. Family doctors were contacted at mean 14.6 months after treatment to determine any complications suffered. There were no complications attributable to method of fixation. In this series, 12 patients underwent 13 procedures and no patient had recurrent diastasis at discharge; 23 patients treated with screw fixation underwent 45 procedures (19 were screw removals. There was 1 case of syndesmotic diastasis. Screw removal resulted in 2 minor complications. Conclusion: Tightrope fixation provideds effective syndesmotic fixation that is maintained at discharge. We do not experience soft tissue complications reported elsewhere.

  17. Evaluation of two dynamic axial fixators for large ruminants. (United States)

    Singh, Gaj Raj; Aithal, Hari Prasad; Amarpal; Kinjavdekar, Prakash; Maiti, Swapan Kumar; Hoque, Mozammel; Pawde, Abhijit Motiram; Joshi, Hem Chandra


    To evaluate healing of a radial osteotomy repaired by application of dynamic axial fixation devices (DAF) in large ruminants. In vivo study of bone healing after application of 2 DAF types. Model I had 2 sidebars, each with a central cylindrical cuff (internally threaded) with 2 detachable connecting rods telescoping within the cuff. Model II had 2 side bars with 2 moveable clamps with multiple holes. Bull calves (n=8; aged, 1.5-2.0 years; weighing, 175-250 kg). A mid-diaphyseal radial osteotomy was repaired by use of a model I (n=4) or model II (n=4) DAF. Calves were monitored for weight bearing, stability of fixation, and radiographically for fracture reduction, alignment and healing at intervals for 6 months. Fixators were removed when there was radiographic evidence of healing. Both the fixators were well tolerated with free movement of adjacent joints. Fragment fixation was maintained until healing in all but 1 model I calf where failure occurred within 7 days. Model II DAF provided more rigid fixation as indicated by early full weight bearing and fracture healing with less callus formation. Functional recovery of repaired limbs occurred within 60 days in surviving calves. Both bilateral DAFs were easy to apply; however, the model II DAF provided better fixation. The model II DAF made of low carbon steel was economical and may be useful for treating long bone fractures in large ruminants.

  18. Dental occlusion ties: A rapid, safe, and non-invasive maxillo-mandibular fixation technology. (United States)

    Johnson, Alan W


    For decades, Erich arch bars have been a standard in establishing maxillo-mandibular fixation (MMF). While reliable, the approach risks sharps injury, consumes operating room time, and inflicts gingival trauma. Newer technologies including screw-based techniques and "hybrid" techniques have improved MMF by reducing sharps injuries and operating room time, but risk injury to tooth roots, nerves, and gingiva. This study aims to establish the application, strengths, and limitations of dental occlusion ties as a novel alternative in maxillo-mandibular fixation. Prospective, non-blinded, human feasibility clinical trial. An iterative prototyping process was used to invent dental occlusion ties (brand name: Minne Ties). Development included 3D printing, cadaver prototype testing, human apical embrasure measurement, and ultimately non-significant risk human clinical trial testing. In the IRB-approved feasibility clinical trial, the devices were applied to mandible and maxilla fracture candidates with fractures amenable to intra-operative MMF with open reduction with internal fixation. The ties were removed prior to extubation. Pre-teens, comminuted fracture patients, and patients requiring post-operative MMF were excluded. Manufactured, sterile prototypes secured MMF successfully in management of unilateral and bilateral mandible and maxilla fractures. All patients reported correction of pre-operative malocclusion. Application times were typically 12-15 minutes for a single surgeon to achieve MMF. Patients incurred negligible gingival trauma from the technology as the ties require no tissue penetration for application. Dental occlusion ties offer a non-invasive solution featuring operating room efficiency, minimized sharps risk, and less bony and soft tissue trauma than current commercialized solutions. Therapeutic, IV.

