Science.gov

Sample records for locked plate fixation

  1. Unicortical versus bicortical locked plate fixation in midshaft clavicle fractures.

    PubMed

    Bravman, Jonathan T; Taylor, Michal L; Baldini, Todd; Vidal, Armando F

    2015-05-01

    Higher rates of poor outcomes in displaced midshaft clavicle fractures treated nonoperatively have recently been reported. Along with expanding indications for operative fixation and increasing application of locked plate constructs, it is unknown whether complications related to bicortical penetration of the clavicle can be avoided using unicortical fixation. The purpose of this study is to compare the biomechanical properties of unicortical and bicortical fixation in precontoured vs manually contoured locking clavicle plates. Forty-eight Sawbone composite human clavicle specimens (item #3408; Pacific Research Laboratories, Vashon, Washington) with a midshaft clavicle osteotomy were reduced and plated in 8 specimens each using a bicortical and unicortical fixation for each of 3 locked plate constructs (3.5-mm LCP Reconstruction Plate; 3.5-mm LCP Superior Clavicle Plate; 3.5-mm LCP Superior Anterior Clavicle Plate; Synthes, Inc, West Chester, Pennsylvania). Specimens were tested for stiffness in axial torsion and cantilever bending and then loaded to failure in 3-point bending. Data were analyzed using 2-way analysis of variance and Tukey's test (P<.05). No significant differences were found between unicortical and bicortical fixation in failure load, cantilever bending, and cross body stiffness. Bicortical fixation was significantly stiffer than unicortical fixation in torsion only for the same plates. Significant differences also existed between plates in torsion. Unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation to avoid complications associated with posteroinferior hardware penetration following clavicle fracture fixation based on the biomechanical performance of these constructs. However, it remains unclear whether these differences will be clinically significant. PMID:25970369

  2. Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

    PubMed

    Karakasli, Ahmet; Hapa, Onur; Erduran, Mehmet; Dincer, Cemal; Cecen, Berivan; Havitcioglu, Hasan

    2015-01-01

    For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

  3. Outcome Analysis of Locking Plate Fixation in Proximal Humerus Fracture

    PubMed Central

    Pathak, Abhishek; Gaur, Sanjiv

    2016-01-01

    Introduction Proximal humerus fractures account for approximately 5% of all fractures. Stable minimally displaced fractures can be treated nonoperatively but the management of displaced fractures remain controversial with various modalities of treatment available. Locking plates provide stable fixation and enable early postoperative mobilization specially in osteoporotic proximal humerus fracture. Aim To evaluate the functional outcome of locking plate fixation and to compare the results of two approaches used for fixation. Materials and Methods This prospective study was conducted at a tertiary level hospital between September 2011 to December 2013. PHILOS plates were used for internal fixation of displaced proximal humerus fractures Neer’s type 2 part, 3 part and 4 part fractures on 26 patients (M/F ratio 1.36:1; mean age 46 years). According to Neer classification, 5,12 and 9 patients had displaced 2, 3 and 4 part fractures respectively. Deltopectoral and deltoid splitting approaches were used for fixation on 13 patients each. Functional outcome was assessed using Constant-Murley shoulder score. Graphpad software version 6.0 was used with Chi-square test and Fisher-exact test are used to compare data. The p-value< 0.05 is considered significant. Results Of the 26 patients, all fractures united radiologically and clinically and average constant score at final follow-up was 72.5. At the final follow-up 8 patients had good score, 10 patients had moderate score, 6 patients had excellent outcome and 2 patients had poor outcome according to Constant score. Mean time to union was 12.3 weeks (9 –15 weeks). Four complications (15.4%) were encountered, 2 cases of varus malunion, 1 case of wound infection which required wound debridement and 1 case of screw cut-out in which screw removal was done. Mean constant score in delto splitting approach was 70.9 and 74 in deltopectoral group (p-value= 0.54). No significant difference existed in constant score in 2 approaches

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

    PubMed Central

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

    2014-01-01

    Introduction Unstable intra articular fractures of distal radius are frequently being managed with open reduction and internal fixation. Of late in some biomechanical studies locking plates have been shown to be better in terms of maintenance of radiological parameters in comparison to non-locking plates. We conducted this study to know whether this biomechanical superiority of locking plates is converted in to better clinical outcomes. Materials and methods A study was conducted in 60 patients (30 in each group) with unstable intra articular fractures of distal radius who were treated by open reduction and internal fixation with locking plates and non-locking plates. Patients were evaluated for radiological parameters (intra articular step off, radial height, radial tilt, volar tilt) and functional parameters (flexion, extension, radial deviation, ulnar deviation, pronation, supination grip strength) at two year follow up. Overall outcome was evaluated by scoring systems of Gartland and Werley and modified Green O' Brien. Results The change in radiological parameters from immediate post op to latest at two year in locking plate group was not significant for radial height, radial tilt, volar tilt, but ulnar variance whereas in non-locking plate there was significant change in radial height, volar tilt, ulnar variance but no significant change in radial inclination. In clinical and functional outcome no significant difference was found at two year follow up. Conclusions Locking plates maintain the radiological parameters better than non-locking plates but functional outcome are same for both plates at two year after surgery. PMID:25983474

