Sample records for locked plate fixation

  1. Locking versus nonlocking palmar plate fixation of distal radius fractures.

    PubMed

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

    2012-11-01

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

  2. Comparison of external fixation, locking and non-locking palmar plating for unstable distal radius fractures in the elderly

    Microsoft Academic Search

    N. Schmelzer-Schmied; P. Wieloch; A. K. Martini; W. Daecke

    2009-01-01

    This study compares the effectiveness of locking and non-locking palmar plating and external fixation for unstable distal\\u000a radius fractures in the elderly. In a retrospective match-paired study, 45 patients aged 50 to 70 years who underwent surgery\\u000a for C1\\/C2 distal radius fractures were evaluated. The surgical procedures were external fixation or plating with locking or\\u000a non-locking palmar plates. Radiological and functional

  3. Failure of volar locking plate fixation of an extraarticular distal radius fracture: A case report

    Microsoft Academic Search

    Jue Cao; Kagan Ozer

    2010-01-01

    BACKGROUND: Volar locking plates provide significant structural stability to the distal radius. Failure of a volar locked plating is a rarely reported complication in the literature. CASE PRESENTATION: A 40 year-old, obese female patient who presented with a displaced extraarticular distal radius fracture, underwent open reduction and internal fixation of the fracture using a volar locking plate. Radiographs taken at

  4. Palmar Fixation of Dorsally Displaced Distal Radius Fractures Using Locking Plates with Smartlock Locking Screws

    Microsoft Academic Search

    T. C. WONG; C. C. YEUNG; Y. CHIU; S. H. YEUNG; F. K. IP

    2009-01-01

    We performed a prospective cohort study on a consecutive series of 35 unstable, dorsally displaced distal radius fractures, which were treated with palmar locking plates and SmartLock locking screws. There were 17 men and 18 women with a mean age of 44 years who were reviewed at a mean follow-up of 10 months. All the fractures healed at a mean

  5. A Pitfall in Fixation of Distal Humeral Fractures with Pre-Contoured Locking Compression Plate

    PubMed Central

    Jayakumar, Prakash; Ring, David

    2015-01-01

    Anatomically precontoured locking plates are intended to facilitate the fixation of articular fractures and particularly those associated with osteoporosis. Fractures of the distal humerus are relatively uncommon injuries where operative intervention can be exceptionally challenging. The distal humeral trochlea provides a very narrow anatomical window through which to pass a fixed-angle locking screw, which must also avoid the olecranon, coronoid, and radial fossae. We describe 3 patients (ages 27, 49, and 73 years) with a bicolumnar fracture of the distal humerus where very short distal locking screws were used. Intra-articular screw placement was avoided but loss of fixation occurred in two patients and a third was treated with a prolonged period of immobilization. We postulate that fixed-angle screw trajectories may make it difficult for the surgeon to place screws of adequate length in this anatomically confined region, and may lead to insufficient distal fixation. Surgical tactics should include placement of as many screws as possible into the distal fragment, as long as possible and that each screw passes through a plate without necessarily locking in. PMID:26110181

  6. The utility of the fluoroscopic skyline view during volar locking plate fixation of distal radius fractures.

    PubMed

    Vaiss, Lucile; Ichihara, Satoshi; Hendriks, Sarah; Taleb, Chihab; Liverneaux, Philippe; Facca, Sybille

    2014-11-01

    Background?Open reduction and internal fixation (ORIF) using a volar locking plate is a common method for treating displaced distal radius fractures. There is, however, the risk of extensor tendon rupture due to protrusion of the screw tips past the dorsal cortex, which cannot always be adequately seen on a lateral fluoroscopic view. We therefore wished to compare the sensitivity of an intraoperative fluoroscopic skyline view to a lateral fluorosocopic view in detecting past pointing of these screws. Material and Methods?Our series included 75 patients with an average age of 59 years who underwent volar locked plate fixation of a displaced distal radius fracture. Intraoperative anteroposterior (AP), lateral, and skyline fluoroscopic views were performed in each case. The number of screws that were seen to protrude past the dorsal cortex of the distal fracture fragment were recorded for both the lateral and skyline views. The number of screws that required exchange was also documented. Results?No screws were seen to protrude past the dorsal cortical bone on the lateral fluroscopic views. 15 of 300 screws (5%) were seen to protrude past the dorsal cortex by an average of 0.8?mm (range, 0.5 to 2 mm) and were exchanged for shorter screws in 11/75 patients. Conclusion?Our results demonstrate that the skyline is more sensitive than a lateral fluoroscopic view at demonstrating protrusion of the screws in the distal fracture fragment following volar locked plate fixation. Level of Evidence?IV. PMID:25364637

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

    Microsoft Academic Search

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

    2003-01-01

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

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

    PubMed Central

    Gupta, Rakesh K.; Sangwan, Kapil; Singh, Vijendra; Walia, Saurav

    2009-01-01

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

  9. Review of 31 cases of anterior thoracolumbar fixation with the anterior thoracolumbar locking plate system.

    PubMed

    Wilson, J A; Bowen, S; Branch, C L; Meredith, J W

    1999-07-15

    Anterior fixation devices for the thoracolumbar spine have gained wide acceptance as viable alternatives to long-segment posterior fixation in cases of thoracolumbar spine trauma. This review was undertaken to evaluate the safety and efficacy of the Synthes anterior thoracolumbar locking plate (ATLP) system. Over a 3-year period, 31 patients with unstable traumatic fractures of the thoracolumbar spine underwent corpectomy, placement of a structural bone graft, and anterior fixation in which the Synthes ATLP system was used. Long-term follow-up data were obtained in 29 patients. Two patients were lost to follow up, one at 4 months and the other at 1 year. In the remaining patients, the average length of follow up was 20 months. In all patients radiographic evidence of solid bone fusion was demonstrated on follow-up plain x-ray films, and there were no signs or symptoms of pseudarthrosis. No patient suffered neurological deterioration as a result of surgery, and there was relatively little morbidity associated with this plating system. To date, none of the patients in this study has developed any delayed complications related to the fixation device. In one patient, who had sustained a severe flexion injury, loosening of the anterior fixation device occurred, and the patient developed progressive kyphosis, which required a posterior stabilization procedure. These results appear slightly better than those obtained in published studies in which other anterior plating systems were used, indicating that this system is safe and effective in the treatment of unstable fractures of the thoracolumbar spine. PMID:16918232

  10. Radiation-Associated Fracture Nonunion of the Clavicle Treated with Locking Plate Fixation and Autologous Bone Grafting

    PubMed Central

    Lee, Sang Yang; Nishida, Kotaro; Kuroda, Ryosuke; Kurosaka, Masahiro

    2012-01-01

    We describe a case of radiation-associated fracture nonunion of the clavicle, which was treated by locking plate fixation and autologous bone grafting. The patient was a 67-year old man who received 70?Gy radiation therapy to treat nasopharyngeal carcinoma. Eight years later, he suffered a pathological fracture of the right clavicle. One year after the fracture, surgical treatment was performed due to persistent pain and weakness. Radiographs demonstrated atrophic nonunion. Bone scan demonstrated hot uptake at both ends of the fractured bone. MRI demonstrated a formation of pseudoarthrosis with fluid collection and suggested bone marrow edema at both ends of the fracture fragments. In surgery, fibrous pseudoarthrosis tissue was excised and both ends of the fracture fragments were refreshed to identify bleeding. Open reduction and internal fixation using a 7-hole locking plate and autologous bone grafting were performed. Successful bony union was obtained 1 year postoperatively, and no adverse events were observed up to 52 months after the operation. Our case suggests that a locking plate provides sufficient fixation and autologous bone grafting is effective in enhancing bone healing in a radiation-associated fracture nonunion of the clavicle in which it is difficult to achieve bony union. PMID:23326273

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

    PubMed

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

    2011-06-01

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

  12. A biomechanical comparison of proximal femoral nails and locking proximal anatomic femoral plates in femoral fracture fixation

    PubMed Central

    Ozkan, Korhan; Türkmen, ?smail; Sahin, Adem; Yildiz, Yavuz; Erturk, Selim; Soylemez, Mehmet Salih

    2015-01-01

    Background: The incidence of fractures in the trochanteric area has risen with the increasing numbers of elderly people with osteoporosis. Although dynamic hip screw fixation is the gold standard for the treatment of stable intertrochanteric femur fractures, treatment of unstable intertrochanteric femur fractures still remains controversial. Intramedullary devices such as Gamma nail or proximal femoral nail and proximal anatomic femur plates are in use for the treatment of intertrochanteric femur fractures. There are still many investigations to find the optimal implant to treat these fractures with minimum complications. For this reason, we aimed to perform a biomechanical comparison of the proximal femoral nail and the locking proximal anatomic femoral plate in the treatment of unstable intertrochanteric fractures. Materials and Methods: Twenty synthetic, third generation human femur models, obtained for this purpose, were divided into two groups of 10 bones each. Femurs were provided as a standard representation of AO/Orthopedic Trauma Associationtype 31-A2 unstable fractures. Two types of implantations were inserted: the proximal femoral intramedullary nail in the first group and the locking anatomic femoral plate in the second group. Axial load was applied to the fracture models through the femoral head using a material testing machine, and the biomechanical properties of the implant types were compared. Result: Nail and plate models were locked distally at the same level. Axial steady load with a 5 mm/m velocity was applied through the mechanical axis of femur bone models. Axial loading in the proximal femoral intramedullary nail group was 1.78-fold greater compared to the plate group. All bones that had the plate applied were fractured in the portion containing the distal locking screw. Conclusion: The proximal femoral intramedullary nail provides more stability and allows for earlier weight bearing than the locking plate when used for the treatment of unstable intertrochanteric fractures of the femur. Clinicians should be cautious for early weight bearing with locking plate for unstable intertrochanteric femur fractures. PMID:26015637

  13. Comparison of Functional Outcome Between Early and Delayed Internal Fixation Using Volar Locking Plate for Distal Radius Fractures.

    PubMed

    Yamashita, Kazuta; Zenke, Yukichi; Sakai, Akinori; Oshige, Toshihisa; Moritani, Shiro; Maehara, Takashi

    2015-06-01

    The purpose of this study was to assess the effect of timing (Early (E) group vs Delayed (D) group) of internal fixation for distal radius fractures on forearm and wrist function in patients who underwent the surgery. The subjects were one hundred six patients who had extra-articular fractures of the dorsally displaced distal radius and were treated with a volar locking plate. The subjects were divided into two groups: E group (Operation on the day of injury or the next day, n = 76 ; and the D group (Operation at 7 days after injury or later, n = 30). Follow-up examinations conducted at 4, 12, and 48 weeks after surgery included measurements of wrist and forearm ranges of motion (ROM), measurement of grip strength (GS), Disability of the Arm, Shoulder and Hand score (DASH), and complications, retrospectively. The patients in both groups improved significantly with respect to ROM, GS, and DASH. At 4 weeks, the patients in the E group had better forearm motion, At 4 and 12 weeks, those who had undergone early surgery had significantly better wrist motion, GS and DASH. At 48 weeks, there were no differences between the groups in ROM, GS, or DASH. Patients with dorsally displaced extra-articular fractures of the distal radius can expect to have better short-term outcomes with early treatment, open reduction and internal fixation using a volar locking plates. PMID:26073500

  14. Early Weight Bearing of Calcaneal Fractures Treated by Intraoperative 3D-Fluoroscopy and Locked-Screw Plate Fixation

    PubMed Central

    Kienast, B; Gille, J; Queitsch, C; Kaiser, M.M; Thietje, R; Juergens, C; Schulz, A.P

    2009-01-01

    Operative therapy of intraarticular fractures of the calcaneus is an established surgical standard. The aim is an accurate reduction of the fracture with reconstruction of Boehler’s angle, length, axis and subtalar joint surface. Intraoperative 3D-fluoroscopy with the Siremobil Iso-C 3D® mobile C-arm system is a valuable assistant for accurate reconstruction of these anatomical structures. Remaining incongruities can be recognized and corrected intraoperatively. The achieved reduction can be fixed by the advantages of an internal fixator (locked-screw plate interface). In the period of October 2002 until April 2007 we operated 136 patients with intraarticular fractures of the calcaneus by means of anatomical reduction, and internal plate fixator under intraoperative control of 3D-fluoroscopy. All patients were supplied with an orthesis after the operation which allowed weight bearing of 10 kg for 12 weeks for the patients operated between October 2002 and October 2004 (Group A). Transient local osteoporosis was observed in all X-Rays at follow-up after an average of 8,6 months. Therefore we changed our postoperative treatment plan for the patients operated between November 2004 and April 2007 (Group B). Weight bearing started with 20 KG after 6 weeks, was increased to 40 KG after 8 weeks and full weight bearing was allowed after 10 weeks for these patients. In no case a secondary dislocation of the fracture was seen. No bone graft was used. At follow up the average American Foot and Ankle Society Score (AOFAS) were 81 for Group_A, compared to 84 for Group B, treated with earlier weight bearing. Autologous bone graft was not necessary even if weight bearing was started after a period of six weeks postoperatively. The combination of 3D-fluoroscopy with locked internal fixation showed promising results. If the rate of patients developing subtalar arthrosis will decrease by this management will have to be shown in long term follow up. PMID:19750017

  15. [Open reduction and internal fixation of a displaced transverse fracture of the sacrum with a locking compression plate].

    PubMed

    Walliser, M; Sommer, Ch

    2003-12-01

    Isolated fractures of the distal sacrum are usually caused by direct trauma. Undisplaced fractures are easily missed on conventional X-ray films. CT scans can disclose the full extent of the fracture. Undisplaced, or minimally displaced fractures can be treated conservatively with analgesics and a restriction to seat for six weeks. In cases of major displacement or neurological symptoms, a digital transanal reduction of the fracture under local or regional anaesthesia can be attempted. If this manoeuvre fails, open reduction and internal fixation are required. Stabilisation is challenging because of the thin bone and the complex shape of the sacrum. In a 15 year old girl with major horizontal displacement and comminution of S4, following a snowboard accident, we achieved sufficient and stable fixation with the new LCP (Locking Compression Plate) system. For six weeks after the operation, the patient was not allowed to sit down. Thereafter, she was free of pain and unrestricted in daily activities and sport. The LCP system has a number of advantages in the fixation of fractures in osteoporotic or thin bone, but clinical experience/skill and careful planning of the operation are crucial. PMID:14753159

  16. Surgical indications in low lumbar burst fractures: experiences with Anterior Locking Plate System and the reduction-fixation system.

    PubMed

    Huang, T J; Chen, J Y; Shih, H N; Chen, Y J; Hsu, R W

    1995-11-01

    A study of 14 surgically treated patients with low lumbar burst fractures (L3 to L5) is reported. Initially, 13 patients presented with incomplete neurologic deficits below the level of injury. The follow-up period ranged from 24 to 40 months, with an average of 30 months. In group 1, seven patients underwent one-stage anterior decompression, fusion, and Anterior Locking Plate System (ALPS) fixation. In Group 2, seven patients had posterior surgery with decompression, portero-lateral fusion, and a short segment fixation, one above and one below the injuried level, with the reduction-fixation transpediculate system. Indications for one-stage anterior surgery consisted of patients with incomplete neurologic deficits, segmental kyphotic deformity caused by loss of anterior vertebral height (< 50%), or canal encroachment < 50%. When there is significant radiologic evidence of lamina fractures, displaced or greenstick type, or injuries that occurred at the L5 level, the posterior approach was undertaken initially. This may be followed by anterior surgery if satisfactory vertebral height restoration or canal clearance was not achieved. Five dura tears (36%) were noted during surgery: two tears in group 1 and three tears in group 2. There were two patients in group 2 (29%) who had screws broken; however, none in group 1 demonstrated implant failure. In the low lumbar region, the step-off ALPS plate is preferable to the straight plate because of the increasing size of the vertebral body toward the caudal area. A low profile and easy application were its advantages. However, the ALPS could not be distracted or compressed anteriorly. PMID:7474007

  17. Locking plate technology: current concepts.

    PubMed

    Greiwe, R Michael; Archdeacon, Michael T

    2007-01-01

    The management of fractures with traditional plating techniques has undergone a paradigm shift over the past 20 years. For many fractures, anatomic reduction using a dynamic compression plate has been the gold standard. However, minimally invasive approaches combined with biologically friendly internal fixation have become accepted methods of complex fracture treatment. The orthopedic literature has demonstrated advantages when comparing locking plate techniques with traditional compression plating techniques, particularly in fractures about the knee. The advantages of locking plates apply most directly to cases of highly comminuted fractures, unstable metadiaphyseal segments, and osteoporotic fractures. The biomechanical properties of locking plates have distinguished and defined their clinical use compared to traditional plates. A thorough understanding of these properties will assist the orthopedic surgeon in choosing the appropriate construct when faced with a difficult fracture. Compression plating requires absolute stability for bone healing. In contrast, locking plates function as "internal fixators" with multiple anchor points. This type of fixed-angle device converts axial loads across the bone to compressive forces across fracture sites, minimizing gap length and strain. The strain theory demonstrates that anatomic reduction is not required for bone healing, and that tolerable strain (2%-10%) can promote secondary bone healing. Callus formation is further promoted when biologically friendly surgical approaches are combined with locking plate "internal fixators". In contrast, conventional plates function by creating an environment where primary bone healing occurs. This plate provides "absolute rigidity" and requires anatomic reduction fixed in compression. Primary bone healing occurs in this manner. In highly comminuted, segmentally deficient, or porotic bone, bone quality is poor and "absolute rigidity" does not exist. Furthermore, soft-tissue stripping adds a biologic insult to the poor bone quality. These disadvantages may lead to poor outcomes such as nonunion, implant failure, malunion, or even infection. These disadvantages remain theoretical, as no prospective studies clearly demonstrate a difference between plating methods in difficult metadiaphyseal or osteoporotic fractures. However, the overwhelming biomechanical evidence has led to a more biologically friendly approach to these fractures. The indications for use of locking plates are evolving. The literature demonstrates low rates of nonunion and overall complication rates with locking plates in difficult metaphyseal and diaphyseal fractures. Anatomic reduction of the articular surface remains paramount. Hybrid techniques that combine the benefits of compression plate fixation with the biological and biomechanical advantages of locking plates are the most likely end result of current locking plate applications. PMID:17288090

  18. THE RESULTS OF VOLAR LOCKING PLATE FIXATION FOR THE FRAGILITY FRACTURE POPULATION WITH DISTAL RADIUS FRACTURE IN JAPANESE WOMEN

    PubMed Central

    KATO, SHUICHI; TATEBE, MASAHIRO; YAMAMOTO, MICHIRO; IWATSUKI, KATSUYUKI; NISHIZUKA, TAKANOBU; HIRATA, HITOSHI

    2014-01-01

    ABSTRACT The purpose of this study was to determine whether volar locking plate fixation for distal radius fracture benefits the fragility fracture population as much as it benefits the non-fragility fracture population. This matched case-control study was conducted based on a multi-center clinical prospective cohort. A comparison of treatment outcomes after volar locking plate fixation was made between females 55 years of age and older (fragility fracture population) and males less than 75 years of age (non-fragility fracture population) by evaluating clinical, radiological, and subjective outcomes using Hand20, a validated patient-rated disability instrument. A total of 170 patients were enrolled in this study. The two cohorts were matched in terms of AO fracture type. The fragility fracture population group and the non-fragility fracture population group each consisted of 50 patients. All objective measurements including wrist range of motion and radiological evaluations, but excluding grip strength, were not significantly different between the two groups. However, the Hand20 at 18 months after surgery was worse in the fragility fracture population group than in the non-fragility fracture population group. Carpal tunnel syndrome was the most frequently encountered complication in the fragility fracture population group, with one case (2%) in the non-fragility fracture population group and six cases (12%) in the fragility fracture population group, but the difference was not significant. In conclusion, there was a significant deficit in the improvement in disability despite favorable radiological and functional outcomes in fragility fracture population patients. Therefore, the fragility fracture population, especially middle-aged or older women, needs to be informed about prolonged disability and the higher risk of upper extremity disorders prior to surgery. PMID:25129996

  19. UK DRAFFT - A randomised controlled trial of percutaneous fixation with kirschner wires versus volar locking-plate fixation in the treatment of adult patients with a dorsally displaced fracture of the distal radius

    PubMed Central

    2011-01-01

    Background Fractures of the distal radius are extremely common injuries in adults. However, the optimal management remains controversial. In general, fractures of the distal radius are treated non-operatively if the bone fragments can be held in anatomical alignment by a plaster cast or orthotic. However, if this is not possible, then operative fixation is required. There are several operative options but the two most common in the UK, are Kirschner-wire fixation (K-wires) and volar plate fixation using fixed-angle screws (locking-plates). The primary aim of this trial is to determine if there is a difference in the Patient-Reported Wrist Evaluation one year following K-wire fixation versus locking-plate fixation for adult patients with a dorsally-displaced fracture of the distal radius. Methods/design All adult patients with an acute, dorsally-displaced fracture of the distal radius, requiring operative fixation are potentially eligible to take part in this study. A total of 390 consenting patients will be randomly allocated to either K-wire fixation or locking-plate fixation. The surgery will be performed in trauma units across the UK using the preferred technique of the treating surgeon. Data regarding wrist function, quality of life, complications and costs will be collected at six weeks and three, six and twelve months following the injury. The primary outcome measure will be wrist function with a parallel economic analysis. Discussion This pragmatic, multi-centre trial is due to deliver results in December 2013. Trial registration Current Controlled Trials ISRCTN31379280 UKCRN portfolio ID 8956 PMID:21914196

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

    2014-01-01

    Background The use of minimally invasive plate osteosynthesis (MIPO) via anterolateral deltoid splitting has good outcomes in the management of proximal humerus fractures. While using this approach has several advantages, including minimal soft tissue disruption, preservation of natural biology and minimal blood loss, there is an increased risk for axillary nerve damage. This study compared the advantages and clinical and radiological outcomes of MIPO or open reduction and internal fixation (ORIF) in patients with proximal humerus fractures. Methods A matched-pair analysis was performed, and patient groups were matched according to age (±3 years), sex and fracture type. Forty-three pairs of patients (average age: MIPO, 63 and ORIF, 61) with a minimum follow-up of 12 months were enrolled in the study group. The patients were investigated radiographically and clinically using the Constant score. Results The MIPO technique required less surgery time and caused less blood loss compared to ORIF (p?Fixation) fracture classification, did not significantly influence the functional results. The complication rate was comparable between both groups. Conclusion The use of MIPO with a locking compression plate in the management of proximal humerus fractures is a safe and superior option compared to ORIF. PMID:24934152

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

    Microsoft Academic Search

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

    2007-01-01

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

  3. Patient-specific distal radius locking plate for fixation and accurate 3D positioning in corrective osteotomy.

    PubMed

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

    2014-11-01

    Preoperative three-dimensional planning methods have been described extensively. However, transferring the virtual plan to the patient is often challenging. In this report, we describe the management of a severely malunited distal radius fracture using a patient-specific plate for accurate spatial positioning and fixation. Twenty months postoperatively the patient shows almost painless reconstruction and a nearly normal range of motion. PMID:25362548

  4. A finite element parametric study of clavicle fixation plates.

    PubMed

    Pendergast, Megan; Rusovici, Razvan

    2015-06-01

    A finite element simulation on a fracture fixated clavicle was performed to study the effects of different fracture fixation parameters on the callus region. Specifically, parameters such as plate material, thickness, plate/bone gap, screw length, and locking vs. non-locking screws were explored. Plate thickness and locking vs. non-locking screws were found to be influential to construct stiffness where plate/bone gap and number of screws were not as sensitive. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25641811

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

    PubMed Central

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

    2015-01-01

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture’s morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology. PMID:25590989

  6. Functional Outcome and Complications at 2.5 Years Following Volar Locking Plate Fixation of Distal Radius Fractures.

    PubMed

    MacFarlane, Robert J; Miller, David; Wilson, Lynn; Meyer, Carl; Kerin, Cronan; Ford, David James; Cheung, Graham

    2015-06-01

    Distal radius fractures are increasingly treated by internal fixation, but there have been relatively few studies relating to functional outcome at 12 months or more. The aim of this study was to ascertain the patient reported function of the wrist at a minimum of 12 months following fixation of a distal radius fracture, the time taken to return to work, and the complication rate. We conducted a retrospective review of 187 consecutive patients treated by a specialist hand and wrist trauma team at a tertiary referral unit over a 5 year period. Mean age was 57.3 years (range 16-93). Median time to surgery was 4 days (interquartile range 2-9). Median follow up was 31 months (interquartile range 23-41 months). The median PRWE score was 3; (range 0-83). There was no difference in outcome in patients who had surgery delayed by greater than 2 weeks (p?>?0.05). The median time to return to work was 5 weeks (interquartile range 1-8 weeks). There were 15 complications (8 %) including 3 tendon injuries. We have demonstrated an early return to work in patients who were employed, a low complication rate, and highly favourable functional outcomes at a mean of 30 months postoperatively. We recommend the use of the DVR plate and involvement of a dedicated hand and wrist trauma team for treatment of unstable fractures of the distal radius. PMID:26078498

  7. Locking plate construct for femoral shaft fractures in skeletally immature patients

    Microsoft Academic Search

    Akram H AMMAD

    Different methods of internal fixation are used in the treatment of femoral shaft fractures. Results of locked plate fixation in adults have been encouraging. A locking plate construct with a standard broad Dynamic Compression Plate (DCP) and 4.5 mm nuts was used in the treatment of femoral shaft fractures in 15 skeletally immature patients. There were 12 boys and three

  8. Biomechanical Evaluation of Volar Locking Plates for Distal Radius Fractures

    Microsoft Academic Search

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

    2008-01-01

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

  9. “Biological” internal fixation of long bone fractures: a biomechanical study of a “noncontact” plate system

    Microsoft Academic Search

    I. A. Karnezis; A. W. Miles; J. L. Cunningham; I. D. Learmonth

    1998-01-01

    Based on existing knowledge of noncontact plates, an experimental prototype of a nonperiosteal contact internal fixation implant (“noncontact internal fixator”) has been designed. The construct rigidity of osteotomised synthetic composite femora, fixed with the noncontact fixator and a reamed, statically-locked intramedullary nail were compared in axial compression, two-plane bending and torsion in four types of diaphyseal fractures. With the exception

  10. Intermittent internal fixation with a locking plate to preserve epiphyseal growth function during limb-salvage surgery in a child with osteosarcoma of the distal femur: a case report.

    PubMed

    Mei, Jiong; Ni, Ming; Jia, Guang-Yao; Chen, Yan-Xi; Zhu, Xiao-Zhong

    2015-05-01

    Limb shortening is a problem associated with surgery for osteosarcoma of the lower extremity in adolescents, as the tumors frequently occur near the epiphysis. Herein we report the use of a less invasive stabilization system (LISS) and an intermittent fixation method to preserve the growth function of epiphysis in an 11-year-old patient with an osteosarcoma of the distal femur.The 11-year-old male presented with left knee enlargement and pain for 2 weeks, and magnetic resonance imaging (MRI) and biopsy were consistent with osteosarcoma of the left distal femur. After preoperative chemotherapy, en bloc tumor resection was performed with margins based on MRI findings preserving the epiphyseal growth plate, the tumor cavity was filled with inactivated bone and bone cement, and a LISS was used to stabilize the femur. Aggressive postoperative chemotherapy was given. Approximately 105 weeks after surgery radiography showed that the distal end of the plate had moved superior to the epiphysis along with bone growth. Locking screws were placed in the distal part of the LISS plate to stabilize the re-implanted bone, and external fixation was not needed.The patient was able to walk with the crutches 1 week postoperatively, and bear weight on the extremity 6 weeks postoperatively. At 6 years after surgery, the patient's height had increased 52?cm, shortening of the affected limb was only 1?cm, and the circumference of the affected limb was 2?cm smaller than that of the contralateral limb. There was no significant discomfort in the affected limb, and there was no gait abnormality. The patient could jump and run, and could participate in sports including basketball and badminton to the same degree as his peers.In summary, the novel method of bone reconstruction and fixation provided good results in a child with an osteosarcoma of the distal femur. This fixation method preserves the osteogenic function of the epiphysis and restored bone integrity simultaneously, and provides good functional recovery. PMID:25997058

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

    PubMed Central

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

    2014-01-01

    Purpose. To analyse the biomechanical characteristics of locking plates under cyclic loading compared to a nonlocking plate in a diaphyseal metacarpal fracture. Methods. Oblique diaphyseal shaft fractures in porcine metacarpal bones were created in a biomechanical fracture model. An anatomical reduction and stabilization with a nonlocking and a comparable locking plate in mono- or bicortical screw fixation followed. Under cyclic loading, the displacement, and in subsequent load-to-failure tests, the maximum load and stiffness were measured. Results. For the monocortical screw fixation of the locking plate, a similar displacement, maximum load, and stiffness could be demonstrated compared to the bicortical screw fixation of the nonlocking plate. Conclusions. Locking plates in monocortical configuration may function as a useful alternative to the currently common treatment with bicortical fixations. Thereby, irritation of the flexor tendons would be avoided without compromising the stability, thus enabling the necessary early functional rehabilitation. PMID:24757429

  12. Four year experience with the AO Anterior Thoracolumbar Locking Plate

    Microsoft Academic Search

    J S Thalgott; M B Kabins; M Timlin; K Fritts; J M Giuffre

    1997-01-01

    For decades spinal surgeons have attempted to design simple, single stage anterior internal fixation systems for the thoracic and lumbar spine. Early devices presented both biomechanical and technical problems. The AO Anterior Thoracolumbar Locking Plate (ATLP) was designed to solve some of the problems encountered with early anterior instrumentation. The ATLP system is constructed in Commercially Pure titanium. It is

  13. Screw prominences related to palmar locking plating of distal radius

    Microsoft Academic Search

    T. S. Sügün; N. Karabay; Y. Gürbüz; K. Özaksar; T. Toros; M. Kayalar

    2011-01-01

    Fixation of unstable distal radius fractures with palmar locking plates provides a stable reduction and early return of function, but complications arising from unrecognized dorsally prominent screws penetrating the extensor compartments are increasingly reported. Standard radiographs and fluoroscopy may not adequately visualize screw lengths, owing to the complex shape of the dorsum of the distal radius. We examined 46 distal

  14. Functional results and complications of locked distal radius volar plates

    Microsoft Academic Search

    M. R. Sánchez-Crespo; F. del Canto-Álvarez; F. Peñas-Díaz; V. de Diego-Gutiérrez; M. Gutiérrez-Santiago; P. Sánchez-Juan

    2009-01-01

    Introduction and purposeIn the last few years, there has been increased aggressiveness in the treatment of distal radius fractures by means of internal fixation. Locked plates prevent metaphyseal collapse even in the presence of osteoporotic or comminuted bone; they also maintain reduction and allow early motion. Nevertheless, there is as yet not enough evidence as to what may be the

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

    PubMed

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

    2015-06-01

    Impact damping by elastic fixation is a principal engineering strategy to increase the durability of load-bearing structures exposed to prolonged dynamic loading. This biomechanical study evaluated axial impact damping provided by a novel dynamic locking plate. In this design, locking screw holes are elastically suspended within a silicone envelope inside the locking plate. Axial impact damping was assessed for 3 distinct fixation constructs applied to bridge a 10-mm fracture gap of a femoral diaphysis surrogate: a standard locking plate, a dynamic locking plate, and an Ilizarov ring fixator. First, the 3 fixation constructs were characterized by determining their axial stiffness. Subsequently, constructs were subjected to a range of axial impact loads to quantify damping of force transmission. Compared with standard locked plating constructs, dynamic plating constructs were 58% less stiff (P < .01) and Ilizarov constructs were 88% less stiff (P < .01). Impact damping correlated inversely with construct stiffness. Compared with standard plating, dynamic plating constructs and Ilizarov constructs dampened the transmission of impact loads by up to 48% (P < .01) and 74% (P < .01), respectively. In conclusion, lower construct stiffness correlated with superior damping of axial impact loads. Dynamic locking plates provide significantly greater impact damping compared with standard locking plates. PMID:25642697

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

    PubMed

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

    2014-09-01

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

  17. The strength of polyaxial locking interfaces of distal radius plates

    Microsoft Academic Search

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

    2009-01-01

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

  18. Outcome of locking compression plates in humeral shaft nonunions

    PubMed Central

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

    2013-01-01

    Background: Nonunion of diaphyseal fractures of the humerus are frequently seen in clinical practice (incidence of up to 15% in certain studies) and osteosynthesis using dynamic compression plates, intra medullary nails and Ilizarov fixators have been reported previously. Locking compression plates (LCP) are useful in the presence of disuse osteoporosis, segmental bone loss and cortical defects that preclude strong fixation. We report a prospective followup study of the outcome of the use of LCP for humeral nonunion following failed internal fixation in which implants other than LCP had been used. Materials and Methods: Twenty four patients with nonunion of humeral shaft fractures following failed internal fixation were included in the study. The mean followup period was 3.4 years (range: 2.4 to 5.7 years) and the minimum followup period was 2 years. Mean age of the patients was 41.04 years (range: 24 to 57 years). All 24 patients underwent osteosynthesis using LCP and autologous bone grafting (cortico-cancellous iliac crest graft combined with or without fibular strut graft). Main outcome measurements included radiographic assessment of fracture union and pre and postoperative functional evaluation using the modified Constant and Murley scoring system. Results: 23 out of 24 fractures united following osteosynthesis. Average time to union was 16 weeks (range: 10 to 28 weeks). Complications included delayed union (n = 2), transient radial nerve palsy (n = 2) and persistent nonunion (n = 1). Functional evaluation using the Constant and Murley score showed excellent results in 11, good in 10, fair in two and poor outcome in one patient. Conclusions: Locking compression plating and cancellous bone grafting is a reliable option for achieving union in humeral diaphyseal nonunion with failed previous internal fixation and results in good functional outcome in patients with higher physiological demands. PMID:23682176

  19. Efficacy of volar and dorsal plate fixation for unstable dorsal distal radius fractures

    PubMed Central

    Chen, Chang-Hong; Zhou, Rong-Kui; Zhen, Hua-Qing; Huang, Lei; Jiao, Ya-Jun

    2015-01-01

    Objective: To compare the efficacy of volar and dorsal plate fixation for unstable dorsal distal radius fractures. Methods: Forty-seven cases were selected from patients undergoing surgical reduction and internal fixation treatment in our hospital from August 2006 to October 2010, with 21 males and 26 females, aged 39-73 years old. Patients were divided into two groups: volar plate fixation group (Group A) which has 32 cases, including 27 cases with locking plate, 5 cases with ordinary T plate, and 4 cases combined with dorsal Kirschner wire fixation; dorsal plate fixation group (Group B) which has 15 cases, including 7 cases with locking plate. The efficacy of the two fixation methods were compared in terms of postoperative wrist function, X-ray score, and postoperative complications. Results: Compared with those of preoperative groups, the volar tilt, ulnar deviation and radial styloid height in both group A and B were significantly improved one week after surgery as shown by X-ray imaging. Comparison of X-ray images one week after surgery with those of six months after surgery showed no significant changes in volar tilt, ulnar deviation or radial styloid height. 87.5% of patients in group A and 86.7% of patients in group B got “excellent” in their wrist function assessment, and there was no significant difference between the two groups (X2=0.825, P=1.000). But patients in group A hax significantly lower incidence rate of postoperative complications than group B (X2=4.150, P=0.042). Conclusion: For unstable distal radius fractures with dorsal displacement, volar plate fixation can achieve satisfactory reduction results, and cause less tendon damage or other complications than dorsal plate fixation.