  19. Outcome of rail fixator system in reconstructing bone gap. (United States)

    Lakhani, Amit; Singh, Deepinderjit; Singh, Randhir


    Bone loss following open fracture or infected gap nonunion is a difficult situation to manage. There are many modes of treatment such as bone grafting, vascularized bone grafting and bone transport by illizarov and monolateral fixator. We evaluated the outcome of rail fixator treatment in reconstructing bone and limb function. We felt that due to problems such as heavy apparatus, persistent pain, deformity of joints and discomfort caused by an Ilizarov ring fixator, rail fixator is a good alternative to treat bone gaps. 20 patients (17 males and 3 females with mean age 30.5 years) who suffered bone loss due to open fracture and chronic osteomyelitis leading to infected gap nonunion. Ten patients suffered an open fracture (Gustilo type II and type III) and 10 patients suffered bone gap following excision of necrotic bone after infected nonunion. There were 19 cases of tibia and one case of humerus. All patients were treated with debridement and stabilization of fracture with a rail fixator. Further treatment involved reconstructing bone defect by corticotomy at an appropriate level and distraction by rail fixator. We achieved union in all cases. The average bone gap reconstructed was 7.72 cm (range 3.5-15.5 cm) in 9 months (range 6-14 months). Normal range of motion in nearby joint was achieved in 80% cases. We had excellent to good limb function in 85% of cases as per the association for the study and application of the method of ilizarov scoring system[ASAMI] score. All patients well tolerated rail fixator with good functional results and gap reconstruction. Easy application of rail fixator and comfortable distraction procedure suggest rail fixator a good alternative for gap reconstruction of limbs.

  20. Design and Optimization of Resorbable Silk Internal Fixation Devices (United States)

    Haas, Dylan S.

    Limitations of current material options for internal fracture fixation devices have resulted in a large gap between user needs and hardware function. Metal systems offer robust mechanical strength and ease of implantation but require secondary surgery for removal and/or result in long-term complications (infection, palpability, sensitivity, etc.). Current resorbable devices eliminate the need for second surgery and long-term complications but are still associated with negative host response as well as limited functionality and more difficult implantation. There is a definitive need for orthopedic hardware that is mechanically capable of immediate fracture stabilization and fracture fixation during healing, can safely biodegrade while allowing complete bone remodeling, can be resterilized for reuse, and is easily implantable (self-tapping). Previous work investigated the use of silk protein to produce resorbable orthopedic hardware for non- load bearing fracture fixation. In this study, silk orthopedic hardware was further investigated and optimized in order to better understand the ability of silk as a fracture fixation system and more closely meet the unfulfilled market needs. Solvent-based and aqueous-based silk processing formulations were cross-linked with methanol to induce beta sheet structure, dried, autoclaved and then machined to the desired device/geometry. Silk hardware was evaluated for dry, hydrated and fatigued (cyclic) mechanical properties, in vitro degradation, resterilization, functionalization with osteoinductive molecules and implantation technique for fracture fixation. Mechanical strength showed minor improvements from previous results, but remains comparable to current resorbable fixation systems with the advantages of self-tapping ability for ease of implantation, full degradation in 10 months, ability to be resterilized and reused, and ability to release molecules for osteoinudction. In vivo assessment confirmed biocompatibility, showed

  1. Biological Nitrogen Fixation In Tropical Dry Forests Of Costa Rica (United States)

    Gei, M. G.; Powers, J. S.


    Evidence suggests that tropical dry forests (TDF) are not nitrogen (N) deficient. This evidence includes: high losses of gaseous nitrogen during the rainy season, high ecosystem soil N stocks and high N concentrations in leaves and litterfall. Its been commonly hypothesized that biological nitrogen fixation is responsible for the high availability of N in tropical soils. However, the magnitude of this flux has rarely if ever been measured in tropical dry forests. Because of the high cost of fixing N and the ubiquity of N fixing legume trees in the TDF, at the individual tree level symbiotic fixation should be a strategy down-regulated by the plant. Our main goal was to determine the rates of and controls over symbiotic N fixation. We hypothesized that legume tree species employ a facultative strategy of nitrogen fixation and that this process responds to changes in light availability, soil moisture and nutrient supply. We tested this hypothesis both on naturally established trees in a forest and under controlled conditions in a shade house by estimating the quantities of N fixed annually using the 15N natural abundance method, counting nodules, and quantifying (field) or manipulating (shade house) the variation in important environmental variables (soil nutrients, soil moisture, and light). We found that in both in our shade house experiment and in the forest, nodulation varied among different legume species. For both settings, the 15N natural abundance approach successfully detected differences in nitrogen fixation among species. The legume species that we studied were able to regulate fixation depending on the environmental conditions. They showed to have different strategies of nitrogen fixation that follow a gradient of facultative to obligate fixation. Our data suggest that there exists a continuum of nitrogen fixation strategies among species. Any efforts to define tropical legume trees as a functional group need to incorporate this variation.