  5. Locking compression plate distal ulna hook plate as alternative fixation for fifth metatarsal base fracture.

    PubMed

    Lee, Sang Ki; Park, Ju Sang; Choy, Won Sik

    2014-01-01

    Intramedullary screw fixation has been the most common treatment for fifth metatarsal base fractures. However, screw application will not achieve accurate reduction in fractures with small fragments, osteoporotic bone, or Lawrence zone 1 fractures. Because of the similar anatomic architecture between the distal ulna and the fifth metatarsal base, the purpose of the present study was to assess the results of a locking compression plate distal ulna hook plate in stabilizing displaced zone 1 or 2 fifth metatarsal base fractures. A total of 19 patients with Lawrence zone 1 (n = 12) or 2 (n = 7) fractures of the fifth metatarsal base were treated surgically with a locking compression plate distal ulna hook plate. The patients were evaluated clinically and radiographically, and the functional outcomes were graded using the American Orthopaedic Foot and Ankle Society midfoot scoring system. Radiographic bony union was obtained in all patients, at an average of 7.4 weeks. The mean American Orthopaedic Foot and Ankle Society midfoot score improved from 26 (range 0 to 45) points preoperatively to 94 (range 72 to 100) points at the final follow-up visit. Three patients developed post-traumatic cubometatarsal arthrosis, and 1 patient developed sural nerve neurapraxia. In our experience, the distal ulna hook plate achieved a high rate of bony consolidation and anatomically suitable fixation in zone 1 or 2 fifth metatarsal base fractures. We suggest that the locking compression plate distal ulna hook plate should be considered as an alternative treatment of multifragmentary, osteoporotic, and tuberosity avulsion (zone 1) fifth metatarsal base fractures.

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

    PubMed Central

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

    2010-01-01

    Treatment options for palatal fractures range from orthodontic braces, acrylic bars, and arch bars for maxillomandibular fixation to internal fixation, with plates and screws placed under the palate mucosa and periosteum, together with pyriform aperture or alveolar plating plus buttress reconstruction. Forty-five patients, ages 4 to 56, were treated using medium- or high-profile locking plates placed over the palatal mucosa as an external fixator for palatal fractures, together with treatment for other associated facial fractures. In open fractures, plates were placed after approximating the edges of the mucosal wounds. Plates and screws for palate fixation were removed at 12 weeks, when computed tomography scans provided evidence of fracture healing. All palatal fractures healed by 12 weeks, with no cases of mucosal necrosis, bone exposure, fistulae, or infections. This approach achieves adequate stability, reduces the risk of bone and mucosal necrosis, and promotes healing of mucosal wounds in case of open fractures. PMID:22132261

  7. Femoral locking plate failure salvaged with hexapod circular external fixation: a report of two cases.

    PubMed

    Ferreira, N; Marais, L C

    2016-08-01

    Femoral non-unions are difficult to treat even for the experienced orthopaedic trauma surgeon. If the non-union follows failure of modern stable internal fixation, the complexity of the management is further increased. We report two cases of stiff hypertrophic femoral non-unions after failed locking plate fixation that were successfully treated with a new hexapod circular external fixator. In addition to providing the necessary stability for functional rehabilitation and union, the hexapod circular fixator software allows gradual correction of deformities in order to restore the normal mechanical alignment of the limb. PMID:27234444

  8. Evidence based postoperative treatment of distal radius fractures following internal locking plate fixation.

    PubMed

    Klein, S M; Prantl, L; Koller, M; Vykoukal, J; Dolderer, J H; Graf, S; Nerlich, M; Loibl, M; Geis, S

    2015-01-01

    Originally, the treatment method of choice for distal radial fractures (DRF) has been a non-operative approach with six to eight weeks of plaster casting. The introduction of volar locking plate systems at the beginning of the 21 st century has pushed trends towards open reduction and internal fixation (ORIF). While the introduction of fixed angle locking plates together with the increasing knowledge on wrist function and related variable outcomes has led to consensus that operative fixation in instable DRF is the treatment method of choice, there is no agreement on a postoperative care of these injuries. The authors will discuss the available evidence for current concepts of postoperative treatment of DRFs following fixed angle fixation under socioeconomical, biomechanical and burden of disease aspects. Further, relevant randomized controlled trials are evaluated with regard to applied postoperative treatment regimes and related risks for complications.

  9. Medial Closing-Wedge Distal Femoral Osteotomy: Fixation With Proximal Tibial Locking Plate

    PubMed Central

    Tírico, Luís Eduardo Passarelli; Demange, Marco Kawamura; Bonadio, Marcelo Batista; Helito, Camilo Partezani; Gobbi, Riccardo Gomes; Pécora, José Ricardo

    2015-01-01

    Distal femoral varus osteotomy is a well-established procedure for the treatment of lateral compartment cartilage lesions and degenerative disease, correcting limb alignment and decreasing the progression of the pathology. Surgical techniques can be performed with a lateral opening-wedge or medial closing-wedge correction of the deformity. Fixation methods for lateral opening-wedge osteotomies are widely available, and there are various types of implants that can be used for fixation. However, there are currently only a few options of implants for fixation of a medial closing-wedge osteotomy on the market. This report describes a medial, supracondylar, V-shaped, closing-wedge distal femoral osteotomy using a locked anterolateral proximal tibial locking plate that fits anatomically to the medial side of the distal femur. This is a great option as a stable implant for a medial closing-wedge distal femoral osteotomy. PMID:26870647