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

    PubMed Central

    2012-01-01

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

  1. Medial Column Arthrodesis Using an Anatomic Distal Fibular Locking Plate.

    PubMed

    Nasser, Ellianne M; LaPorta, Guido A; Trott, Kasandra

    2014-07-01

    The medial column fusion is performed for a multitude of etiologies, including peritalar subluxation deformity, Charcot arthropathy, trauma, post-traumatic degenerative joint disease, and rheumatoid arthritis. Various surgical techniques have been described for medial column arthrodesis. We describe a new fixation method using an anatomic distal fibular locking plate for medial column arthrodesis. This technique provides a rigid construct in compromised or at risk bone. After a review of the surgical technique, we outline 2 case examples of patients with peritalar subluxation and Charcot arthropathy. PMID:24998041

  2. Four year experience with the AO Anterior Thoracolumbar Locking Plate.

    PubMed

    Thalgott, J S; Kabins, M B; Timlin, M; Fritts, K; Giuffre, J M

    1997-05-01

    For decades spinal surgeons have attempted to design simple, single stage anterior internal fixation systems for the thoracic and lumbar spine. Early devices presented both biomechanical and technical problems. The AO Anterior Thoracolumbar Locking Plate (ATLP) was designed to solve some of the problems encountered with early anterior instrumentation. The ATLP system is constructed in Commercially Pure titanium. It is a low profile device indicated for use for unstable burst fractures in the anterior column; metastatic tumor management; and degenerative diseases of the thoracolumbar spine between levels T10 and L5. Implantation of the device involves direct anterior decompression with sagittal reduction and corpectomy. This is followed by grafting reconstruction, and plate fixation. This device has been implanted in 25 patients with an average follow-up of 38 months. There were five (5) broken screws in three (3) patients, and no broken plates. Implant related postoperative complications included two misplaced screws. Preliminary results indicate that the ATLP system seems to be a safe, low profile, MRI/CT compatible device that provides definitive single stage fixation of the anterior spinal column. PMID:9160452

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

    Microsoft Academic Search

    RE Anakwe; LAK Khan; RE Cook; JE McEachan

    2010-01-01

    BACKGROUND: Distal radius fractures are common. The increasing prevalence of osteoporosis contributes to frequently complex articular injuries sustained even after low energy falls. The best method of treating complex type C distal radius fractures is debated. Locked volar plating and external fixation are both widely used with good reported results. Measures of success are traditionally based on technical measurements or

  4. Cervical spine locking plate: in vitro biomechanical testing.

    PubMed

    Smith, S A; Lindsey, R W; Doherty, B J; Alexander, J W; Dickson, J H

    1993-03-01

    The AO cervical spine locking plate (CSLP) for anterior subaxial fixation was recently received increasing clinical acclaim, yet to date the in vitro mechanical properties of this implant have not been reported. To determine the in vitro biomechanical properties of this device, five fresh human cadaver cervical spines were subjected to nondestructive testing in flexion and torsion in three stages: stage 1: intact spine; stage 2: destabilized spine; stage 3: destabilized spine with CSLP. Stage 3 specimens were also subjected to large angular displacement testing to assess the integrity of the fixation. In flexion, mean spinous process displacement was 1.21 mm for stage 1, 3.19 mm for stage 2, and 1.37 mm, for stage 3. Mean torsional stiffness was 2.86 Nm/degree in stage 1, 1.82Nm/degree in stage 2, and 2.20Nm/degree in stage 3. Large angular displacement testing in stage 3 resulted in screw loosening from the bone in two specimens; no screw plate loosening occurred. In our severely destabilized in vitro model, the CSLP restored flexion stability but not rotational stability. This suggests that supplemented bracing or fixation may be required to restore torsional stability. PMID:20054921

  5. Comminuted quadrilateral plate fracture fixation through the iliofemoral approach.

    PubMed

    Sen, Ramesh Kumar; Tripathy, Sujit Kumar; Aggarwal, Sameer; Goyal, Tarun; Mahapatra, Santosh Kumar

    2013-02-01

    Comminuted quadrilateral plate fracture with medial displacement is a technically difficult fracture to treat. Minimal bone stock, proximity to the hip joint with limited surgical access, and difficulty in obtaining a stable fixation at this area, contribute to the surgical challenge of open reduction and internal fixation. Fixation of a medial buttress plate in an infrapectineal fashion is a well-described technique to address such fractures. However, this plate alone may be inadequate to buttress all the fragments in a grossly comminuted quadrilateral plate fracture. An additional spring plate is often placed underneath the infrapectineal plate to hold the fracture fragments. Conventionally, these spring plates are fixed to the ilium superiorly while the other end buttresses the quadrilateral plate when placed underneath the infrapectineal reconstruction plate. The standard ilioinguinal approach and modified Stoppa approach have been described for the surgical access to the quadrilateral plate. Both the approaches have some limitations in addressing quadrilateral plate fracture. The ilioinguinal approach requires extensive dissection and mobilisation of inguinal neurovascular bundle. The modified Stoppa approach does not permit visualisation of the entire anterior column and the hip joint. The authors, in this article, describe the fixation of the comminuted quadrilateral plate fracture through the iliofemoral approach combined with a medial ilioinguinal window. The technique involves fixation of a spring plate (Allis T-plate) at right angle to the infrapectineal buttress plate (90°-90° plate construct). The vertical limb of the T-plate is fixed to the iliopectineal eminence whereas the horizontal limb buttresses the quadrilateral plate Hence, this technique addresses fractures of both the iliopectineal eminence and the quadrilateral plate. Other than that, the iliofemoral approach permits direct visualisation of the entire anterior column and the hip joint without the necessity to dissect the ilioinguinal neurovascular structures. PMID:23199759

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

    PubMed

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

    2014-12-01

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

  7. Comparative study of single lateral locked plating versus double plating in type C bicondylar tibial plateau fractures

    PubMed Central

    Neogi, Devdatta Suhas; Trikha, Vivek; Mishra, Kaushal Kant; Bandekar, Shivanand M.; Yadav, Chandra Shekhar

    2015-01-01

    Background: Bicondylar tibial plateau fractures are complex injuries and treatment is challenging. Ideal method is still controversial with risk of unsatisfactory results if not treated properly. Many different techniques of internal and external fixation are used. This study compares the clinical results in single locked plating versus dual plating (DP) using two incision approaches. Our hypothesis was that DP leads to less collapse and change in alignment at final followup compared with single plating. Materials and Methods: 61 cases of Type C tibial plateau fractures operated between January 2007 and June 2011 were included in this prospective study. All cases were operated either by single lateral locked plate by anterolateral approach or double plating through double incision. All cases were followed for a minimum of 24 months radiologically and clinically. The statistical analysis was performed using software SPSS 10.0 to analyze the data. Results: Twenty nine patients in a single lateral locked plate and 32 patients in a double plating group were followed for minimum 2 years. All fractures healed, however there was a significant incidence of malalignment in the single lateral plating group. Though there was a significant increase in soft tissue issues with the double plating group; however, there was only 3.12% incidence of deep infection. There was no significant difference in Hospital for special surgery score at 2 years followup. Conclusion: Double plating through two incisions resulted in a better limb alignment and joint reduction with an acceptable soft tissue complication rate. PMID:26015609

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  11. Effectiveness of external fixator combined with T-plate internal fixation for the treatment of comminuted distal radius fractures.

    PubMed

    Han, L R; Jin, C X; Yan, J; Han, S Z; He, X B; Yang, X F

    2015-01-01

    This study compared the efficacy between external fixator combined with palmar T-plate internal fixation and simple plate internal fixation for the treatment of comminuted distal radius fractures. A total of 61 patients classified as type C according to the AO/ASIF classification underwent surgery for comminuted distal radius fractures. There were 54 and 7 cases of closed and open fractures, respectively. Moreover, 19 patients received an external fixator combined with T-plate internal fixation, and 42 received simple plate internal fixation. All patients were treated successfully during 12-month postoperative follow-up. The follow-up results show that the palmar flexion and dorsiflexion of the wrist, radial height, and palmar angle were significantly better in those treated with the external fixator combined with T-plate compared to those treated with the simple plate only (P < 0.05); however, there were no significant differences in radial-ulnar deviation, wrist range of motion, or wrist function score between groups (P > 0.05). Hence, the effectiveness of external fixator combined with T-plate internal fixation for the treatment of comminuted distal radius fractures was satisfactory. Patients sufficiently recovered wrist, forearm, and hand function. In conclusion, compared to the simple T-plate, the external fixator combined with T-plate internal fixation can reduce the possibility of the postoperative re-shifting of broken bones and keep the distraction of fractures to maintain radial height and prevent radial shortening. PMID:25867441

  12. Minimally invasive plate fixation of the tibia

    PubMed Central

    Coulter, Gareth; Pai, Vishal

    2006-01-01

    The treatment of fractures of the distal third of the tibia has evolved with the development of improved imaging and surgical techniques. The outcome of treatment using conventional fixation is poor. We report a study on indirect reduction in 26 patients. All cases achieved radiological union and full weight bearing. The good to excellent results suggest that this method should be considered in metaphyseal fractures where intra-medullary nails are not suitable. PMID:16960719

  13. A novel fixation system for acetabular quadrilateral plate fracture: a comparative biomechanical study.

    PubMed

    Zha, Guo-Chun; Sun, Jun-Ying; Dong, Sheng-Jie; Zhang, Wen; Luo, Zong-Ping

    2015-01-01

    This study aims to assess the biomechanical properties of a novel fixation system (named AFRIF) and to compare it with other five different fixation techniques for quadrilateral plate fractures. This in vitro biomechanical experiment has shown that the multidirectional titanium fixation (MTF) and pelvic brim long screws fixation (PBSF) provided the strongest fixation for quadrilateral plate fracture; the better biomechanical performance of the AFRIF compared with the T-shaped plate fixation (TPF), L-shaped plate fixation (LPF), and H-shaped plate fixation (HPF); AFRIF gives reasonable stability of treatment for quadrilateral plate fracture and may offer a better solution for comminuted quadrilateral plate fractures or free floating medial wall fracture and be reliable in preventing protrusion of femoral head. PMID:25802849

  14. Treatment of femoral subtrochanteric fractures with proximal lateral femur locking plates

    PubMed Central

    Hu, Sun-jun; Zhang, Shi-min; Yu, Guang-rong

    2012-01-01

    OBJECTIVE: To study the outcome of subtrochanteric hip fractures treated with proximal lateral femur locking plate. METHOD: We retrospectively reviewed the clinical results of 48 cases of femoral subtrochanteric fractures treated with proximal lateral femur locking plates from January 2008 to May 2010. The progress of fracture healing, as well as the occurrence of complications, was recorded. The function of the hip joint was evaluated by the Harris social index and the Parker and Palmer mobility score one year after the operation. RESULT: 45 patients were followed up until fracture union or a revision surgery. Among the 45 patients, 43 patients obtained fracture union without further intervention. Thirty-eight fractures healed with no loss of position at 1-year follow-up. There were no cases of hip screw cutting through the femoral head. The mean score of the Harris social index was 86.5±9.8 (73~95). The mean Parker and Palmer mobility score was 7.4±2.1 (3~9). CONCLUSION: The proximal lateral femur locking plate is the kind of stable and effective internal fixation for treating subtrochanteric hip fractures which has the advantage of stable fixation especially for the lateral femoral wall fracture. Level of Evidence IV, Case Series. PMID:24453626

  15. Plate fixation adds stability to two-level anterior fusion in the cervical spine: a randomized study using radiostereometry.

    PubMed

    Zoëga, B; Kärrholm, J; Lind, B

    1998-01-01

    This study evaluated whether addition of a cervical spine locking plate (CSLP) in two-level disc fusions improved the postoperative stability and reduced the time to healing. Radiostereometric analysis was used to obtain precise recordings of the three-dimensional motion between the fused vertebrae. Eighteen consecutive patients were operated on with excision of two adjacent cervical discs and anterior horseshoe grafting with autologous bone (Smith Robinson technique). Nine patients were randomized to stabilization with autologous bone grafting and CSLP plate fixation and nine patients to grafting without fixation. Clinical symptoms in terms of pain in the neck and the arm were analysed preoperatively and after 1 year using a visual analogue scale (VAS). The patients operated without a plate displayed increased rotations around the transverse axis, corresponding to the development of a kyphosis [mean value no plate/plate 14.4 degrees/0.8 degrees (repeated measure ANOVA: P < 0.01)]. The mean compression was 3.2 mm larger in patients operated without a plate (repeated measure ANOVA: P < 0.01). Patients operated without a plate had more arm pain at the 1-year follow up (P < 0.05, Mann-Whitney U test). The VAS score for neck pain did not differ significantly between the two groups. Plate fixation could not be demonstrated to increase the healing rate, promote more rapid fusion or influence the frequency of graft complications. PMID:9765038

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

    PubMed

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

    2015-01-01

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

  17. Surgical treatment of unstable distal radius fractures with volar locking plates

    Microsoft Academic Search

    Kenichi Murakami; Yoshihiro Abe; Kazuhisa Takahashi

    2007-01-01

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

  18. Use of cylindrical titanium mesh and locking plates in anterior cervical fusion. Technical note.

    PubMed

    Das, K; Couldwell, W T; Sava, G; Taddonio, R F

    2001-01-01

    After performing anterior cervical corpectomy or discectomy for cervical spondolytic myelopathy or radiculopathy, iliac crest bone graft and fibular auto- or allograft is often used to achieve arthrodesis in the cervical spine. The purpose of this study was to evaluate the use of a cylindrical titanium mesh and locking plate system as an alternative technique in achieving anterior cervical fusion and maintaining lordosis. Hospital records and radiographs of 38 patients who underwent anterior cervical discectomies (28 patients) or corpectomies (10 patients) from 1995 to 1997 were reviewed retrospectively. All patients had undergone arthrodesis in which autograft and a cylindrical titanium mesh and anterior locking plate fixation were used after discectomy or corpectomy. There were 20 men and 18 women (mean age 46.1 years; range 34-72 years). Presenting symptoms included radiculopathy (61%), myelopathy (37%), and neck pain (2%). Preoperative and postoperative radiographs were studied, and data were obtained on the following: overall lordosis or kyphosis of the cervical spine, segmental lordosis or kyphosis at each surgically treated level, and evidence of fusion. In all of the patients in whom lordosis was present preoperatively, lordosis was maintained during the follow-up period. The overall fusion rate was 100%. The average change in overall lordosis or kyphosis related to the fixation devices was 1.2 degrees (range 1-5 degrees) the average segmental change was 2.3 degrees (range 0-5 degrees); and the mean follow up was 16 months (range 12-36 months). Anterior cervical fusion with cylindrical titanium mesh and cervical locking plate system is an effective method of achieving arthrodesis and maintaining alignment in the cervical spine. The construct may provide additional load-sharing function, and it avoids the use of cadaveric bone or the need for harvesting tricortical iliac crest autograft. PMID:11147858

  19. Volar Fixed-Angle Fixation of Distal Radius Fractures: The DVR Plate

    Microsoft Academic Search

    Jorge Orbay; Alejandro Badia; Roger K. Khoury; Eduardo Gonzalez; Igor Indriago

    2004-01-01

    Volar fixed-angle fixation of distal radius fractures is a new method of treatment that provides the benefits of stable internal fixation without incurring the disadvan- tages of the dorsal approach. The DVR plate is a new fixation implant that was introduced specifically for the purpose of managing both dorsal and volar displaced fractures from the volar aspect. Experience gained ap-

  20. Outcomes of Pin and Plaster Versus Locking Plate in Distal Radius Intraarticular Fractures

    PubMed Central

    Bahari-Kashani, Mahmoud; Taraz-Jamshidy, Mohammad Hosein; Rahimi, Hassan; Ashraf, Hami; Mirkazemy, Masoud; Fatehi, Amirreza; Asadian, Mariam; Rezazade, Jafar

    2013-01-01

    Background Distal radius fractures are among the most prevalent fractures predictive of probable occurrence of other osteoporotic fractures. They are treated via a variety of methods, but the best treatment has not been defined yet. Objectives This study was performed to compare the results of open reduction and internal fixation with locking plates versus the pin and plaster method. Materials and Methods In this prospective study, 114 patients aged 40 to 60 years with Fernandez type III fracture referring to Imam-Reza and Mehr hospitals of Mashhad from 2009 to 2011, were selected randomly; after obtaining informed consent, they were treated with pin and plaster fixation (n = 57) or internal fixation with the volar locking plate (n = 57). They were compared at the one year follow up. Demographic features and standard radiographic indices were recorded and MAYO, DASH and SF - 36 tests were performed. Data was analyzed by SPSS software version 13, with descriptive indices, Mann-Whitney and Chi-square tests. Results SF-36 test demonstrated a better general health (P < 0.001), mental health (P = 0.006), physical functioning (P < 0.001), social functioning (P < 0.001) and energy/fatigue (P < 0.001) in LCP group. However, pain (P = 0.647) was not significantly different between the groups. Physical limitation (P < 0.001) and emotional limitation (P < 0.001) were greater in the pin and plaster group. Also, in the LCP group mean MAYO score (P < 0.001) was more than pin and plaster group. Mean DASH score was not different between the groups (P = 0.218). The rate of acceptable results of radiographic indices (P < 0.001), grip strength (P < 0.001) and range of motion in supination-pronation (P < 0.001) in LCP method were better than the pin and plaster method. Conclusions In treatment of intra-articular distal radius fractures in middle-aged patients internal fixation with locking plates may be prefered to pin and plaster as the treatment of choice. PMID:24350132

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

    PubMed Central

    2013-01-01

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

  2. Biomechanical evaluation of Caspar and Cervical Spine Locking Plate systems in a cadaveric model.

    PubMed

    Clausen, J D; Ryken, T C; Traynelis, V C; Sawin, P D; Dexter, F; Goel, V K

    1996-06-01

    There exist two markedly different instrumentation systems for the anterior cervical spine: the Cervical Spine Locking Plate (CSLP) system, which uses unicortical screws with a locking hub mechanism for attachment, and the Caspar Trapezial Plate System, which is secured with unlocked bicortical screws. The biomechanical stability of these two systems was evaluated in a cadaveric model of complete C5-6 instability. The immediate stability was determined in six loading modalities: flexion, extension, right and left lateral bending, and right and left axial rotation. Biomechanical stability was reassessed following fatigue with 5000 cycles of flexion-extension, and finally, the spines were loaded in flexion until the instrumentation failed. The Caspar system stabilized significantly in flexion before (p < 0.05) but not after fatigue, and it stabilized significantly in extension before (p < 0.01) and after fatigue (p < 0.01). The CSLP system stabilized significantly in flexion before (p < 0.01) but not after fatigue, and it did not stabilize in extension before or after fatigue. The moment needed to produce failure in flexion did not differ substantially between the two plating systems. The discrepancy in the biomechanical stability of these two systems may be due to differences in bone screw fixation. PMID:8847569

  3. Biomechanics of Far Cortical Locking

    PubMed Central

    Bottlang, Michael; Feist, Florian

    2011-01-01

    The development of FCL was motivated by a conundrum: locked plating constructs provide inherently rigid stabilization, yet they should facilitate biological fixation and secondary bone healing that relies on flexible fixation to stimulate callus formation. Recent studies have confirmed that the high stiffness of standard locked plating constructs can suppress interfragmentary motion to a level that is insufficient to reliably promote secondary fracture healing by callus formation. Furthermore, rigid locking screws cause an uneven stress distribution that may lead to stress fracture at the end screw and stress shielding under the plate. This review summarizes four key features of FCL constructs that have shown to enhance fixation and fracture healing: Flexible fixation, load distribution, progressive stiffening, and parallel interfragmentary motion. Specifically, flexible fixation provided by FCL reduces the stiffness of a locked plating construct by 80–88% to actively promote callus proliferation similar to an external fixator. Load distribution is evenly shared between FCL screws to mitigate stress risers at the end screw. Progressive stiffening occurs by near cortex support of FCL screws and provides additional support under elevated loading. Finally, parallel interfragmentary motion by s-shaped flexion of FCL screws has shown to induce symmetric callus formation. In combination, these features of FCL constructs have shown to induce more callus and to yield significantly stronger and more consistent healing compared to standard locked plating constructs. As such, FCL constructs function as true internal fixators by replicating the biomechanical behavior and biological healing response of external fixators. PMID:21248556

  4. [Initial clinical experiences with the cervical spine titanium locking plate].

    PubMed

    Arnold, W

    1990-12-01

    The titanium CS (cervical spine) locking plate is a system that takes account not only of biochemical aspects, in the choice of material, but also new biomechanical aspects. With the help of a new hollow screwing system, such stability is achieved that in many cases there is no need for a second, dorsal, operation. Ten patients, most of whom had unstable fractures, have so far been treated. No complications attributable to this implantation system were observed. A further step in the attainment of security and stability by operative treatment of cervical spine disorders has been achieved with this system. PMID:2281326

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

    PubMed

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

    2013-09-01

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

  6. Combined Effect of a Locking Plate and Teriparatide for Incomplete Atypical Femoral Fracture: Two Case Reports of Curved Femurs

    PubMed Central

    Tsuchie, Hiroyuki; Miyakoshi, Naohisa; Nishi, Tomio; Abe, Hidekazu; Segawa, Toyohito; Shimada, Yoichi

    2015-01-01

    In surgical treatment for atypical femoral fractures (AFFs), reconstruction nail fixation is recommended for both complete and incomplete fractures. Although it has been reported that AFF is affected by many factors, The ASBMR Task Force 2013 Revised Case Definition of AFFs states that a curved femur is often seen in Asian patients. It is sometimes difficult to insert a nail into a femur in incomplete AFF patients with severely curved femurs. We report two incomplete bisphosphonate-related AFF patients with marked femoral curvatures treated by locking plates and teriparatide, showing early bone unions and favorable long-term outcomes. PMID:26101679

  7. Bone ingrowth and stress shielding with a porous surface coated fracture fixation plate.

    PubMed

    Pilliar, R M; Cameron, H U; Binnington, A G; Szivek, J; Macnab, I

    1979-09-01

    The extent of bone remodelling under metal fixation plates attached to bone by (i) normal screw fixation and (ii) bone ingrowth into a porous metallic surface underlayer sintered to the metal plate was investigated. Extensive bone remodelling was observed under the integrally bonded porous surface layered plate. This remodelling could be attributed to the more extensive stress transfer from bone to metal plate because of the good bone-to-implant bonding. The importance of stress shielding with high stiffness implants is demonstrated. PMID:383716

  8. Design and experimental evaluation of adjustable bone plates for mandibular fracture fixation.

    PubMed

    Cervantes, Thomas M; Slocum, Alexander H; Seldin, Edward B

    2012-01-01

    Conventional bone plates are commonly used for surgical mandibular fracture fixation. Improper alignment between bone segments, however, can result in malocclusion. Current methods of fixation require a surgeon to visually align segments of bone and affix a metal plate using bone screws, after which little can be done to adjust alignment. A method of adjusting fracture alignment after plate placement, without screw removal, presents an improvement over costly and risky revision surgery. A modified bone plate has been designed with a deformable section to give surgeons the ability to reduce misalignments at the fracture site. The mechanics of deformation for various adjustment mechanisms was explored analytically, numerically, and experimentally to ensure that the adjustable plate is comparable to conventional bone plates. A static force of 358.8 N is required to deform the adjustable bone plate, compared with predicted values of 351 N using numerical simulation and 362 N using a simple beam theory. Dynamic testing was performed to simulate in vivo loading conditions and evaluate load-capacity in both deformed and un-deformed bone plates. Results indicate that bending stiffness of a rectangular bone plate is 709 N/mm, compared with 174 N/mm for an octagonal plate and 176 N/mm for standard plates. Once deformed, the rectangular and octagonal plates had a stiffness of 323 N/mm and 228 N/mm, respectively. Un-deformed and deformed adjustable bone plates have efficacy in bone segment fixation and healing. PMID:22036033

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

    PubMed

    Choi, Sungwook; Kang, Hyunseong; Bang, Hyeongsig

    2014-08-01

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

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

    Microsoft Academic Search

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

    2003-01-01

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

  11. Dynamic locking plates provide symmetric axial dynamization to stimulate fracture healing.

    PubMed

    Tsai, Stanley; Fitzpatrick, Daniel C; Madey, Steven M; Bottlang, Michael

    2015-08-01

    Axial dynamization of an osteosynthesis construct can promote fracture healing. This biomechanical study evaluated a novel dynamic locking plate that derives symmetric axial dynamization by elastic suspension of locking holes within the plate. Standard locked and dynamic plating constructs were tested in a diaphyseal bridge-plating model of the femoral diaphysis to determine the amount and symmetry of interfragmentary motion under axial loading, and to assess construct stiffness under axial loading, torsion, and bending. Subsequently, constructs were loaded until failure to determine construct strength and failure modes. Finally, strength tests were repeated in osteoporotic bone surrogates. One body-weight axial loading of standard locked constructs produced asymmetric interfragmentary motion that was over three times smaller at the near cortex (0.1?±?0.01?mm) than at the far cortex (0.32?±?0.02?mm). Compared to standard locked constructs, dynamic plating constructs enhanced motion by 0.32?mm at the near cortex and by 0.33?mm at the far cortex and yielded a 77% lower axial stiffness (p?plating constructs were at least as strong as standard locked constructs under all test conditions. In conclusion, dynamic locking plates symmetrically enhance interfragmentary motion, deliver controlled axial dynamization, and are at least comparable in strength to standard locked constructs. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1218-1225, 2015. PMID:25721801

  12. Unstable diaphyseal fractures of both bones of the forearm in children: plate fixation versus intramedullary nailing.

    PubMed

    Fernandez, F F; Egenolf, M; Carsten, C; Holz, F; Schneider, S; Wentzensen, A

    2005-10-01

    This retrospective study evaluated the results of plating versus intramedullary fixation in the management of unstable, diaphyseal fractures of both bones of the forearm in children. Of the 64 children included, 45 were treated with intramedullary fixation, 19 with plating. Only A3 forearm fractures of the middle third or the transition zones were included; Galeazzi, Monteggia, and Greenstick fractures were excluded. Full radiological follow-up to union was obtained in all cases and 60 patients returned for clinical evaluation 32.3 months (plating) and 20.6 months (intramedullary fixation) after injury. The functional outcome did not differ significantly. In the intramedullary fixation group, we found two major complications (refracture and non-union) and nine minor complications (two delayed unions, three thumb neuropathies, two rod migrations, two skin infections). In the plate group, there were two major complications (refractures) and one minor complication (thumb neuropathy). Plating resulted in significantly worse results for surgical approach, operating times, frequency and duration of hospitalisation, and cosmetic outcome. In conclusion, intramedullary fixation of an unstable forearm fracture in skeletally immature patients is a safe, child-friendly, minimally invasive technique that allows early functional treatment with an excellent functional and cosmetic outcome. PMID:16122742

  13. Evaluation of functional outcome and complications of locking calcaneum plate for fracture calcaneum

    PubMed Central

    Kumar, Surender; Krishna, Loveneesh G.; Singh, Davinder; Kumar, Pawan; Arora, Sumit; Dhaka, Sunil

    2015-01-01

    Background Open reduction and internal fixation (ORIF) is the treatment of choice for displaced intra-articular calcaneal fracture at many orthopaedic trauma centres. In this prospective study, we evaluated the functional outcome and complications of locking compressive calcaneum plate for displaced intra-articular fracture calcaneum. Methods Between October 2011 and March 2012, 30 patients with displaced intra-articular fracture calcaneum attending the outdoor and emergency of our institute were included in the study. All the included patients were operated using standard lateral approach and followed up to 1 year. Results Of 30 patients, 14 (48%) patients were Sander's type II, 10 (33%) were type III, and 6 (20%) were type IV. All the patients were evaluated post-operatively. Articular surface of posterior facet of calcaneum and crucial angle of Gissane was maintained in all patients. Four patients had post-operative Boehler's angle <20° and 26 patients had between 21° and 40°. All the patients having post-operative Boehler's angle <20° were type IV as compared to types II and III (statistically significant). Ninety-six percentage of patients having post-operative Boehler's angle 21–40° were more satisfied at 1 year as compared to 25% of patients having post-operative Boehler's angle <20° (statistically significant). Complications were present in 6 (20%) patients. Conclusion ORIF with locking compressive plate in displaced intra-articular fracture calcaneum gives good outcome. Results are more favourable in less comminuted as compared to more comminuted. Maintenance of Boehler's angle is also necessary for satisfactory results along with maintenance of articular congruence of posterior facet of calcaneum and crucial angle of Gissane. PMID:26155049

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

    NASA Astrophysics Data System (ADS)

    Warren, Paul B.

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

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

    E-print Network

    Ray, Donald Reagan

    1970-01-01

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

  16. Biomechanics of Fixation of Distal Radius Fractures: Comparison between Volar Plate Fixator (VPF) and NonBridging External Fixator (NBX)

    Microsoft Academic Search

    Takahiro Sano

    2008-01-01

    Fracture of the distal radius is one of the most frequent injuries, and it represents about 20% of all adults taken into emergency rooms. A number of studies suggest various methods to reduce the dislocation and to secure fragments of the distal radius. In this study, the Non-Bridging External Wrist Fixator System (NBX), a pre-market-released product manufactured by NUTEK Inc.

  17. Double-loop locking cross-stitch suture and suspension fixation for medial collateral ligament origin reconstruction.