  2. Intraocular lens fixation with Dacron mesh: Part II. (United States)

    Peyman, G A; Koziol, J; Janevicius, R


    We studied the feasibility of fixation of an intraocular lens in the posterior chamber by utilizing Dacron mesh to stimulate cellular ingrowth from the posterior iris surface. Tissue ingrowth into the Dacron mesh occurred five days after Dacron implantation and a firm adhesion between Dacron and the iris developed in a consistent and localized manner. Dacron fibers, when placed in contact with the posterior iris surface, induce fibroblastic and pigmented epithelial tissue ingrowth around the fibers. Fixation of the lens with and without the posterior lens capsule and vitreous is compared in vitrectomized and nonvitrectomized eyes. It is possible to achieve fixation without support from the posterior lens capsule and vitreous.


    Directory of Open Access Journals (Sweden)

    I. V. Savelyeva


    Full Text Available Abstract. The possibility of serological diagnosis of cholera using cholera enterotoxic diagnostics kit in complement fixation test to detect anti-enterotoxic antibodies in sera of patients with cholera caused by hybrid variants of the El Tor biovar has been demonstrated. In patients with mild course of cholera anti-enterotoxic antibodies were detected in titres 1:50 and 1:200 in paired sera obtained on the 7th and 14th days of disease, respectively (fourfold titre increase. In patients with the course of medium severity 32-fold titre increase was recorded from the titre 1:100 in serum obtained on the fifth day of disease till the titre 1:3200 — on the twelfth day of disease. Antibodies titers reached 1:1600 and 1:800 were revealed in two medium course patients (adult and infant of 10 months on the sixth day of disease.

  4. Hybrid Gear (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)


    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  5. The path exchange method for hybrid LCA. (United States)

    Lenzen, Manfred; Crawford, Robert


    Hybrid techniques for Life-Cycle Assessment (LCA) provide a way of combining the accuracy of process analysis and the completeness of input-output analysis. A number of methods have been suggested to implement a hybrid LCA in practice, with the main challenge being the integration of specific process data with an overarching input-output system. In this work we present a new hybrid LCA method which works at the finest input-output level of detail: structural paths. This new Path Exchange method avoids double-counting and system disturbance just as previous hybrid LCA methods, but instead of a large LCA database it requires only a minimum of external information on those structural paths that are to be represented by process data.

  6. Closed reduction with CT-guided screw fixation for unstable sacroiliac joint fracture-dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Baskin, Kevin M.; Cahill, Ann Marie; Kaye, Robin D. [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Born, Christopher T. [Temple University Hospital/Temple Children' s Hospital, Temple Sports Medicine, Marlton, NJ (United States); Grudziak, Jan S. [Children' s Hospital of Pittsburgh, Department of Orthopedic Surgery, Pittsburgh, PA (United States); Towbin, Richard B.


    Unstable posterior pelvic ring fractures and dislocations are uncommon but potentially life-threatening injuries in children. Early definitive management reduces risk of immediate complications as well as chronic pain and gait dysfunction. Conventional operative therapy carries substantial risk of extensive blood loss and iatrogenic neurological and vascular injury. Minimally invasive image-guided intervention may further reduce immediate risk and improve long-term outcome. To describe CT-guided closed reduction and internal fixation (CRIF) and review outcomes of unstable fracture-dislocation of the sacroiliac (SI) joint in children. Between 2000 and 2003, three children (two girls, one boy) age 8-14 years were referred to interventional radiology for treatment of unstable SI joint fracture-dislocation not adequately treated with anterior external fixation alone. The three affected SI joints (two left, one right) were treated in a combined approach by pediatric interventional radiologists and orthopedic surgeons, using a percutaneous approach under CT guidance. Over a threaded guiding pin, 7.3 mm cannulated screws were used to achieve stable reduction of the affected SI joints. One screw was removed after slight (2 mm) migration. No neurovascular or other complications occurred. All patients had satisfactory healing with near-anatomic reduction, although recovery of the youngest was delayed by associated spinal injury. Compared to open surgical alternatives, CRIF under CT guidance reduces operating time, decreases blood loss, and allows early definitive fixation and immediate non-weight-bearing mobilization with a low rate of complication for unstable posterior pelvic ring fractures. In addition, CT-guided placement of the guide pin may allow safer screw positioning and may minimize the total number of screws needed to achieve pelvic stability. (orig.)