  10. 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

  11. The Utility of the Fluoroscopic Skyline View During Volar Locking Plate Fixation of Distal Radius Fractures

    PubMed Central

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

    2014-01-01

    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

  12. Early outcomes of proximal humerus fracture fixation with locking plate and intramedullary fibular strut graft.

    PubMed

    Tan, Edwin; Lie, Denny; Wong, M K

    2014-09-01

    Proximal humerus fractures are commonly encountered in elderly patients. Surgical treatment demonstrates high complication rates, including varus construct collapse and screw cutout. In this study, the authors evaluate the clinical outcome of locking plate fixation with intramedullary fibular strut graft augmentation as a primary surgical treatment in the prevention of early collapse and screw cutout. A total of 9 patients were evaluated. Surgery was performed for displaced proximal humerus fractures between April and December 2011. Patients were either class 2, 3, or 4, according to Neer classification. Mean patient age was 75.4 years. Preoperative and immediate, 6-week, and 3-month postoperative radiographs were evaluated. Head-shaft angles were measured to assess for varus collapse and displacement. Range of motion, complication rates, and functional recovery were also evaluated. Patients underwent open reduction and internal fixation with placement of an intramedullary fibular strut graft. Fixation was achieved with a Philos plate (Synthes, Oberdorf, Switzerland). Reduction and fixation were evaluated with radiographs. Passive exercises and range of motion were allowed immediately postoperatively, and all patients achieved active abduction and forward flexion 6 weeks postoperatively. Shoulder radiographs taken 12 weeks postoperatively revealed no loss of reduction or screw cutout. The introduction of the locking plate has improved outcomes. The addition of an intramedullary strut graft has shown improved preliminary results. Maintained reduction was observed in all 9 patients in the early postoperative period, and good functional motion was achieved. No incidence of screw cutout was recorded.

  13. Locking plate fixation of distal femoral fractures is a challenging technique: a retrospective review

    PubMed Central

    Toro, Giuseppe; Calabrò, Giampiero; Toro, Antonio; de Sire, Alessandro; Iolascon, Giovanni

    2015-01-01

    Summary Distal femoral fractures have typically a bimodal occurrence: in young people due to a high-energy trauma and in older people related to a low-energy trauma. These fractures are associated to a very high morbidity and mortality in elderly. Distal femoral fractures might be treated with plates, intramedullary nails, external fixations, and prosthesis. However, difficulties in fracture healing and the rate of complications are important clinical issues. The purpose of this retrospective review was to present our experience in treatment of distal femoral fracture in a sample of older people in order to evaluate the technical pitfalls and strategies used to face up the fractures unsuccessfully treated with locking plates. We included people aged more than 65 years, with a diagnosis of distal femoral fracture, treated with locking plates. We considered ‘unsuccessfully treated’ the cases with healing problems or hardware failures. Of the 12 patients (9 females and 3 males; mean aged 68.75 ± 3.31 years) included, we observed 3 ‘unsuccessfully cases’, 2 due to nonunions and 1 due to an early hardware failure, all treated using a condylar blade plate with a bone graft. One patient obtained a complete fracture healing after 1 year and in the other cases there was a nonunion. We observed as most common technical pitfalls: inadequate plate lengthening, fracture bridging, and number of locking screws. The use of locking plates is an emerging technique to treat these fractures but it seems more challenging than expected. In literature there is a lack of evidences about the surgical management of distal femoral fractures that is still an important challenge for the orthopaedic surgeon that has to be able to use all the fixation devices available. PMID:27134634

  14. Managing Vancouver B1 fractures by cerclage system compared to locking plate fixation - a biomechanical study.

    PubMed

    Gordon, Katharina; Winkler, Martin; Hofstädter, Thomas; Dorn, Ulrich; Augat, Peter

    2016-06-01

    With increasing life expectancy and number of total hip arthroplasties (THA), the need for revision surgery is increasing too. The aim of this study was to evaluate the optimal fracture treatment for a clinically characteristic Vancouver B1 fracture. We hypothesized that locking plate fixation has biomechanical advantages over fixation with a simple cerclage system. Additionally, we hypothesized that removal of the primary short stem and revision with a long stem would show biomechanical benefit. The biomechanical testing was performed with a static and a dynamic loading protocol on twenty 4th Generation sawbones. These were divided into four different groups (n = 5 each). In group 1, the primary uncemented short stem remained and the fracture was stabilized with a locking plate. In group 2, the primary stem remained and the fracture was stabilized with a cerclage stabilization system containing two stabilizers and four cerclages. In group 3, the primary stem was replaced by an uncemented long revision stem and the fracture was fixed with a locking plate. In group 4, the short stem was replaced by a long revision stem and the fracture was fixed with the cerclage system. Static testing revealed that the revision of the short stem with the long stem caused a 2-fold (p < 0.001, ANOVA) increase of axial stiffness. In dynamic testing, the number of cycles to failure was 4 times (p < 0.001, ANOVA) higher with the long revision stem. Compared to locked plating cerclage wiring demonstrated a 26% more cycles to failure (p = 0.031, ANOVA). The load to failure was 91% larger (p < 0.001, ANOVA) with the long revision stem and 11% smaller with locked plating (p < 0.001, ANOVA). In conclusion, the present biomechanical study indicates that periprosthetic Vancouver B1 fractures can be sufficiently fixed by simple cerclage systems. Revision with a long replacement stem provides a superior mechanical stability regardless of type of osteosynthesis fixation and is therefore a viable

  15. Biomechanical comparison of locking plate and crossing metallic and absorbable screws fixations for intra-articular calcaneal fractures.