    PubMed

    Li, C J; Wang, B C; Liu, D Q

    2014-01-01

    The purpose of this study was to summarize the clinical application and results of the double-loop locking cross-stitch suture and suspension fixation method for medial collateral ligament origin reconstruction. Thirty-six patients (21 males, 15 females) with an average age of 40 years (range = 17-58 years), who underwent treatment for acute fracture of the medial collateral ligament at our hospital from February 2008 to May 2009, were included in this study. All patients presented unilateral injuries (17 right-sided, 19 left-sided) and underwent repair with the double-loop locking cross-stitch suture and suspension fixation method. All incisions in this group of patients healed by first intention. Thirty-two patients were followed up for 6-20 months (average = 12 months). There were no reports of wound infection, ligament re-fracture or other complications in the follow-up period. Based on the Lysholm knee-scoring scale, the patients received a 100% excellent and good rating (20 patients - excellent score, 12 patients - good score) postoperatively. The advantages of the double-loop locking cross-stitch suture and suspension fixation method are a smaller incision, reliable fixation, and early restoration of knee joint stability. It is, therefore, an effective and low-risk method for the reconstruction of medial collateral ligament origin. PMID:25078597

  18. Flexor tendon repair after rupture caused by volar plate fixation of the distal radius.

    PubMed

    Rubensson, Carin C; Ydreborg, Karin; Boren, Linda; Karlander, Lars-Erik

    2015-04-01

    Volar plate fixation of unstable fractures of the distal radius is preferred by a majority of surgeons today. One known complication is the rupture of flexor tendons. The aim of this paper is to present flexor tendon ruptures after volar plate fixation analysing the clinical outcome after tendon surgery, aetiology, and methods of prevention. Seventeen consecutive ruptures in 14 patients were included. The incidence was 1.4%. Three patients declined tendon surgery. Eleven patients were treated with a free tendon graft. Only two patients showed excellent results regarding mobility in the thumb and/or fingers. Analysis of radiographs demonstrated sub-optimal placement of plate or screws in all cases. Rupture of a flexor tendon is a serious complication where the functional outcome after surgical reconstruction is uncertain. Early removal of the plate when the placement is sub-optimal or when local volar tenderness appears would probably prevent many ruptures. PMID:25162925

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

    PubMed Central

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

    2010-01-01

    To investigate the effects of scattered radiation when a thin titanium plate (thickness, 0.05 cm) used for skull fixation in cerebral nerve surgery is irradiated by a 4-MV photon beam. We investigated the dose distribution of radiation inside a phantom that simulates a human head fitted with a thin titanium plate used for post-surgery skull fixation and compared the distribution data measured using detectors, obtained by Monte Carlo (MC) simulations, and calculated using a radiation treatment planning system (TPS). Simulations were shown to accurately represent measured values. The effects of scattered radiation produced by high-Z materials such as titanium are not sufficiently considered currently in TPS dose calculations. Our comparisons show that the dose distribution is affected by scattered radiation around a thin high-Z material. The depth dose is measured and calculated along the central beam axis inside a water phantom with thin titanium plates at various depths. The maximum relative differences between simulation and TPS results on the entrance and exit sides of the plate were 23.1% and – 12.7%, respectively. However, the depth doses do not change in regions deeper than the plate in water. Although titanium is a high-Z material, if the titanium plate used for skull fixation in cerebral nerve surgery is thin, there is a slight change in the dose distribution in regions away from the plate. In addition, we investigated the effects of variation of photon energies, sizes of radiation field and thickness of the plate. When the target to be irradiated is far from the thin titanium plate, the dose differs little from what it would be in the absence of a plate, though the dose escalation existed in front of the metal plate. PMID:20589117

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

    PubMed

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

    2014-01-01

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

  1. Displaced avulsion fractures of the posterior cruciate ligament: Treated by stellate steel plate fixation

    PubMed Central

    Li, Lijun; Tian, Wei

    2015-01-01

    Background: The open reduction with internal fixation is an effective approach for treatment of avulsion fracture of posterior cruciate ligament. The previously used internal fixation materials including hollow screws, absorbable screw, tension bands and sutures have great defects such as insufficient fixation strength, susceptibility to re-fracture, etc. Stellate steel plate is novel material for internal fixation which has unique gear-like structure design. We used stellate steel plate for treatment of displaced avulsion fractures of posterior cruciate ligament in this study. Materials and Methods: 14 patients (9 men, 5 women; aged, 19–35 years; mean age, 28 years) with displaced avulsion fractures of the tibial insertion of the posterior cruciate ligament were retrospectively analyzed between June 2009 and June 2011. The mean duration from injury to the operation was 8.3 days (range 6–15 days). All the patients were treated with open reduction and internal fixation of a stellate steel plate (DePuy, Raynham, MA 02767, USA). The Lysholm-Tegner knee function score criteria were used to analyze results. Results: The mean followup was 24.6 months (range 18–32 months). After 6 months, all the fractures healed and knee joint activity was normal, with no knee stiffness or instability. The Lysholm-Tegner scores were 97.1 ± 1.7 points at the final followup. Conclusion: Owing to its unique gear structure, the stellate steel plate design can effectively fix an avulsion fracture block and it is a simple operation with short postoperative rehabilitation time and firm fixation. PMID:26015605

  2. Subclavian artery injury secondary to clavicular plate fixation: a novel operative approach

    PubMed Central

    Perera, Kalpa G.; Clifford, Celia; Maddock, Lachlan

    2015-01-01

    We present the case of a 32-year-old male with a delayed symptomatic left subclavian artery pseudoaneurysm secondary to protruding screws from prior perpendicular clavicular plate fixations. The pseudoaneurysm development and our operative approach are unique to the few similar cases available in the literature. The patient presented with a progressive pulsatile mass behind his left clavicle associated with paraesthesia. Angiography demonstrated a subclavian pseudoaneurysm adjacent to a prominent fixation screw. Offending screws were removed and the pseudoaneurysm was repaired using a reversed greater saphenous vein graft. This case illustrates an unusual aetiology for pseudoaneurysm development and highlights a successful operative intervention. PMID:25877827

  3. Clinical application of a new plate fixation system in open-door laminoplasty.

    PubMed

    Jiang, Liangjun; Chen, Weishan; Chen, Qixin; Xu, Kan; Wu, Qionghua; Li, Fangcai

    2012-02-01

    The purpose of this retrospective clinical series was to evaluate the benefits and complications of plate fixation for open-door laminoplasty in cervical spondylotic myelopathy with multilevel spinal stenosis compared with open-door laminoplasty without fixation. Forty-nine patients underwent open-door laminoplasty for cervical myelopathy with multilevel spinal stenosis with at least 13 months of follow-up. A plate was used as the sole method of fixation between the lateral mass and lamina with 3 screws. Computed tomography scans obtained pre- and postoperatively were assessed for plate complications and spinal canal enlargement. Pre- and postoperative neurological condition was assessed by the Japanese Orthopedic Association (JOA) myelopathy score. Overall cervical spine range of motion (ROM) was measured in full flexion and extension radiographs pre- and postoperatively. No restenosis due to door reclosure was noted, and no plates failed. No screws were backed out or broken. Almost all patients showed neurological improvement. The JOA score increased by 3.9±0.7 points in the suture group and 4.3±0.8 points in the plate group (P>.05). The postoperative increase in mean anteroposterior diameter of the spinal canal from C3 to C7 was 4.5±0.6 mm in the suture group and 5.1±0.5 mm in the plate group. The greater mean anteroposterior diameter increase in the plate group was statistically significant (P<.01). The mean cervical ROM decreased in the plate and suture groups postoperatively (P<.001). No significant difference was found in mean cervical ROM reduction between the groups (P>.05). No difference in axial symptoms was found between the 2 groups. PMID:22310411

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

    PubMed

    Illukka, E; Boudrieau, R J

    2014-01-01

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

  5. Microsurgical anterior decompression and internal fixation with iliac bone graft and titanium plates for treatment of cervical intervertebral disc herniation

    Microsoft Academic Search

    M. Miihlbauer; W. Saringer; M. Aichholzer; M. Sunder-Plassmann

    1995-01-01

    Summary 42 cervical interbody fusions with iliac bone graft and titanium plate fixation were performed between October 1991 and March 1994. The mean follow up period in this study was 10.7 months. In 32 cases fusion was done for 1 and in 10 cases for 2 segments. 2 different types of plates were used. In 25 cases micro-osteosynthesis plates and

  6. Use of self-tapping metal screws for temporary fixation of a resorbable plate system in maxillofacial surgery.

    PubMed

    Iwai, Toshinori; Omura, Susumu; Aoki, Noriaki; Tohnai, Iwai

    2015-05-01

    Resorbable plate systems have been used in maxillofacial surgery to obviate the need for plate removal. However, resorbable plates and screws are very costly, and refixation with additional screws may be necessary when reduction or repositioning of the bone segment is inaccurate. Here we report the use of self-tapping metal screws for temporary fixation of a resorbable plating system in maxillofacial surgery to avoid the use of additional screws following inaccurate fixation or the reuse of resorbable screws, which may result in loosening. PMID:25974798

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

    Microsoft Academic Search

    Brett Peterson; Varun Gajendran; Robert M. Szabo

    2008-01-01

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

  8. Geometric nonlinear analysis by using refined triangular thin plate element and free form membrane locking

    Microsoft Academic Search

    Zhu Jufen; Chen Wanji

    1997-01-01

    Based on a large deformation variational principle with relaxed interelement continuity requirement in the total Lagranginan description, a refined triangular thin plate element for geometric nonlinear analysis has been developed. By introducing special element displacement functions into the geometric stiffness matrix, the membrane locking phenomenon is relieved effectively. The numerical results are presented to show that the present element possesses

  9. Comparing the effect of volar plate fixators and external fixators on outcome of patients with intra-articular distal radius fractures: A clinical trial

    PubMed Central

    Safdari, Mohammadreza; Koohestani, Mahmoodreza Mohajer

    2015-01-01

    Background: Distal radius fractures (DRFs) are much more prone to malunion than unstable extra-articular fractures. There is no clear consensus concerning what the proper treatment should be, and the best approach to use for displaced DRFs remains challenging. Objective: To compare the effect of two different therapeutic surgical methods, i.e., volar plate fixators and external fixators, on outcomes of patients with intra-articular distal radius fractures. Methods: From May 2010 to November 2014, 76 subjects who had experienced intra-articular fractures of the distal radius were enrolled in this double-blind, randomized, controlled trial in Imam Ali Hospital in Bojnourd, Iran. The patients were divided into two groups, i.e., 1) patients who were treated with internal fixation using the volar plate (group A) and 2) patients who were treated with external fixators (group B). The primary outcome was a composite measure of the patient’s quality of life using three different scores, i.e., 1) the MAYO score, 2) Disabilities of the Arm, Shoulder, and Hand (DASH (score, and 3) the Short Form (36) (SF-36) Health Survey score. Results: A total of 76 patients were allocated randomly to groups A and B. The mean ages for external fixator cases and volar plate cases were 51.7 and 46.3, respectively. No significant age distribution was seen between the two groups (p=0.348). Gender distribution between the two groups was not significantly different (p=0.022). Grip power was significantly different between the two groups, but no significant differences were detected in range of motion (p=0.008, p=0.367, respectively). The MAYO score was significantly higher in the open reduction and internal fixation (ORIF) group, and, according to the SF-36 test, the ORIF group also a higher level of general mental and physical health, social functioning, and personal physical functioning than the other group. However, postoperatively, the mental discomfort and physical discomfort were more prevalent in the external fixator group. The DASH score was not significantly different between the two groups (p=0.124). Conclusions: ORIF and its subtitle, volar plate fixation, is a more preferred surgical procedure than the external fixator for the treatment of intra-articular distal radius fractures. This conclusion is important when one considers cost-effectiveness and an earlier return to work. Trial registration: The trial is registered at the Thai Clinical Trial Registry (clinicaltrials.in.th) with the TCR identification number TCTR20150609002 Funding: The authors received no financial support for the research, authorship, and/or publication of this article.

  10. Comparison of Results between Hook Plate Fixation and Ligament Reconstruction for Acute Unstable Acromioclavicular Joint Dislocation

    PubMed Central

    Yoon, Jong Pil; Lee, Byoung-Joo; Nam, Sang Jin; Chung, Seok Won; Jeong, Won-Ju; Min, Woo-Kie

    2015-01-01

    Background In the present study, we aimed to compare clinical and radiographic outcomes between hook plate fixation and coracoclavicular (CC) ligament reconstruction for the treatment of acute unstable acromioclavicular (AC) joint dislocation. Methods Forty-two patients who underwent surgery for an unstable acute dislocation of the AC joint were included. We divided them into two groups according to the treatment modality: internal fixation with a hook plate (group I, 24 cases) or CC ligament reconstruction (group II, 18 cases). We evaluated the clinical outcomes using a visual analog scale (VAS) for pain and Constant-Murley score, and assessed the radiographic outcomes based on the reduction and loss of CC distance on preoperative, postoperative, and final follow-up plain radiographs. Results The mean VAS scores at the final follow-up were 1.6 ± 1.5 and 1.3 ± 1.3 in groups I and II, respectively, which were not significantly different. The mean Constant-Murley scores were 90.2 ± 9.9 and 89.2 ± 3.5 in groups I and II, respectively, which were also not significantly different. The AC joints were well reduced in both groups, whereas CC distance improved from a mean of 215.7% ± 50.9% preoperatively to 106.1% ± 10.2% at the final follow-up in group I, and from 239.9% ± 59.2% preoperatively to 133.6% ± 36.7% at the final follow-up in group II. The improvement in group I was significantly superior to that in group II (p < 0.001). Furthermore, subluxation was not observed in any case in group I, but was noted in six cases (33%) in group II. Erosions of the acromion undersurface were observed in 9 cases in group I. Conclusions In cases of acute unstable AC joint dislocation, hook plate fixation and CC ligament reconstruction yield comparable satisfactory clinical outcomes. However, radiographic outcomes based on the maintenance of reduction indicate that hook plate fixation is a better treatment option. PMID:25729525

  11. Ulnar styloid fracture in distal radius fractures managed with volar locking plates: to fix or not?

    PubMed

    Gogna, Paritosh; Selhi, Harpal Singh; Mohindra, Mukul; Singla, Rohit; Thora, Ankit; Yamin, Mohammad

    2014-12-01

    Distal radius fracture is usually associated with ulnar styloid fracture. Whether to fix the ulnar styloid or not remains a surgical dilemma as some surgeons believe that their repair is imperative while others feel that they should be managed conservatively. This prospective study involved 47 patients with unilateral fracture of the distal radius who met the inclusion criterion and underwent open reduction and internal fixation with volar locking plates; 28 patients (12 males and females?=?16) had an associated ulnar styloid fracture (Group A) while 19 (7 males; 12 females) did not have any ulnar styloid fracture (Group B). At the time of final evaluation both the groups were compared clinically by measuring the grip strength and range of motion around the wrist and the radiologically by measuring radial angle, radial length, volar angle and ulnar variance. Subjective assessment was done using DASH score and final assessment using Demerit point system of Saito. In Group A, average time for consolidation was 9.4 weeks, 17 patients developed non-union of the ulnar styloid, average DASH scores was 4.4 and according to Demerit point system of Saito, there were 78.5 % excellent, 17.9 % good and 3.6 % fair results; there were 2 cases of loss of reduction out of which one had persistent ulnar sided wrist pain. In Group B the average time for consolidation was 10.2 weeks, average DASH score was 3.8.and Demerit point system of Saito yielded 78.9 % excellent, 15.8 % good and 5.3 % fair results. There was one case of loss of reduction and one case of carpal tunnel syndrome which was managed conservatively. Both groups attained excellent range of motion, grip strength and well maintained the post operative radiological parameters. The comparison of clinico-radiological parameters in both groups was found to be statistically insignificant. To conclude, ulnar styloid fracture or its non union does not affect the outcome of an adequately fixed distal end radius fracture. We urge caution in electing operative treatment of non-united fracture of the ulnar styloid until better scientific report for treatment of pain associated with these fracture is available. PMID:25414551

  12. A multiresolution finite element method based on a new locking-free rectangular Mindlin plate element

    E-print Network

    Xia, Yi-Ming

    2015-01-01

    A locking-free rectangular Mindlin plate element with a new multi-resolution analysis (MRA) is proposed and a multireolution finite element method is hence presented. The MRA framework is formulated out of a mutually nesting displacement subspace sequence. The MRA endows the proposed element with the resolution level (RL) to adjust the element node number, thus modulating structural analysis accuracy accordingly. As a result, the traditional 4-node rectangular Mindlin plate element and method is a mono-resolution one and also a special case of the proposed element and method. The meshing for the monoresolution plate element model is based on the empiricism while the RL adjusting for the multiresolution is laid on the rigorous mathematical basis. The accuracy of a structural analysis is actually determined by the RL, not by the mesh. The rational MRA enables the implementation of the multiresolution Mindlin plate element method to be more rational and efficient than that of the conventional monoresolution or o...

  13. Distal Radius Osteotomy with Volar Locking Plates Based on Computer Simulation

    Microsoft Academic Search

    Junichi Miyake; Tsuyoshi Murase; Hisao Moritomo; Kazuomi Sugamoto; Hideki Yoshikawa

    2011-01-01

    Background  Corrective osteotomy using dorsal plates and structural bone graft usually has been used for treating symptomatic distal radius\\u000a malunions. However, the procedure is technically demanding and requires an extensive dorsal approach. Residual deformity is\\u000a a relatively frequent complication of this technique.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  We evaluated the clinical applicability of a three-dimensional osteotomy using computer-aided design and manufacturing techniques\\u000a with volar locking plates

  14. Do angle stable implants provide advantages? Treatment of distal radius fractures with the locking compression plate (LCP)

    Microsoft Academic Search

    A. Prokop; A. Jubel; J. Andermahr; K. E. Rehm

    2004-01-01

    Can distal radius fractures be held in place with palmar locking compression plates (LCPs) and heal completely without an additional bone transplant? From 1 March 2001 to 1 September 2002, 40 patients with distal radius fractures (CCF: 2× A2, 13× A3, 2× C1, 22× C2 and 1× C3 fractures) were treated with locking compression small fragment titanium plates. In 37

  15. Femoral supracondylar focal dome osteotomy with plate fixation for acute correction of frontal plane knee deformity.

    PubMed

    El Ghazaly, Sherif Ahmed; El-Moatasem, El-Hussein Mohamed

    2015-04-01

    Focal dome osteotomy (FDO) allows deformity correction without secondary translational deformity. The purpose of this study was to evaluate the degree of correction and knee functional outcome after correction of frontal knee deformity using femoral supracondylar FDO fixed with plate and screws. A prospective study included 12 consecutive cases of femoral frontal plane deformity that underwent correction using supracondylar focal osteotomy fixed by plate and screws. Average age was 27 years, while mean follow-up was 2.1 years. Functional assessment was done using the Hospital for Special Surgery (HSS) knee score. The HSS knee score improved from 85 to 96.8 points. Desired correction was achieved in all cases. Postoperative mechanical axis analysis on long film and scanogram showed no secondary deformity. The overall postoperative mechanical axis was at 3.2 mm medially (range 2-5 mm). Autogenous bone graft was not used in any case, and uneventful osteotomy union was achieved at a mean of 13.8 weeks. Minor complications were encountered in two cases. There were no implant failures or reoperations. Supracondylar FDO of the femur with plate fixation is a reproducible technique that can produce full correction of distal femoral frontal plane deformity, while avoiding creating a secondary deformity. Knee function was improved with good patient satisfaction. PMID:25861038

  16. Derotational femoral osteotomy technique with locking nail fixation for adolescent femoral antetorsion: surgical technique and preliminary study.

    PubMed

    Pailhé, Régis; Bedes, Laurent; Sales de Gauzy, Jerôme; Tran, Richard; Cavaignac, Etienne; Accadbled, Franck

    2014-11-01

    Rotational femoral osteotomies for excessive femoral antetorsion may be considered only for symptomatic adolescents. Our main objective was to describe our femoral osteotomy technique. Preoperative planning was performed clinically and with the EOS imaging system. Percutaneous osteotomy was performed on distal femoral metaphysis under radioscopic control. Fixation was achieved with an antegrade locking nail. Rotation was checked precisely using a specially designed protractor before distal locking. We carried out a prospective pilot study between 2009 and 2010 on six patients (nine procedures). All the patients included presented a symptomatic femoral antetorsion greater than 20°. Clinical parameters including range of hip mobility and femoral antetorsion were measured every 2 months during the first 6 months, and then every year until skeletal maturation was reached. We obtained orthoroentgenograms using the same technique at each follow-up and torsional analysis by EOS 3D Imaging at 6 months. The average correction of the femoral antetorsion was 19.0 ± 4.0° (range, 13-25°). The average time of union was 3 ± 1.2 months (range, 2-6 months). Patients returned to full weight bearing at an average of 2.6 ± 0.4 months (range, 2-4 months). One patient experienced an early secondary displacement in varus for which a reoperation was required. We believe that this technique can accurately achieve derotational femoral osteotomies. A study is ongoing to evaluate the clinical results of this technique including mechanical and cosmetic advantages. PMID:25153645

  17. [Analysis of tendon injuries accompanying distal radius fractures using volar locking plates].

    PubMed

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

    2014-12-01

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

  18. Arthroscopic assistance does not improve the functional or radiographic outcome of unstable intra-articular distal radial fractures treated with a volar locking plate: a randomised controlled trial.

    PubMed

    Yamazaki, H; Uchiyama, S; Komatsu, M; Hashimoto, S; Kobayashi, Y; Sakurai, T; Kato, H

    2015-07-01

    There is no consensus on the benefit of arthroscopically assisted reduction of the articular surface combined with fixation using a volar locking plate for the treatment of intra-articular distal radial fractures. In this study we compared the functional and radiographic outcomes of fluoroscopically and arthroscopically guided reduction of these fractures. Between February 2009 and May 2013, 74 patients with unilateral unstable intra-articular distal radial fractures were randomised equally into the two groups for treatment. The mean age of these 74 patients was 64 years (24 to 92). We compared functional outcomes including active range of movement of the wrist, grip strength and Disabilities of the Arm, Shoulder, and Hand scores at six and 48 weeks; and radiographic outcomes that included gap, step, radial inclination, volar angulation and ulnar variance. There were no significant differences between the techniques with regard to functional outcomes or radiographic parameters. The mean gap and step in the fluoroscopic and arthroscopic groups were comparable at 0.9 mm (standard deviation (sd) 0.7) and 0.7 mm (sd 0.7) and 0.6 mm (sd 0.6) and 0.4 mm (sd 0.5), respectively; p = 0.18 and p = 0.35). Arthroscopic reduction conferred no advantage over conventional fluoroscopic guidance in achieving anatomical reduction of intra-articular distal radial fractures when using a volar locking plate. Cite this article: Bone Joint J 2015; 97-B:957-62. PMID:26130352

  19. Overlapping intramedullary nailing after failed minimally invasive locked plating for osteoporotic distal femur fractures - Report of 2 cases.

    PubMed

    Yoo, Je-Hyun; Kim, Seok-Woo; Kwak, Yoon-Hae; Kim, Hyung-Jun

    2015-06-01

    Minimally invasive plate osteosynthesis (MIPO) using a locking plate has been widely used for distal femur fractures in the elderly with osteoporosis and yielded favourable results. However, implant failure and subsequent periplate fracture have still occurred owing to the controversy of concepts regarding locked plating. The treatment after failed MIPO in elderly patients is very challenging and has been not yet addressed definitely in the literature, although several options can be considered. We report the successful outcomes of two cases treated with overlapping intramedullary (IM) nailing for implant failure and periplate fracture after MIPO for osteoporotic distal femur fracture, along with simple tips of distal interlocking of IM nail. PMID:25624271

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

    E-print Network

    Keiser, Michael

    1995-01-01

    The goal of internal fixation procedures is the restoration of normal structure and function to the injured bone. Internal fixation devices are utilized to increase the stability of fracture segments, transfer loads across ...

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

    E-print Network

    Keiser, Michael

    1995-01-01

    The goal of internal fixation procedures is the restoration of normal structure and function to the injured bone. Internal fixation devices are utilized to increase the stability of fracture segments, transfer loads across the fracture site...

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

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

    PubMed Central

    2010-01-01

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

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

    E-print Network

    Ray, Donald Reagan

    1970-01-01

    48 II COMPUTER PROGRAM FOR DETERMINING MOMENTS OP INERTIA AND LOCATION OF CENTROID OF BONE CROSS SECTION. III MACHINE AND FIRTURE CALIBRATION IV ELASTIC RESPONSE OF BONE-PLATE COMPOSITE FOR EACH COMBINATION OF PLATE DIMENSIONS AND FASTENER SIZE... Experiment. General Plate Design. 15 17 18 Influence of Fastener Size on Plate Capacity. . . . 26 10 Influence of Plate Width on Plate Capacity. Influence of Plate Length on Plate Capacity Failure Envelope for All Tests. Calibration Curve for Test...

  5. Augmentation of implant fixation in osteoporotic bone.

    PubMed

    Jones, Clifford B

    2012-12-01

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

  6. Biomechanical analysis of expansion screws and cortical screws used for ventral plate fixation on the cervical spine

    PubMed Central

    Ullrich, Bernhard; Huber, Gerd; Morlock, Michael M.

    2009-01-01

    Compared to bicortical screws, the surgical risk of injuring intraspinal structures can be minimized with the use of monocortical screws. However, this reduction should not be achieved at the expense of the stability of the fixation. With monocortical stabilization, the expansion screws have the potential of absorbing high loads. Therefore, they are expected to be a suitable alternative to bicortical screws for revision surgeries and in osteoporotic bone. The purpose of this in vitro study was to investigate the stiffness of the two screw-plate systems used for ventral stabilization of the cervical spine, by focusing on the suitability of expansion screws as tools for revision treatments. The study was conducted in ten functional units of human cervical spines. The device sample stiffness was determined for four conditions using a turning moment of 2.25 N m each around one of the three principle axes. The conditions were native, destabilized, primarily stabilized with one of the screw-plate systems, followed by secondary stabilization using the expansion screw implant. The stabilized samples achieved a comparable, in most cases higher stiffness than the native samples. The samples undergoing secondary stabilization using expansion screws tend to display greater stiffness for all three axes compared to the primarily stabilized samples. The achieved tightening moment of the screws was higher than the one achieved with primary fixation. Both plates revealed similar primary stability. Revision surgeries with secondary instrumentation achieve a high stiffness of the screwed up segments. Monocortical expansion screws combined with a trapezoidal plate allow ventral stabilization of the cervical spine that is comparable to the plate fixation using bicortical screws. PMID:19588171

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

    E-print Network

    Nori, Meera

    1994-01-01

    A wide range of prosthetic devices for internal fixation of the skeleton exist. Each aims to lend support to the injured limb, so as to restore the traumatized osseous and associated soft tissue to pre-fracture strength ...

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

    E-print Network

    Nori, Meera

    1994-01-01

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

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

    Microsoft Academic Search

    Rodrigo G Pagnano; Rodrigo Okubo; Jose B Volpon

    2011-01-01

    Background  Rotational osteotomy is frequently indicated to correct excessive femoral anteversion in cerebral palsy patients. Angled blade\\u000a plate is the standard fixation device used when performed in the proximal femur, but extensile exposure is required for plate\\u000a accommodation. The authors developed a short locked intramedullary nail to be applied percutaneously in the fixation of femoral\\u000a rotational osteotomies in children with cerebral

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

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

    PubMed Central

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

    2015-01-01

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

  12. Heterogeneous plate locking in the South–Central Chile subduction zone: Building up the next great earthquake

    Microsoft Academic Search

    M. Moreno; D. Melnick; M. Rosenau; J. Bolte; J. Klotz; H. Echtler; J. Baez; K. Bataille; J. Chen; M. Bevis; H. Hase; O. Oncken

    2011-01-01

    We use Global Positioning System (GPS) velocities and kinematic Finite Element models (FE-models) to infer the state of locking between the converging Nazca and South America plates in South–Central Chile (36°S?46°S) and to evaluate its spatial and temporal variability. GPS velocities provide information on earthquake-cycle deformation over the last decade in areas affected by the megathrust events of 1960 (Mw=9.5)

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

    PubMed

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

    2011-01-01

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

  14. Palmar locking plates for corrective osteotomy of latent malunion of dorsally tilted distal radial fractures without structural bone grafting.

    PubMed

    Tarng, Yih-Wen; Yang, Shan-Wei; Hsu, Chien-Jen

    2011-06-01

    The purpose of this retrospective study was to investigate the clinical and radiological outcomes following corrective osteotomy for nascent malunion of distal radial fractures with dorsal tilt using palmar-locking plates without using autologous structural bone grafting for dorsal cortex support. The fractures were dorsally angulated distal radial fractures (AO types A2, A3, and C1) with neglected or delayed treatment for 5 to 8 weeks. Fractures were repaired using 2.4-mm palmar locking plates. Dorsal cortical defects at the osteotomy sites were filled with incipient healing callus. Radiographs were obtained before correction and at 2 and 6 weeks and 3, 4.5, 6, and 12 months postoperatively. Palmar tilt, radial inclination, and ulnar variance were measured. There were no cases of loss reduction, implant failure, or delayed fracture union without structural bone graft and casting. Clinical assessments included active range of motion of the wrist and function based on the Mayo Wrist Score. Even with wrist immobilization for >1 month preoperatively, all patients had excellent Mayo Wrist Scores at 4.5 months due to early postoperative rehabilitation. No further changes were apparent between 4.5- and 12-month follow-up.The palmar locking plates provided sufficient stability for corrective osteotomy within 8 weeks of injury without the need for structural bone grafting. Furthermore, casting immobilization was also unnecessary, and a good wrist range of motion was restored early after rehabilitation. PMID:21667904

  15. Comparison of limited-contact dynamic compression plate and locking compression plate constructs for proximal interphalangeal joint arthrodesis in the horse.

    PubMed

    Rocconi, Richard A; Carmalt, James L; Sampson, Sarah N; Elder, Steve H; Gilbert, Eric E

    2015-06-01

    This study compared in vitro monotonic and cyclic mechanical properties of equine proximal interphalangeal joint arthrodeses stabilized using an open or closed technique combined with axial 4.5 mm narrow limited-contact dynamic compression plate (LC-DCP) or 4.5 mm narrow locking compression plate (LCP). Ten forelimb pairs were randomly assigned to LCP or LC-DCP groups. One limb in each pair was assigned to either open or closed technique. Limbs were tested for cyclic fatigue at 20 000 cycles and then single-cycle to failure under 3-point dorsopalmar bending. There was no significant difference in stiffness of constructs during cyclic fatigue testing or on force or stiffness at failure in single cycle to failure testing between open and closed techniques or between plate types. Both implants, surgical technique, or combinations thereof are suitable for clinical use. More work is necessary to define the interaction between implant type and surgical technique. PMID:26028685

  16. Treatment of fractures of the mandible and maxilla by mini titanium plate fixation systems in dogs and cats.

    PubMed

    Bilgili, H; Kurum, B

    2003-11-01

    Mini titanium plates were used to repair certain fractures of the maxilla and mandible in dogs and cats, under general anaesthesia. The location of the fractures treated were: corpus mandible, one dog; corpus mandible and symphysis, two dogs; caudal mandible, two dogs; rostral mandible, one dog; maxilla, one dog; nasal bone, one dog; corpus mandible and symphysis, one cat; caudal mandible, one cat; and maxilla, one cat. The healing periods varied from 6 to 9 weeks. In seven cases, implants were removed after a period of 3.5 to 18 months. In four cases the implants were left in place. The follow up period was between 8 and 36 months. In ten cases the procedure was successful, however in one case the outcome was not satisfactory due to a broken plate. There were no instances of dental malocclusion, nonunion, malunion, osteomyelitis or soft tissue infection. Eating, playing with toys, a fast transition to solid food and a quick return to normal jaw movements were observed. In our hands, the mini titanium plate fixation system was a safe and effective method for repairing certain maxillary and mandibular fractures in dogs and cats. PMID:15086106

  17. OPEN REDUCTION AND INTERNAL FIXATION OF INTRA ARTICULAR AND UNSTABLE FRACTURES OF THE DISTAL RADIUS USING THE AO DISTAL RADIUS PLATE

    Microsoft Academic Search

    D. A. CAMPBELL

    2000-01-01

    This study reports the results of open reduction and internal fixation of 25 dorsally displaced distal radial fractures using a specifically designed plate for the distal radius, the AO pi plate (Synthes Ltd, Paoli, USA). Twenty-one of these fractures were complex and intra-articular (AO Type ‘C’). Measurement of range of motion of the affected wrist at an average follow-up of

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

    PubMed

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

    2015-05-01

    Fractures of the distal humerus are most commonly fixed by open reduction and internal fixation, using plates and screws, either in a locking or in a non-locking construct. Three different plating systems are commonly used in practice. The most important differences between them are in plate orientation, which affects both the rigidity of the osteosynthesis and invasiveness of the surgical procedure. Unfortunately, there is no common agreement between surgeons about which plate configuration brings the best clinical outcome. In this study, we investigate the theoretical rigidity of plate osteosyntheses considering two types of AO/ASIF configurations (90° angle between plates), Mayo clinic (Acumed) configuration (180° between plates) and dorsal fixation of both plates. We also compared the results for cases with and without contact between the bone fragments. In the case of no bone contact, the Mayo clinic plate configuration is found to be the most rigid, followed by both AO/ASIF plate configurations, and the least rigid system is the Korosec plate configuration. On the other hand, no significant differences between all types of fixation configurations are found in cases with contact in-between the bone fragments. Our findings show that this contact is very important and can compensate for the lack of load carrying capacity of the implants. This could therefore incite other implant fixation solutions, leading to less invasive surgical procedures and consequently improved clinical outcome. PMID:25663513

  19. A simple method to ensure proper screw position and plate size selection using the Morscher cervical spine locking plate. Technical note.

    PubMed

    Ball, P A; Benzel, E C; Baldwin, N G

    1994-04-01

    The use of bone plate instrumentation with screw fixation has proved to be a useful adjunctive measure in anterior cervical spine fusion surgery. Proper fitting, positioning, and attachment of this instrumentation have been shown to be frequently suboptimal if done without radiographic guidance. The most commonly used method of radiographic assistance for placement of this instrumentation is fluoroscopy. While this gives satisfactory technical results, it is expensive and time-consuming, and exposes the patient and the operating room personnel to ionizing radiation. The authors present a simple technique to ensure screw placement and plate fitting using Kirschner wires and a single lateral radiograph. This technique saves time, reduces exposure to radiation, and has led to satisfactory results in over 20 operative cases. PMID:8151358

  20. Heterogeneous plate locking in the South-Central Chile subduction zone: Building up the next great earthquake

    NASA Astrophysics Data System (ADS)

    Moreno, M.; Melnick, D.; Rosenau, M.; Bolte, J.; Klotz, J.; Echtler, H.; Baez, J.; Bataille, K.; Chen, J.; Bevis, M.; Hase, H.; Oncken, O.

    2011-05-01

    We use Global Positioning System (GPS) velocities and kinematic Finite Element models (FE-models) to infer the state of locking between the converging Nazca and South America plates in South-Central Chile (36°S - 46°S) and to evaluate its spatial and temporal variability. GPS velocities provide information on earthquake-cycle deformation over the last decade in areas affected by the megathrust events of 1960 (Mw= 9.5) and 2010 (Mw= 8.8). Our data confirm that a change in surface velocity patterns of these two seismotectonic segments can be related to their different stages in the seismic cycle: Accordingly, the northern (2010) segment was in a final stage of interseismic loading whereas the southern (1960) segment is still in a postseismic stage and undergoes a prolonged viscoelastic mantle relaxation. After correcting the signals for mantle relaxation, the residual GPS velocity pattern suggests that the plate interface accumulates slip deficit in a spatially and presumably temporally variable way towards the next great event. Though some similarity exist between locking and 1960 coseismic slip, extrapolating the current, decadal scale slip deficit accumulation towards the ~ 300-yr recurrence times of giant events here does neither yield the slip distribution nor the moment magnitude of the 1960 earthquake. This suggests that either the locking pattern is evolving in time (to reconcile a slip deficit distribution similar to the 1960 earthquake) or that some asperities are not persistent over multiple events. The accumulated moment deficit since 1960 suggests that highly locked patches in the 1960 segment are already capable of producing a M ~ 8 event if triggered to fail by stress transfer from the 2010 event.

  1. Pronator-sparing technique for volar plating of distal radius fractures.

    PubMed

    Cannon, Tyler A; Carlston, Cory V; Stevanovic, Milan V; Ghiassi, Alidad D

    2014-12-01

    Acute distal radius fractures are commonly treated by volar locking plate fixation and typically involve reflection of the pronator quadratus for adequate exposure of the fracture. Recently, attention has been centered on the role and repair of the pronator quadratus. This article presents an alternative approach to fixation of distal radius fractures with a pronator-sparing technique that offers similar short-term radiographic outcomes to the conventional volar plating approach. PMID:25447006

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

    PubMed

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

    2013-09-01

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

  3. Fixed-Angle Volar Plate Fixation for Distal Radius Fractures in Immunosuppressed Patients

    Microsoft Academic Search

    Erik D. Peterson; David G. Dennison

    2008-01-01

    The aim of this study was to define the outcome and complications following open reduction and internal fixed-angle plating\\u000a of distal radius fractures for patients on chronic immunosuppression medications. A retrospective study identified 11 patients\\u000a with distal radius fractures that had been on chronic immunosuppressive medication. The mean patient age was 59.9 years (40–82 years).\\u000a According to the Orthopedic Trauma Association classification,

  4. Fixation of sternal fracture using absorbable plating system, three years follow-up

    PubMed Central

    Katballe, Niels; Pilegaard, Hans

    2015-01-01

    Sternal fractures occur due to severe chest wall trauma in a small number of patients. They are often conservatively treated. The surgical intervention, although controversial, is indicated in case of deformity, severe pain, and ventilatory complications. We report the first case where absorbable plate has been used to fix a traumatic fracture in a 42-year-old female. After 3 years, the patient is still free of symptoms and CT scanning reveals intact sternal bone structure.

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

    PubMed Central

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

    2010-01-01

    Plate osteosynthesis is one treatment option for the stabilization of long bones. It is widely accepted to achieve bone healing with a dynamic and biological fixation where the perfusion of the bone is left intact and micromotion at the fracture gap is allowed. The indications for a dynamic plate osteosynthesis include distal tibial and femoral fractures, some midshaft fractures, and adolescent tibial and femoral fractures with not fully closed growth plates. Although many lower limb shaft fractures are managed successfully with intramedullary nails, there are some important advantages of open-reduction-and-plate fixation: the risk of malalignment, anterior knee pain, or nonunion seems to be lower. The surgeon performing a plate osteosynthesis has the possibility to influence fixation strength and micromotion at the fracture gap. Long plates and oblique screws at the plate ends increase fixation strength. However, the number of screws does influence stiffness and stability. Lag screws and screws close to the fracture site reduce micromotion dramatically. Dynamic plate osteosynthesis can be achieved by applying some simple rules: long plates with only a few screws should be used. Oblique screws at the plate ends increase the pullout strength. Two or three holes at the fracture site should be omitted. Lag screws, especially through the plate, must be avoided whenever possible. Compression is not required. Locking plates are recommended only in fractures close to the joint. When respecting these basic concepts, dynamic plate osteosynthesis is a safe procedure with a high healing and a low complication rate. PMID:21808699

  6. Effect of screw position on single cycle to failure in bending and torsion of a locking plate-rod construct in a synthetic feline femoral gap model.