  7. [Improved minimally invasive DHS internal fixation for old age patients with intertrochanteric fractures]. (United States)

    Zhang, Wei-hong; Zhang, Jun-bo


    To discuss the improved minimally invasive DHS fixation for treatment of intertrochanteric fractures in aged and the influence on the lateral wall of the femoral. From January 2005 to December 2010,480 aged patients with intertrochanteric fractures were treated by modified minimally invasive DHS fixation. There were 21 males and 268 females,with an average age of 78.3 years old ranging from 60 to 103 years. Aaccording to the Evans type,there were 166 cases of type 1,212 of type II , 86 of type 111, 16 of type IV, among them 46 cases had the dangerous fractures of the lateral wall. The incision length,blood loss volume,time from extending surgical incision in the side panel to close and postoperative complications were observed and recorded. At 1 month, 3 and 6 months after operation,the patients were followed-up,the outcome were evaluated according to the imaging evaluation index and clinical effect assessment indexes. The surgical incision length averaged (8.0+/-1.2) cm, peri-operative bleeding averaged (150.0+/-6.4) ml,time from extending the incision in the operation to close incision averaged (22.0+/-1.3) min, 1 case had postoperative rupture of the external wall, and 3 cases had tension screw cut out in the femoral head,4 cases had excessive shrink back. Postoperative 6 months basic daily living skills (BADL) averaged (14.8+/-1.1) scores, and the ability of walk averaged (6.40+/-0.34) scores. Improved minimally invasive DHS fixation for treatment of intertrochanteric fractures in aged had advantages of small trauma surgery,short wound exposure time, less peri-operative bleeding and the integrity of the lateral wall after operation, the basic daily living skills and ability to walk has an ideal recovery activities, satisfied clinical curative effect.

  8. Outcomes of lumbopelvic fixation in the treatment of complex sacral fractures using minimally invasive surgical techniques. (United States)

    Jazini, Ehsan; Weir, Tristan; Nwodim, Emeka; Tannous, Oliver; Saifi, Comron; Caffes, Nicholas; Costales, Timothy; Koh, Eugene; Banagan, Kelley; Gelb, Daniel; Ludwig, Steven C


    Complex sacral fractures with vertical and anterior pelvic ring instability treated with traditional fixation methods are associated with high rates of failure and poor clinical outcomes. Supplemental lumbopelvic fixation (LPF) has been applied for additional stability to help with fracture union. The study aimed to determine whether minimally invasive LPF provides reliable fracture stability and acceptable complication rates in cases of complex sacral fractures. This is a retrospective cohort study at a single level I trauma center. The sample includes 24 patients who underwent minimally invasive LPF for complex sacral fracture with or without associated pelvic ring injury. Reoperation for all causes, loss of fixation, surgical time, transfusion requirements, length of hospital stay, postoperative day at mobilization, and mortality were evaluated. Patient charts from 2008 to 2014 were reviewed. Of the 32 patients who underwent minimally invasive LPF for complex sacral fractures, 24 (12 male, 12 female) met all inclusion and exclusion criteria. Outcome measures were assessed with a retrospective chart review and radiographic review. The authors did not receive external funding for this study. Acute reoperation was 12%, and elective reoperation was 29%. Two (8%) patients returned to the operating room for infection, one (4.2%) required revision for instrumentation malposition, and seven (29%) underwent elective removal of instrumentation. No patient experienced failure of instrumentation or loss of correction. Average surgical time was 3.6 hours, blood loss was 180 mL, transfusion requirement was 2.1 units of packed red blood cells, and postoperative mobilization was on postoperative day 5. No mortalities occurred as a result of the minimally invasive LPF procedure. Compared with historic reports of open LPF, our results demonstrate reliable maintenance of reduction and acceptable complication rates with minimally invasive LPF for complexsacral fractures. The