    PubMed

    Ni, Ming; Wong, Duo Wai-Chi; Mei, Jiong; Niu, Wenxin; Zhang, Ming

    2016-09-01

    The locking plate and percutaneous crossing metallic screws and crossing absorbable screws have been used clinically to treat intra-articular calcaneal fractures, but little is known about the biomechanical differences between them. This study compared the biomechanical stability of calcaneal fractures fixed using a locking plate and crossing screws. Three-dimensional finite-element models of intact and fractured calcanei were developed based on the CT images of a cadaveric sample. Surgeries were simulated on models of Sanders type III calcaneal fractures to produce accurate postoperative models fixed by the three implants. A vertical force was applied to the superior surface of the subtalar joint to simulate the stance phase of a walking gait. This model was validated by an in vitro experiment using the same calcaneal sample. The intact calcaneus showed greater stiffness than the fixation models. Of the three fixations, the locking plate produced the greatest stiffness and the highest von Mises stress peak. The micromotion of the fracture fixated with the locking plate was similar to that of the fracture fixated with the metallic screws but smaller than that fixated with the absorbable screws. Fixation with both plate and crossing screws can be used to treat intra-articular calcaneal fractures. In general, fixation with crossing metallic screws is preferable because it provides sufficient stability with less stress shielding.

  16. PERPENDICULAR DOUBLE-PLATE FIXATION WITH LOCKING SYSTEM FOR ACROMION PEDICLE FRACTURE

    PubMed Central

    Zhu, Junkun; Pan, Zhijun; Zheng, Rongzong; Lan, Shuhua

    2016-01-01

    Objective : To describe the surgical technique and preliminary clinical outcomes in a series of open reduction internal fixation of basal acromion process fractures applying a double-plating technique. Methods : Nine consecutive patients, mean age 33.4 years old (range, 23-61 years old) with unilateral acromion fracture (Type 3 AO/OTA) with more than 1cm displacement who underwent fixation utilizing a locked double-plating technique, were evaluated on average at 7.8 months (range, 3-15 months) for outcomes related to pain, shoulder function, and surgical complications. Results : Eight patients recovered with complete radiographic union and favorable shoulder function. One case failed to be fully evaluated for more than 3 months follow-up. The overall scores of Constant, Shoulder Pain and Disability Index (SPADI) and DASH for the eight patients reviewed were 91.9± 6.31, 3.11± 3.79 and 5.2± 6.35, respectively. No post-operative infection or surgical hardware irritation was identified at final follow-up of these eight patients. Conclusion : While more evidence is needed to justify its advantages over traditional implants, perpendicular double-plate with a locking system may be indicated for acromion pedicle fracture treatment, since it performed well for fracture healing and joint function rehabilitation. Level of Evidence IV, Therapeutic Study. PMID:26981047

  17. A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries.

    PubMed

    Nguyentat, Annie; Camisa, William; Patel, Sandeep; Lagaay, Pieter

    2016-01-01

    Previous biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone. Complex rotational ankle injuries involve an increased number of fractures, which can result in instability, potentially requiring the same fixed angle properties afforded by locking plates. However, the mechanical indication for locking plate technology has not been tested in this fracture model. The purpose of the present study was to compare the biomechanical properties of locking and conventional plate fixation for distal fibula fractures in trimalleolar ankle injuries. Fourteen (7 matched pairs) fresh-frozen cadaver leg specimens were used. The bone mineral density of each was obtained using dual x-ray absorptiometry scans. The fracture model simulated an OTA 44-B3.3 fracture. The syndesmosis was not disrupted. Each fracture was fixated in the same fashion, except for the distal fibula plate construct: locking (n = 7) and one-third tubular (n = 7). The specimens underwent axial and torsional cyclic loading, followed by torsional loading to failure. No statistically significant differences were found between the locking and conventional plate constructs during both fatigue and torque to failure testing (p > .05). Our specimen bone mineral density averages did not represent poor bone quality. The clinical implication of the present study is that distal fibular locking plates do not provide a mechanical advantage for trimalleolar ankle injuries in individuals with normal bone density and in the absence of fracture comminution.

  18. Use of a Locked Fibular Plate for Fixation of a Vertical Shear Medial Malleolus Fracture: A Case Report.

    PubMed

    Blake, Sean; Yakubek, George; Shaer, James

    2015-01-01

    Vertical shear fractures of the medial malleolus are less common than transverse fractures. These fractures are often treated with lag screws, posteromedial buttress plating, antiglide plates, and neutralization plates with screws. We report on a 37-year-old male who had fractured his ankle after tripping and falling into a ditch. Initially, the patient was treated with closed reduction and a splint for a trimalleolar fracture with a laterally subluxed talus. However, on review of his preoperative radiographs and computed tomography studies, we confirmed a medial malleolus fracture with a vertical shear pattern and communition. Recently, a contoured fibular locking plate has been developed. We considered this plate to be effective for containing the bone in part because of its broader plate design. We present a case in which a fibular locking plate was used successfully as a neutralization plate as an alternative fixation method for a vertical shear medial malleolar fracture. PMID:26253474

  19. Locking plate versus retrograde intramedullary nail fixation for tibiotalocalcaneal arthrodesis: A retrospective analysis