    PubMed

    Niederhäuser, Simone K; Tepic, Slobodan; Weber, Urs T

    2015-05-01

    OBJECTIVE To evaluate the effect of screw position on strength and stiffness of a combination locking plate-rod construct in a synthetic feline femoral gap model. SAMPLE 30 synthetic long-bone models derived from beechwood and balsa wood. PROCEDURES 3 constructs (2 locking plate-rod constructs and 1 locking plate construct; 10 specimens/construct) were tested in a diaphyseal bridge plating configuration by use of 4-point bending and torsion. Variables included screw position (near the fracture gap and far from the fracture gap) and application of an intramedullary pin. Constructs were tested to failure in each loading mode to determine strength and stiffness. Failure was defined as plastic deformation of the plate or breakage of the bone model or plate. Strength, yield angle, and stiffness were compared by use of a Wilcoxon test. RESULTS Placement of screws near the fracture gap did not increase bending or torsional stiffness in the locking plate-rod constructs, assuming the plate was placed on the tension side of the bone. Addition of an intramedullary pin resulted in a significant increase in bending strength of the construct. Screw positioning did not have a significant effect on any torsion variables. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study suggested that, in the investigated plate-rod construct, screw insertion adjacent to the fracture lacked mechanical advantages over screw insertion at the plate ends. For surgeons attempting to minimize soft tissue dissection, the decision to make additional incisions for screw placement should be considered with even more caution. PMID:25909372

  7. [Biomechanical study of angle-stable anterior atlanto-axial spondylodesis plate].

    PubMed

    Kandziora, F; Ludwig, K; Pflugmacher, R; Haas, N P; Mittlmeier, T

    2001-03-01

    The optimum fixation method to achieve atlantoaxial fusion after odontoid resection is still subject to discussion. Isolated posterior surgical procedures for treatment of irreducible atlantoaxial kyphosis with spinal cord compression are associated with a high rate of morbidity and mortality. Transoral atlantoaxial plate fixation has been described by Harms as a fixation technique after odontoid resection. The purpose of this study was to compare biomechanically a new anterior atlantoaxial locking plate (AALP) with the Harms plate and the atlantoaxial transarticular screw fixation described by Magerl. Sixteen human cadaver craniocervical specimens were tested in flexion, extension, rotation, and bending with a nondestructive flexibility method using a nonconstrained testing apparatus. Five different groups were examined: (1) control group (intact) (n = 16), (2) unstable group (after dissection of the atlantoaxial ligaments and odontoidectomy) (n = 16), (3) Harms group (transoral atlantoaxial plate fixation) (n = 8), (4) AALP group (anterior atlantoaxial locking plate fixation) (n = 8), and (5) Magerl group (transarticular atlantoaxial screw fixation) (n = 16). Stiffness in any direction was significantly higher in the AALP specimens and those fixated with the Magerl method than in the Harms, control, or unstable specimens. The difference in stiffness between the AALP and Magerl reconstruction groups was not statistically significant. Experimentally, the AALP was significantly stiffer than the Harms plate. The AALP provided stiffness equal to transarticular screw fixation according to Magerl. A question that cannot be answered by this in vitro study concerns the level of rigidity required to obtain long-term stability and fusion by atlantoaxial fixation methods. However, it may be assumed that the more spinal motion is eliminated the greater the chance of definite spinal fusion. Therefore, it seems reasonable that the most reliable and rigid fixation method would be the method of choice. PMID:11501010

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

    E-print Network

    Rodriguez, Douglas E.

    2010-01-14

    While there is continuing interest in bioresorbable materials for orthopedic fixation devices, the major challenge in utilizing these materials in load-bearing applications is creating materials sufficiently stiff and strong to sustain loads...

  9. Failure of a retinacular flap to prevent dorsal wrist pain after titanium Pi plate fixation of distal radius fractures

    Microsoft Academic Search

    Peter P. Chiang; Stephanie Roach; Mark E. Baratz

    2002-01-01

    Patients with distal radius fractures that had been treated with a dorsal Pi plate and retinacular flap covering the transverse limb of the Pi plate were evaluated clinically and radiographically. Nine of 20 patients (45%) required plate removal for dorsal wrist pain. Three of the remaining 11 who retained the plate had dorsal tenderness over the wrist extensors. There were

  10. Early complications of volar plating of distal radius fractures and their relationship to surgeon experience

    Microsoft Academic Search

    Christina M. Ward; Taften L. Kuhl; Brian D. Adams

    2011-01-01

    Background  Fractures of the distal radius are among the most common fractures in adults. Recently, there has been a trend towards open\\u000a reduction and internal fixation of these fractures through a volar approach. The purpose of this study was to assess the early\\u000a complications of volar locking plate fixation of distal radius fractures with an emphasis on defining the relationship between

  11. Stability of volar locking plate systems for AO type C3 fractures of the distal radius: biomechanical study in a cadaveric model

    Microsoft Academic Search

    Shuzo Kamei; Denju Osada; Kazuya Tamai; Nakayuki Kato; Morimitsu Takai; Masahiro Kameda; Yutaka Nohara

    2010-01-01

    Background  The purpose of the present study was to compare the relative stability of five volar locking plates (all of which are available\\u000a for the treatment of intraarticular fractures of the distal radius) under loading conditions simulating the physiological\\u000a forces that occur during early active mobilization.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Five plating techniques were applied to surgically simulated AO type C3.2 distal radius fractures in

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

    Microsoft Academic Search

    Christoph Bartl; Dirk Stengel; Thomas Bruckner; Inga Rossion; Steffen Luntz; Christoph Seiler; Florian Gebhard

    2011-01-01

    Background  Fractures of the distal radius represent the most common fracture in elderly patients, and often indicate the onset of symptomatic\\u000a osteoporosis. A variety of treatment options is available, including closed reduction and plaster casting, K-wire-stabilization,\\u000a external fixation and open reduction and internal fixation (ORIF) with volar locked plating. The latter is widely promoted\\u000a by clinicians and hardware manufacturers. Closed reduction

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

    PubMed Central

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

    2014-01-01

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

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

    E-print Network

    Rodriguez, Douglas E.

    2010-01-14

    .1 Significance, Objectives, and Outcomes .............................................. 1 1.2 Background ........................................................................................... 6 1.2.1 Bioresorbable Polymers and Characterization... ................................................................. 25 2.5 Aluminum mold with cavity dimensions of 16mm x 10mm x 10mm ............ 28 2.6 Polymer mass variation of PDLA and PGA under isothermal holding [44]... 29 2.7 Picture of glass mold used to create PDLGA plate...

  15. Biomechanical comparison of internal fixation techniques for the Akin osteotomy of the proximal phalanx.

    PubMed

    Chacon, Yolanda; Fallat, Lawrence M; Dau, Nathan; Bir, Cynthia

    2012-01-01

    The Akin osteotomy is performed at the proximal phalanx for correction of an abducted great toe in a hallux abducto valgus deformity. Several internal fixation techniques have been widely advocated; however, their respective stabilities have not been compared. A biomechanical analysis was performed comparing 5 commonly used fixation techniques for the Akin osteotomy to determine the strongest method in simulated weightbearing in sawbone models. An Akin osteotomy was uniformly performed on 25 sawbones and fixated with 5 different internal fixation types, including a 2-hole locking plate and locking screws, a heat-sensitive memory staple (8 mm × 8 mm), a 28-gauge monofilament wire, 2.7-mm bicortical screws, and crossed 0.062-in. Kirschner wires. The results of simulated weightbearing load to failure rates with an Instron compression device demonstrated the following mean load to failures: crossed Kirschner wire, 57.05 N; 2-hole locking plate, 36.49 N; monofilament wire, 35.69 N; heat-sensitive memory staple, 34.32 N; and 2.7-mm bicortical screw, 13.66 N. Statistical analysis demonstrated the crossed Kirschner wire technique performed significantly better than the other fixation techniques (p < .007); the 4 other techniques were found not to be significantly different statistically (p = .041) from each another. Our study results suggest a crossing Kirschner wire construct significantly increases the stability of the Akin osteotomy in a sawbone model. This might be clinically extrapolated in an effort to improve patient outcomes because these osteotomies can undergo nonunion and malunion, resulting in postoperative pain and swelling. PMID:22819001

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

    PubMed Central

    2012-01-01

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

  17. Les fractures intraarticulaires du radius distal à déplacement postérieur traitées par plaque palmaire à stabilité angulaire. Technique et résultats Dorsally displaced intra-articular distal radius fractures treated by locked palmar plate. Technique and results

    Microsoft Academic Search

    J. G. Boretto; G. L. Gallucci; V. A. Alfie; A. Donndorff; P. De Carli; Miembro Superior; Carlos Ottolenghi

    Objectives. - The purpose of this study was to evaluate the results and complications of locked palmar plating in patients with articular fracture of the distal radius. Methods. - Twenty-two patients were reviewed retrospectively. The average age was 68 years. All fractures were classified as Type C according to the AO classification. Clinical and functional examination including range of motion,

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

    PubMed

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

    2015-02-01

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

  19. Along-strike variations in seismic structure of the locked-sliding transition on the plate boundary beneath the southern part of Kii Peninsula, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kurashimo, E.; Iidaka, T.; Iwasaki, T.; Saiga, A.; Umeyama, E.; Tsumura, N.; Sakai, S.; Hirata, N.

    2013-12-01

    The Nankai trough region, where the Philippine Sea Plate (PHS) subducts beneath the SW Japan arc, is a well-known seismogenic zone of interplate earthquakes. A narrow zone of nonvolcanic tremor has been found in the SW Japan fore-arc, along strike of the arc (Obara, 2002). The epicentral distribution of tremor corresponds to the locked-sliding transition estimated from thermal and deformation models (Hyndman et al., 1995). The spatial distribution of the tremor is not homogeneous in a narrow belt but is spatially clustered. Obara [2002] suggested fluids as a source for tremor because of the long duration and the mobility of the tremor activity. The behavior of fluids at the plate interface is a key factor in understanding fault slip processes. Seismic reflection characteristics and seismic velocity variations can provide important information on the fluid-related heterogeneity of structure around plate interface. However, little is known about the deeper part of the plate boundary, especially the transition zone on the subducting plate. To reveal the seismic structure of the transition zone, we conducted passive and active seismic experiments in the southern part of Kii Peninsula, SW Japan. Sixty 3-component portable seismographs were installed on a 60-km-long line (SM-line) nearly perpendicular to the direction of the subduction of the PHS with approximately 1 km spacing. To improve accuracy of hypocenter locations, we additionally deployed six 3-component seismic stations around the survey line. Waveforms were continuously recorded during a five-month period from December, 2009. In October of 2010, a deep seismic profiling was also conducted. 290 seismometers were deployed on the SM-line with about 200 m spacing, on which five explosives shots were fired as controlled seismic sources. Arrival times of local earthquakes and explosive shots were used in a joint inversion for earthquake locations and 3-D Vp and Vp/Vs structures, using the iterative damped least-squares algorithm, simul2000 (Thurber and Eberhart-Phillips, 1999). To obtain the detailed structure image of the transition zone on the subducting plate, the explosive shot data recorded on the SM-line were processed using the seismic reflection technique. Seismic reflection image shows the lateral variation of the reflectivity along the top of the PHS. A clear reflection band is present where the clustered tremors occurred. The depth section of Vp/Vs structure shows the lateral variation of the Vp/Vs values along the top of the PHS. Clustered tremors are located in and around the high Vp/Vs zone. These results suggest the occurrence of the tremors may be associated with fluids dehydrated from the subducted oceanic lithosphere.

  20. The management of traumatic cervical bilateral facet fracture-dislocations with unicortical anterior plates.

    PubMed

    Razack, N; Green, B A; Levi, A D

    2000-10-01

    The goal of this study was to evaluate single-level anterior cervical discectomy and stabilization for bilateral facet fracture dislocations using bone graft and anterior titanium plates with unicortical screw fixation in the clinical setting. We conducted a retrospective review during a consecutive 6-year period of patients treated in a single institution for traumatic single-level cervical bilateral facet fracture-dislocation. All fracture-dislocations that could be aligned with traction were subsequently stabilized using an anterior cervical discectomy with bone graft and titanium unicortical locking plates. All patients were examined after operation for radiographic evidence of healing and neurologic outcome. Twenty-two patients (M:F ratio, 16:6; average age, 47.7 years) underwent an anterior cervical discectomy and stabilization with either an allograft (n = 12) or an autograft (n = 10) and a titanium unicortical locking plate. Most patients had sustained a spinal cord injury (87%) or a radicular injury (9%). The average follow-up was 32 months, with a minimum follow-up of 1 year (range, 13 to 77 months). There was one instrumentation-related failure, but all 22 patients ultimately had evidence of stability at the instrumented level on the final follow-up examination. Anterior fixation with unicortical cervical locking plates as a single procedure offers an excellent surgical alternative in the management of many cervical bilateral facet fracture dislocations in patients who can be reduced preoperatively. PMID:11052345

  1. The initial experience with closed interlocking intramedullary fixation.

    PubMed

    Grmela, M; Mihula, A; Fiala, O; D?dek, T; Záhorák, K

    1991-01-01

    Authors present the initial experience with the closed locked intramedullary fixation of long bones (mainly the tibial bone) in conditions of the Teaching Hospital. Possible improvisation is reported on when lacking the foreign osteosynthetical material. PMID:1815322

  2. Ilizarov hip reconstruction without external fixation: a new technique

    PubMed Central

    Lenze, U.; Hasler, C. C.

    2010-01-01

    Purpose The Ilizarov hip reconstruction is a well accepted but complication-prone operative salvage procedure in chronically dislocated hips, not least due to the long-term application of external fixation. Although the advantages of fully implantable devices are well known in limb lengthening and are described consistently, until now, external fixation has been used exclusively to perform the Ilizarov hip reconstruction procedure. We present a new technique of Ilizarov hip reconstruction with purely internal implants. Methods A 14-year-old girl with a history of spina bifida presented with a 4-cm-short right leg, a Trendelenburg gait and a complex neurological disease expression. Because of refusal of external fixation by the patient and significantly lower complication rates, an Ilizarov hip reconstruction without external fixation was performed. A locking compression plate was applied to fix the proximal femoral valgus-extension osteotomy and a motorised intramedullary distraction nail was used for the distal, lengthening–varisation osteotomy. Results A healing index of 33 days/cm and full weight bearing after 6 months were noted. At the 1 year follow-up, the patient showed an improvement of the Trendelenburg gait, as well as successful leg equalisation. Satisfaction to a high degree was additionally noted by factors such as reduced pain, the ability to wear workaday clothes and cosmetically appealing scars. No complications were recorded. Conclusion The exclusive use of internal implants for Ilizarov hip reconstruction is a feasible and patient-friendly alternative to traditional methods. Their use, however, may be restricted by geometric preconditions. PMID:21629378

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

    PubMed

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

    2014-01-01

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

  4. A new adhesive technique for internal fixation in midfacial surgery

    Microsoft Academic Search

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

    2008-01-01

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

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

    Microsoft Academic Search

    Jorge L Orbay; Diego L Fernandez

    2004-01-01

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

  6. Evaluation of 3 Fixation Devices for Tibial-Sided Anterior Cruciate Ligament Graft Backup Fixation.

    PubMed

    Verioti, Christopher A; Sardelli, Matthew C; Nguyen, Tony

    2015-07-01

    We conducted a study to biomechanically evaluate 3 methods of tibial-sided fixation for anterior cruciate ligament reconstruction: fully threaded interference screw only, interference screw backed with 4.75-mm SwiveLock anchor, and fully threaded bio-interference screw backed with 4.5-mm bicortical screw (all Arthrex). Thirty skeletally mature porcine tibiae were used. The first group was prepared by graft fixation within the tibial tunnel using only an interference screw. The second and third groups included an interference screw with 2 types of secondary fixation: 4.5-mm bicortical post and SwiveLock anchor. Mechanical testing consisted of 500 cycles between 50 and 250 N at 1 Hz, followed by a pull to failure conducted at 20 mm per minute. Ultimate load-to-failure testing demonstrated the largest mean (SD) load tolerated in the post/washer group, 1148 (186) N, versus the SwiveLock group, 1007 (176) N, and the screw-only group, 778 (139) N. There was no statistical difference between the 2 backup fixation groups. Use of a SwiveLock anchor as backup fixation at the tibial side in soft-tissue anterior cruciate ligament reconstruction is a safe, effective alternative to a bicortical post and provides statistically equivalent pullout strength with unlikely requirement for future hardware removal. PMID:26161768

  7. External fixation in comminuted, displaced intra-articular fractures of the distal radius: is it sufficient?

    Microsoft Academic Search

    J. Arora; A. C. Malik

    2005-01-01

    Introduction: External fixation has been extensively used to treat the intra-articular fractures of the distal radius and it has several distinct advantages over conventional POP cast and plate fixation. However, the limitation of external fixation to achieve articular congruity in the comminuted intra-articular fractures of the distal radius has been documented in the literature. This could be because external fixation

  8. Locked nailing of severely comminuted or segmental humeral fractures.

    PubMed

    Lin, Jinn; Hou, Sheng-Mou

    2003-01-01

    Some comminuted or segmental humeral fractures have been well-treated by functional bracing, but some also have been reported to have a bad outcome. If surgery is required, unlocked nailing has the disadvantage of unstable fixation, and plating has the disadvantage of extensive soft tissue injury. In the current study, closed locked nailing was used to treat 23 Orthopaedic Trauma Association Type C humeral fractures (C1, five; C2, three; C3, 15). The patients were 12 men and 11 women with a mean age of 42.4 years. There were 16 closed fractures and four Type I, two Type II, and one Type IIIA open fractures. Eight fractures were in the proximal third, seven in the middle third, and eight in the distal third. With one nailing, 21 of 23 (91%) fractures achieved solid union in an average of 13.2 weeks. The two nonunions eventually united after another revision nailing and bone grafting. No patients had significant impairment of elbow function. Excellent or satisfactory shoulder function was obtained in 20 patients. Closed locked nailing showed reliable treatment results for severely comminuted or segmental humeral fractures. The keys to success include compression of the fractures, static locking, postoperative external support, and experienced surgical technique. PMID:12579019

  9. Locking mechanism

    SciTech Connect

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

    1997-01-01

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

  10. Locking Bolt

    NASA Technical Reports Server (NTRS)

    Boswell, B. E.

    1983-01-01

    Locking ball in bolt head holds wrench in place. Head of bolt contains locking ball and releases pin to grasp box wrench or other tool. Installed in cramped spaces that prevent operator from using both hands or maneuverability restricted by bulky clothing or obstacles.

  11. Tectonic Plates and Plate Boundaries

    NSDL National Science Digital Library

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

  12. Strength analysis of clavicle fracture fixation devices and fixation techniques using finite element analysis with musculoskeletal force input.

    PubMed

    Marie, Cronskär

    2015-08-01

    In the cases, when clavicle fractures are treated with a fixation plate, opinions are divided about the best position of the plate, type of plate and type of screw units. Results from biomechanical studies of clavicle fixation devices are contradictory, probably partly because of simplified and varying load cases used in different studies. The anatomy of the shoulder region is complex, which makes it difficult and expensive to perform realistic experimental tests; hence, reliable simulation is an important complement to experimental tests. In this study, a method for finite element simulations of stresses in the clavicle plate and bone is used, in which muscle and ligament force data are imported from a multibody musculoskeletal model. The stress distribution in two different commercial plates, superior and anterior plating position and fixation including using a lag screw in the fracture gap or not, was compared. Looking at the clavicle fixation from a mechanical point of view, the results indicate that it is a major benefit to use a lag screw to fixate the fracture. The anterior plating position resulted in lower stresses in the plate, and the anatomically shaped plate is more stress resistant and stable than a regular reconstruction plate. PMID:25850983

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

    PubMed

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

    2009-09-18

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

  14. Histoplasma complement fixation

    MedlinePLUS

    Histoplasma complement fixation is a blood test that checks for infection due to a fungus called Histoplasma capsulatum ( H. ... for Histoplasma antibodies using a laboratory method called complement fixation. This technique checks if your body has ...

  15. Parallel plating for a sternomanubrial dislocation.

    PubMed

    Gaines, Robert J; Wilson, Addison; Antevil, Jared; Demaio, Marlene

    2012-08-01

    Sternomanubrial dislocations are rare injuries. Although few cases of this injury have been reported in the literature, the etiology has varied widely: trampoline injury, seizures, falls from height, sporting injuries, gradual deformities from spine fractures, and motor vehicle collisions. This injury has been classified into 2 types: in type I, the sternal body is displaced posteriorly to the manubrium, and in the more common type II, the sternal body is displaced anteriorly. The sternomanubrial joint is an amphiarthroidal joint that bears hyaline cartilage on both surfaces connected by a fibrocartilage meniscus. It serves a protective role to vital thoracic structures and is an anterior stabilizing strut to the thorax, assisting the thoracic spine in upright stability. It is important to not ignore type I dislocations because posterior sternum displacement is a harbinger of injury to the pulmonary tree, heart, and esophagus. Chronic instability at this joint can lead to dyspnea and dysphasia due to sternum displacement. In the right scenario, type II injuries are occasionally treated conservatively with palliative treatment until the sternum heals with malformation. This article describes the case of a 20-year-old man who was treated surgically for symptomatic type II sternomanubrial dislocation with dual anterior locked plating. Locked plating gives the benefit of unicortical fixation, with the screws and plate acting as a unit to resist motion. Screw pullout and failure is less common, and the construct is more resistant for this application. The patient returned to full participation in activities of daily living and military duty 4 months postoperatively. PMID:22868620

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

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

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

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

    PubMed Central

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

    2007-01-01

    Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling. Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled, and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2 anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position (ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and 1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after 6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate. These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed 2 years postoperatively. PMID:17684777

  18. Safety lock-out device for electrical appliances

    DOEpatents

    Cliff, P.L. Jr.

    1996-07-09

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

  19. Safety lock-out device for electrical appliances

    DOEpatents

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

    1996-01-01

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

  20. Gel Cassette Preparation1 1. Place a Short Plate on top of the Spacer Plate.

    E-print Network

    Raizada, Manish N.

    plates into the Casting Frame, keeping the Short Plate facing front. Insure both plates are flush at the bottom on a level surface. 3. Lock the pressure cams to secure the glass plates. 4. Engage the spring loaded lever and place the gel cassette assembly on the gray casting stand gasket. Insure the horizontal

  1. Mechanical properties of two canine iliac fracture fixation systems

    E-print Network

    VanGundy, Thomas Eugene

    1988-01-01

    to plate fixation for o lique canine iliac fracture fixation. The savings on implant fees and ease of lag screw application also may be a consideration for the veterinary surgeon. REFERENCES 1. Brinker WO, Piermattei DL, Flo GL. Handbook of Small..., for providng the funding that made this project possible. vi1 TABLE OF CONTENTS Page INTRODUCTION MATERIALS AND METHODS RESULTS Specimen Dimensions Static Testing Dynamic Testing DISCUSSION Pretesting Considerations Testing Considerations...

  2. Guide to radiation fixatives

    SciTech Connect

    Tawil, J.J.; Bold, F.C.

    1983-11-01

    This report identifies and then characterizes a variety of substances available in the market place for potential effectiveness as a fixative on radiologically contaminated surfaces. The substances include both generic chemicals and proprietary products. In selecting a fixative for a particular application, several attributes of the fixative may be relevant to the choice. These attributes include: toxicity, durability, and cleanliness and removability. In addition to the attributes of the fixative, one should also take into account certain characteristics of the site to be treated. These characteristics relate to climate, nature of the surface, use to which the treated surface will be put, subsequent cleanup operations, and type of neighboring surfaces. Finally, costs and potential environmental effects may influence the decision. A variety of fixatives are evaluated with respect to these various attributes and summarized in a reference table.

  3. Suture locking of isolated internal locking knotless suture anchors is not affected by bone quality

    PubMed Central

    Woodmass, Jarret M; Matthewson, Graeme; Ono, Yohei; Bois, Aaron J; Boorman, Richard S; Lo, Ian KY; Thornton, Gail M

    2015-01-01

    Purpose The purpose of this study was to evaluate the mechanical performance of different suture locking mechanisms including: i) interference fit between the anchor and the bone (eg, 4.5 mm PushLock, 5.5 mm SwiveLock), ii) internal locking mechanism within the anchor itself (eg, 5.5 mm SpeedScrew), or iii) a combination of interference fit and internal locking (eg, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S). Methods Anchors were tested in foam blocks representing normal (20/8 foam) or osteopenic (8/8 foam) bone, using standard suture loops pulled in-line with the anchor to isolate suture locking. Mechanical testing included cyclic testing for 500 cycles from 10 N to 60 N at 60 mm/min, followed by failure testing at 60 mm/min. Displacement after 500 cycles at 60 N, number of cycles at 3 mm displacement, load at 3 mm displacement, and maximum load were evaluated. Results Comparing 8/8 foam to 20/8 foam, load at 3 mm displacement and maximum load were significantly decreased (P<0.05) with decreased bone quality for anchors that, even in part, relied on an interference fit suture locking mechanism (ie, 4.5 mm PushLock, 5.5 mm SwiveLock, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S). Bone quality did not affect the mechanical performance of 5.5 mm SpeedScrew anchors which have an isolated internal locking mechanism. Conclusion The mechanical performance of anchors that relied, even in part, on interference fit were affected by bone quality. Isolated internal locking knotless suture anchors functioned independently of bone quality. Anchors with a combined type (interference fit and internal locking) suture locking mechanism demonstrated similar mechanical performance to isolated internal locking anchors in osteopenic foam comparing similar sized anchors. Clinical relevance In osteopenic bone, knotless suture anchors that have an internal locking mechanism (isolated or combined type) may be advantageous for secure tendon fixation to bone. PMID:26124683

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

    PubMed Central

    2014-01-01

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

  5. In vitro biomechanical comparison of six different fixation methods following 5-mm sagittal split advancement osteotomies.

    PubMed

    Oguz, Y; Watanabe, E R; Reis, J M; Spin-Neto, R; Gabrielli, M A; Pereira-Filho, V A

    2015-08-01

    The sagittal split ramus osteotomy (SSRO) is a surgical technique used widely to treat many congenital and acquired mandibular discrepancies. Stabilization of the osteotomy site and the potential for skeletal relapse after the procedure are still major problems. The aim of this study was to compare the mechanical stability of six methods of rigid fixation in SSRO using a biomechanical test model. Sixty polyurethane replicas of human hemimandibles were divided into six groups. In group I, the osteotomies were fixed with two four-hole titanium miniplates; in group II, with one four-hole miniplate; in group III, with one four-hole miniplate+a bicortical screw; in group IV, with a grid miniplate; in group V, with a four-hole locking miniplate; and in group VI, with a six-hole miniplate. A linear load in the premolar region was applied to the hemimandibles. The resistance forces (N) needed to displace the distal segment by 1, 3, and 5mm were recorded and the data transmitted from the load cell to a computer. One-way analysis of variance with Tukey's post hoc test was performed to compare the means between groups. For the three displacement conditions, there was a strong tendency for the 2.0-mm plate+screw and the grid plate to have higher values. PMID:25840861

  6. Photographic fixative poisoning

    MedlinePLUS

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

  7. Safe Osteocutaneous Radial Forearm Flap Harvest with Prophylactic Internal Fixation

    PubMed Central

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

    2011-01-01

    We studied the efficacy of prophylactic plate fixation technique and a modified harvest of the osteocutaneous radial forearm free flap (OCRFFF) to minimize the incidence of postoperative donor radius pathological fracture. We retrospectively studied of the first 70 consecutive patients undergoing OCRFFF harvest by the University of Kansas Head and Neck Microvascular Reconstruction Team. Mean follow-up was 13 months. One of two patients undergoing OCRFFF harvest without prophylactic fixation developed a pathological radius fracture. The 68 subsequent OCRFFF patients underwent prophylactic fixation of the donor radius, and none developed a symptomatic radius fracture. Five of 68 patients did have a radiographically visible fracture requiring no intervention. The plate fixation technique was further modified to exclude monocortical screws in the radius bone donor defect (subsequent 39 patients), without any further fractures detected. One patient required forearm hardware removal for an attritional extensor tendon tear. The described modified OCRFFF harvest and prophylactic plate fixation technique may eliminate postoperative pathological fracture of the donor radius. Donor morbidity is similar to that of the fasciocutaneous radial forearm free flap , affording safe use of OCRFFF in head and neck reconstruction. PMID:22942941

  8. Safe osteocutaneous radial forearm flap harvest with prophylactic internal fixation.

    PubMed

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

    2011-09-01

    We studied the efficacy of prophylactic plate fixation technique and a modified harvest of the osteocutaneous radial forearm free flap (OCRFFF) to minimize the incidence of postoperative donor radius pathological fracture. We retrospectively studied of the first 70 consecutive patients undergoing OCRFFF harvest by the University of Kansas Head and Neck Microvascular Reconstruction Team. Mean follow-up was 13 months. One of two patients undergoing OCRFFF harvest without prophylactic fixation developed a pathological radius fracture. The 68 subsequent OCRFFF patients underwent prophylactic fixation of the donor radius, and none developed a symptomatic radius fracture. Five of 68 patients did have a radiographically visible fracture requiring no intervention. The plate fixation technique was further modified to exclude monocortical screws in the radius bone donor defect (subsequent 39 patients), without any further fractures detected. One patient required forearm hardware removal for an attritional extensor tendon tear. The described modified OCRFFF harvest and prophylactic plate fixation technique may eliminate postoperative pathological fracture of the donor radius. Donor morbidity is similar to that of the fasciocutaneous radial forearm free flap , affording safe use of OCRFFF in head and neck reconstruction. PMID:22942941

  9. Plate Tectonics: Plate Interactions

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2006-11-01

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

  10. Management of fractures of the distal third tibia by minimally invasive plate osteosynthesis – A prospective series of 50 patients

    PubMed Central

    Paluvadi, Siddhartha Venkata; Lal, Hitesh; Mittal, Deepak; Vidyarthi, Kandarp

    2014-01-01

    Background Minimally invasive plate osteosynthesis (MIPO) is an established technique for fixation of fractures of the distal third tibia. Our study aimed to manage intra articular and extraarticular fractures of the distal third tibia by the minimally invasive plate osteosynthesis technique and follow them prospectively. Clinical and radiological outcomes were studied and clinical indications & efficacy of the procedure reviewed. Though many studies on the subject have been done previously, these have been retrospective reviews or small series. Methods From May 2010 to May 2013, 50 patients of closed distal tibial fractures were operated by MIPO technique with a distal tibial anatomical locking plate having 4.5/5 proximal and 3.5/4 distal screw holes. The follow up duration was for 3 years. Results The mean fracture healing time was 21.4 weeks (range 16–32 weeks) and average AOFAS score 95.06 was out of a total possible 100 points. At last follow up, superficial infection occurred in 5 patients (10%); deep infection, implant failure and malunion in 1-patient each (2%). Conclusion MIPO technique provides good, though slightly delayed bone healing and decreases incidence of nonunion and need for bone grafting. This technique should be used in distal tibia fractures where locked nailing cannot be done like fractures with small distal metaphyseal fragments, vertical splits, markedly comminuted fractures and in fractures with intra-articular extension. PMID:25983486

  11. Stephen Crews Lab February 21, 2009 Embryo Fixation

    E-print Network

    Crews, Stephen

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

  12. Minimal locked trees

    E-print Network

    Ballinger, Brad

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

  13. Alternative methods in fixation for capital osteotomies in hallux valgus surgery.

    PubMed

    Zelen, Charles M; Young, Nathan J

    2013-07-01

    The surgical correction of hallux valgus has evolved since it was first described. Many osteotomies and fixation methods have been described and results have improved. Innovative new fixation methods include the Mini TightRope, new absorbable implants, and plating options. This article discusses the evolution of capital osteotomies as well as the evolution of fixation. Also presented is a case study of a novel method of achieving solid fixation across an osteotomy using a high-frequency sonic device to insert a bioresorbable pin. PMID:23827488

  14. Overview of locking systems

    SciTech Connect

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

    1993-12-01

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

  15. Lock For Valve Stem

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.; Guirguis, Kamal S.

    1991-01-01

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

  16. Update: Biological Nitrogen Fixation.

    ERIC Educational Resources Information Center

    Wiseman, Alan; And Others

    1985-01-01

    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,…

  17. The Fixation of Nitrogen.

    ERIC Educational Resources Information Center

    Andrew, S. P. S.

    1978-01-01

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

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

    PubMed Central

    2013-01-01

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

  19. Sternal salvage with rigid fixation in the setting of a massive mediastinal aortic pseudoaneurysm: a case report and review of the literature.

    PubMed

    Shifrin, David A; Sohn, Samuel M; Stouffer, Chadwick W; Hooker, Robert L; Renucci, John D

    2008-10-01

    Reconstruction of sternal nonunion following surgical resection can be difficult. Presented here is a case of sternal salvage with rigid fixation in the face of a massive aortic pseudoaneurysm. Plating is a safe and efficient technique that provides bone approximation and results in long term rigid sternal fixation. This case report highlights the history and biomechanical theory and examines the safety and clinical outcomes of sternal reconstruction with plating fixation. PMID:18033747

  20. Dorsal Plating of Unstable Distal Radius Fractures Using a Bio-Absorbable Plating System and Bone Substitute

    Microsoft Academic Search

    S. GANGOPADHYAY; K. RAVI; G. PACKER

    2006-01-01

    This study reports the results of open reduction and internal fixation of 26 unstable, intraarticular, dorsally displaced fractures of the distal radius using a bio-absorbable dorsal distal radius (Reunite) plate and calcium phosphate (Biobon) bone substitute. The bio-absorbable plate has the advantage of being low profile, easily contourable and angularly stable. In the majority of cases, this plate produces functional

  1. Quick-Change Anode for Plating

    NASA Technical Reports Server (NTRS)

    Beasley, J. L.

    1987-01-01

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

  2. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

    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.