  9. Arthroscopic percutaneous inverted mattress suture fixation of isolated greater tuberosity fracture of humerus. (United States)

    Jang, Suk-Hwan; Song, Han-Eui; Choi, Seung-Hyuk


    The purpose of the study was to evaluate the clinical and radiographic outcomes of treatment in patients with isolated greater tuberosity (GT) fractures of humerus using arthroscopic percutaneous inverted mattress suture fixation technique. We attempted to use the arthroscopic percutaneous inverted mattress suture fixation technique in 17 consecutive cases with isolated displaced GT fractures. Fourteen patients were successfully treated without switching to other methods and were available for follow-up at a mean of 22 months (range: 17-38 months) after surgery. For assessment of clinical outcomes, we evaluated the range of motion and the visual analog scale (VAS) score, the shoulder index of the American Shoulder and Elbow Surgeons (ASES), and the Korean Shoulder Scale (KSS). At the final follow-up, the VAS improved to 1.0 points (range: 0-3), the mean ASES score improved to 86.9 points (range: 78.3-100) and the KSS improved to 88.6 points (range: 82-100) postoperatively. Mean union time was 10 weeks. Mean forward flexion was 167.8° (range: 140-180°), mean external rotation in neutral position was 36° (range: 20-70°), and mean internal rotation was at the 12th thoracic level (range: T6-L3) at final follow-up. Three cases were switched to open surgery after attempted arthroscopic technique due to large fragment or osteoporosis. In select cases, the arthroscopic percutaneous inverted mattress suture fixation of GT fracture is a simple and reproducible technique with encouraging early results.

  10. Translimbal fixation of posterior chamber lenses. (United States)

    Yospaiboon, Yosanan; Wongwai, Pantipa; Ratanapakorn, Tanapat; Sinawat, Suthasinee


    To evaluate the result of a surgical technique to insert and secure a standard posterior chamber lens through a simple limbal incision in eyes that had no capsular support or whose capsule was inadvertently ruptured during extracapsular cataract extraction. Retrospective review of the medical records of patients who underwent translimbal fixation of posterior chamber lenses according to age, gender, preoperative visual acuity, postoperative visual acuity, follow-up period and any complications, especially those that may be related to the surgical technique. Twelve patients were recruited in the present study. The patents' age ranged from 31 to 77 years, with a mean of 62.58 years. There were 9 male and 3 female patients. The preoperative visual acuity ranged from hand motion to counting fingers, and the postoperative visual acuity ranged from 6/6 to 6/24 except one patient who had postoperative visual acuity of counting fingers due to a pre-existing macular hole. The length of follow-up period ranged from 3 to 12 months, with a mean of 6.17 months. There was no clinically significant lens-related complication. This simple surgical technique controls the location of the needle entry and exit to decrease the risk of bleeding and increase the chance of ciliary sulcus placement. An inferior groove was made to bury the suture knot and was sutured closed to prevent the knot erosion through the conjunctiva.


    Directory of Open Access Journals (Sweden)

    Gompa Parameswara Rao


    Full Text Available BACKGROUND Postoperative patients of ankle fracture patients can be made weightbearing as tolerated immediately following surgery. Immediate Weightbearing As Tolerated (IWBAT allows patients to return to ambulation and activities of daily living faster and may facilitate rehabilitation. MATERIALS AND METHODS Retrospectively, patients were identified who have ORIF after unstable ankle injuries had treated by the senior author. Patients were excluded if they were not IWBAT based on specific criteria or if they did meet followup requirement. RESULTS After the study, it was seen that only 1/26 patients was noted to have loss of fixation. This was found at the 6-week followup and was attributed to a missed syndesmotic injury. At 2-weeks follow up, 2 patients had peri-incisional erythema that resolved with a short course of oral antibiotics. At 6-week follow up, 20 patients were wearing normal shoes and 6 patients continued to wear the Cam Boot for comfort. CONCLUSION It was seen that IWBAT in a certain subset of patients with stable osteosynthesis following an ankle fracture were at a safe alternative to a period of protected weightbearing.