    PubMed Central

    Zhang, Chi; Shi, Zhongmin; Mei, Guohua

    2015-01-01

    Background: Tibiotalocalcaneal arthrodesis (TTCA) surgery is indicated for the end-stage disease of the tibiotalar and subtalar joints. Although different fixation technique of TTCA has been proposed to achieve high fusion rate and low complication rate, there is still no consensus upon this point. The purpose of this study is to compare the clinical efficacy of retrograde intramedullary nail fixation (RINF) and locking plate fixation (LPF) for TTCA. Materials and Methods: Fifty four patients who underwent TTCA through the lateral approach with lateral fibular osteotomy using RINF (32 patients, 18 male/14 female, mean age: 48) or LPF (22 patients, 12 male/10 female, mean age: 51) between January 2007 and January 2010 were retrospectively analyzed. Demographic and clinical characteristics, surgery (operation time, blood loss) outcomes (postoperative fusion rates, visual analog scale and foot and ankle surgery score and complications) were compared. Results: The LPF group had a shorter operation time (72.3 ± 9.2 vs. 102.8 ± 11.1 min, P < 0.001), less blood loss (75.9 ± 20.2 vs. 140.0 ± 23.8 ml, P < 0.001) and less intraoperative fluoroscopy sessions (3.6 ± 0.9 vs. 8.4 ± 1.3, P < 0.001) than the RINF group. Patients were followed up for 12–24 months (mean of 16.2 months). Both groups had similar postoperative fusion rates (90.6% and 95.4%) and the LPF group showed a nonsignificant lower complication rate (18.2% vs. 28.1% respectively). Patients at higher risk on nonunion due to rheumatoid diseases may have a lower nonunion rate with LPF than RINF (one out of eight vs. three out of nine, P < 0.001). Conclusions: The LPF for TTCA was simpler to perform compared with RINF, but with similar postoperative outcomes and complication rates. PMID:26015614

  20. Complex fractures of the proximal humerus in the elderly--outcome and complications after locking plate fixation.

    PubMed

    Schliemann, B; Siemoneit, J; Theisen, Ch; Kösters, C; Weimann, A; Raschke, M J

    2012-05-01

    Open reduction and internal fixation (ORIF) with locking plates or primary arthroplasty remains a controversial issue in the management of complex proximal humerus fractures. Aim of this study was to evaluate the surgeon- and patient-based outcome of patients older than 65 years who underwent ORIF using locking plate fixation of a 3- or 4-part fracture of the proximal humerus. Twenty-seven patients older than 65 years were treated with locking plate fixation (PHILOS, Fa. Synthes, Umkirch, Germany). At an average follow-up of 44 months, the clinical and the subjective outcome were evaluated, and complications were analyzed. The mean age- and gender-related Constant score was 70% (30–100%) compared with 92% (47–108%) of the contralateral non-injured shoulder. The mean DASH score was 29 points (0–71). Five patients (18.5%) showed clinical signs of an impingement, which was related to malpositioning of the plate in 3 cases. Screw cutout was seen in 22.2% (6 patients). Avascular necrosis of the head or the tubercula was found in 8 patients (29.6%). The revision rate was 29.6%. However, the patients considered the functional status of their shoulder as “good” or “satisfactory.” The functional and patient-orientated results of the locking plate fixation of complex displaced proximal humerus fractures in the elderly are comparable to those of primary arthroplasty and minimally invasive treatment. Proper surgical technique (screw length, plate position) is mandatory for reducing the revision rate.

  1. The biomechanical effect of bone quality and fracture topography on locking plate fixation in periprosthetic femoral fractures.

    PubMed

    Leonidou, Andreas; Moazen, Mehran; Lepetsos, Panagiotis; Graham, Simon M; Macheras, George A; Tsiridis, Eleftherios

    2015-02-01

    Optimal management of periprosthetic femoral fractures (PFF) around a well fixed prosthesis (Vancouver B1) remains controversial as adequate fixation needs to be achieved without compromising the stability of the prosthesis. The aim of this study was to highlight the effect of bone quality i.e. canal thickness ratio (CTR), and fracture topography i.e. fracture angle and its position in relation to the stem, on the biomechanics of a locking plate for a Vancouver B1 fracture. A previously corroborated simplified finite element model of a femur with a cemented total hip replacement stem was used in this study. Canal thickness ratio (CTR) and fracture topography were altered in several models and the effect of these variations on the von Mises stress on the locking plate as well as the fracture displacement was studied. Increasing the CTR led to reduction of the von Mises stress on the locking plate as well as the fracture movement. In respect to the fracture angle with the medial cortex, it was shown that acute angles resulted in lower von Mises stress on the plate as opposed to obtuse angles. Furthermore, acute fracture angles resulted in lower fracture displacement compared to the other fractures considered here. Fractures around the tip of the stem had the same biomechanical effect on the locking plate. However, fractures more distal to the stem led to subsequent increase of stress, strain, and fracture displacement. Results highlight that in good bone quality and acute fracture angles, single locking plate fixation is perhaps an appropriate management method. On the contrary, for poor bone quality and obtuse fracture angles alternative management methods might be required as the fixation might be under higher risk of failure. Clinical studies for the management of PFF are required to further support our findings.

  2. Biomechanical stability of a volar locking-screw plate versus fragment-specific fixation in a distal radius fracture model.