  3. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

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

  4. Plate TectonicsPlate Tectonics Plate TectonicsPlate Tectonics

    E-print Network

    Siebel, Wolfgang

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

  5. Tangential views of the articular surface of the distal radius—aid to open reduction and internal fixation of fractures

    Microsoft Academic Search

    Deepak Kumar; L Breakwell; S. C Deshmukh; B. K Singh

    2001-01-01

    Open reduction and internal fixation of comminuted, displaced intra-articular or potentially unstable fractures of the distal radius with plate and screws has increasingly become a favoured treatment. Intra-operative assessment of fixation with the help of an image intensifier has always been difficult because of the anatomy of the distal radius. Imaging of the implants placed as distal as possible to

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

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

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

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

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

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

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

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

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

  9. How A Lock Works

    NSDL National Science Digital Library

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

  10. Occipito-cervical fusion using posterior titanium plates

    Microsoft Academic Search

    I. H. Lieberman; J. K. Webb

    1998-01-01

    Occipito-cervical fusion may be indicated for instability of the occipito-cervical junction or atlanto-axial spine secondary\\u000a to a wide spectrum of pathology. Many techniques exist to stabilize the spine until fusion is achieved. Recent reports of\\u000a plate fixation have been favorable. In this study we set out to determine the effectiveness and advantages of titanium plate\\u000a fixation when used to stabilize

  11. Absorbable biologically based internal fixation.

    PubMed

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

    2015-01-01

    Absorbable devices for use in internal fixation have advanced over the years to become reliable and cost-effective alternatives to metallic hardware. In the past, biodegradable fixation involved a laborious implantation process, and induced osteolysis and inflammatory reactions. Modern iterations exhibit increased strength, smoother resorption, and lower rates of reactivity. A newer generation manufactured from silk has emerged that may address existing limitations and provide a greater range of fixation applications. PMID:25440418

  12. Management of equine skull fractures using fixation with polydioxanone sutures.

    PubMed

    Schaaf, K L; Kannegieter, N J; Lovell, D K

    2008-12-01

    Ten horses presented with severe distortion of the facial contour, crepitus on palpation and mild to moderate epistaxis. Individual horses also showed ocular damage, ptosis, severe dyspnoea and movement of the facial bones concurrent with respiration. The fracture fragments were exposed using a large curvilinear incision and elevated using a retractor, periosteal elevator, chisel or Steinmann pin. The fracture fragments were unstable following reduction and fixation was necessary. Stabilisation was achieved with polydioxanone sutures placed through holes drilled in opposing sides of the fracture lines. Polydioxanone sutures provided good stability and had better handling properties than wire. There was good apposition of fracture edges and minimal complications. Use of polydioxanone sutures can also avoid the expense and complexity of plate fixation in selected cases, and should be considered as an alternative to fixation with stainless steel wire in any facial fracture that adjoins stable bone. PMID:19076771

  13. Nitrogen fixation apparatus

    DOEpatents

    Chen, Hao-Lin (Walnut Creek, CA)

    1984-01-01

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

  14. Rotatable stem and lock

    DOEpatents

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

    1984-01-01

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

  15. Rotatable stem and lock

    DOEpatents

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

    1981-10-27

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

  16. Perforation of the Third Extensor Compartment by the Drill Bit During Palmar Plating of the Distal Radius

    Microsoft Academic Search

    W. PICHLER; W. GRECHENIG; H. CLEMENT; G. WINDISCH; N. P. TESCH

    2009-01-01

    The frequency of penetration into the third extensor compartment when drilling the distal screw holes was assessed for four different palmar distal radius plates in 160 cadaver forearms. Penetration into this compartment occurred in 43%. Different plates had different penetration rates: 3.5 LCP four-hole locking T-plate: 20%, 3.5 LCP three-hole locking plate: 42.5%, 2.4 palmar LCP standard plate and the

  17. Eighth international congress on nitrogen fixation

    SciTech Connect

    Not Available

    1990-01-01

    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.

  18. DINITROGEN FIXATION IN ILLINOIS BUNDLEFLOWER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMillan] is a warm-season perennial forage legume that may serve as a pulse crop. Its productivity is influenced by its N2 fixation capability. Our objective was to estimate symbiotic N2 fixation of three Illinois bundleflower accessions from ...

  19. Overdesign of external fixation systems.

    PubMed

    Habboushe, M P

    1992-05-01

    This article reviews 850 cases of open fractures of the extremities caused by high velocity missiles and shell fragments, and treated by two varieties of external fixation devices. If a protocol for grading the severity of injury is followed, the results encourage avoiding sophisticated, expensive, and overdesigned external fixation systems. PMID:1589355

  20. Surgical rib fixation - technical aspects.

    PubMed

    Marasco, Silvana; Saxena, Pankaj

    2015-05-01

    Surgical rib fixation (SRF) for severe rib fracture injuries is increasingly becoming an accepted treatment modality. There is now adequate evidence in randomised controlled trials that rib fixation in flail chest patients reduces ventilator times, intensive care stay and costs of treatment in ventilator dependent patients [1-3]. Despite this, rib fixation has not become standard of care for these patients and remains a treatment modality practised by few centres, usually those with large trauma loads who see high volumes of severe rib fracture injury patients. The purpose of this article is to outline the available prostheses, indications, operative planning and techniques of rib fixation. Surgical approaches to rib fractures in anterior, lateral and posterior positions are described as are the use of currently available cortical and medullary fixation prostheses. PMID:25624272

  1. Temporary intra-operative reduction techniques for tibial fracture fixation: A review of the literature.

    PubMed

    Beazley, J C; Hull, P

    2010-12-01

    Accurate intra-operative reduction and maintenance of reduction is essential for successful fixation of tibial fractures. Although many tibial fractures can be reduced with minimal manipulation, numerous techniques have been described to facilitate fixation of more difficult fractures. These include use of a traction table, manual traction techniques, temporary distracters, reduction clamps and temporary unicortical plating. This article reviews the literature and assesses the options available for the temporary reduction and maintenance of reduction of tibial fractures prior to definitive fixation. PMID:20691444

  2. 4. STONE BUILDER'S PLATE CANAL GATES, AND DIVERSION SPILLWAYS. ...

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

    4. STONE BUILDER'S PLATE CANAL GATES, AND DIVERSION SPILLWAYS. - Canal Road Bridge, Canal Road spanning Delaware Canal Diversion, Locks 22 & 23 in Delaware Canal State Park in Williams Township, Raubsville, Northampton County, PA

  3. The variable finesse locking technique

    Microsoft Academic Search

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

    2006-01-01

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

  4. Concept of variable angle locking-evolution and mechanical evaluation of a recent technology.

    PubMed

    Lenz, Mark; Wahl, Dieter; Gueorguiev, Boyko; Jupiter, Jesse B; Perren, Stephan Marcel

    2015-07-01

    Applications for fracture-adapted screw positioning offered by variable angle locking screws are increasing. The locking strength of the variable angle locking mechanism at different insertion angles was compared to conventional fixed angle locking screws. Stainless steel (S) and titanium (Ti) variable and fixed angle 2.4?mm locking screws, inserted at different inclinations (0°-15°), and locked at 0.8?Nm were subjected to a load-to-failure test. Ultimate failure moment at the screw-head interface and failure mode of the screws were determined. Significant differences were detected by one-way ANOVA (p?locking screws inserted at 2°-10° inclination exhibited a failure moment comparable to the 0° position (S 1.67±?0.04?Nm; Ti 1.67?±?0.14?Nm) and failed predominantly at the screw neck, with the head remaining fixed to the plate. Inserted at 15° inclination, screws revealed a lower failure moment (S 1.33?±?0.06?Nm, Ti 1.58?±?0.05Nm), and failed predominantly by breakout of the head thread. Fixed angle locking screws inserted at an inclination >2° did not lock properly in the plate hole, providing insufficient locking strength. Variable angle locking screws offer a stable head-locking mechanism at different inclinations, comparable to the locking strength of orthogonal inserted fixed angle locking screws. Marginal inclinations >15° should be used with care. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:988-992, 2015. PMID:25676391

  5. Indications and techniques for anterior cervical plating.

    PubMed

    Rhee, John M; Park, Jong-Beom; Yang, Jun-Young; Riew, Daniel K

    2005-12-01

    Anterior cervical plating is commonly performed to stabilize anterior cervical fusions. Modern plating options include dynamic plates, with screws that can either toggle within fixed holes or translate within slotted holes. Regardless of the plating system used, paramount to success and avoidance of complications with plated anterior cervical fusions are meticulous plating techniques, exacting graft carpentry, and understanding the biomechanical limitations of plating in certain situations, such as multilevel corpectomies reconstructed with a single-strut graft. In order to prevent graft-related complications associated with long-strut grafts, additional posterior fixation and fusion, or alternative corpectomy constructs, such as multilevel anterior cervical discectomy and fusion, corpectomy-discectomy, and corpectomy-corpectomy, should be considered instead if the pattern of stenosis allows. PMID:16565534

  6. Plate Tectonics

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2007-03-21

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

  7. Plate motion

    SciTech Connect

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

    1991-01-01

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

  8. PEEK and LOCK

    E-print Network

    III, Donald Eastlake

    1968-11-01

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

  9. ''Old'' locked inflation

    SciTech Connect

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

    2009-05-15

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

  10. The Digital Locke Project

    NSDL National Science Digital Library

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

  11. Locking Nut and Bolt

    NASA Technical Reports Server (NTRS)

    Bishop, R.

    1983-01-01

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

  12. Plate Tectonics

    NSDL National Science Digital Library

    Mrs. Rohlfing

    2011-02-03

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

  13. Failure of posterior titanium atlantoaxial cable fixation

    Microsoft Academic Search

    Rolando Garcia; Stephen Gorin

    2003-01-01

    Background context: The operative treatment of rotatory atlantoaxial instability remains controversial. The use of cable fixation has largely replaced the use of wire for interlaminar fixation. Although cable fixation offers biomechanical advantages over wire fixation, it is still at risk of fatigue failure. The authors were unable to locate any published reports of fatigue failure of titanium cables in the

  14. Fracture risk and initial fixation of a cementless glenoid implant: the effect of numbers and types of screws.

    PubMed

    Suarez, Daniel R; Valstar, Edward R; Rozing, Piet M; van Keulen, Fred

    2013-10-01

    The initial fixation of an anatomical cementless glenoid component, provided by different numbers and types of screws, and the risk of bone fracture were evaluated by estimating the bone-implant interface micromotions and the principal strains around the prosthesis. Four different fixation configurations using locking or compression screws were tested. Estimation of the micromotions at the bone-implant interface was performed both experimentally, using an in vitro model, and computationally, using a numerical model. Principal bone strains were estimated using the numerical model. Subject variability was included by modelling two different bone qualities (healthy and rheumatoid bone). For the fixation configurations that used two screws, experimental and modelling results found that the micromotions at the bone-implant interface did not change with screw type. However, screw type had a significant effect on fixation when only one screw was used; in this case, a locking screw resulted in less micromotion at the bone-implant interface compared with the compression screw. Bone strains were predicted by the numerical model, and strains were found to be independent of the screw type; however, the predicted strain levels calculated in rheumatoid bone were larger than the strain levels that may cause bone damage for most considered arm positions. Predicted bone strain in healthy bone did not reach this level. While proper initial component fixation that allows biological fixation can be achieved by using additional screws, the risk of bone failure around the screws must be considered, especially in cases of weak bone. PMID:23804951

  15. Plate Boundaries

    NSDL National Science Digital Library

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

  16. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  17. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  18. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit squarely...

  19. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  20. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  1. Wound complication of minimally invasive plate osteosynthesis in distal tibia fractures

    PubMed Central

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

    2007-01-01

    Nowadays, the use of minimally invasive plate osteosynthesis (MIPO) in the management of fracture of the distal tibia is common. The various advantages of the MIPO technique, namely, preserving blood supply and better bone healing, have been described extensively in the literature. However, this technique is not without complication. Among all the complications, infection is one of the commonest. In the last 3 years, we have performed 48 cases of MIPO in treating distal tibia fractures. Our study was to evaluate the clinical outcome of these cases, with special attention to the infection rate and our experience in managing these infection cases. Our results showed that the average time until the patient started to bear full weight was 9.4 weeks. The average time for bony union was 18.7 weeks. There were 7 cases of late infection among these 48 cases. The rate was 15%. The presence of late infection had no obvious effect on the time to bony union. Twenty-five patients (52%) had the implants removed and the most common reason was skin impingement by the implant. The clinical presentation and management of these late infections are discussed. In conclusion, MIPO fixation of distal tibia fractures using a metaphyseal locking plate is safe and efficient. However, complications such as late wound infection and impingement are relatively common. The overall clinical outcome is still good despite the presence of these complications. PMID:17572892

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

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

    PubMed

    Stuck, B A; Heller, T

    2011-11-01

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

  4. Revision of anterior cervical pseudoarthrosis with anterior allograft fusion and plating.

    PubMed

    Coric, D; Branch, C L; Jenkins, J D

    1997-06-01

    Anterior cervical discectomy and fusion is an efficacious procedure used to treat a variety of cervical spinal disorders, including spondylosis, myelopathy, herniated discs, trauma, and degenerative disc disease. Pseudarthrosis, or failure of fusion, may be the most common complication of spinal fusion procedures. Nineteen consecutive patients with symptomatic pseudarthrosis following failed anterior cervical fusions were treated with anterior cervical revision using iliac crest allografts and either the Cervical Spine Locking Plate system (10 patients) or the Trapezial Osteosynthetic Plate system (nine patients). The mean age of the nine men and 10 women undergoing treatment was 49.1 years (range 25-72 years). Eleven patients (57.9%) exhibited pseudarthrosis at one level, six (31.5%) at two levels, and two (10.5%) at three levels. The indications for revision were intractable neck pain with radiculopathy (17 patients) or myelopathy (two patients), with evidence of pseudarthrosis on plain cervical radiography as well as computerized tomography (CT) or single-photon emission computerized tomography (SPECT) scanning, or both. All eight patients evaluated with SPECT showed increased focal uptake consistent with pseudarthrosis, which was subsequently confirmed intraoperatively in all eight. The average follow-up period was 22.4 months (range 12-42 months). Solid osseous fusion was achieved over all 28 levels in all 18 patients available for follow-up review (100%). One patient died 4 months postoperatively from myocardial infarction related to preexisting coronary artery disease. There were no intraoperative complications; postoperatively, two patients (10.5%) experienced transient hoarseness. Anterior revision of failed cervical fusions using allograft interbody fusion material and anterior plating is a safe and efficacious procedure. In this series, the use of allografts avoided donor site morbidity without adversely affecting fusion rates. Rigid internal fixation was achieved by means of anterior plating without increasing surgical morbidity rates. The SPECT imaging technique has the potential to reliably confirm the diagnosis of pseudarthrosis. PMID:9171175

  5. Plate Tectonics

    NSDL National Science Digital Library

    Smoothstone

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

  6. Plate Tectonics

    NSDL National Science Digital Library

    Mrs. Walls

    2011-01-30

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

  7. Injection locking of excimer lasers

    SciTech Connect

    Bigio, I.J.; Slatkine, M.

    1981-01-01

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

  8. Tectonic Plates and Plate Boundaries

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2005-12-17

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

  9. Observation of two distinct phase states in a self-phase-locked type II phase-matched optical parametric oscillator.

    PubMed

    Mason, E J; Wong, N C

    1998-11-15

    We demonstrate self-phase locking in a type II phase-matched optical parametric oscillator by mutual injection locking. An intracavity quarter-wave plate provides polarization mixing between the orthogonally polarized signal and idler that induces signal-idler self-phase locking when their frequency difference is within the capture range. We observed two distinct phase states that differ in their oscillator thresholds and their signal-idler phase differences, in good agreement with theory. PMID:18091897

  10. A new adhesive technique for internal fixation in midfacial surgery

    PubMed Central

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

    2008-01-01

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

  11. Volar fixation for dorsally displaced fractures of the distal radius: A preliminary report

    Microsoft Academic Search

    Jorge L. Orbay; Diego L. Fernandez

    2002-01-01

    Using a volar approach to avoid the soft tissue problems associated with dorsal plating, we treated a consecutive series of 29 patients with 31 dorsally displaced, unstable distal radial fractures with a new fixed-angle internal fixation device. At a minimal follow-up time of 12 months the fractures had healed with highly satisfactory radiographic and functional results. The final volar tilt

  12. Quantum noise locking

    Microsoft Academic Search

    Kirk McKenzie; Eugeniy E. Mikhailov; Keisuke Goda; Ping Koy Lam; Nicolai Grosse; Malcolm B. Gray; Nergis Mavalvala; David E. McClelland

    2005-01-01

    Quantum optical states which have no coherent amplitude, such as squeezed vacuum states, cannot rely on standard readout techniques to generate error signals for control of the quadrature phase. Here we investigate the use of asymmetry in the quadrature variances to obtain a phase-sensitive readout and to lock the phase of a squeezed vacuum state, a technique which we call

  13. Self-Locking Connector

    NASA Technical Reports Server (NTRS)

    Gaspar, K.

    1983-01-01

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

  14. Positioning and locking apparatus

    DOEpatents

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

    1985-06-19

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

  15. Lock for hydraulic actuators

    NASA Technical Reports Server (NTRS)

    Wood, R. H.

    1981-01-01

    Two clamps hold rod in fixed extension from cylinder even when power is off, converting actuator into stiff structural member. Locked actuator is useful as mechanical support or linkage or as fail-safe device in case of loss of hydraulic pressure. Potential applications include manufacturing processes and specialized handling and holding devices.

  16. Molybdenum Trafficking for Nitrogen Fixation

    PubMed Central

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

    2009-01-01

    The molybdenum nitrogenase is responsible for most biological nitrogen fixation, a prokaryotic metabolic process that determines the global biogeochemical cycles of nitrogen and carbon. Here we describe the trafficking of molybdenum for nitrogen fixation in the model diazotrophic bacterium Azotobacter vinelandii. The genes and proteins involved in molybdenum uptake, homeostasis, storage, regulation, and nitrogenase cofactor biosynthesis are reviewed. Molybdenum biochemistry in A. vinelandii reveals unexpected mechanisms and a new role for iron-sulfur clusters in the sequestration and delivery of molybdenum. PMID:19772354

  17. Complement fixation test to C. burnetii

    MedlinePLUS

    The complement fixation test to C. burnetii is a blood test that checks for infection due to bacterium called ... for Coxiella antibodies using a laboratory method called complement fixation. This technique checks if the body has ...

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

    PubMed Central

    Howat, William J.; Wilson, Beverley A.

    2014-01-01

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

  19. CARBON FIXATION BY CULTURED CLAMSCARBON FIXATION BY CULTURED CLAMSCARBON FIXATION BY CULTURED CLAMSCARBON FIXATION BY CULTURED CLAMS Patrick BakerPatrick Baker

    E-print Network

    Florida, University of

    CARBON FIXATION BY CULTURED CLAMSCARBON FIXATION BY CULTURED CLAMSCARBON FIXATION BY CULTURED, Gainesville, FL, USA Clam Farming in FloridaClam Farming in Florida Calculating Carbon per Clam Bag E t l th E th g Calculating Carbon per Clam Bag Eat a clam, save the EarthEat a clam, save the Earth · Northern

  20. FIXATIVES AND EMBEDDING MEDIA FOR IMMUNOCYTOCHEMISTRY

    Microsoft Academic Search

    B. B. Rawdon

    1998-01-01

    In this article fixation and embedding procedures compatible with preparation of animal tissues for immunocytochemistry are reviewed. A number of methods is available for light microscopic immunocytochemistry: these include cryostat, freeze-dried and wax sections of tissue fixed with either vapour or immersion fixatives. Use of the microwave oven to fix tissues for immunocytochemistry is also discussed. Fixation methods for immuno-electron

  1. Occipital condyle to cervical spine fixation in the pediatric population.

    PubMed

    Kosnik-Infinger, Libby; Glazier, Steven S; Frankel, Bruce M

    2014-01-01

    Fixation at the craniovertebral junction (CVJ) is necessary in a variety of pediatric clinical scenarios. Traditionally an occipital bone to cervical fusion is preformed, which requires a large amount of hardware to be placed on the occiput of a child. If a patient has previously undergone a posterior fossa decompression or requires a decompression at the time of the fusion procedure, it can be difficult to anchor a plate to the occipital bone. The authors propose a technique that can be used when faced with this difficult challenge by using the occipital condyle as a point of fixation for the construct. Adult cadaveric and a limited number of case studies have been published using occipital condyle (C-0) fixation. This work was adapted for the pediatric population. Between 2009 and 2012, 4 children underwent occipital condyle to axial or subaxial spine fixation. One patient had previously undergone posterior fossa surgery for tumor resection, and 1 required decompression at the time of operation. Two patients underwent preoperative deformity reduction using traction. One child had a Chiari malformation Type I. Each procedure was performed using polyaxial screw-rod constructs with intraoperative neuronavigation supplemented by a custom navigational drill guide. Smooth-shanked 3.5-mm polyaxial screws, ranging in length from 26 to 32 mm, were placed into the occipital condyles. All patients successfully underwent occipital condyle to cervical spine fixation. In 3 patients the construct extended from C-0 to C-2, and in 1 from C-0 to T-2. Patients with preoperative halo stabilization were placed in a cervical collar postoperatively. There were no new postoperative neurological deficits or vascular injuries. Each patient underwent postoperative CT, demonstrating excellent screw placement and evidence of solid fusion. Occipital condyle fixation is an effective option in pediatric patients requiring occipitocervical fusion for treatment of deformity and/or instability at the CVJ. The use of intraoperative neuronavigation allows for safe placement of screws into C-0, especially when faced with a challenging patient in whom fixation to the occipital bone is not possible or is less than ideal. PMID:24206344

  2. Transit Fixatives: An Innovative Study

    PubMed Central

    A, Ravi Prakash; G, Sreenath; JK, Sonia Bai; NDVN, Shyam

    2015-01-01

    Background: Universally accepted fixative is 10% formalin which has been used for preserving the tissues and their architecture. In certain conditions, formalin might not be readily available for immediate fixation. We here by explore more economical, eco-friendly and easily available solutions that can be used as transit media/ transporting media for tissue specimens. Materials and Methods: The study included commonly available solutions like Spirit, Saline, Betadine solution, Hydrogen peroxide (H2O2), Local anesthesia (L.A), Rose water, Coconut oil, Coconut water, Ice cold water, Honey and Milk while keeping formalin as control. The fresh tissue sample was cut into multiple bits and placed in different containers for a period of 8 hours before transferring to formalin solution. Conclusion: Transit fixatives are very important in certain situations where formalin is not readily available. These fixatives can be used to fix the tissues for a period of at least 8 hours without causing any damage or distortion before they are fixed in formalin solution. PMID:25954725

  3. COMPARISON OF TWO MODERATELY THICK PLATE ELEMENTS BASED ON THE ABSOLUTE NODAL COORDINATE FORMULATION

    Microsoft Academic Search

    Marko K. Matikainen; A. L. Schwab; Aki M. Mikkola

    2009-01-01

    Two formulations for a flexible 3-D quadrilateral moderatelythick plate element based on the absolute nodal coordinate formulation are comp ared. The two approaches consist of a fully parameterized plate element and a fully parameter ized plate element with linearized transverse shear angles to overcome slow convergence and cu rvature locking. For the sake of verification of the formulations and numerical

  4. Releasable Locking Mechanisms

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  5. Frequency comb injection locking of mode locked lasers

    NASA Astrophysics Data System (ADS)

    Gat, Omri; Kielpinski, David

    2013-03-01

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

  6. Plate Tectonics

    NSDL National Science Digital Library

    2006-01-01

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

  7. A Fast-Locking Digital Phase-Locked Loop

    Microsoft Academic Search

    Mahmoud Fawzy Wagdy; Srishti Vaishnava

    2006-01-01

    A conventional digital phase-locked loop (DPLL) is designed using (Baker et al., 2003) to operate at 1GHz using 0.18 mum CMOS technology; its lock time is 4.19 mus. By adding a coarse\\/fine tuning control unit composed of a digital-to-analog converter (DAC) and a counter as well as switching the currents of the charge pump, a fast-locking DPLL results, with a

  8. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Mechanical locking required in accordance...and Instructions § 236.338 Mechanical locking required in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance...

  9. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  10. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  11. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  12. 4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON ...

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

    4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON RIGHT. 20TH CENTURY ELECTRIC LIFT LOCKS ON LEFT. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

  13. Modernization of the Hydrostatic Drive of Lower Gate Locks in Waterworks Gabcikovo

    NASA Astrophysics Data System (ADS)

    Stra?ár, Karol

    2011-12-01

    This paper deals with analysis of the combined load on hydraulic cylinder. Based on measurements of the parameters of the hydraulic cylinder and accurate calculations conclusions were drawn. Measurements were made on the lower hydrostatic drive gate locks at the waterworks Gabcikovo. Method of fixation of the hydraulic cylinder creates added bending torques which causes deformation of piston rod. The results are an effort to find relationship between dimensions, loading and safe operation.

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

    PubMed

    Huang, Weijie; Luo, Tao

    2013-03-01

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

  15. Reversed Contralateral LISS Plate for Vancouver B1 Periprosthetic Femoral Shaft Fractures.

    PubMed

    Russo, Matthew; Malekzadeh, A Stephen; Hampton, Chadwick; Hymes, Robert; Schwartzbach, Cary; Schulman, Jeffrey

    2015-06-01

    The authors reviewed all patients treated for periprosthetic femur fractures between March 1, 2007, and January 31, 2010 at the senior author's institution. Demographic features, mechanism of injury, radiographs, and computed tomography scans were reviewed to determine the type and stability of the femoral implant at the time of injury. All Vancouver B1 fractures were treated with a novel technique that used a contoured distal femoral locking plate intended for the contralateral femur and reversed to accommodate the ipsilateral femoral bow and contour of the proximal femur. Fixation was achieved around the implant with percutaneously placed unicortical and/or bicortical screws. Radiographs were reviewed for fracture healing, malunion, implant failure, and prosthetic loosening. Fifteen patients were identified and underwent the procedure as described. One patient died soon after surgery of complications from a ruptured preexisting esophageal ulcer. Of the remaining 14 patients, the average duration of follow-up was 25 months (range, 6-31 months). Two patients did not achieve union; however, repeat interpretation of the presenting radiographs showed likely misdiagnosed Vancouver B2 fractures. The first patient had late aseptic loosening and underwent revision surgery 22 weeks postoperatively. The other had early loss of fixation that required revision with a long stem prosthesis. Other complications included 1 deep venous thrombosis and 2 superficial wound infections. The infections were successfully treated with a single formal irrigation and debridement, primary closure, and a short course of oral antibiotics. Ultimately, in 86% of patients (12/14), fracture healing occurred with this biologically friendly technique. [Orthopedics. 2015; 38(6):e467-e472.]. PMID:26091218

  16. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  17. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  18. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

  19. Proximal humeral fractures: pin, plate, or replace.

    PubMed

    Neviaser, Robert J; Resch, Herbert; Neviaser, Andrew S; Crosby, Lynn A

    2015-01-01

    Proximal humeral fractures are becoming increasingly common in individuals older than 60 years, with only fractures of the hip and distal radius occurring with a higher frequency. Most proximal humeral fractures can be managed without surgery; however, if a fracture is displaced or angulated, surgical treatment may be required. There are four main options for the surgical management of proximal humeral fractures: minimally invasive percutaneous reduction and fixation, open reduction and periarticular plating, hemiarthroplasty, and reverse total shoulder arthroplasty. PMID:25745906

  20. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  1. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  2. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 4 2014-10-01 2014-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other...DEVICES, AND APPLIANCES Definitions § 236.765 Locking, mechanical. An arrangement of locking bars, dogs, tappets,...

  3. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  4. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  5. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  6. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  7. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  8. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  9. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...4 2014-10-01 2014-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation...Interlocking Inspection and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall...

  10. 49 CFR 236.329 - Bolt lock.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 4 2011-10-01 2011-10-01 false Bolt lock. 236.329 Section 236.329 Transportation...Interlocking Rules and Instructions § 236.329 Bolt lock. Bolt lock shall be so maintained that signal governing...

  11. 49 CFR 236.329 - Bolt lock.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 4 2012-10-01 2012-10-01 false Bolt lock. 236.329 Section 236.329 Transportation...Interlocking Rules and Instructions § 236.329 Bolt lock. Bolt lock shall be so maintained that signal governing...

  12. 49 CFR 236.329 - Bolt lock.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Bolt lock. 236.329 Section 236.329 Transportation...Interlocking Rules and Instructions § 236.329 Bolt lock. Bolt lock shall be so maintained that signal governing...

  13. 49 CFR 236.329 - Bolt lock.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 4 2013-10-01 2013-10-01 false Bolt lock. 236.329 Section 236.329 Transportation...Interlocking Rules and Instructions § 236.329 Bolt lock. Bolt lock shall be so maintained that signal governing...

  14. 49 CFR 236.329 - Bolt lock.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 4 2014-10-01 2014-10-01 false Bolt lock. 236.329 Section 236.329 Transportation...Interlocking Rules and Instructions § 236.329 Bolt lock. Bolt lock shall be so maintained that signal governing...

  15. Peen plating

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  16. Plate Tectonics

    NSDL National Science Digital Library

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

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

    PubMed

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

    2013-06-01

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

  18. Is distal locking of long nails for intertrochanteric fractures necessary? A clinical study

    PubMed Central

    Vopat, Bryan G.; Kane, Patrick M.; Truntzer, Jeremy; McClure, Philip; Paller, David; Abbood, Emily; Born, Christopher

    2014-01-01

    Background Few clinical studies have examined the utility of distal interlocking nails when fixing intertrochanteric fractures with intramedullary devices. In this study we performed a retrospective analysis comparing fixation method of intertrochanteric fractures with either a long unlocked cephalomedullary nail versus a long locked cephalomedullary nail. Our hypothesis was there would be no difference in device related failures or complications in stable intertrochanteric fractures treated with long locked or long unlocked cephalomedullary nails. Methods A retrospective chart review was performed of all stable intertrochanteric fractures treated with a long cephalomedullary nail between 2006 and 2012 at our institution. Clinical history as well as perioperative radiography was carefully reviewed for all subjects. AO classification, the use of locked or unlocked technique, and failure status was recorded. Results Overall, a device related failure rate of 1.8% (2/107) was observed for stable intertrochanteric fractures treated with long cephalomedullary nails. No statistical difference in failure rate was found between locked and unlocked nails within our studied population (0% long locked (0/56) versus 3.9% long unlocked (2/51), p = 0.224). Conclusion This clinical study supports our hypothesis that long cephalomedullary nails do not need to be locked for stable intertrochanteric fractures. We found no difference in failure rates between the two approaches across 107 patients. PMID:25983504

  19. Antifungal Lock Therapy

    PubMed Central

    Walraven, Carla J.

    2013-01-01

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

  20. Sacrospinous ligament fixation for vaginal vault prolapse

    Microsoft Academic Search

    T. Lantzsch; C. Goepel; M. Wolters; H. Koelbl; H. D. Methfessel

    2001-01-01

    Introduction. To assess intra- and postoperative complications and to look for long term follow-up results in women with sacrospinous ligament\\u000a fixation. Methods. Between 1988 and 1999, 200 women (mean age 59.8 years, range 33 to 83 years) underwent vaginal unilateral sacrospinous ligament\\u000a fixation. 172 patients had had prior hysterectomy. In 28 patients concomitant hysterectomy and sacrospinous ligament fixation\\u000a was performed.

  1. Homodyne locking of a squeezer

    E-print Network

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

    2009-07-19

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

  2. Design of a head fixation device for experiments in behaving monkeys.

    PubMed

    Isoda, Masaki; Tsutsui, Ken-Ichiro; Katsuyama, Narumi; Naganuma, Tomoka; Saito, Naohiro; Furusawa, Yoshihito; Mushiake, Hajime; Taira, Masato; Tanji, Jun

    2005-02-15

    We have designed a new device for head fixation of behaving monkeys. The fixation device consists of a duralumin head ring mounted with four screw holders. It is firmly fixed to the animal's skull with four stainless steel screw pins. The head ring is then attached to a primate chair in any desirable position and angle using a set of adjustable plates. The device has been used for behavioral training that requires accurate gaze monitoring and for recording single-unit activity over a several-month period. The advantage of our device is that it is simple to use; it can be attached readily without major surgical procedures and it can be quickly removed when experiments are not running. This head fixation system is suitable for behavioral experiments and single-unit recording studies. It may also be applicable for studies on functional imaging of the macaque brain, by constructing it of non-magnetic materials. PMID:15661310

  3. Delayed Esophageal Pseudodiverticulum after Anterior Cervical Spine Fixation: Report of 2 Cases

    PubMed Central

    Sadrizadeh, Ali; Soltani, Ehsan; Abili, Mehdi; Dehghanian, Paria

    2015-01-01

    Introduction: Although perforation of the esophagus, in the anterior cervical spine fixation, is well established, cases with delayed onset, especially cases that present pseudodiverticulum, are not common. In addition, management of the perforation in this situation is debated. Case Report: Delayed esophageal pseudodiverticulum was managed in two patients with a history of anterior spine fixation. Patients were operated on, the loose plate and screws were extracted, the wall of the diverticulum was excised, the perforation on the nasogastric tube was suboptimally repaired, and a closed suction drain was placed there. The NGT was removed on the 7th day and barium swallow demonstrated no leakage at the operation site; therefore, oral feeding was started without any problem Conclusion: In cases with delayed perforation, fistula, or diverticulum removal of anterior fixation instruments, gentle repair of the esophageal wall without persistence on definitive and optimal perforation closure, wide local drainage, early enteral nutrition via NGT, and antibiotic prescription is suggested. PMID:25938087

  4. Modeling fixation locations using spatial point processes.

    PubMed

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

    2013-01-01

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

  5. Surgical treatment of fractures of the distal radius with plates: a comparison of palmar and dorsal plate position

    Microsoft Academic Search

    Rainer Letsch; Manfred Infanger; Jörg Schmidt; Hans-Jürgen Kock

    2003-01-01

    IntroductionWhile most fractures of the distal radius can be treated successfully by conservative means, some fractures—especially the more complicated fracture types—require surgical fixation. One of the operative techniques is plate osteosynthesis, which can be performed in either a dorsal or a palmar plate position.Materials and methodsThis study reports on 122 fractures of the distal radius treated by open reduction and

  6. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Lock, electric, forced drop. 236.758 Section 236.758...Definitions § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically forced down to the locked...

  7. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Lock, electric, forced drop. 236.758 Section 236.758...Definitions § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically forced down to the locked...

  8. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Lock, electric, forced drop. 236.758 Section 236.758...Definitions § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically forced down to the locked...

  9. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Lock, electric, forced drop. 236.758 Section 236.758...Definitions § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically forced down to the locked...

  10. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Lock, electric, forced drop. 236.758 Section 236.758...Definitions § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically forced down to the locked...

  11. PERIODATE-LYSINE-PARAFORMALDEHYDE FIXATIVE A NEW FIXATIVE FOR IMMUNOELECTRON MICROSCOPY

    Microsoft Academic Search

    PAUL K. NAKANE

    A new fixative which primarily stabilizes carbohydrate moieties was developed for immunoelectron microscopy. It contains periodate, lysine and paraformaldehyde. Theoreti- cally, the carbohydrates are oxidized by periodate and cross-linked by lysine. The fixative can preserve antigenicity as well as paraformaldehyde and ultrastructure as well as glutaraldehyde. Using this fixative and the peroxidase-labeled antibody technique, base- ment membrane antigen was localized

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

    Microsoft Academic Search

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

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

  13. Carpal Canal Pressures after Volar Plating of Distal Radius Fractures

    Microsoft Academic Search

    D. A. FULLER; M. BARRETT; R. K. MARBURGER; R. HIRSCH

    2006-01-01

    Elevated pressures within the carpal canal are known to occur after distal radius fractures. Controversy exists regarding prophylactic carpal tunnel release after open reduction with internal fixation of distal radius fractures. The purpose of this study was to determine the tissue pressures within the carpal canal after volar plating of distal radius fractures. This study was a prospective, observational, IRB

  14. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, H.L.