  12. Self-consistent estimation of mislocated fixations during reading.

    Directory of Open Access Journals (Sweden)

    Ralf Engbert

    Full Text Available During reading, we generate saccadic eye movements to move words into the center of the visual field for word processing. However, due to systematic and random errors in the oculomotor system, distributions of within-word landing positions are rather broad and show overlapping tails, which suggests that a fraction of fixations is mislocated and falls on words to the left or right of the selected target word. Here we propose a new procedure for the self-consistent estimation of the likelihood of mislocated fixations in normal reading. Our approach is based on iterative computation of the proportions of several types of oculomotor errors, the underlying probabilities for word-targeting, and corrected distributions of landing positions. We found that the average fraction of mislocated fixations ranges from about 10% to more than 30% depending on word length. These results show that fixation probabilities are strongly affected by oculomotor errors.

  13. Odontoid screw fixation for fresh and remote fractures

    National Research Council Canada - National Science Library

    Rao, Ganesh; Apfelbaum, Ronald I


    .... If a patient requires surgical treatment of an odontoid process fracture, the timing of treatment may affect fusion rates, particularly if direct anterior odontoid screw fixation is selected as the treatment method...

  14. 21 CFR 888.3010 - Bone fixation cerclage. (United States)


    ...) Identification. A bone fixation cerclage is a device intended to be implanted that is made of alloys, such as cobalt-chromium-molybdenum, and that consists of a metallic ribbon or flat sheet or a wire. The device is...

  15. Effect of Phosphorus Fertilizer on Nitrogen Fixation by Some Grain ...

    African Journals Online (AJOL)


    5698. Effect of Phosphorus Fertilizer on Nitrogen Fixation by Some Grain Legume Varieties in Sudano – Sahelian Zone of North Eastern Nigeria. *H. Yakubu, J. D. Kwari and M.K. Sandabe. Department of Soil Science,. University of Maiduguri.

  16. Consumption externalities and preference complementarities


    Cleary, Rebecca; Carlson, Andrea


    Social interactions can lead to a variety of phenomena including consumption externalities and complementarities. Consumption externalities arise when the choices of others have an effect on the total value of a household's purchases; complementarities arise when the choices of others have an effect on the marginal value of a household's purchases. This paper develops a conceptual model that separately identifies consumption externalities and complementarities and illustrates their significan...

  17. Household External Finance and Consumption


    Besley, Timothy J.; Meads, Neil; Surico, Paolo


    This paper uses mortgage data to construct a measure of terms on which households access to external finance, and relates it to consumption at both the aggregate and cohort levels. The Household External Finance (HEF) index is based on the spread paid by risky borrowers in the mortgage market. There is evidence that the terms of access to external finance matter more for the consumption of young cohorts in U.K. data. Results are robust to a wide variety of specifications.

  18. Incumbent's Incentive under Network Externalities


    Kim, Jaehong


    This paper shows that an incumbent monopolist's incentive confronting a new entrant depends on the degree of product differentiation and the strength of network externality. If products are homogeneous, the incumbent never wants to invite entry regardless of the degree of network externality. On the other hand, if products are differentiated, duopoly profit is higher than the monopoly profit when products are more differentiated and/or the network externality is weak. Conversely, the incumben...

  19. Intuitionistic hybrid logic

    DEFF Research Database (Denmark)

    Braüner, Torben


    Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area.......Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area....

  20. The Relationship Between Iron and Nitrogen Fixation in Trichodesmium spp. (United States)


    fixation by the cyanobacterium Trichodesmium sp GBR -TRLI101. Fems Microbiol Ecol 45: 203-209. Fu, F.X., and Bell, P.R.F. (2003b) Growth, N2 fixation and...gradient across the inner bacterial membrane to the outer membrane to allow the transport of large molecules like siderophores into the periplasm of gram...type Fe3+ transporter (Koster, 2001). YP_722814 is homologous to an inner membrane component of a binding protein dependent transport system and is

  1. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity.

    Directory of Open Access Journals (Sweden)

    Volkhard Schroth

    Full Text Available In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1 subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2 objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory effect, the smaller the objective (motor effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves.