    PubMed

    Cooper, Ellis O; Segalman, Keith A; Parks, Brent G; Sharma, Krishna M; Nguyen, Augustine

    2007-04-01

    Eight matched pairs of cadaveric radii were osteotomized by removing a 4-mm dorsal wedge of bone at the level of the sigmoid notch designed to simulate dorsal comminution. They were then fixed with either a volar locking-screw plate or fragment-specific fixation. All constructs underwent biomechanical testing in a custom-designed, custom-fabricated 4-point bending device. No statistically significant difference in stiffness was noted between the groups. Linear displacement and angulation at the osteotomy site were significantly less in the group with fragment-specific fixation at loads expected to be encountered during postoperative rehabilitation. Angulation at the osteotomy site was significantly less in the locking-screw plate group at higher loads.

  3. Treatment of Unstable Posterior Pelvic Ring Fracture with Pedicle Screw-Rod Fixator Versus Locking Compression Plate: A Comparative Study

    PubMed Central

    Bi, Chun; Wang, Qiugen; Nagelli, Christopher; Wu, Jianhong; Wang, Qian; Wang, Jiandong

    2016-01-01

    Background The aim of this study was to assess the clinical results of treatment for unstable posterior pelvic fractures using a pedicle screw-rod fixator compared to use of a locking compression plate. Material/Methods A retrospective study was performed between June 2010 and May 2014 and the data were collected from 46 patients with unstable posterior pelvic ring fractures. All patients were treated using either a pedicle screw-rod fixator (study group, 24 patients) or locking compression plate (control group, 22 patients). In these patients, causes of injury included traffic accidents (n=27), fall from height (n=12), and crushing accidents (n=7). The quality of reduction and radiological grading were assessed. Clinical assessments included the operation time, times of X-ray exposures, bleeding volume during operation, incision length, and Majeed postoperative functional evaluation. Results No iatrogenic neurovascular injuries occurred during the operations in these 2 groups. The average follow-up time was 24.5 months. All fractures were healed. The significant differences (P<0.05) between the 2 groups were operation duration, size of incision, and intraoperative bleeding volume. Statistically significant differences in the Majeed postoperative functional evaluation and times of X-ray exposures were not found between the 2 groups. Conclusions Similar clinical effects were achieved in treating the posterior pelvic ring fractures using the pedicle screw-rod fixator and the locking compression plate. However, the pedicle screw-rod fixator has the advantages of smaller incision, shorter duration of the operation, and less bleeding volume compared to using the locking compression plate. PMID:27748355

  4. 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.

  5. 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

  6. Possibility of Fixation of a Distal Radius Fracture With a Volar Locking Plate Through a 10 mm Approach.

    PubMed

    Naito, Kiyohito; Zemirline, Ahmed; Sugiyama, Yoichi; Obata, Hiroyuki; Liverneaux, Philippe; Kaneko, Kazuo

    2016-06-01

    The management of distal radius fractures has dramatically improved due to the development of a locking plate system. In addition, mini-invasive surgery has been performed in a lot of surgical fields in recent years. The aim of the present study is to investigate the possibility of fixation of a distal radius fracture with a volar locking plate through a 10 mm approach. Eighteen patients with distal radius fracture (mean age: 66 y; range, 28 to 88 y; 8 males and 10 females) were operated on using a volar locking plate. The incision for plating was always 10 mm long. The clinical, cosmetic, and radiologic outcomes were investigated. At 3 months' follow-up, the range of motion of the wrist joint was 67.5 degrees in flexion, 65.6 degrees in extension, 88.3 degrees in pronation, and 88.3 degrees in supination. The % grip strength compared to the healthy side ranged from 35% to 100%. The VAS, Q-DASH, and modified Mayo scores were 0.7, 8.5, and 93.3, respectively (excellent in all 18 patients). Bone union was achieved on plain x-ray radiography and cosmetic problems were satisfied in all patients. Our results suggest that it is possible to achieve fixation of a distal radius fracture with a volar locking plate through a 10 mm approach. However, its applicability to surgery must be carefully examined. If any difficulties in plate installation or approach occur during this intervention, it will be necessary to consider switching to a conventional approach. We believe that surgeons must not adhere to a mini-invasive approach. PMID:27015408

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

    PubMed

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

    2014-01-01

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

  8. Bilateral traumatic proximal humerus fractures managed by open reduction and internal fixation with locked plates.

    PubMed

    Jaiswal, Atin; Kachchhap, Naiman Deepak; Chaterjee, Rupak; Tanwar, Yashwant Singh; Habib, Masood; Singh, Satya Prakash

    2013-01-01

    Fractures of the proximal humerus are uncommon in young patients. Although bilateral fracture of proximal humerus itself is rare, association with epilepsy and electrocution is frequent. Only one case of traumatic bilateral proximal humerus fracture has been reported in the literature. We report a rare case of bilateral traumatic displaced proximal humerus fractures in a 40 years old male patient, which was treated by means of open reduction and internal fixation with proximal humerus locked pates on both sides and obtained a good functional outcome.