    1983-08-16

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

  15. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, Hao-Lin (Walnut Creek, CA)

    1983-01-01

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

  16. Payload Launch Lock Mechanism

    NASA Technical Reports Server (NTRS)

    Young, Ken (Inventor); Hindle, Timothy (Inventor)

    2014-01-01

    A payload launch lock mechanism includes a base, a preload clamp, a fastener, and a shape memory alloy (SMA) actuator. The preload clamp is configured to releasibly restrain a payload. The fastener extends, along an axis, through the preload clamp and into the base, and supplies a force to the preload clamp sufficient to restrain the payload. The SMA actuator is disposed between the base and the clamp. The SMA actuator is adapted to receive electrical current and is configured, upon receipt of the electrical current, to supply a force that causes the fastener to elongate without fracturing. The preload clamp, in response to the fastener elongation, either rotates or pivots to thereby release the payload.

  17. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Tracheal tube fixation device. 868.5770 Section...Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube fixation device is a device used to...

  18. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Tracheal tube fixation device. 868.5770 Section...Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube fixation device is a device used to...

  19. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Tracheal tube fixation device. 868.5770 Section...Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube fixation device is a device used to...

  20. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Tracheal tube fixation device. 868.5770 Section...Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube fixation device is a device used to...

  1. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Tracheal tube fixation device. 868.5770 Section...Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube fixation device is a device used to...

  2. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Spinal intervertebral body fixation orthosis. 888.3060 Section 888.3060...Spinal intervertebral body fixation orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a device intended to...

  3. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Spinal intervertebral body fixation orthosis. 888.3060 Section 888.3060...Spinal intervertebral body fixation orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a device intended to...

  4. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...false Spinal interlaminal fixation orthosis. 888.3050 Section 888.3050...3050 Spinal interlaminal fixation orthosis. (a) Identification. A spinal interlaminal fixation orthosis is a device intended to...

  5. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...false Spinal interlaminal fixation orthosis. 888.3050 Section 888.3050...3050 Spinal interlaminal fixation orthosis. (a) Identification. A spinal interlaminal fixation orthosis is a device intended to...

  6. A magnetorheological fluid locking device

    NASA Astrophysics Data System (ADS)

    Kavlicoglu, Barkan; Liu, Yanming

    2011-04-01

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

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

    Microsoft Academic Search

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

    2001-01-01

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

  8. Eighth international congress on nitrogen fixation. Final program

    SciTech Connect

    Not Available

    1990-12-31

    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.

  9. Pedicle Instrumentation Failure in Thoracolumbar Fixation

    Microsoft Academic Search

    Mohamed Lotfy; Nasser M. Sayed Ahmed; Alaa A. Farag; Walid Raafat; Walid A. Badawy; Hossam Ibrahim; Islam Abou El Fotouh; Ahmed Saleh

    2007-01-01

    Objective: The authors reviewed factors related to the surgical techniques resulting in failure of the construct of the internal fixation of thoracolumbar fractures through transpedicular screw systems and how to be avoided. Patients and Methods: The authors reviewed 280 consecutive patients with traumatic thoracolumbar fractures who underwent spinal surgical fixation with short segment transpedicular screw instrumentation at three institutions, between

  10. Biochemical Approaches to Improved Nitrogen Fixation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving symbiotic nitrogen fixation by legumes has emerged again as an important topic on the world scene due to the energy crisis and lack of access to nitrogen fertilizer in developing countries. We have taken a biochemical genomics approach to improving symbiotic nitrogen fixation in legumes. L...

  11. Bioabsorbable fixation in orthopaedic surgery and traumatology

    Microsoft Academic Search

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

    2000-01-01

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

  12. Whole Animal Perfusion Fixation for Rodents

    PubMed Central

    Gage, Gregory J.; Kipke, Daryl R.; Shain, William

    2012-01-01

    The goal of fixation is to rapidly and uniformly preserve tissue in a life-like state. While placing tissue directly in fixative works well for small pieces of tissue, larger specimens like the intact brain pose a problem for immersion fixation because the fixative does not reach all regions of the tissue at the same rate 5,7. Often, changes in response to hypoxia begin before the tissue can be preserved 12. The advantage of directly perfusing fixative through the circulatory system is that the chemical can quickly reach every corner of the organism using the natural vascular network. In order to utilize the circulatory system most effectively, care must be taken to match physiological pressures 3. It is important to note that physiological pressures are dependent on the species used. Techniques for perfusion fixation vary depending on the tissue to be fixed and how the tissue will be processed following fixation. In this video, we describe a low-cost, rapid, controlled and uniform fixation procedure using 4% paraformaldehyde perfused via the vascular system: through the heart of the rat to obtain the best possible preservation of the brain for immunohistochemistry. The main advantage of this technique (vs. gravity-fed systems) is that the circulatory system is utilized most effectively. PMID:22871843

  13. [Intrascleral haptic fixation of intraocular lenses].

    PubMed

    Scharioth, G B

    2014-03-01

    Scharioth's intrascleral haptic fixation in cases of no or insufficient capsular support has become a standardized and safe procedure for long-term fixation of intraocular lenses. The surgical technique is explained in detail. The postoperative results have demonstrated a low complication rate and a lack of contraindications for this technique. PMID:24549683

  14. Nitrogen fixation in Lake Mendota, Madison, Wisconsin

    Microsoft Academic Search

    MARGUERITE SHERMAN TORREY; G. F. LEE

    1976-01-01

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

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

    E-print Network

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

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

    SciTech Connect

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

    1987-02-03

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

  17. Carbon consequences of a nitrogen fixation feedback

    NASA Astrophysics Data System (ADS)

    Levy, J.; Medvigy, D.; Hedin, L.; Batterman, S. A.; Xu, X.

    2014-12-01

    Tropical forests constitute a globally important carbon sink but it is unclear how their productivity and carbon storage depend upon nutrients. There is increasing evidence of an ecosystem carbon-nitrogen feedback mechanism, by which symbiotic dinitrogen (N2) fixing trees can provide the nitrogen needed to maintain high rates of forest biomass growth following disturbance. Field-based evaluation of this feedback is difficult, however, as the expected effects on forest carbon stores would emerge very slowly, over decades to centuries of ecological succession. Moreover, there is no known way to inhibit the fixation process in trees without causing structural damage and perturbing the carbon cycle. Coupled land biogeochemistry-vegetation models offer a way to examine the role of feedbacks that unfold over successional time. However, it is unclear how the process of nitrogen fixation ought to be represented in models so that they can capture the potential effect of fixation on the long-term forest carbon sink. In this study, we integrate a newly developed individual-based model with field observations across Panamanian tropical forests to address: 1) whether N2 fixation enhances tropical forest carbon storage; 2) whether models must resolve fixation at the individual plant level to capture the fixation feedback; and 3) whether fixation interacts with plant functional types (i.e., early, mid, vs. late succession) to determine the carbon sink? We find that forests that have fixation recover faster and store more carbon in the long term than forests without fixation. This results in 94-118% more plant carbon stored by 30 years and an additional 13 tons C ha -1 stored over 300 years when compared to forests without fixation. Additionally, resolving fixation at the individual plant level is necessary to capture nitrogen dynamics over time and is particularly important for modeling succession and disturbance events. Finally, we find that the overall fixation effect is the result of two processes, the direct effect of the fixation on carbon accumulation and the indirect effect of fixation on the successional plant functional type sequence.

  18. Cavity-locked ring down spectroscopy

    SciTech Connect

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

    2000-01-01

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

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

    PubMed

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

    1998-01-01

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

  20. Minimally invasive plate osteosynthesis for humerus diaphyseal fractures

    PubMed Central

    Shetty, M Shantharam; Kumar, M Ajith; Sujay, KT; Kini, Abhishek R; Kanthi, Kiran G

    2011-01-01

    Background: Minimally invasive plate osteosynthesis (MIPO) technique is reported as a satisfactory procedure for the treatment of humeral shaft fractures by the anterior approach by several authors. However, none of the published reports had a significant follow-up nor have they reported patient outcomes. We evaluated the clinical, radiographic, and functional outcome over a minimum follow-up of 2 years using the same MIPO technique to humeral shaft fracture. Materials and Methods: 32 adult patients with diaphyseal fractures of the humerus treated with MIPO between June 2007 and October 2008 were included in the study. Patients with metabolic bone disease, polytrauma, and Gustilo and Anderson type 3 open fractures with injury severity score >16 were excluded from the study. All cases were treated with closed indirect reduction and locking plate fixation using the MIPO technique. The surgery time, radiation exposure, and time for union was noted. The shoulder and elbow function was assessed using the UCLA shoulder and Mayo elbow performance scores, respectively. Results: Of the 32 patients in the study, 19 were males and 13 were females. The mean age was 39 years (range: 22–70 years). Twenty-seven of the thirty-two patients (84.3%) had the dominant side fractured. We had eight cases of C2 type; five cases of C1 and A2 type; four cases of B2 type; three cases each of B3, B1, and A1 type; and one case of A3 type of fracture. The mean surgical time was 91.5 minutes (range: 70–120 minutes) and mean radiation exposure was 160.3 seconds (range: 100–220 seconds). The mean radiological fracture union time was 12.9 weeks (range: 10–20 weeks). Shoulder function was excellent in 27 cases (84.3%) and good in remaining 5 cases (15.6%) on the UCLA score. Elbow function was excellent in 26 cases (81.2%), good in 5 cases (15.6%), and fair in 1 case (3.1%) who had an associated olecranon fracture that was fixed by tension band wire in the same sitting. Conclusion: MIPO of the humerus gives good functional and cosmetic results and should be considered one of the management options in the treatment of humeral diaphyseal fractures. PMID:22144745

  1. Security and Lock-In

    Microsoft Academic Search

    Tom Lookabaugh; Douglas C. Sicker

    The cases of set-top boxes in the U. S. cable industry, video games and their cartridges, and printers and their cartridges all illustrate ways in which security technology can play an enhanced role in lock-in of customers by their suppliers through creation of substantial switching costs. Openness of technology, normally an inhibitor of lock-in, can be argued against in the

  2. Locked-in, walked out

    PubMed Central

    Kearney, Seamus; McCann, John; Hawkins, Stanley

    2011-01-01

    Locked in syndrome is typically associated with significant morbidity and mortality. We report a patient who had an unusually good recovery from locked in syndrome due to pontine infarction. The good recovery exhibited by our patient may have resulted from resolution of oedema at the site of infarction and brainstem plasticity being augmented by initial supportive measures in the intensive care unit and early, intensive rehabilitation. PMID:23526844

  3. Dinitrogen fixation in aphotic oxygenated marine environments

    PubMed Central

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

    2013-01-01

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

  4. Methodological Underestimation of Oceanic Nitrogen Fixation Rates

    PubMed Central

    Mohr, Wiebke; Großkopf, Tobias; Wallace, Douglas W. R.; LaRoche, Julie

    2010-01-01

    The two commonly applied methods to assess dinitrogen (N2) fixation rates are the 15N2-tracer addition and the acetylene reduction assay (ARA). Discrepancies between the two methods as well as inconsistencies between N2 fixation rates and biomass/growth rates in culture experiments have been attributed to variable excretion of recently fixed N2. Here we demonstrate that the 15N2-tracer addition method underestimates N2 fixation rates significantly when the 15N2 tracer is introduced as a gas bubble. The injected 15N2 gas bubble does not attain equilibrium with the surrounding water leading to a 15N2 concentration lower than assumed by the method used to calculate 15N2-fixation rates. The resulting magnitude of underestimation varies with the incubation time, to a lesser extent on the amount of injected gas and is sensitive to the timing of the bubble injection relative to diel N2 fixation patterns. Here, we propose and test a modified 15N2 tracer method based on the addition of 15N2-enriched seawater that provides an instantaneous, constant enrichment and allows more accurate calculation of N2 fixation rates for both field and laboratory studies. We hypothesise that application of N2 fixation measurements using this modified method will significantly reduce the apparent imbalances in the oceanic fixed-nitrogen budget. PMID:20838446

  5. Preliminary clinical and radiographic results with the Fixion intramedullary nail: an inflatable self-locking system for long bone fractures

    Microsoft Academic Search

    Stefano Lepore; Nicola Capuano; Luciano Lepore; Gaetano Romano

    2000-01-01

    We present a new inflatable self-locking intramedullary nailing system for the treatment of long bone fractures. The features\\u000a of this system and the advantages of the technique include: fixation along the entire length of the nail, lack of proximal\\u000a or distal interlocking screws, optional reaming, reduced exposure of the surgeon to X-ray and reduced operating room time.\\u000a First preliminary clinical

  6. Mandibular fractures treated with maxillomandibular fixation screws (MMFS method).

    PubMed

    Imazawa, Takashi; Komuro, Yuzo; Inoue, Masahiro; Yanai, Akira

    2006-05-01

    The purpose of the treatment of mandibular fractures is to restore proper dental occlusion and stable temporomandibular joint movement, as well as the reduction of the displaced fracture. Consideration must be given to the selection of the most appropriate surgical and rehabilitation methods in such patients. Typical surgical methods for the treatment of mandibular fractures include the arch bar method or plating at the location of the fracture combined with fixing the mandible to the maxilla using the arch bar method. However arch bars and circumdental wires, which require teeth for fixation, damage teeth and periodontal tissue, and tend to be uncomfortable for patients during the fixation period. Moreover, daily maintenance of oral hygiene is difficult for patients with an arch bar. Surgeons are also exposed to the risk of blood-transmitted diseases through skin punctures by wires when affixing these devices. For these reasons, we chose to study the potential of the MMFS method, which is thought to lessen all of the following problems: tissue damage, operating time, patient discomfort, and possible exposure to percutaneous infectious disease due to puncture of gloves and skin by the wires. We demonstrated the utility of the MMFS method in the present study. PMID:16770195

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

    PubMed

    Suzuki, E Y; Suzuki, B

    2007-12-01

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

  8. Life on a tidally-locked planet

    E-print Network

    Singal, Ashok K

    2014-01-01

    A tidally-locked planet in its orbit around a star keeps the same face towards the star. This happens when the rotation period of the planet around its own axis becomes equal to its revolution period around the star. Many questions then arise. What gives rise to a tidal locking? Are there any tidally-locked planets somewhere? What will be the atmospheric system of a tidally-locked planet? Could life be sustained on a tidally-locked planet? What will be a sort of DAY in the life of a denizen of a tidally-locked planet? We dwell on these questions.

  9. Nitrogen fixation on Arctic glaciers, Svalbard

    NASA Astrophysics Data System (ADS)

    Telling, Jon; Anesio, Alexandre M.; Tranter, Martyn; Irvine-Fynn, Tristram; Hodson, Andy; Butler, Catriona; Wadham, Jemma

    2011-09-01

    Glacier surfaces contain a wide diversity of microorganisms and can host a range of microbial activities. However, microbial nutrient cycling on glaciers is poorly understood. This study is the first to document nitrogen fixation (nitrogenase activity) on glaciers and demonstrate its importance in supporting microbial growth. Rates of nitrogen fixation (nitrogenase activity) in cryoconite holes on three valley glaciers in Svalbard ranged from <2.0 to 99.9 ?mol ethylene m-2 d-1 with rates inversely correlated to concentrations of available inorganic nitrogen. Annual inputs of nitrogen by nitrogen fixation on a glacier catchment scale are more than 2 orders of magnitude lower than the combined nitrogen inputs from snowmelt and rain. However, nitrogen fixation can be important for supporting microbial growth on the glaciers during the middle to late melt season after the snowline has retreated upslope.

  10. Methanotrophy Induces Nitrogen Fixation in Boreal Mosses

    NASA Astrophysics Data System (ADS)

    Tiirola, M. A.

    2014-12-01

    Many methanotrophic bacterial groups fix nitrogen in laboratory conditions. Furthermore, nitrogen (N) is a limiting nutrient in many environments where methane concentrations are highest. Despite these facts, methane-induced N fixation has previously been overlooked, possibly due to methodological problems. To study the possible link between methanotrophy and diazotrophy in terrestrial and aquatic habitats, we measured the co-occurrence of these two processes in boreal forest, peatland and stream mosses using a stable isotope labeling approach (15 N2 and 13 CH4 double labeling) and sequencing of the nifH gene marker. N fixation associated with forest mosses was dependent on the annual N deposition, whereas methane stimulate N fixation neither in high (>3 kg N ha -1 yr -1) nor low deposition areas, which was in accordance with the nifH gene sequencing showing that forest mosses (Pleurozium schreberi and Hylocomium splendens ) carried mainly cyanobacterial N fixers. On the other extreme, in stream mosses (Fontinalis sp.) methane was actively oxidized throughout the year, whereas N fixation showed seasonal fluctuation. The co-occurrence of the two processes in single cell level was proven by co-localizing both N and methane-carbon fixation with the secondary ion mass spectrometry (SIMS) approach. Methanotrophy and diazotrophy was also studied in peatlands of different primary successional stages in the land-uplift coast of Bothnian Bay, in the Siikajoki chronosequence, where N accumulation rates in peat profiles indicate significant N fixation. Based on experimental evidence it was counted that methane-induced N fixation explained over one-third of the new N input in the younger peatland successional stages, where the highest N fixation rates and highest methane oxidation activities co-occurred in the water-submerged Sphagnum moss vegetation. The linkage between methanotrophic carbon cycling and N fixation may therefore constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. It is still an open issue whether methanotrophy induces N fixation directly or by enhancing phototrophic or heterotrophic N fixation.

  11. Obituary: Martha Locke Hazen, 1931-2006

    NASA Astrophysics Data System (ADS)

    Williams, Thomas R.; Willson, Lee Anne

    2007-12-01

    Longtime Harvard Curator of Astronomical Photographs and AAVSO officer Martha Hazen passed away on 23 December 2006 at Hingham, Massachusetts, after a short illness due to acute myelogenous leukemia. One of four children of Harold Locke and Katherine (neé Salisbury) Hazen, Martha was born in Cambridge, Massachusetts, on 15 July 1931, and raised in the Town of Belmont, near Cambridge, where she lived for most of her life. Her father coined the term "servo-mechanism" while serving as an engineering professor and dean for graduate students at the Massachusetts Institute of Technology. Her mother majored in chemistry at Mount Holyoke College. After receiving an A.B. in astronomy from Mount Holyoke College in 1953, Martha earned a Ph.D. in astronomy in 1958 from the University of Michigan, defending a dissertation on the distribution of intensity in elliptical galaxies in the Virgo cluster. Martha's marriage to William Liller in 1959, and the births of two children, inevitably slowed down her progress in observational astronomy. As a research fellow of the Harvard College Observatory, Martha continued to observe two to three weeks a year in Chile, and to reduce those observations and publish the results for sixteen years. Martha's first publication, at least as far as Astrophysics Data System includes the literature, was with Alice Farnsworth on the 1952 occultations of stars by the Moon, published in the Astronomical Journal (1953). In 1958 she joined L. R. Doherty and D. H. Menzel on a short note about the calculation of line profiles in a stratified atmosphere, her only theory paper. Martha's most cited paper is "The Distribution of Intensity in Elliptical Galaxies of the Virgo Cluster," (ApJ, 132, p.306, 1960). There she acknowledges Allan Sandage for suggesting the problem and providing some of the data. Her second most cited paper is "Photometric histories of QSOs - Two QSOs with large light amplitude," (Liller, M. H. & Liller, W., ApJ (Letters), 199, p. L133-L135, 1975). Progressing to smaller objects, other frequently cited papers are on eta Carinae and spectroscopic binaries in the globular cluster M3. All of these, and most of her other papers, involve photographic photometry, mostly using archival data. In 1969, Harvard appointed Martha Curator of Astronomical Photographs, placing her in responsible charge of the world renowned Harvard Plate Archives. Under attack during the mid-1950s because it occupied too much physical space, the collection had been neglected for over a decade when Martha assumed this additional responsibility. Though she continued to observe for a few years thereafter, her stewardship of the invaluable plate archives gradually demanded her full attention, which it held until her retirement in 2002. In her thirty-three years as curator of the plate stacks, as the archive is popularly known, Martha made numerous friends in both the professional and amateur communities. Astronomical researchers on a wide variety of topics relied on her detailed knowledge of the collection to guide them to important discoveries or discovery confirmations on the old plates, and to historical understanding of results in which some detail of origin needed clarification. Martha researched and documented the characteristics of nearly a hundred separate telescopic cameras used to take the plates archived in the collection. Much of this information was ephemeral, having been passed orally from observer to observer and was in danger of passing from human memory. This was, in itself, an enormous and valuable undertaking as it ensures the utility of the plates for future research. More importantly, Martha conserved and catalogued the all important logbooks that record the date, time, and other exposure circumstances for each of the plates in the collection. The full measure of Martha's long-term contribution in this regard undoubtedly will be realized as the digitization of the entire collection of plates is completed. The Digital Access to a Sky Century from Harvard (DASCH) project will ow

  12. Special Aspects of Nitrogen Fixation by Blue-Green Algae

    Microsoft Academic Search

    Rosalie M. Cox; P. Fay

    1969-01-01

    When carbon dioxide fixation was over 90% inhibited by CMU, nitrogen fixation remained unaffected in nitrogen-starved cells of Anabaena cylindrica. In normal cells under the same conditions nitrogen fixation was about 50% inhibited by CMU. These data suggest, first, that nitrogen fixation in this organism is independent of reducing potential generated by non-cyclic photo-electron transport and, secondly, that nitrogen fixation

  13. Dangerous Earth: A Plate Tectonic Story

    NSDL National Science Digital Library

    This article and accompanying questions discusses the fact that several of the Earth's tectonic plates move at about the same speed as fingernails grow - around 35 mm per year - and that the plates are made of lithosphere (crust plus the upper part of the mantle). Students will also learn that beneath the lithosphere is the asthenosphere, part of the upper mantle that is ductile because it contains 1-10 percent molten material as films around the crystals. In addition they will find that the Earth's magnetic field has flipped (the N pole becoming the S pole, and vice versa) many times throughout geological time, resulting in rocks with varying directions of magnetism. They will also find that as tectonic plates move apart, new rock is formed and this locks in the direction of the magnetic field at the time.

  14. Pin loosening in external skeletal fixation 

    E-print Network

    Vittal, Bamini

    1993-01-01

    OF TABLES Page TABLE 1 Table showing the problems and complications of external fixations. TABLE 2 Table showing the experimental design. . . 22 TABLE 3 Table showing the number of cadaver dogs tested and the twist out rates and the pull out rates... included a chapter outlining technical details pertinent to the prevention of unnecessary complications associated with the use of external fixation. While their discussion of the strategies for avoiding complications was extensive, Shaar and Document...

  15. Biological nitrogen fixation: A scientific perspective

    Microsoft Academic Search

    R. H. Burris

    1988-01-01

    The discoveries of Hellriegel and Wilfarth ended the period of controversy about the existence of biological N2 fixation and launched a period featuring the agronomic application of the inoculation of legumes. Serious studies of the\\u000a biochemistry of N2 fixation started in the late 1920's, and defined some of the basic properties of the N2-fixing system. Application of15N as a tracer

  16. Stability of external skeletal fixation clamps

    E-print Network

    Sandel, Mark Eugene

    1995-01-01

    STABILITY OF EXTERNAL SKELETAL FIXATION CLAMPS A Thesis by MARK EUGENE SANDEL Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1995 Major... Eugene Sandel, B. S. , Texas A%M University Chair of Advisory Committee: Dr. William A. Hyman External skeletal fixation is commonly used for treatment of many orthopedic diseases and injuries in both human and animal patients. It is mainly used...

  17. Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

    SciTech Connect

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

    1999-05-01

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

  18. Lock detection in Costas loops

    NASA Technical Reports Server (NTRS)

    Mileant, A.; Hinedi, S.

    1992-01-01

    Previous analyses of lock detector algorithms for Costas loops have ignored the effects of the inherent correlation between samples of the phase error process. In this paper, both analysis and simulations are used to quantify the effects of phase correlation on lock detection for the 'square law' and 'absolute value' type detectors. Results are obtained which depict the lock detection probability as a function of loop signal-to-noise ratio for a given false alarm rate. It is shown that the square law detector experiences less degradation due to phase jitter than the absolute value detector and that the degradation in detector signal-to-noise ratio is more pronounced for squarewave than for sinewave signals.

  19. Fracture fixation problems in osteoporosis.

    PubMed

    Strømsøe, Knut

    2004-02-01

    Osteoporosis, or loss of bone mass and microarchitectural deterioration of bone tissue, does not only enhance risk of fracture but also represents a problem in osteofixation of fractures in fracture treatment. Aging of the western population changes the epidemiology of fractures. An increasing socioeconomic interest in geriatric traumatology makes the need for much urgent study in the field of osteoporotic fractures self evident. It is no longer the province of only one medical group to look for fragmented solutions in the treatment of osteoporotic fractures. Efforts have to be united across professional boundaries to meet the challenge of this problem. Assessment of bone mineral may be used in evaluation of fracture risk but also in the choice of implant as well as in the design of implants used in fracture treatment. The differences in mechanical properties of different types of bone in the same individual have to be respected. Changes in the pattern of fractures and problems with implant anchorage in bone, due to a demographic increase in patients with osteoporosis remain problems requiring new solutions. Still basic principals in fracture treatment may not be eclipsed by new fixation devices. PMID:14736465

  20. 49 CFR 236.706 - Bed, locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...AND APPLIANCES Definitions § 236.706 Bed, locking. That part of an interlocking machine that contains or holds the tappets, locking bars, crosslocking, dogs and other apparatus used to interlock the...

  1. 49 CFR 236.761 - Locking, electric.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...236.761 Locking, electric. The combination of one or more electric locks and controlling circuits by means of which levers of an interlocking machine, or switches or other units operated in connection with signaling and interlocking, are secured...

  2. 49 CFR 236.761 - Locking, electric.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...236.761 Locking, electric. The combination of one or more electric locks and controlling circuits by means of which levers of an interlocking machine, or switches or other units operated in connection with signaling and interlocking, are secured...

  3. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...DEVICES, AND APPLIANCES Definitions § 236.757 Lock, electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet,...

  4. The end of locked inflation

    NASA Astrophysics Data System (ADS)

    Copeland, E. J.; Rajantie, A.

    2005-02-01

    We investigate the end of the inflationary period in the recently proposed scenario of locked inflation, and consider various constraints arising from density perturbations, loop corrections, parametric resonance and defect formation. We show that in a scenario where there is one long period of locked inflation, it is not possible to satisfy all of these constraints without having a period of saddle inflation afterwards, which would wipe out all observable signatures. On the other hand, if one does not insist on satisfying the loop correction constraint, saddle inflation can be avoided, but then inflation must have ended through parametric resonance.

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

    Microsoft Academic Search

    Matthias Jacobi; Peter Wahl; Georges Kohut

    2010-01-01

    BACKGROUND: A possible difficulty in intra-articular fracture of the distal radius is the displacement tendency of the radial styloid process due to the tension of the brachioradialis tendon. METHODS: Ten patients treated within one year for complex distal radius fractures by double-plating technique with a radial buttress plate and volar locking plate, through a single volar approach, were followed prospectively

  6. Heterodyne Locking of an Integrated Optical Phase-Locked Loop

    E-print Network

    Coldren, Larry A.

    and photodetectors. I. INTRODUCTION An optical phase-locked loop (OPLL) is a control system that exhibits both of a local voltage-controlled oscillator (VCO). The mixer produces a phase error signal that is filtered frequency. In an OPLL, however, a photodetector detects a phase difference between an input optical signal

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

    PubMed

    Shuker, Sabri T

    2013-07-01

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

  8. Tectonic Plates and Plate Boundaries (WMS)

    NSDL National Science Digital Library

    Eric Sokolowsky

    2004-06-14

    The earths crust is constantly in motion. Sections of the crust, called plates, push against each other due to forces from the molten interior of the earth. The areas where these plates collide often have increased volcanic and earthquake activity. These images show the locations of the plates and their boundaries in the earths crust. Convergent boundaries are areas where two plates are pushing against each other and one plate may be subducting under another. Divergent boundaries have two plates pulling away from each other and indicate regions where new land could be created. Transform boundaries are places where two plates are sliding against each other in opposite directions, and diffuse boundaries are places where two plates have the same relative motion. Numerous small microplates have been omitted from the plate image. These images have been derived from images made available by the United States Geological Surveys Earthquake Hazards Program.

  9. Injection locking in IMPATT diode oscillators.

    NASA Technical Reports Server (NTRS)

    Gupta, M. S.; Lomax, R. J.

    1971-01-01

    A model for an injection-locked IMPATT diode oscillator is presented and used to calculate the locking behavior of the oscillator at different operating points. The model is compared with earlier theories of injection locking in IMPATT diode oscillators and the calculated results are compared with experimental observations.

  10. Reachability under Contextual Locking Rohit Chadha1

    E-print Network

    Parthasarathy, Madhusudan

    they can be simultaneously reached in an execution of the program. The problem is important for static in the concurrent program, such as locks, barriers, etc. However, it turns out that even when synchronization set of locks. Popular programming paradigms that limit the lock usage patterns have been identified

  11. 75 FR 2129 - Lock+TM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

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

  12. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  13. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  14. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 4 2014-10-01 2014-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

  15. GMSK modulation of subharmonic injection locked oscillators

    Microsoft Academic Search

    T. Finateu; J.-B. Begueret; Y. Deval; F. Badets

    2005-01-01

    This paper presents theoretical results on phase modulation of injection locked oscillators. Experimental results on a 2-GHz fifth subharmonic injection locked oscillator (SBILO) integrated in a 0.35-?m BiCMOS STMicroelectronics technology are presented. Measured phase error added by the SBILO once locked by a GMSK modulated signal is negligible.

  16. Exploring Lesser Antilles subduction zone locking through modeling of cGPS and earthquake seismology data.

    NASA Astrophysics Data System (ADS)

    Higgins, M.; Weber, J. C.; Robertson, R. E. A.

    2014-12-01

    We are undertaking a study to better determine the locking characteristics of Lesser Antilles subduction zone using new cGPS data from 20 stations in the Lesser Antilles volcanic islands and outboard islands in the forearc sliver. The new data come from the SRC, IGS and IPGP cGPS networks. Each site we use has a minimum of 3 years of data, and raw site velocities have average uncertainties in the horizontal on order ? 2 mm/yr. Eventually, we also hope to incorporate vertical velocities, which have slightly larger uncertainties, into the model along with earthquake slip vectors from the Harvard CMT catalog. We model the cGPS data using Defnode, which performs inverse modeling using the Okada (1985; 1992) method to determine the elastic slip distribution along block (CA plate, NA plate, SA plate, forearc sliver) boundaries. Free parameters are the distribution of locking ratios of the fault representing the subduction zone, and deformation in each block. Our model's weakness is that it is constrained by data from islands with a limited distribution in trying to model a large area. Using the SRC earthquake catalogue, the subduction zone was gridded and we summed the total seismic moment for each grid cell, using only M>3.5 earthquakes with low RMS values. The gridded seismic moment rates were then averaged over the length of time of the complete catalog. Several models were then produced with Defnode and a solution optimization technique that estimated the locking ratio distribution. The models' resulting seismic moment rates are then compared against those gleaned from the SRC catalogue. Previous works have suggested that subducting ridges on the NA plate may indeed be locked, this work also tries to identify the locking ratio of these ridges.

  17. The Biggest Plates on Earth: Plate Tectonics

    NSDL National Science Digital Library

    In this lesson, students investigate the movement of Earth's tectonic plates, the results of these movements, and how magnetic anomalies present at spreading centers document the motion of the crust. As a result of this activity, students will be able to describe the motion of tectonic plates, differentiate between three types of plate boundaries, infer what type of boundary exists between two tectonic plates, and understand how magnetic anomalies provide a record of geologic history and crustal motion around spreading centers. As an example, they will also describe plate boundaries and tectonic activity in the vicinity of the Juan de Fuca plate adjacent to the Pacific Northwest coast of North America.

  18. Tidal Locking Of The Earth

    Microsoft Academic Search

    Michael Koohafkan

    2006-01-01

    The Moon's orbit and spin period are nearly synchronized, or tidally locked. Could the Moon's orbit and the Earth's spin eventually synchronize as well? The Moon's gravitational pull on the Earth produces tides in our oceans, and tidal friction gradually lengthens our days. Less obvious gravitational interactions between the Earth and Moon may also have effects on Earth's spin. The

  19. Mechanisms of stochastic phase locking

    Microsoft Academic Search

    André Longtin

    1995-01-01

    Periodically driven nonlinear oscillators can exhibit a form of phase locking in which a well-defined feature of the motion occurs near a preferred phase of the stimulus, but a random number of stimulus cycles are skipped between its occurrences. This feature may be an action potential, or another crossing by a state variable of some specific value. This behavior can

  20. Osteomyelitis after TightRope(®) fixation of the ankle syndesmosis: a case report and review of the literature.

    PubMed

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

    2015-01-01

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

  1. One point fixation of zygomatic tripod fractures in the zygomatic buttress through Keen's intraoral approach: A review of 30 cases

    PubMed Central

    Dakir, Abu; Muthumani, T.; Prabu, N. P.; Mohan, Rakesh; Maity, Abhishek

    2015-01-01

    For decades, facial beauty and esthetics have been one of the most important quests of the human race. The lateral prominence and convexity of the zygomatic bone makes it the most important bone for providing the aesthetic facial look and sets up the facial width but at the same time this prominence and convexity makes this bone more vulnerable to injury. Zygomatic complex fractures or tripod fractures are the second most common fractures after nasal fractures among facial injuries. Several studies have been undertaken regarding the reduction and fixation of zygomatic fractures with mini plates and screws. In 2002 Fujioka et al in vivo studies successfully proved that one point fixation at the zygomaticomaxillary complex gives three point alignment and sufficient rigidity when the fractures are not comminuted. In this article, 30 cases have been reviewed with one point fixation of zygomatic complex tripod fractures at the zygomatic buttress through Keen's intraoral approach along with advantages and disadvantages. PMID:26015722

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

    PubMed

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

    2015-02-01

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

  3. A comparison of four tibial-fixation systems in hamstring-graft anterior ligament reconstruction.

    PubMed

    Robert, Henri; Bowen, Mark; Odry, Guillaume; Collette, Michel; Cassard, Xavier; Lanternier, Hubert; De Polignac, Thierry

    2015-02-01

    The aim of this study was to evaluate at time-zero four tibial fixations on four major criteria: the elongation and cyclic stiffness of the hamstring graft construct under cyclic loading, the yield load and pullout stiffness under load at failure. Four fixation systems were tested: the Delta screw, the WasherLoc, the TightRope Reverse and the tape locking screw on 32 tibiae of adult pigs using 32 pairs of human semitendinosus and gracilis tendons. Two tests were performed: cyclic tests using loads at 70-220 N, to measure the elongation at the end of the cycles, followed by load-to-failure testing to measure the yield load and the cyclic stiffness. The mean elongation was 1.23 mm for the TLS, 3.81 mm for the Delta, 3.59 mm for the WasherLoc and 3.91 mm for the TightRope. The mean yield loads and SD were 1,015 ± 129 N for the TLS, 844 ± 394 N for the Delta, 511 ± 95 N for the WasherLoc and 567 ± 112 N for the TightRope. The results showed the significant superiority of TLS and Delta over WasherLoc and tibial TightRope in regard to yield load. The results showed the significant superiority of TLS over the other fixations in regard to slippage. The TLS system and the Delta screw provide a better quality of primary fixation to the tibia, but further in vitro studies are needed. PMID:24816761

  4. The Fixation and Saccade P3

    PubMed Central

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

    2012-01-01

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

  5. Nitrogen fixation and nitrogen fertilization of soybeans.

    PubMed

    Merbach, W; Jacob, H J

    1996-08-01

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

  6. Plate Tectonics: Consequences of Plate Interactions

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2006-11-01

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

  7. Caribbean plate tectonics

    NSDL National Science Digital Library

    Sting

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

  8. Implant failure in a proximal femoral fracture treated with dynamic hip screw fixation

    PubMed Central

    Dabis, John; Abdul-Jabar, Hani B.; Dabis, Hosam

    2015-01-01

    Dynamic hip screw fixation is a common orthopaedic procedure and to date, still can cause difficulties to the senior trauma surgeon. We present a case where an extra-capsular fracture of the proximal femur was managed with a dynamic hip screw (DHS) fixation. She proceeded to the operating theatre, where the fracture was stabilized with a 75-mm DHS and short-barrelled plate. The implant position was checked with intraoperative screening and the position accepted. Following attempted mobilization at 11 days post-operatively, the patient developed a recurrence of her preoperative pain. X-ray showed that the implant screw had separated from the barrel. Later scrutiny of the intraoperative screening films revealed that the barrel and screw were not engaged at the time of surgery. Intraoperative screening films should be carefully checked to ensure congruity of implant components. PMID:26136561

  9. Implant failure in a proximal femoral fracture treated with dynamic hip screw fixation.

    PubMed

    Dabis, John; Abdul-Jabar, Hani B; Dabis, Hosam

    2015-01-01

    Dynamic hip screw fixation is a common orthopaedic procedure and to date, still can cause difficulties to the senior trauma surgeon. We present a case where an extra-capsular fracture of the proximal femur was managed with a dynamic hip screw (DHS) fixation. She proceeded to the operating theatre, where the fracture was stabilized with a 75-mm DHS and short-barrelled plate. The implant position was checked with intraoperative screening and the position accepted. Following attempted mobilization at 11 days post-operatively, the patient developed a recurrence of her preoperative pain. X-ray showed that the implant screw had separated from the barrel. Later scrutiny of the intraoperative screening films revealed that the barrel and screw were not engaged at the time of surgery. Intraoperative screening films should be carefully checked to ensure congruity of implant components. PMID:26136561

  10. Radial artery pseudoaneurysm complication from use of AO\\/ASIF volar distal radius plate: A case report

    Microsoft Academic Search

    Khiem D Dao; Eric Venn-Watson; Alexander Y Shin

    2001-01-01

    A case of pseudoaneurysm of the radial artery after fixation of a distal radius using the AO\\/ASIF volar distal radius plate system is presented. This unusual complication resulted from inadequate fracture stabilization and plate preparation. Technical tips on plate shortening and preparation of the cut ends are emphasized. (J Hand Surg 2001;26A:448-453. Copyright © 2001 by the American Society for

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

    PubMed

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

    2014-08-22

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

  12. Biometric recognition via fixation density maps

    NASA Astrophysics Data System (ADS)

    Rigas, Ioannis; Komogortsev, Oleg V.