  2. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity (United States)

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang


    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves. PMID:26431525

  3. Chemical fixation to arrest phospholipid signaling for chemical cytometry. (United States)

    Proctor, Angela; Sims, Christopher E; Allbritton, Nancy L


    Chemical cytometry is a powerful tool for measuring biological processes such as enzymatic signaling at the single cell level. Among these technologies, single-cell capillary zone electrophoresis (CZE) has emerged as a powerful tool to assay a wide range of cellular metabolites. However, analysis of dynamic processes within cells remains challenging as signaling pathways are rapidly altered in response to changes in the cellular environment, including cell manipulation and storage. To address these limitations, we describe a method for chemical fixation of cells to stop the cellular reactions to preserve the integrity of key signaling molecules or reporters within the cell and to enable the cell to act as a storage reservoir for the reporter and its metabolites prior to assay by single-cell CZE. Fluorescent phosphatidylinositol 4,5-bisphosphate reporters were loaded into cells and the cells were chemically fixed and stored prior to analysis. The reporter and its metabolites were electrophoretically separated by single-cell CZE. Chemical fixation parameters such as fixative, fixation time, storage solution, storage duration, and extraction solution were optimized. When cells were loaded with a fluorescent C6- or C16-PIP2 followed by glutaraldehyde fixation and immediate analysis, 24±2% and 139±12% of the lipid was recoverable, respectively, when compared to an unfixed control. Storage of the cells for 24h yielded recoverable lipid of 61±3% (C6-PIP2) and 55±5% (C16-PIP2) when compared to cells analyzed immediately after fixation. The metabolites observed with and without fixation were identical. Measurement of phospholipase C activity in single leukemic cells in response to an agonist demonstrated the capability of chemical fixation coupled to single-cell CZE to yield an accurate snapshot of cellular reactions with the probe. This methodology enables cell assay with the reporter to be separated in space and time from reporter metabolite quantification while

  4. Postinflammatory ossicular fixation: CT analysis with surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, J.D.; Wolfson, R.J.; Marlowe, F.I.; Popky, G.L.


    Postinflammatory ossicular fixation is a common problem encountered by the otologic surgeon upon exploration because of conductive hearing loss in patients with chronic otitis media. These nonotosclerotic noncongenital lesions take three pathologic forms: fibrous tissue fixation (chronic adhesive otitis media), hyalinization of collagen (tympanosclerosis), and new bone formation (fibro-osseous sclerosis). More than 300 patients with the clinical diagnosis of chronic otitis media have been examined. This study encompasses 23 proved cases.

  5. Visual fixation as equilibrium: Evidence from superior colliculus inactivation (United States)

    Goffart, Laurent; Hafed, Ziad M.; Krauzlis, Richard J.


    During visual fixation, the image of an object is maintained within the fovea. Previous studies have shown that such maintenance involves the deep superior colliculus (dSC). However, the mechanisms by which the dSC supports visual fixation remain controversial. According to one view, activity in the rostral dSC maintains gaze direction by preventing neurons in the caudal dSC from issuing saccade commands. An alternative hypothesis proposes that gaze direction is achieved through equilibrium of target position signals originating from the two dSC. Here we show in monkeys that artificially reducing activity in the rostral half of one dSC results in a biased estimate of target position during fixation, consistent with the second hypothesis, rather than an inability to maintain gaze fixation as predicted by the first hypothesis. After injection of muscimol at rostral sites in the dSC, fixation became more stable since microsaccade rate was reduced rather than increased. Moreover, the scatter of eye positions was offset relative to pre-inactivation baselines. The magnitude and the direction of the offsets depended upon both the target size and the injected site in the collicular map. Other oculomotor parameters, such as the accuracy of saccades to peripheral targets and the amplitude and velocity of fixational saccades, were largely unaffected. These results suggest that the rostral half of the dSC supports visual fixation through a distributed representation of behaviorally-relevant target position signals. The inactivation-induced fixation offset establishes the foveal visual stimulation that is required to restore the balance of activity between the two dSC. PMID:22855812