  9. Biomechanics of humerus fracture fixation by locking, cortical, and hybrid plating systems in a cadaver model.

    PubMed

    Sutherland, George B; Creekmore, Tina; Mukherjee, Debi P; Ogden, Alan L; Anissian, Lucas; Marymont, John V

    2010-08-11

    The goal of this study was to discover how locking or cortical screws or a hybrid of both would perform in stabilizing a simulated humerus fracture. We simulated stripping of screw threads or poor bone quality by overdrilling the screw hole, and also studied a control group with no overdrilling. A total of 38 fresh frozen cadaver humeri were divided into 2 groups: 16 undergoing overdrilling with a drill bit 0.3 mm less than the diameter of the screw and 22 undergoing no overdrilling. A 4-point bending test followed torsional fatigue of 1000 cycles with an amplitude of +/-10 degrees. The post-fatigued samples were retested in the same way after tightening the loose screws if necessary. Finally, each fatigued specimen was tested for failure in torsion at 0.5 Hz by applying a maximum rotational displacement of 60 degrees .The bending stiffness values (Nm/mm) of cortical and locking screws, with the exception of the hybrid system, were significantly higher for the overdrilled group than the non-overdrilled (cortical, 6.9 vs 5.6; locking, 9.1 vs 6.3; hybrid, 8.4 vs 6.8). Fatigue had no effect on the bending stiffness of all the screw/plate systems (cortical, 6.9 vs 7.4; locking, 9.1 vs 8.8; hybrid, 8.5 vs 8.1). The overdrilling had no effect on the failure loads and displacements for all the screws except cortical screws, where the failure displacement was significantly higher for the overdrilling group. The torsional stiffness retentions after 1000 cycles were significantly different for overdrilled specimens in the cortical screws group only.Overdrilling had a minimal effect on bending and torsional properties. The results of the locking and hybrid were close, and the cortical screw had only slightly lower bending stiffness.

  10. Difficulties encountered removing locked plates

    PubMed Central

    Raja, S; Imbuldeniya, AM; S, Garg; Groom, G

    2012-01-01

    INTRODUCTION Locked plates are commonly used to obtain fixation in periarticular and comminuted fractures. Their use has also gained popularity in repairing fractures in osteoporotic bone. These plates provide stable fixation and promote biological healing. Over the last 3 years, we have used over 150 locked plates with varying success to fix periarticular fractures involving mainly the knee and ankle. In this study, we report our clinical experience and the difficulties encountered when removing locked plates in adult patients with a variety of indications including implant failure, infection, non-union and a palpable symptomatic implant. METHODS A retrospective analysis was performed of patients enrolled prospectively into a database. Included in the study were 36 consecutive adult patients who each underwent the procedure of locked plate removal in a single inner city level 1 trauma centre. Data collected included primary indication for fixation, indication for implant removal, time of the implant in situ, grade of operating surgeon and difficulties encountered during the procedure. RESULTS Implant removal was associated with a complication rate of 47%. The major problems encountered were difficulty in removing the locked screws and the implant itself. A total of ten cold welded screws were found in eight cases. Removal was facilitated by high speed metal cutting burrs and screw removal sets in all but one case, where a decision was made to leave the plate in situ. CONCLUSIONS The majority of studies investigating implant removal and problems encountered in doing so report a relatively high complication rate. With the advent of locking plates and their growing popularity, difficulties are now being seen intra-operatively when removing them. There is a paucity of data, however, specifically directed at locking plate removal. We recommend that surgeons should be aware of the potential complications while removing locked plates. Fluoroscopic control and all

  11. Clinical results of using the proximal humeral internal locking system plate for internal fixation of displaced proximal humeral fractures.

    PubMed

    Norouzi, Masoud; Naderi, Mohammad Nasir; Komasi, Mehdi Hemmati; Sharifzadeh, Seyyed Reza; Shahrezaei, Mostafa; Eajazi, Alireza

    2012-05-01

    Proximal humerus fractures are accounting for 4-5% of all fractures with increasing incidence. Proximal Humeral Internal Locking System (PHILOS) plate is a new plate which permits early mobility and lowers the risk of complications. The aim of this study was to evaluate the functional outcome and the complication rate after using this plate. Between 2006-2008, 37 patients with displaced 2-, 3-, and 4-part fractures of the proximal humerus underwent surgery using PHILOS plate. The mean range of follow-up was 12 months. Twenty patients were aged 60 years and younger, and 17 were aged older than 60 years. The average American Shoulder and Elbow Surgeons (ASES) score at the final follow-up was 77.62. According to Michener and colleagues classification, 5.4% of patients had an excellent outcome, 72.9% were minimally functionally limited, 16.2% were moderately functionally limited, and 5.4% were maximally functionally limited. The average ASES score between patients 60 years and older and those 60 years and younger was not different significantly. One patient developed avascular necrosis of the humeral head, 2 patients developed an infection, and no patients developed a nonunion. Fixation with PHILOS plate can be considered a good method with high union rates for this kind of fracture, especially in the older population with osteoporotic bone.

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

    PubMed

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

    2014-11-01

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

  13. The concept of locking plates.

    PubMed

    Cronier, P; Pietu, G; Dujardin, C; Bigorre, N; Ducellier, F; Gerard, R

    2010-05-01

    After a short historical review of locking bone plates since their inception more than a century ago to the success of the concept less than 15 years ago with today's plates, the authors present the main locking mechanisms in use. In the two broad categories - plates with fixed angulation and those with variable angulation - the screw head is locked in the plate with a locknut by screwing in a threaded chamber on the plate or by screwing through an adapted ring. The authors then provide a concrete explanation, based on simple mechanical models, of the fundamental differences between conventional bone plates and locking plates and why a locking screw system presents greater resistance at disassembly, detailing the role played by the position and number of screws. The advantages of epiphyseal fixation are then discussed, including in cases of mediocre-quality bone. For teaching purposes, the authors also present assembly with an apple fixed with five locking screws withstanding a 47-kg axial load with no resulting disassembly. The principles of plate placement are detailed for both the epiphysis and diaphysis, including the number and position of screws and respect of the soft tissues, with the greatest success assured by the minimally invasive and even percutaneous techniques. The authors then present the advantages of locking plates in fixation of periprosthetic fractures where conventional osteosynthesis often encounters limited success. Based on simplified theoretical cases, the economic impact in France of this type of implant is discussed, showing that on average it accounts for less than 10% of the overall cost of this pathology to society. Finally, the possible problems of material ablation are discussed as well as the means to remediate these problems.