    2014-05-01

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

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

    Microsoft Academic Search

    Kasetti J. Ravikumar; Gavin Marsh

    2000-01-01

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

  14. Performance of arm locking in LISA

    SciTech Connect

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

    2009-11-15

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

  15. MICROBIOLOGY: A Fifth Pathway of Carbon Fixation

    NSDL National Science Digital Library

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

    2007-12-14

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

  16. Hemiarthroplasty versus internal fixation for displaced intracapsular fractures of the hip in elderly men: a pilot randomised trial.

    PubMed

    Parker, M J

    2015-07-01

    A total of 56 male patients with a displaced intracapsular fracture of the hip and a mean age of 81 years (62 to 94), were randomised to be treated with either a cemented hemiarthroplasty (the Exeter Trauma Stem) or reduction and internal fixation using the Targon Femoral Plate. All surviving patients were reviewed one year after the injury, at which time restoration of function and pain in the hip was assessed. There was no statistically significant difference in mortality between the two groups (7/26; 26.9% for hemiarthroplasty vs 10/30; 33.3% for internal fixation). No patient treated with a hemiarthroplasty required further surgery, but eight patients treated by internal fixation did (p = 0.005), five requiring hemiarthroplasty and three requiring total hip arthroplasty. Those treated by internal fixation had significantly more pain (p = 0.02). The restoration of mobility and independence were similar in the two groups. These results indicate that cemented hemiarthroplasty gives better results than internal fixation in elderly men with a displaced intracapsular fracture of the hip. Cite this article: Bone Joint J 2015;97-B:992-6. PMID:26130358

  17. Surgical Strategies to Improve Fixation in the Osteoporotic Spine: The Effects of Tapping, Cement Augmentation, and Screw Trajectory

    PubMed Central

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

    2013-01-01

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

  18. Antibiotic cement-coated plates for management of infected fractures.

    PubMed

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

    2015-02-01

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

  19. Locking mechanism for indexing device

    SciTech Connect

    Lindenmeyer, C.W.

    1982-01-25

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

  20. Locking mechanism for indexing device

    SciTech Connect

    Lindemeyer, C.W.

    1984-08-14

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

  1. Digital phase-lock loop

    NASA Technical Reports Server (NTRS)

    Thomas, Jr., Jess B. (Inventor)

    1991-01-01

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

  2. Improved Phase-Lock Detector

    NASA Technical Reports Server (NTRS)

    Bronstein, L. M.

    1982-01-01

    Single detection channel is used alternately by in-phase (I) and quadrature (Q) signals, under control of a dither switch. By eliminating errors caused by unbalance of the I and Q channels, this dither-balanced detector reduces false locking. Can be used to improve detection probability and reduce false alarm probability for any loop that must acquire signal with low signal-to-noise ratio.

  3. Potassium fixation of different soil types and nutrient levels

    Microsoft Academic Search

    K. Sardi; G. Csitari

    1998-01-01

    Potassium (K) fixation plays a significant role in the soil?plant system influencing the effectiveness of fertilizaiton. Among the factors controlling fixation capacity of soils, clay mineralogy and soil moisture are of primary importance. The objective of this experiment was to study the K fixation capacity of different soil types and K levels as well as to develop quantitative relationships between

  4. Unfixing Design Fixation: From Cause to Computer Simulation

    ERIC Educational Resources Information Center

    Dong, Andy; Sarkar, Somwrita

    2011-01-01

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

  5. Eye movement and visual fixation during profound sleepiness

    Microsoft Academic Search

    W. R. Miles; H. R. Laslett

    1931-01-01

    Five college men who had gone without sleep for 66 hours were studied by photographing their eye movements and consecutive fixations of two points separated by a visual angle of 40 degrees. Speed of saccadic eye movements was 30% below normal; visual fixations were profoundly modified; corrective movements were larger and less exact; there was wavering of fixation and drifting

  6. Nitrogen control of nitrogen fixation in free-living diazotrophs

    E-print Network

    Merrick, Mike

    Chapter 9 Nitrogen control of nitrogen fixation in free-living diazotrophs M. J. MERRICK Department of nitrogen fixation is found distributed amongst a taxonomically very diverse range of microorganisms the efficiency of nitrogen fixation some common themes are now becoming clear. The physiological issues

  7. An eye fixation database for saliency detection Subramanian Ramanathan

    E-print Network

    Sebe, Nicu

    An eye fixation database for saliency detection in images Subramanian Ramanathan Harish Katti+ Nicu- an eye fixation database compiled from a pool of 758 images and 75 subjects. Eye fixations feature-driven approaches em- ployed by saliency computation algorithms. The database comprises fix- ation

  8. Complex fractures of the distal radius treated with angular stability plates

    Microsoft Academic Search

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

    2009-01-01

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

  9. Influence of connecting plate on construct stiffness of spinal implants and motion of adjacent segments

    Microsoft Academic Search

    Hon So

    2003-01-01

    An in vitro biomechanical study compared the influence of connecting plates on construct stiffness and motion of adjacent segments. Twelve porcine lumbar spines were destabilized by laminectomy and instrumented at the L3 and L4 vertebrae by one of three transpedicular screw fixation systems: Cotrel?Dubousset, Diapason, and a newly designed implant (FPI).The current study demonstrated that connecting plates significantly increased the

  10. Copper Map Plate Detail

    USGS Multimedia Gallery

    A portion of the engraving on the plate used to print points, lines, and text in black ink. Engravings on the plate are left-to-right reversed. This plate was cleaned and treated to improve the visibility of the engraving. The plate was used to print the Washington [D.C.] and vicinity, 1:31,680-sca...

  11. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

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

  12. Plate Tectonics Animation

    NSDL National Science Digital Library

    2002-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Lamb, Simon; Smith, Euan

    2013-06-01

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

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

    PubMed

    Nietner, Thorben; Jarutat, Tiantom; Mertens, Alfred

    2012-09-01

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

  15. Nitrogen fixation : the microbial world the nitrogen cycle and nitrogen fixation

    NSDL National Science Digital Library

    Jim Deacon

    2007-01-01

    A nicely organized, reader friendly webpage. Provides a table of natural and synthetic nitrogen fixation processes. Includes photographs of plants, roots and nitrogen fixing bacteria nodules. A graphic representation of the nitrogen cycle is included.

  16. ORIGINAL ARTICLE Carbon and nitrogen fixation and

    E-print Network

    Capone, Douglas G.

    cells of Anabaena oscillarioides Radu Popa1 , Peter K Weber2 , Jennifer Pett-Ridge2 , Juliette A Finzi3 incubations of Anabaena oscillarioides, we imaged the cellular distributions of C, N and P and 13 C and 15 N: cyanobacteria; heterocyst; nitrogen fixation; nitrogenase; Anabaena Introduction Some cyanobacteria are uniquely

  17. Stability of external skeletal fixation clamps 

    E-print Network

    Sandel, Mark Eugene

    1995-01-01

    FIGURES INTRODUCTION TABLE OF CONTENTS Page 1V V1 BACKGROUND Loads Applied to Skeletal Components . . . . Terminology. . Basic Biomechanics . . . . . . . . . . . . . . . Implant Failure and Complications . . . . . . . . . . . . MEI... complications associated with the use of external fixation. This document is styled after journal of Biomechanical Engineering. Unfortunately, they did not provide any documentation on the incidence or the details of the associated complications. However...

  18. Chemical fixation of sewage sludge derived ash

    Microsoft Academic Search

    Farhana Mohamed; I. Y. Sam Cheng; Ruey S. Huang; Evelyn C. Santos

    1991-01-01

    Los Angeles processes sewage sludge by dehydration and combustion at its Hyperion Treatment Plant. The ash product is usually classified as hazardous because of its heavy metal content, and four readily?available fixing agents have been evaluated for possible use as stabilizers. The ash leachability was assessed before and after fixation using the California Waste Extraction Test. The leaching characteristics of

  19. WHITE LUPIN NITROGEN FIXATION UNDER PHOSPHORUS DEFICIENCY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White lupin is highly adapted to growth in a low P environment. The objective of the present study was to evaluate whether white lupin grown under P-stress has adaptations in nodulation and N2 fixation that facilitate continued functioning. Nodulated plants were grown in silica sand supplied with N-...

  20. Adjustment of fixation duration in visual search

    Microsoft Academic Search

    Ignace Th. C. Hooge; Casper J. Erkelens

    1998-01-01

    To investigate whether fixation durations are adjusted to the duration of a foveal analysis task, we designed a search task in which each stimulus element yielded information about the position of the target. We asked subjects to look for the target by making eye movements in the direction indicated by each stimulus element. We explicitly asked the subjects to make

  1. Biomechanical evaluation of rotator cuff fixation methods

    Microsoft Academic Search

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

    1989-01-01

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

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

    SciTech Connect

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

    1988-01-01

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

  3. Parking lock mechanism for a vehicle having an infinitely variable transmission

    SciTech Connect

    Takano, T.; Takahashi, M.

    1987-02-24

    This patent describes a parking lock mechanism for a vehicle having an infinitely variable transmission having a main shaft, a forward gear train, a reverse gear train, coupling means for engaging either of the forward and reverse gear trains with the main shaft, and a selector level for selecting a forward drive range, reverse drive range, and parking lock range. The improvement described here comprises: a parking pawl provided to be engaged with one of locking notches formed on one of rotative members on an output shaft of the transmission; first means for actuating the parking pawl to engage it with one of the locking notches; second means comprising a cam plate rotated by the operation of the selector lever and a cam follower operatively connected to the coupling means for transmitting the operation of the selector lever to the coupling means for selecting the drive ranges and the parking range, the second means being so arranged that the parking range is selected after the selection of the reverse drive range; and the cam plate being so arranged that when the parking range is selected, the cam follower remains at a reverse drive range position to keep the engagement of the reverse gear train.

  4. [Studies of explanted shot-peened osteosynthesis plates].

    PubMed

    Starker, M; Ungethüm, M; Zichner, L

    1986-01-01

    Shot peening is a cold-working process to increase the fatigue life of osteosynthesis plates. Using ceramic particles for this process we observed no change in the corrosive properties of the plates. Up to now we implanted 37 shot peened osteosynthesis plates for fixation of intertrochanteric osteotomies. 13 plates were explanted after an average time of 14,2 months. We investigated the plates as well as the tissue surrounding the implants. Metallurgic specimens showed not so many pittings at the shot peened plates in the region of the screw hole as were seen at the polished plates after the same period of implantation. By histological investigation corrosive products or fretting particles were detected mostly in the region of the screws. Only a few metal particles were found in the region between the screw holes. Analysing the elements which were black or red-brown coloured in histological specimens by scanning electron microscopy we identified these particles as metal components. But there was a great difference in the relation of the particles found in the tissue compared to the components forming the plates alloy. This is due to the difference of distribution of the metal components at the surface of the implant in comparison with the central part of the plate. These austenitic stainless steels are protected by an enrichment of Cr in the surface layer. This could be shown in the shot peened plates as well as in the polished plates. The results of our investigations show a corrosive behaviour which is at least equal at both plates types in laboratory investigations as well as after implantations in men.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3751250

  5. 1. LOCK CHAMBER, LOOKING NORTH. WITH A DEPTH OF 16 ...

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

    1. LOCK CHAMBER, LOOKING NORTH. WITH A DEPTH OF 16 FEET, LOCK #28 WAS THE DEEPEST LOCK IN THAT PORTION OF THE OHIO AND ERIE CANAL BETWEEN AKRON AND CLEVELAND, HENCE ITS POPULAR NAME,'DEEP LOCK'. - Ohio & Erie Canal, Lock No. 28, East of Junction of Major & Riverview Roads, Peninsula, Summit County, OH

  6. Phase-lock loop frequency control and the dropout problem

    NASA Technical Reports Server (NTRS)

    Attwood, S.; Kline, A. J.

    1968-01-01

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

  7. VIEW LOOKING NORTHEAST, LOCK 35 IS ON THE RIGHT. CANAL ...

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

    VIEW LOOKING NORTHEAST, LOCK 35 IS ON THE RIGHT. CANAL WORKERS ARE CLEANING TRASH GRATES TO LOCK 35 WATER INLET. ENTRANCE TO OLD LOCK 71 ON LEFT. NOTE THE SEDIMENT BUILD UP IN THE ENTRANCE CHANNEL TO OLD LOCK 71. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

  8. Mapping Plate Tectonic Boundaries

    NSDL National Science Digital Library

    Michael Kerwin

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

  9. The EndoPearl device increases fixation strength and eliminates construct slippage of hamstring tendon grafts with interference screw fixation

    Microsoft Academic Search

    Andreas Weiler; Manuel Richter; Gerhard Schmidmaier; Frank Kandziora; Norbert P. Südkamp

    2001-01-01

    Purpose: The EndoPearl (Linvatec, Largo, FL), a biodegradable device to augment the femoral interference screw fixation of hamstring tendon grafts has been developed. The first objective of this study was to compare the initial fixation strength of quadrupled hamstring tendons and biodegradable interference screw fixation with and without the application of the EndoPearl device. The second objective was to determine

  10. Material characterization of glass\\/polypropylene composite bone plates according to the forming condition and performance evaluation under a simulated human body environment

    Microsoft Academic Search

    Seok-Won Park; Seong-Hwan Yoo; Song-Tao An; Seung-Hwan Chang

    The mechanical performance of a composite bone plate made of a glass\\/polypropylene (Twintex) for the biologic fixation of diaphyseal long bone fractures was investigated in this paper. To find out the most appropriate forming condition of the composite bone plate, tensile and bending tests and microscopic observations of the specimens fabricated by various forming conditions were carried out. The measured

  11. Delayed Rupture of the Flexor Pollicis Longus Tendon After Inappropriate Placement of the ? Plate on the Volar Surface of the Distal Radius

    Microsoft Academic Search

    James A. Nunley; Peter R. Rowan

    1999-01-01

    The ? plate (Synthes Ltd, Paoli, PA) was designed to fit the unique contour of the dorsal aspect of the distal radius. Complications of ? plate fixation of the dorsal distal radius have been previously reported to include both extensor tenosynovitis and delayed extensor tendon rupture. We report a case of rupture of the flexor pollicis longus tendon associated with

  12. Spring-Loaded-Bolt Locking Device

    NASA Technical Reports Server (NTRS)

    Calco, Frank S.

    1990-01-01

    Locking device designed to clamp small objects temporarily onto object or vehicle that accelerates. Intended to be used in place of toggle clamp, which can snap out of lock during excessive shock or vibration or because of accidental contact of person or object with toggle locking handle. Device looks and operates somewhat like spring-loaded door bolt. Moderate vibrations do not cause accidental unlocking.

  13. Dark Carbon Fixation: An Important Process in Lake Sediments

    PubMed Central

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

    2013-01-01

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

  14. Robust quantum data locking from phase modulation

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  15. Microcontroller-based locking in optics experiments

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    E-print Network

    US Army Corps of Engineers

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

  17. RH Lock: A Scalable Hierarchical Spin Lock Zoran Radovic and Erik Hagersten

    E-print Network

    Hagersten, Erik

    to neighbor- ing processors when a lock is released, which will create a fast lock handover time as well of a shared-memory application is often limited by contention for some critical section, often access- ing-and-set locks imple- mentations perform worse at high contention, i.e., the more important the critical section

  18. An effective fixative for glucocorticoid receptors in fetal tissues

    SciTech Connect

    Koga, T.; Kurisu, K.

    1982-01-01

    As a preliminary study in an autoradiographic study of glucocorticoid (GC) receptor localization in orofacial tissues of mouse fetuses, a search was made to determine the most effective fixative for preservation of the GC-receptor complex. Twelve-day-old mouse fetuses were administered tritiated triamcinolone acetonide (/sup 3/H-TAC) intraamniotically and subsequently processed by one of the following three procedures: freeze-drying, prefixation with Karnovsky's fixative, or the catechin fixative (Karnovsky's fixative containing 1% D-catechin) and postfixation with osmium tetroxide. Light microscopic autoradiography and liquid scintillation counting of the specimens revealed that the catechin fixative gave the best results for fixation of the steroid-receptor complex and preservation of tissue structure. Light and electron microscopic autoradiographic studies of the time course of the localization of /sup 3/H-TAC in palatal shelves supported the catechin fixative as being the most effective in preservation of GC-receptor or ligand complexes.

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

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

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

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

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

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

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

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

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

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

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

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

  3. Southwick Osteotomy Stabilised with External Fixator

    PubMed Central

    Grubor, Predrag; Mitkovic, Milorad; Grubor, Milan

    2014-01-01

    ABSTRACT Introduction: Epiphysiolysis of the femoral head is the most common accident occurring towards the end of pre-puberty and puberty growth. Case report: The author describes the experience in the treatment of chronic epiphysiolysis in two patients treated by Southwick osteotomy. The site is accessed by way of a 15-cm long lateral skin incision and the trochanteric region is reached through the layers. The osteotomy angles prepared beforehand on a thin aluminium model are used to mark the Southwick osteotomy site on the anterior and lateral sides at the level of the lesser trochanter. Before performing the trochanteric osteotomy, two Mitkovi? convergent pins type M20 are applied distally and proximally, above the planned osteotomy site. A tenotomy of the iliopsas muscle is performed, and then the previously marked bone triangle is redissected up to three quarters of the width of the femur. The distal part of the femur is rotated inwards, so that the patella is turned towards the ceiling. The osteotomised fragments of the femur are adapted, repositioned and fixated by installing an external fixator on the previously placed pins. Two more pins are placed, one proximally and one distally, with a view to adequately stabilising the femur. The patient was mobile from day two after the surgery. If, after the surgery, the lead surgeon realises that there is a requirement to make a correction of 5, 10 and 15 degrees of the valgus, varus, anteversion or retroversion deformity, the correction shall be performed without surgically opening the patient, using the fixator pins. Conclusion: After performing a Southwick osteotomy it is easier to adapt, reposition and fixate the osteotomised fragments of the femur using a fixator type M20. Adequate stability allows regaining mobility quickly, which in turn is the best prevention of chondrolysis of the hip. It is possible to make post-operative valgus, varus, anteversion and retroversion corrections of 5, 10 and 15 degrees without performing a surgery. Once the osteotomy is healed, the fixator type M20 is removed without any additional surgery. PMID:25568571

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

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

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

  5. Non-metallic fixatives in orthopedic surgery. Some aspects of their present and future properties.

    PubMed

    Vainio, J

    1978-08-30

    Some materials obviously possess bone fixing properties and may hence be used in anchoring prostheses to the bone, in filling bone defects and even in the fixation of fractures. The commercial bone cements are an example of materials already used today, and their development and basic properties are known. Some newer materials, which seem to possess bone fixing properties of a different kind are also, described. The polycarboxylate cements used in dentistry adhere to bone and metals by complex formation. Some hydrophilic materials, which absorb water while setting, have a self-locking capacity. Very strong composite resins can be obtained by mixture of suitable materials. A firm fixation may result from the growth of bone into some porous materials implanted into bone. Biodegradable products disappear from the tissues after some length of time, thus allowing healing to take place by a normal regenerative process. It is concluded that newer and better cementing materials are needed and that such materials may be expected soon to become available. PMID:718400

  6. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...gas-safe space. (b) Each air lock must: (1) Consist...doors from a gas-safe area; (5) Have a pressure...of the gas-dangerous area on the weather deck...gas carrier may have an air lock unless the space:...

  7. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...gas-safe space. (b) Each air lock must: (1) Consist...doors from a gas-safe area; (5) Have a pressure...of the gas-dangerous area on the weather deck...gas carrier may have an air lock unless the space:...

  8. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...gas-safe space. (b) Each air lock must: (1) Consist...doors from a gas-safe area; (5) Have a pressure...of the gas-dangerous area on the weather deck...gas carrier may have an air lock unless the space:...

  9. Injection locking conditions under small periodic excitations

    Microsoft Academic Search

    Mark M. Gourary; Sergey G. Rusakov; Sergey L. Ulyanov; Michael M. Zharov; Brian J. Mulvaney; Kiran K. Gullapalli

    2008-01-01

    Injection locking of oscillators subject to small periodic excitations is derived from existence conditions of the solution of the small signal harmonic balance degenerate system. The resulting expression for the locking range can be applied to any oscillator circuit with arbitrary periodic injection waveform, and can be easily implemented into a circuit simulator. The application of the general expression to

  10. Nose tip locking device. [Patent application

    Microsoft Academic Search

    J. A. Andersen; G. R. Harty

    1976-01-01

    Nose tip securing devices are described for releasably locking a nose tip onto a space reentry vehicle so that even if the nose tip is radioactive, it may be safely attached and detached from the vehicle. A mechanism is provided for locking and releasing a nose tip to a vehicle comprising a shaft having first and second ends, the first

  11. Past, Present, Future Erosion at Locke Island

    SciTech Connect

    Bjornstad, Bruce N.

    2006-08-08

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

  12. Spatial and Dynamic Aspects of Visual Fixation

    Microsoft Academic Search

    G. M. JONESAND; J. H. Milsum

    1965-01-01

    The physiological processes concerned with the difficult dynamic task of fixating the retinal image during normal body and head movement are examined with a control engineering perspective. Spatial relationships between the two main system inputs (visual and vestibular) and three main outputs (operating on the eye-in-skull, skull-on-body, and body-in-space platforms) are examined in the context of the geometry of the

  13. Pin loosening in external skeletal fixation

    E-print Network

    Vittal, Bamini

    1993-01-01

    30 Ncm were considered representative of loose pins. The failure mode in pull out tests is generally shear fracture of interfacial tissues. The reason for the higher torque in specimen 9 could be because the bone marrow contained more substantial... of the fractured bone during the healing process. Loosening of percutaneous fixation pins commonly occurs. Pin loosening is considered the most significant feature in the development of pin tract osteomyelitis. The causes of pin loosening are under investigation...

  14. Nitrogen Fixation by Myxophyceae from Marine Environments

    Microsoft Academic Search

    W. D. P. Stewart

    1964-01-01

    SUMMARY Two blue-green algae from marine environments, Calothrix scopulorum and Nostoc entophytum, vigorously fixed 15N-labelled nitrogen in artificial sea-water free from combined nitrogen and, rather faster, in natural sea- water. A proportion of the nitrogen fixed was liberated into the medium. After a 7-day exposure period the extracellular nitrogen had a lower enrichment with 16N than the intracellular nitrogen. Fixation

  15. The PLATES Project

    NSDL National Science Digital Library

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

  16. Understanding Plate Motions

    NSDL National Science Digital Library

    The representation shows divergent boundaries, convergent boundaries, transform boundaries, and plate boundary zones through a series of diagrams. Some of the diagrams are accompanied by a photographs. Accompanying text explains plate movement at each type of boundary.

  17. Portable Plating System

    NASA Technical Reports Server (NTRS)

    Flores, R.

    1984-01-01

    Plating system mounted on portable cart includes 30-gallon (23.5 liter) electrolyte tank, filler pump, heaters, replenishing anodes, plating rectifiers and tank rectifier to continously remove contaminants.

  18. External Resource: Plate Tectonics

    NSDL National Science Digital Library

    1900-01-01

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

  19. Plate Tectonics: Further Evidence

    NSDL National Science Digital Library

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

  20. Earth's Decelerating Tectonic Plates

    SciTech Connect

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

    2008-08-22

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

  1. Medial submuscular plating of the femur in a series of paediatric patients: a useful alternative to standard lateral techniques.

    PubMed

    Nayagam, S; Davis, B; Thevendran, G; Roche, A J

    2014-01-01

    We describe the technique and results of medial submuscular plating of the femur in paediatric patients and discuss its indications and limitations. Specifically, the technique is used as part of a plate-after-lengthening strategy, where the period of external fixation is reduced and the plate introduced by avoiding direct contact with the lateral entry wounds of the external fixator pins. The technique emphasises that vastus medialis is interposed between the plate and the vascular structures. A total of 16 patients (11 male and five female, mean age 9.6 years (5 to 17)), had medial submuscular plating of the femur. All underwent distraction osteogenesis of the femur with a mean lengthening of 4.99 cm (3.2 to 12) prior to plating. All patients achieved consolidation of the regenerate without deformity. The mean follow-up was 10.5 months (7 to 15) after plating for those with plates still in situ, and 16.3 months (1 to 39) for those who subsequently had their plates removed. None developed a deep infection. In two patients a proximal screw fractured without loss of alignment; one patient sustained a traumatic fracture six months after removal of the plate. Placing the plate on the medial side is advantageous when the external fixator is present on the lateral side, and is biomechanically optimal in the presence of a femoral defect. We conclude that medial femoral submuscular plating is a useful technique for specific indications and can be performed safely with a prior understanding of the regional anatomy. PMID:24395325

  2. Mesh fixation alternatives in laparoscopic ventral hernia repair.

    PubMed

    Muysoms, Filip E; Novik, Bengt; Kyle-Leinhase, Iris; Berrevoet, Frederik

    2012-12-01

    Since the introduction of laparoscopic ventral hernia repair, there has been an ongoing dispute over the optimal method of fixating the mesh against the abdominal wall. In general, one could say that the more penetrating the fixation used, the stronger the fixation, but at the cost of increased acute postoperative pain. The occurrence of chronic pain in some patients has led to the search for less permanent penetrating fixation, but without risking a less stable mesh fixation and increased recurrences due to shift or shrinkage of the mesh. Avoiding transfascial sutures by using a double crown of staples has been proposed and recently absorbable fixation devices have been developed. Some surgeons have proposed fixation with glue to reduce the number of staples, or even eliminate them entirely. The continuously increasing multitude of marketed meshes and fixating devices leads to unlimited options in mesh fixation combination and geometry. Therefore, we will never be able to get a clear view on the benefits and pitfalls of every specific combination. Clearance of the anterior abdominal wall from peritoneal fatty tissue and correct positioning of the mesh with ample overlap of the hernia defect are possibly as important as the choice of mesh and fixation. Other topics that are involved in successful outcomes but not addressed in this article are adequate training in the procedure, appropriate selection of patients, and careful adhesiolysis to minimize accidental visceral injuries. PMID:23225589

  3. Medial malleolar fractures: a biomechanical study of fixation techniques.

    PubMed

    Fowler, T Ty; Pugh, Kevin J; Litsky, Alan S; Taylor, Benjamin C; French, Bruce G

    2011-08-01

    Fracture fixation of the medial malleolus in rotationally unstable ankle fractures typically results in healing with current fixation methods. However, when failure occurs, pullout of the screws from tension, compression, and rotational forces is predictable. We sought to biomechanically test a relatively new technique of bicortical screw fixation for medial malleoli fractures. Also, the AO group recommends tension-band fixation of small avulsion type fractures of the medial malleolus that are unacceptable for screw fixation. A well-documented complication of this technique is prominent symptomatic implants and secondary surgery for implant removal. Replacing stainless steel 18-gauge wire with FiberWire suture could theoretically decrease symptomatic implants. Therefore, a second goal was to biomechanically compare these 2 tension-band constructs. Using a tibial Sawbones model, 2 bicortical screws were compared with 2 unicortical cancellous screws on a servohydraulic test frame in offset axial, transverse, and tension loading. Second, tension-band fixation using stainless steel wire was compared with FiberWire under tensile loads. Bicortical screw fixation was statistically the stiffest construct under tension loading conditions compared to unicortical screw fixation and tension-band techniques with FiberWire or stainless steel wire. In fact, unicortical screw fixation had only 10% of the stiffness as demonstrated in the bicortical technique. In a direct comparison, tension-band fixation using stainless steel wire was statistically stiffer than the FiberWire construct. PMID:21815575

  4. Locking mechanism strength of absorbable ligating devices.

    PubMed

    Hay, D L; von Fraunhofer, J A; Chegini, N; Masterson, B J

    1988-03-01

    The locking mechanism strengths of the absorbable Absolok and Lactomer ligating clips and the absorbable Lactomer staple have been determined following implantation in an animal model. Three sizes of each type of clip and the single size of staple were enclosed in open mesh nylon pouches and implanted subcutaneously in rabbits for periods of 4, 7, 14, 21, and 28 days before tensile testing of the lock mechanisms. No change in the lock mechanism strength was detected for the Absolok clips before 21 days. The Lactomer clips and staples, however, showed significant decrease in lock mechanism strength within 7 days of implantation, this loss increasing with longer implantation times. A proportion of all the devices were found to have dissolved to an extent that precluded testing at 21 and 28 days. The findings indicate that the lock mechanisms of absorbable ligating clips differ significantly in their short-term (30 days) durability. PMID:3360813

  5. Plate Tectonic Theory

    NSDL National Science Digital Library

    John Louie

    This is the web site for a Plate Tectonics Theory class at The University of Nevada, Reno. The home page/syllabus contains links to several of the topics covered in the course. The topics with web based lecture materials are earthquake seismology, structure of the Earth, composition of the Earth, lithospheric deformation, the plate tectonics paradigm, and the driving mechanisms of plate tectonics.

  6. Paper terahertz wave plates.

    PubMed

    Scherger, Benedikt; Scheller, Maik; Vieweg, Nico; Cundiff, Steven T; Koch, Martin

    2011-12-01

    We present a low-cost terahertz wave plate based on form birefringence fabricated using ordinary paper. Measurements of the transfer function of the wave plate between polarizers closely agree with predictions based on the measured complex indices of refraction of the effective medium. For the design frequency, the dependence on wave plate angle also agrees with theory. PMID:22273881

  7. Laser induced copper plating

    Microsoft Academic Search

    A. K. Al-Sufi; H. J. Eichler; J. Salk; H. J. Riedel

    1983-01-01

    Argon laser induced plating of copper spots and lines from copper sulfate solutions on glass and phenolic resin paper has been investigated. The substrates had to be precoated with an evaporated copper film. The highest plating rates have been obtained with a small film thickness of 25 nm. Spots with a thickness up to 30 ?m were plated.

  8. Plate Tectonic Primer

    NSDL National Science Digital Library

    Lynn Fichter

    This site gives an in-depth look at the theory of plate tectonics and how it works. The structure of the Earth is discussed, with brief rock type descriptions. The structure of the lithosphere, plate boundaries, interplate relationships, and types of plates are all covered in detail.

  9. Earthquakes and Plate Tectonics

    NSDL National Science Digital Library

    This article describes the theory of plate tectonics and its relation to earthquakes and seismic zones. Materials include an overview of plate tectonics, a description of Earth's crustal plates and their motions, and descriptions of the four types of seismic zones.

  10. Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility

    PubMed Central

    Qiao, Bo; Li, Jidong; Zhu, Qingmao; Guo, Shuquan; Qi, Xiaotong; Li, Weichao; Wu, Jun; Liu, Yang; Jiang, Dianming

    2014-01-01

    An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. PMID:24669191

  11. Strength of surgical wire fixation. A laboratory study.

    PubMed

    Guadagni, J R; Drummond, D S

    1986-08-01

    Because of the frequent use of stainless steel wire in spinal surgery and to augment fracture fixation, several methods of securing wire fixation were tested in the laboratory to determine the relative strength of fixation. Any method of fixation stronger than the yield strength of the wire is sufficient. Square knots, knot twists, symmetric twists, and the AO loop-tuck techniques afforded acceptable resistance against tension loads, but the wire wrap and AO loop technique were unacceptable. The double symmetric twist, which is frequently used for tension banding, was barely acceptable. The symmetric twist technique was the most practical because it is strong enough, efficient in maintaining tension applied during fixation, and least likely to cause damage to the wire. To optimize the fixation strength of the symmetrical twist, at least two twists are required at a reasonably tight pitch. PMID:3731592

  12. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

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

  13. Angular shear plate

    DOEpatents

    Ruda, Mitchell C. (Tucson, AZ); Greynolds, Alan W. (Tucson, AZ); Stuhlinger, Tilman W. (Tucson, AZ)

    2009-07-14

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

  14. Malachite green photosensitive plates.

    PubMed

    Solano, C

    1989-08-15

    An experimental study of the behavior of malachite green sensitized plates was carried out. The transmittance variation of the irradiated plates was taken as a parameter. It has been observed that photoreduction in the malachite green plates is present only when ammonium dichromate is added to the plates. The introduction of external electron donors does not improve the photochemical reaction. It has been determined that malachite green molecules form a weak complex with the dichromate molecules and this complex can only be destroyed photochemically. This effect can explain the limited response of the malachite green dichromated plates. PMID:20555732

  15. Discovering Plate Boundaries

    NSDL National Science Digital Library

    Alison Henning

    Students are initially assigned to one of four maps of the world: Seismology, Volcanology, Geochronology or Topography. They are also given a map of the world's plate boundaries and are asked to classify the boundaries based upon the data from their assigned map. Students are then assigned to a tectonic plate, such that each plate group contains at least one "expert" on each map. As a group, they must classify their plate's boundaries using data from all four maps. Recent volcanic and seismic events are discussed in the plate tectonic context. Has minimal/no quantitative component Uses geophysics to solve problems in other fields

  16. Combined finite element and multibody musculoskeletal investigation of a fractured clavicle with reconstruction plate.