  6. Parametric analysis of glenoid implant design and fixation type. (United States)

    Geraldes, Diogo M; Hansen, Ulrich; Amis, Andrew A


    Common post-operative problems in shoulder arthroplasty such as glenoid loosening and joint instability may be reduced by improvements in glenoid design, shape, material choice, and fixation method. A framework for parametric analysis of different implant fixation configurations was developed in order to efficiently sift through potential glenoid component designs. We investigated the influence of design factors such as fixation type, component thickness, and peg position, number, diameter, and length in a multi-factorial design investigation. The proposed method allowed for simultaneous comparison of the mechanical performance of 344 different parametric variations of 10 different reference geometries with either large central fixation features or small peripheral pegs, undergoing four different worst-case scenario loading conditions, and averaging 64.7 s per model. The impact of design parameters were assessed for different factors responsible for post-operative problems in shoulder arthroplasty, such as bone volume preservation, stresses in the implant, central displacement or fixation stability, and the worst performing geometries all relied on conventional central fixation. Of the remaining geometries, four peripheral fixation configurations produced von Mises stresses comfortably below the material's yield strength. We show that the developed method allows for simple, direct, rapid, and repeatable comparison of different design features, material choices, or fixation methods by analyzing how they influence the bone-implant mechanical environment. The proposed method can provide valuable insight in implant design optimization by screening through multiple potential design modifications at an early design evaluation stage and highlighting the best performing combinations according to the failure mechanism to mitigate. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:775-784, 2017. © 2016 Orthopaedic Research Society

  7. Minimal Invasive Percutaneous Fixation of Thoracic and Lumbar Spine Fractures

    Directory of Open Access Journals (Sweden)

    Federico De Iure


    Full Text Available We studied 122 patients with 163 fractures of the thoracic and lumbar spine undergoing the surgical treatment by percutaneous transpedicular fixation and stabilization with minimally invasive technique. Patient followup ranged from 6 to 72 months (mean 38 months, and the patients were assessed by clinical and radiographic evaluation. The results show that percutaneous transpedicular fixation and stabilization with minimally invasive technique is an adequate and satisfactory procedure to be used in specific type of the thoracolumbar and lumbar spine fractures.

  8. Biomechanical Study of Acetabular Tridimensional Memoryalloy Fixation System (United States)

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


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

  9. Dyslexic children are confronted with unstable binocular fixation while reading.

    Directory of Open Access Journals (Sweden)

    Stephanie Jainta

    Full Text Available Reading requires three-dimensional motor control: saccades bring the eyes from left to right, fixating word after word; and oblique saccades bring the eyes to the next line of the text. The angle of vergence of the two optic axes should be adjusted to the depth of the book or screen and--most importantly--should be maintained in a sustained manner during saccades and fixations. Maintenance of vergence is important as it is a prerequisite for a single clear image of each word to be projected onto the fovea of the eyes. Deficits in the binocular control of saccades and of vergence in dyslexics have been reported previously but only for tasks using single targets. This study examines saccades and vergence control during real text reading. Thirteen dyslexic and seven non-dyslexic children read the French text "L'Allouette" in two viewing distances (40 cm vs. 100 cm, while binocular eye movements were measured with the Chronos Eye-tracking system. We found that the binocular yoking of reading saccades was poor in dyslexic children (relative to non-dyslexics resulting in vergence errors; their disconjugate drift during fixations was not correlated with the disconjugacy during their saccades, causing considerable variability of vergence angle from fixation to fixation. Due to such poor oculomotor adjustments during reading, the overall fixation disparity was larger for dyslexic children, putting larger demand on their sensory fusion processes. Moreover, for dyslexics the standard deviation of fixation disparity was larger particularly when reading at near distance. We conclude that besides documented phoneme processing disorders, visual/ocular motor imperfections may exist in dyslexics that lead to fixation instability and thus, to instability of the letters or words during reading; such instability may perturb fusional processes and might--in part--complicate letter/word identification.

  10. Dyslexic children are confronted with unstable binocular fixation while reading. (United States)

    Jainta, Stephanie; Kapoula, Zoï


    Reading requires three-dimensional motor control: saccades bring the eyes from left to right, fixating word after word; and oblique saccades bring the eyes to the next line of the text. The angle of vergence of the two optic axes should be adjusted to the depth of the book or screen and--most importantly--should be maintained in a sustained manner during saccades and fixations. Maintenance of vergence is important as it is a prerequisite for a single clear image of each word to be projected onto the fovea of the eyes. Deficits in the binocular control of saccades and of vergence in dyslexics have been reported previously but only for tasks using single targets. This study examines saccades and vergence control during real text reading. Thirteen dyslexic and seven non-dyslexic children