    PubMed

    Cronskär, Marie; Rasmussen, John; Tinnsten, Mats

    2015-01-01

    This paper addresses the evaluation of clavicle fixation devices, by means of computational models. The aim was to develop a method for comparison of stress distribution in various fixation devices, to determine whether the use of multibody musculoskeletal input in such model is applicable and to report the approach. The focus was on realistic loading and the motivation for the work is that the treatment can be enhanced by a better understanding of the loading of the clavicle and fixation device. The method can be used to confirm the strength of customised plates, for optimisation of new plates and to complement experimental studies. A finite element (FE) mesh of the clavicle geometry was created from computed tomography data and imported into the FE solver where the model was subjected to muscle forces and other boundary conditions from a multibody musculoskeletal model performing a typical activity of daily life. A reconstruction plate and screws were also imported into the model. The combination models returned stresses and displacements of plausible magnitudes in all included parts and the result, upon further development and validation, may serve as a design guideline for improved clavicle fixation. PMID:24156391

  17. Antimicrobial efficacy of surface-coated external fixation pins.

    PubMed

    Furkert, Franz H; Sörensen, Jan H; Arnoldi, Jörg; Robioneck, Bernd; Steckel, Hartwig

    2011-06-01

    In clinical applications, colonization of metal implants by adhesive and biofilm-forming bacteria not only prolong healing but create additional healthcare costs for implant revision and antimicrobial treatment. An in vitro assay was established investigating the antimicrobial surface activity of external fixation pins intended for use in bone fractures and deformities. Test articles made out of stainless steel and coated with a polymer-containing nanoparticulate silver were compared to non-coated reference controls out of stainless steel, copper and titanium. Staphylococcus epidermidis, known as a predominant cause for implant-related infections was used as test organism. Test pins and bacteria were incubated for a period of 20 h found to be sufficient for initiating biofilm formation. After removing non- and low-adherent bacteria by rinsing, two methods were used to isolate high-adherent (sessile) bacteria from the implant surfaces. Besides shaking the implants in a solution containing small glass beads, a cytobrush technique was used to mechanically harvest viable bacteria. Finally, the amount of detached bacteria was determined by plate counts. Several parameters identified to be critical within the different removal procedures such as the inoculum concentration and the shaking time in the presence of glass beads as well as time of the cytobrush treatment were analysed. The final test scheme resulted in the use of an inoculum of 10(5) colony forming units (CFU) per millilitre, ten rinsing steps for the removal of low adherent bacteria and 5 min of shaking in the presence of glass beads, detaching the high-adherent bacteria. Due to subjective variations impacting the outcome of the procedure, the cytobrush technique was not favoured and finally rejected. Using the in vitro assay developed, it could be demonstrated that fixation pins coated with silver show a 3 log step reduction in the number of biofilm-forming bacteria compared to a non-coated stainless steel or titanium implant. Pins made out of copper showed the highest antimicrobial efficacy, as the number of detached bacteria was found to be below the detection limit, they served as a positive control within this test. PMID:21442392

  18. Calibration and Standardization of Microwave Ovens for Fixation of Brain and Peripheral Nerve Tissue

    Microsoft Academic Search

    Jonathan B. Leonard; Ann M. Dvorak

    1998-01-01

    Rapid and reproducible fixation of brain and peripheral nerve tissue for light and electron microscopy studies can be done in a microwave oven. In this review we report a standardized nomenclature for diverse fixation techniques that use microwave heating: (1) microwave stabilization, (2) fast and ultrafast primary microwave–chemical fixation, (3) microwave irradiation followed by chemical fixation, (4) primary chemical fixation

  19. Delay locked loop integrated circuit.

    SciTech Connect

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  20. Assessment of biological nitrogen fixation in grassland and associated sites

    Microsoft Academic Search

    K. Vlassak; E. A. Paul; R. E. Harris

    1973-01-01

    Summary  The extent of nitrogen fixation in native grassland on clay soil was measured using the C2H2 reduction assay. Undisturbed soil cores incubated in microcanopies in the field indicated fixation rates of 2 kg N\\/ha per\\u000a season. Less nitrogen fixation activity was found in associated cultivated soils. Other sites on different soil associations\\u000a were found capable of fixing 1 kgN\\/ha or

  1. Buckminsterfullerenes A non-metal system for nitrogen fixation

    Microsoft Academic Search

    Yoshiaki Nishibayashi; Makoto Saito; Sakae Uemura; Shin-ichi Takekuma; Hideko Takekuma; Zen-ichi Yoshida

    2004-01-01

    In all nitrogen-fixation processes known so far - including the industrial Haber-Bosch process, biological fixation by nitrogenase enzymes and previously described homogeneous synthetic systems - the direct transformation of the stable, inert dinitrogen molecule (N2) into ammonia (NH3) relies on the powerful redox properties of metals. Here we show that nitrogen fixation can also be achieved by using a non-metallic

  2. Monitoring In Vivo Load Transmission Through an External Fixator

    Microsoft Academic Search

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

    2010-01-01

    This work presents a portable non-invasive external fixator to assess and monitor fracture healing in real time. To evaluate\\u000a the potential of this fixator, a transverse osteotomy was performed in the tibia of six adult sheep (mean age 3 ± 0.5 years\\u000a and weight 63 ± 5 kg). The fractures were stabilized by a specially designed unilateral external fixator, which was instrumented

  3. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (inventor)

    1984-01-01

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

  4. Theta phase shift in spike timing and modulation of gamma oscillation: a dynamic code for spatial alternation during fixation in rat hippocampal area CA1

    PubMed Central

    Nishida, Hiroshi; David Redish, A.; Lauwereyns, Johan

    2014-01-01

    Although hippocampus is thought to perform various memory-related functions, little is known about the underlying dynamics of neural activity during a preparatory stage before a spatial choice. Here we focus on neural activity that reflects a memory-based code for spatial alternation, independent of current sensory and motor parameters. We recorded multiple single units and local field potentials in the stratum pyramidale of dorsal hippocampal area CA1 while rats performed a delayed spatial-alternation task. This task includes a 1-s fixation in a nose-poke port between selecting alternating reward sites and so provides time-locked enter-and-leave events. At the single-unit level, we concentrated on neurons that were specifically active during the 1-s fixation period, when the rat was ready and waiting for a cue to pursue the task. These neurons showed selective activity as a function of the alternation sequence. We observed a marked shift in the phase timing of the neuronal spikes relative to the theta oscillation, from the theta peak at the beginning of fixation to the theta trough at the end of fixation. The gamma-band local field potential also changed during the fixation period: the high-gamma power (60–90 Hz) decreased and the low-gamma power (30–45 Hz) increased toward the end. These two gamma components were observed at different phases of the ongoing theta oscillation. Taken together, our data suggest a switch in the type of information processing through the fixation period, from externally cued to internally generated. PMID:24478159

  5. A new generation of lock and tag

    SciTech Connect

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

    1992-04-01

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

  6. A new generation of lock and tag

    SciTech Connect

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

    1992-04-01

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

  7. Comparison of plate-screw systems used in mandibular fracture reduction: finite element analysis.

    PubMed

    Lovald, Scott T; Khraishi, Tariq; Wagner, Jon; Baack, Bret; Kelly, James; Wood, John

    2006-10-01

    A finite element model of the human dentate mandible has been developed to provide a comparison of fixation systems used currently for fracture reduction. Volume domains for cortical bone, cancellous bone, and teeth were created and meshed in ANSYS 8.0 based on IGES curves created from computerized tomography data. A unilateral molar clench was loaded on the model with a fracture gap simulated along the symphysis. Results based on Von Mises stress in cortical and cancellous bone surrounding the screws, and on fracture surface spatial fixation, show some relative differences between different screw-plate systems, yet all were judged to be appropriate in their reduction potential. PMID:16995751

  8. Decreased Fronto-Temporal Interaction during Fixation after Memory Retrieval

    PubMed Central

    Sasaki, Hiroki; Mori, Harushi; Kunimatsu, Akira; Ohtomo, Kuni; Jimura, Koji; Konishi, Seiki

    2014-01-01

    Previous studies have revealed top-down control during memory retrieval from the prefrontal cortex to the temporal cortex. In the present functional MRI study, we investigated whether the fronto-temporal functional interaction occurs even during fixation periods after memory retrieval trials. During recency judgments, subjects judged the temporal order of two items in a study list. The task used in the present study consisted of memory trials of recency judgments and non-memory trials of counting dots, and post-trial fixation periods. By comparing the brain activity during the fixation periods after the memory trials with that during the fixation periods after the non-memory trials, we detected heightened brain activity in the lateral prefrontal cortex, the lateral temporal cortex and the hippocampus. Functional interactions during the fixation periods after the memory vs. non-memory trials as examined using a psychophysiological interaction revealed a decreased interaction from the lateral prefrontal cortex to the lateral temporal cortex, but not to the hippocampus. The functional interaction between the same frontal and temporal regions was also present during the memory trials. A trial-based functional connectivity analysis further revealed that the fronto-temporal interaction was positive and decreased during the fixation periods after the memory trials, relative to the fixation periods after the non-memory trials. These results suggest that the fronto-temporal interaction existed during the post-trial fixation periods, which had been present during the memory trials and temporally extended into the fixation periods. PMID:25340398

  9. Effects of hook plate on shoulder function after treatment of acromioclavicular joint dislocation

    PubMed Central

    Chen, Chang-Hong; Dong, Qi-Rong; Zhou, Rong-Kui; Zhen, Hua-Qing; Jiao, Ya-Jun

    2014-01-01

    Introduction: Internal fixation with hook plate has been used to treat acromioclavicular joint dislocation. This study aims to evaluate the effect of its use on shoulder function, to further analyze the contributing factors, and provide a basis for selection and design of improved internal fixation treatment of the acromioclavicular joint dislocation in the future. Methods: A retrospective analysis was performed on patients treated with a hook plate for acromioclavicular joint dislocation in our hospital from January 2010 to February 2013. There were 33 cases in total, including 25 males and 8 females, with mean age of 48.27 ± 8.7 years. There were 29 cases of Rockwood type III acromioclavicular dislocation, 4 cases of type V. The Constant-Murley shoulder function scoring system was used to evaluate the shoulder function recovery status after surgery. Anteroposterior shoulder X-ray was used to assess the position of the hook plate, status of acromioclavicular joint reduction and the occurrence of postoperative complications. Results: According to the Constant-Murley shoulder function scoring system, the average scores were 78 ± 6 points 8 to 12 months after the surgery and before the removal of the hook plate, the average scores were 89 ± 5 minutes two months after the removal of hook plate. Postoperative X-ray imaging showed osteolysis in 10 cases (30.3%), osteoarthritis in six cases (18.1%), osteolysis associated with osteoarthritis in four cases(12.1%), and steel hook broken in one case (3%). Conclusion: The use of hook plate on open reduction and internal fixation of the acromioclavicular joint dislocation had little adverse effect on shoulder function and is an effective method for the treatment of acromioclavicular joint dislocation. Osteoarthritis and osteolysis are the two common complications after hook plate use, which are associated with the impairment of shoulder function. Shoulder function will be improved after removal of the hook plate. PMID:25356110

  10. Endotracheal tube fixation methods for optimal stability: a comparison of adhesive tape, suture, and tape-suture fixation.

    PubMed

    Farbod, Frank; Tuli, Puneet; Robertson, Bernard F; Jackson, Ian T

    2010-07-01

    Accidental extubation of an intubated patient is a serious consideration in the surgical patient. Adequate fixation in the intubated patient is essential to prevent potentially life-threatening complications. Several methods of endotracheal tube fixation have been described in the literature. In this study, we examine 3 common methods of fixation: adhesive tape alone, suture, and tape-suture. Testing occurred in a laboratory setting with 2 fresh cadavers. Endotracheal tubes were inserted, using the methods of fixation in question. We subjected each fixation technique to progressively increasing weight to determine which technique is most resistant to accidental removal. We found that fixation of the tube by combining tape around the tube with a suture through the tape is the best noninvasive technique of the 3 methods evaluated in cases where movement of the head is anticipated. PMID:20613600

  11. Phase-locked loops and their application

    NASA Technical Reports Server (NTRS)

    Lindsey, W. C. (editor); Simon, M. K.

    1978-01-01

    A collection of papers is presented on the characteristics and capabilities of phase-locked loops (PLLs), along with some applications of interest. The discussion covers basic theory (linear and nonlinear); acquisition; threshold; stability; frequency demodulation and detection; tracking; cycle slipping and loss of lock; phase-locked oscillators; operation and performance in the presence of noise; AGC, AFC, and APC circuits and systems; digital PLL; and applications and miscellaneous. With the rapid development of IC technology, PLLs are expected to be used widely in consumer electronics.

  12. Parallel Digital Phase-Locked Loops

    NASA Technical Reports Server (NTRS)

    Sadr, Ramin; Shah, Biren N.; Hinedi, Sami M.

    1995-01-01

    Wide-band microwave receivers of proposed type include digital phase-locked loops in which band-pass filtering and down-conversion of input signals implemented by banks of multirate digital filters operating in parallel. Called "parallel digital phase-locked loops" to distinguish them from other digital phase-locked loops. Systems conceived as cost-effective solution to problem of filtering signals at high sampling rates needed to accommodate wide input frequency bands. Each of M filters process 1/M of spectrum of signal.

  13. Phase locking an IMPATT device in the pulsed mode

    Microsoft Academic Search

    F. R. Domer; R. H. Kyle

    1967-01-01

    Phase locking of pulsed avalanche diode oscillators has been demonstrated. During the locking process, changes in phase between the locking signal and oscillator have been observed. These observations indicate that emission of identical pulses does not necessarily imply that the diode and locking frequencies are the same.

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

    Microsoft Academic Search

    Steven D. Maschke; Peter J. Evans; David Schub; Richard Drake; Jeffrey N. Lawton

    2007-01-01

    Introduction  Extensor tendon irritation and attritional tendon ruptures are potentially serious complications after open reduction and\\u000a internal fixation of distal radius fractures. These complications are well recognized after dorsal plating of distal radii;\\u000a and these are now being reported after errant screw placement during volar fixed-angle plating. Intraoperative detection of\\u000a improper screw placement is critical, as corrective action can be taken

  15. Titanium alloys for fracture fixation implants.

    PubMed

    Disegi, J A

    2000-12-01

    This paper is intended to provide an overview of the composition, mechanical properties, biocompatibility, and clinical applications for titanium alloys that are used for fracture fixation implants. A new class of titanium implant alloys has emerged in recent years that exhibits a beta microstructure and a unique combination of mechanical properties. Important information regarding notch sensitivity testing and clinical significance is also discussed. Attributes such as stress corrosion cracking resistance, fatigue strength, and wear characteristics are also essential for specific clinical applications, but are beyond the scope of this presentation. PMID:11270074

  16. Trochanteric fixation using a third-generation cable device--minimum follow-up of 3 years.

    PubMed

    Patel, Shelain; Soler, Juan A; El-Husseiny, Moataz; Pegg, Derek J; Witt, Johan D; Haddad, Fares S

    2012-03-01

    Third-generation trochanteric fixation cable systems are designed to overcome implant breakage, nonunion, and bony escape. The study prospectively assessed the functional and radiologic outcomes using such an implant. Forty-seven trochanteric fixations in 46 patients were performed over 4 years at 2 institutions using the Accord Cable Plate system (Smith and Nephew, Memphis, Tenn). Serial evaluation at a mean follow-up of 57 months demonstrated that the mean Harris hip scores improved from 52.3 preoperatively to 88.2 postoperatively (P < .001), and the mean pain score improved from 6.2 to 2.3, respectively (P < .001). No cable breakage, fretting, or fraying occurred. There were 2 cases of nonunion. A third-generation cable system appears to improve upon early-generation implants and provide favorable outcomes for reattachment of a trochanteric fragment in a variety of clinical scenarios. PMID:21908164

  17. Biomechanical analysis of acetabular revision constructs: is pelvic discontinuity best treated with bicolumnar or traditional unicolumnar fixation?

    PubMed

    Gililland, Jeremy M; Anderson, Lucas A; Henninger, Heath B; Kubiak, Erik N; Peters, Christopher L

    2013-01-01

    Pelvic discontinuity in revision total hip arthroplasty presents problems with component fixation and union. A construct was proposed based on bicolumnar fixation for transverse acetabular fractures. Each of 3 reconstructions was performed on 6 composite hemipelvises: (1) a cup-cage construct, (2) a posterior column plate construct, and (3) a bicolumnar construct (no. 2 plus an antegrade 4.5-mm anterior column screw). Bone-cup interface motions were measured, whereas cyclical loads were applied in both walking and descending stair simulations. The bicolumnar construct provided the most stable construct. Descending stair mode yielded more significant differences between constructs. The bicolumnar construct provided improved component stability. Placing an antegrade anterior column screw through a posterior approach is a novel method of providing anterior column support in this setting. PMID:22595181

  18. “To observe well … and thence to make himself rules”: John Locke’s principles and practice of child healthcare

    Microsoft Academic Search

    A N Williams

    2007-01-01

    It is often forgotten that the philosopher John Locke (1632–1704) was a highly regarded physician with a lifelong interest in medicine and was frequently consulted on medical matters, including the health of children. This child health aspect in Locke’s history has been largely ignored, with even modern commentaries on Locke and medicine giving it only a cursory mention. However, it

  19. Pneumatic wall-locking geophone system

    DOEpatents

    Kuhlman, Harland L. (Minneapolis, MN); Cumerlato, Calvin L. (Minneapolis, MN); Tweeton, Daryl R. (Apple Valley, MN)

    1991-01-01

    A seismic signal receiving system is provided for use in boreholes to receive seismic waves in carrying out geophysical investigations. The system includes three pairs of opposed plates, each of the pairs of plates including oppositely facing outer surfaces for engagement with opposite sides of a borehole. A seismic receiver is mounted on the inner surface of each of the plates for receiving seismic signals. A double-acting, fluid-operated actuator selectively causes relative movement of the plates of the pairs of plates away from each other to provide expansion thereof so as to enable the plates to engage the walls of a borehole and selectively causes relative movement of the plates of the pairs of plates toward each other to provide retraction thereof so as to enable the system to be removed from a borehole. The pairs of plates each comprise a relatively long plate and a relatively short plate. An expandable linkage interconnects the long plates at the distal ends thereof. The plates are mechanically biassed into the retracted state so that the plates return to this state in the event of a system failure.

  20. WFPDB: European Plate Archives

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Milcho

    2007-08-01

    The Wide-Field Plate Database (WFPDB) gives an inventory of all wide-field (>~ 1 sq. deg) photographic observations archived in astronomical institutions over the world. So it facilitates and stimulates their use and preservation as a valuable source of information for future investigations in astronomy. At present WFPDB manages plate-index information for 25% of all existing plates providing on-line access from Sofia (http://www.skyarchive.org/search) and in CDS, Strasbourg. Here we present the new development of WFPDB as an instrument for searching of long term brightness variations of different sky objects stressing on the European photographic plate collections (from existing 2 million wide-field plates more than 55% are in Europe: Germany, Russia, Ukraine, Italy, Czech Republic, etc.). We comment examples of digitization (with flatbed scanners) of the European plate archives in Sonneberg, Pulkovo, Asiago, Byurakan, Bamberg, etc. and virtual links of WFPDB with European AVO, ADS, IBVS.

  1. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  2. Folder Lock 6.1.5

    NSDL National Science Digital Library

    2009-01-01

    Those persons concerned with the security of their files, folders, or USB drives should make an inquiry into this handy application. Folder Lock helps users create encrypted storages called "lockers", which they can then use to keep their private files, complete with a password. This particular version is free to try, and visitors can also elect to pay $39.95 at the conclusion of the trial period. Folder Lock 6.1.5 is compatible with computers running Windows 95 and newer.

  3. Lock-Out / Tag-Out

    NSDL National Science Digital Library

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

  4. Fourier domain mode locking pulse fiber laser

    Microsoft Academic Search

    D. Chen

    2010-01-01

    A novel pulse fiber laser is proposed based on the modulation of the lasing wavelength. Different from conventional amplitude\\u000a or phase modulated mode-locking fiber lasers, the proposed fiber laser is with a so-called Fourier domain mode locking (FDML)\\u000a operation (i.e., the cavity round-trip time of the optical pulse should match the period that the open time window of the\\u000a tunable

  5. Resonance lock and planetary dynamics

    NASA Astrophysics Data System (ADS)

    Haghighipour, Nader

    1999-11-01

    The main purpose of this study is to utilize the method of partial averaging in order to analyze the dynamics of a planetary system while captured in resonance. A restricted planar circular three-body system, consisting of a star and two planets, is studied as a simple model for a planetary system. The mass of the inner planet is considered to be larger and the system is assumed to be moving in a freely rotating uniform interplanetary medium with constant density. Numerical integrations of this system indicate a resonance capture when the dynamical friction of the interplanetary medium is taken into account. As a result of this resonance trapping, the ratio of orbital periods of the two planets becomes nearly commensurable and the eccentricity and semimajor axis of the osculating orbit of the outer planet and also its angular momentum and total energy become constant. It appears from the numerical work that the resulting commensurability and also the resonant values of the orbital elements of the outer planet are essentially independent of the initial relative positions of the two bodies. In order to analytically explain this resonance phenomenon, the method of partial averaging near a resonance is utilized and the dynamics of the partially averaged system at resonance is studied. The finding that resonance lock occurs for all initial relative positions of the two planets is confirmed by analyzing the dynamics of the first order partially averaged system at resonance. It is also shown in this study that the first- order partially averaged system at resonance does not provide a complete picture of the evolutionary dynamics of the system and the similarity between the dynamical behavior of the averaged system and the main planetary system holds only for short time intervals. To overcome these limitations, the method of partial averaging near a resonance is extended to the second order of perturbation and a complete picture of the dynamical behavior of the system at resonance is presented. It is shown that the dynamics of the second-order partially averaged system at resonance resembles the dynamical evolution of the main system during the resonance lock in general. Analytical explanations for the evolution of the orbital elements of the main system while captured in resonance are also presented.

  6. The main objective of this pamphlet is YOUR SAFETY when "locking through"!

    E-print Network

    US Army Corps of Engineers

    lock under full control FFllaasshhiinngg GGrreeeenn Enter lock Air Horn Signals 1 Long Blast ­ Enter landward lock 2 Long Blasts ­ Enter riverward lock 1 Short Blast ­ Leave landward lock 2 Short Blasts of the lock approach wall. 3. When approaching a lock, wait for the green light and the whistle signal from

  7. Geology - Plate Tectonics

    NSDL National Science Digital Library

    Visitors to this site can learn about the theory of plate tectonics, the history of its development, and the mechanisms that drive the formation, movement, and destruction of continents and tectonic plates. A selection of animations depicts the movements of crustal plates and continents through time. Each animation is accompanied by an interactive time scale that provides links to descriptions of the geology and paleontology of the selected era or period.

  8. Atlantoaxial Rotatory Fixation in Adults Patient

    PubMed Central

    Jeon, Sei Woong; Moon, Seung Myung; Choi, Sun Kil

    2009-01-01

    Atlantoaxial rotatory fixation (AARF) in adult is a rare disorder that occurs followed by a trauma. The patients were presented with painful torticollis and a typical 'cock robin' position of the head. The clinical diagnosis is generally difficult and often made in the late stage. In some cases, an irreducible or chronic fixation develops. We reported a case of AARF in adult patient which was treated by immobilization with conservative treatment. A 25-year-old female was presented with a posterior neck pain and limitation of motion of cervical spine after a traffic accident. She had no neurological deficit but suffered from severe defect on the scalp and multiple thoracic compression fractures. Plain radiographs demonstrated torticollis, lateral shift of odontoid process to one side and widening of one side of C1-C2 joint space. Immobilization with a Holter traction were performed and analgesics and muscle relaxants were given. Posterior neck pain and limitation of the cervical spine's motion were resolved. Plain cervical radiographs taken at one month after the injury showed that torticollis disappeared and the dens were in the midline position. The authors reported a case of type I post-traumatic AARF that was successfully treated by immobilization alone. PMID:19444353

  9. Hiatus Hernia Repair with Bilateral Oesophageal Fixation

    PubMed Central

    Martin, David

    2015-01-01

    Background. Despite advances in surgical repair of hiatus hernias, there remains a high radiological recurrence rate. We performed a novel technique incorporating bilateral oesophageal fixation and evaluated outcomes, principally symptom improvement and hernia recurrence. Methods. A retrospective study was performed on a prospective database of patients undergoing hiatus hernia repair with bilateral oesophageal fixation. Retrospective and prospective quality of life (QOL), PPI usage, and patient satisfaction data were obtained. Hernia recurrence was assessed by either barium swallow or gastroscopy. Results. 87 patients were identified in the database with a minimum of 3 months followup. There were significant improvements in QOL scores including GERD HRQL (29.13 to 4.38, P < 0.01), Visick (3 to 1), and RSI (17.45 to 5, P < 0.01). PPI usage decreased from a median of daily to none, and there was high patient satisfaction (94%). 57 patients were assessed for recurrence with either gastroscopy or barium swallow, and one patient had evidence of recurrence on barium swallow at 45 months postoperatively. There was an 8% complication rate and no mortality or oesophageal perforation. Conclusions. This study demonstrates that our technique is both safe and effective in symptom control, and our recurrence investigations demonstrate at least short term durability. PMID:26065030

  10. Atlantoaxial rotatory fixation in adults patient.

    PubMed

    Jeon, Sei Woong; Jeong, Je Hoon; Moon, Seung Myung; Choi, Sun Kil

    2009-04-01

    Atlantoaxial rotatory fixation (AARF) in adult is a rare disorder that occurs followed by a trauma. The patients were presented with painful torticollis and a typical 'cock robin' position of the head. The clinical diagnosis is generally difficult and often made in the late stage. In some cases, an irreducible or chronic fixation develops. We reported a case of AARF in adult patient which was treated by immobilization with conservative treatment. A 25-year-old female was presented with a posterior neck pain and limitation of motion of cervical spine after a traffic accident. She had no neurological deficit but suffered from severe defect on the scalp and multiple thoracic compression fractures. Plain radiographs demonstrated torticollis, lateral shift of odontoid process to one side and widening of one side of C1-C2 joint space. Immobilization with a Holter traction were performed and analgesics and muscle relaxants were given. Posterior neck pain and limitation of the cervical spine's motion were resolved. Plain cervical radiographs taken at one month after the injury showed that torticollis disappeared and the dens were in the midline position. The authors reported a case of type I post-traumatic AARF that was successfully treated by immobilization alone. PMID:19444353

  11. Tension band wiring for proximal femoral varus osteotomy fixation in children.

    PubMed

    Maranho, Daniel Augusto; Pagnano, Rodrigo Gonçalves; Volpon, José Batista

    2014-08-01

    For proximal varus osteotomy of the femur in children, a stable fixation, is a concern regarding the safety and the protection of the surgery. The methods of fixation are mostly represented by plating systems; however, the tension band wiring is a simple and eligible option for fixation of proximal femur osteotomy. The purpose of this retrospective case series study is to evaluate outcomes and bone remodelation after using the tension band wiring technique to fixate proximal femoral varus osteotomies in children.The study enrolled 20 patients who underwent femoral varus osteotomy to treat Legg-Calvé-Perthes disease and other causes of necrosis of the femoral head. The mean patient age at the time of surgery was 7.4 ± 2.3 years (range, 4.3-13.8 y), and the follow-up period averaged 10 ± 4.3 years (range, 4.7-20.8 y). To assess the effects of the osteotomy at the neck-shaft angle and its evolution over time, radiographs obtained preoperatively and during the follow-up were analyzed. The neck-shaft angle was measured independently by 2 observers, and intraclass correlation coefficients (ICCs) were assessed for reliability.The ICC analysis showed good reliability. There was a significant reduction in the neck-shaft angle (P < 0.001) between the preoperative and the immediate postoperative periods, with an estimated difference of 14.3°. Between the immediate and the early postoperative periods, the estimated difference was 2.1°, which indicated a significant increase in the neck-shaft angle (P = 0.003). Between the early postoperative period and the final evaluation, there was a significant increase (P < 0.001), with an estimated difference of 7.0°. No implant failures or other complications were observed, but 1 case of peri-implant femoral fracture occurred >17 years postsurgery.The tension band wiring technique proved to be a simple and effective method for fixating proximal femoral varus osteotomy in children.The level IV is appropriated for our study (case series, retrospective). PMID:25101990

  12. Plate Motion Calculator

    NSDL National Science Digital Library

    Lou Estey

    This program calculates tectonic plate motion at any location on Earth using one or more plate motion models. The possible plate motion models are GSRM v1.2 (2004), CGPS (2004), HS3-NUVEL1A, REVEL 2000, APKIM2000.0, HS2-NUVEL1A, NUVEL 1A, NUVEL 1, and two models for ITRF2000. Plates or frames are selected from dropdown lists or can be entered by the user. Position coordinates can be entered in geographic coordinates (decimal degrees, or degrees/minutes/seconds) or in WGS84 cartesian XYZ, as either a single point or multiple points.

  13. Plate Motion and Crustal Deformation Estimated with Geodetic Data from the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Argus, Donald F.; Heflin, Michael B.

    1995-01-01

    We use geodetic data taken over four years with the Global Positioning System (GPS) to estimate: (1) motion between six major plates and (2) motion relative to these plates of ten sites in plate boundary zones. The degree of consistency between geodetic velocities and rigid plates requires the (one-dimensional) standard errors in horizontal velocities to be approx. 2 mm/yr. Each of the 15 angular velocities describing motion between plate pairs that we estimate with GPS differs insignificantly from the corresponding angular velocity in global plate motion model NUVEL-1A, which averages motion over the past 3 m.y. The motion of the Pacific plate relative to both the Eurasian and North American plates is observed to be faster than predicted by NUVEL-1A, supporting the inference from Very Long B ase- line Interferometry (VLBI) that motion of the Pacific plate has speed up over the past few m.y. The Eurasia-North America pole of rotation is estimated to be north of NUVEL-1A, consistent with the independent hypothesis that the pole has recently migrated northward across northeast Asia to near the Lena River delta. Victoria, which lies above the main thrust at the Cascadia subduction zone, moves relative to the interior of the overriding plate at 30% of the velocity of the subducting plate, reinforcing the conclusion that the thrust there is locked beneath the continental shelf and slope.

  14. Precision of sustained fixation in trained and untrained observers.

    PubMed

    Cherici, Claudia; Kuang, Xutao; Poletti, Martina; Rucci, Michele

    2012-01-01

    During visual fixation, microscopic eye movements shift the image on the retina over a large number of photoreceptors. Although these movements have been investigated for almost a century, the amount of retinal image motion they create remains unclear. Currently available estimates rely on assumptions about the probability distributions of eye movements that have never been tested. Furthermore, these estimates were based on data collected with only a few, highly experienced and motivated observers and may not be representative of the instability of naive and inexperienced subjects in experiments that require steady fixation. In this study, we used a high-resolution eye-tracker to estimate the probability distributions of gaze position in a relatively large group of human observers, most of whom were untrained, while they were asked to maintain fixation at the center of a uniform field in the presence/absence of a fixation marker. In all subjects, the probability distribution of gaze position deviated from normality, the underlying assumption of most previous studies. The resulting fixational dispersion of gaze was much larger than previously reported and varied greatly across individuals. Unexpectedly, the precision by which different observers maintained fixation on the marker was best predicted by the properties of ocular drift rather than those of microsaccades. Our results show that, during fixation, the eyes move by larger amounts and at higher speeds than commonly assumed and highlight the importance of ocular drift in maintaining accurate fixation. PMID:22728680

  15. 3, 10491080, 2006 Fate of N2 fixation

    E-print Network

    Boyer, Edmond

    BGD 3, 1049­1080, 2006 Fate of N2 fixation M. R. Mulholland Title Page Abstract Introduction from N2 fixation M. R. Mulholland Department of Ocean, Earth and Atmospheric Sciences, Old Dominion 2006 ­ Published: 19 July 2006 Correspondence to: M. R. Mulholland (mmulholl@odu.edu) 1049 #12;BGD 3

  16. Possibilities for the Enhancement of Biological Nitrogen Fixation

    Microsoft Academic Search

    J. R. Postgate

    1977-01-01

    Modern developments in plant science and knowledge of nitrogen fixation have opened exciting medium and long term possibilities: (1) Extended exploitation of existing systems such as exotic legumes; nonleguminous shrubs; the newly discussed grass associations; wider use of 'green manures'. (2) Augmentation of the effectiveness of existing systems by altering the complement of nitrogen fixation (nif) genes; altering the genetic

  17. Cultivar effects on nitrogen fixation in peas and lentils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Application of monorail fixator for femoral gap nonunion.

    PubMed

    Agrawal, Hemendra-Kumar; Jaiman, Ashish; Khatkar, Vipin; Sharma, Vinod-Kumar

    2014-01-01

    Difficult femoral nonunion takes account of infective nonunion and aseptic gap nonunion. Limb length discrepancy and nonunion need to be tackled simultaneously. Conventionally Ilizarov ring fixator is in vogue but it has some limitations. To overcome these, monorail fixator is an effective alternative. Persistent good results can be obtained if we can get a perfect anatomical alignment and good regeneration. PMID:25098853

  19. Sacroiliac screw fixation: A mini review of surgical technique

    PubMed Central

    Alvis-Miranda, Hernando Raphael; Farid-Escorcia, Hector; Alcalá-Cerra, Gabriel; Castellar-Leones, Sandra Milena; Moscote-Salazar, Luis Rafael

    2014-01-01

    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. PMID:25336831

  20. Dry Matter Accumulation and Dinitrogen Fixation of Annual Medicago Species

    Microsoft Academic Search

    Yanping Zhu; Craig C. Sheaffer; Michael P. Russelle; Carroll P. Vance

    1998-01-01

    for predicting the net N contribution of annual medics in cropping systems and for selecting species with high Assessment of the N2 fixation potential of annual medics (Medicago N2 fixation under regional environmental conditions and spp.) in the upper Midwest is important for predicting the net N contribution to cropping systems. Our objectives were to determine farming practices. the dry