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

    PubMed Central

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

    2014-01-01

    The aim of the study was to examine the correlation between the chosen position of screws and the complications observed in patients who underwent locked plating of proximal humeral fractures. We evaluated radiographs of 367 patients treated by locked-plating for proximal humeral fractures. Radiographs were taken at one day, 6 weeks, 3 months and 6 months after surgery, and were analyzed for secondary fracture displacement, loss of fixation, cutting out of screws and necrosis of the humeral head. Secondary loss of fixation occurred in 58 cases (15.8%) and among those cutting out of screws was observed in 25 cases (6.8%). In cases of secondary loss of fixation a mean of 6.7 screws were used to fix the fracture (vs 6.6, P=0.425). There was neither significant correlation between position of screws and the occurrence of postoperative loss of fixation in Spearman correlation nor relationship from backward logistic regression analysis. Loss of fixation following locked plating of proximal humeral fractures does not relate to the number of screws and their positions in the humeral head. In consequence, anatomic fracture reduction and restoration of the humeral head-shaft angle are still important factors and should not be disregarded. PMID:25002940

  15. 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.

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

    PubMed Central

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

    2015-01-01

    Introduction: Distal radius fracture (DRF) is a common injury and various treatment modalities including open reduction and internal fixation (ORIF) with volar locking plate are available. More recently, a non-invasive external fixator has been used. Aims: To prospectively compare the use of a non-invasive external fixator with early dynamisation for DRF against ORIF with volar locking plate control group. Methods: Consecutive patients with closed DRF were included in a prospective case-controlled study. Patients were assigned to non-invasive external fixator or ORIF. Minimum follow-up was two years. Follow-up was at weeks 2, 4, 6, 8, 12, 26 and at one and two-year post-operatively. The outcome measures included demographic details, injury mechanism, AO fracture type, risk factors, body mass index (BMI), ulnar styloid fracture and dorsal comminution, radiographs, grip strength and DASH score. Results: Consecutive 50 patients were treated either with non-invasive external fixator (25/50) or with ORIF (25/50) and the mean age of the two groups was 53 years (SD 17.1) and 49 years (SD 19.5), respectively. Demographics were matched in two groups. In the non-invasive external fixator group, there were 10 AO Type-A, 5 Type-B and 10 Type-C fractures. The ORIF group included 8 Type-A, 6 Type-B and 11 Type-C fractures. The mean DASH score at three-months and one-year post-injury in non-invasive fixator group was 12.2 (SD 3.1) and 3.5 (SD 0.7), respectively, significantly greater than those of ORIF group 14.5 (SD 5.6) and 11.2 (SD 4.4), respectively (p < 0.05). Conclusion: DRF treated with non-invasive external fixator can give functional results superior to ORIF at three-months and the trend is maintained at one and two-year post-operatively. PMID:27163089

  17. 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

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

    PubMed Central

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

    2012-01-01

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

  19. 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

  20. 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

  1. Reducing Postoperative Fracture Displacement After Locked Plating of Proximal Humerus Fractures: Current Concepts.

    PubMed

    Newman, Jared; Kahn, Mani; Gruson, Konrad I

    2015-07-01

    The incidence of proximal humerus fractures in the elderly has been rising. Concomitantly, operative fixation with use of locking plates has been increasing. Postoperative complications of locking plate fixation, particularly in the setting of osteoporotic bone, include screw penetration of the articular surface, progressive fracture displacement, and avascular necrosis. Intraoperative techniques to enhance the fixation construct and reduce complications include use of rotator cuff sutures, bone void fillers (fibular strut allograft, cancellous allograft, autograft, bone cement), appropriate placement of divergent and shorter locking screws, and medial calcar reduction and support. More recent clinical and biomechanical studies suggest that use of these strategies may reduce complications after locked plating of osteoporotic proximal humerus fractures. Furthermore, a multidisciplinary approach to the evaluation and treatment of osteoporosis may be beneficial in these patients.

  2. Reducing Postoperative Fracture Displacement After Locked Plating of Proximal Humerus Fractures: Current Concepts.

    PubMed

    Newman, Jared; Kahn, Mani; Gruson, Konrad I

    2015-07-01

    The incidence of proximal humerus fractures in the elderly has been rising. Concomitantly, operative fixation with use of locking plates has been increasing. Postoperative complications of locking plate fixation, particularly in the setting of osteoporotic bone, include screw penetration of the articular surface, progressive fracture displacement, and avascular necrosis. Intraoperative techniques to enhance the fixation construct and reduce complications include use of rotator cuff sutures, bone void fillers (fibular strut allograft, cancellous allograft, autograft, bone cement), appropriate placement of divergent and shorter locking screws, and medial calcar reduction and support. More recent clinical and biomechanical studies suggest that use of these strategies may reduce complications after locked plating of osteoporotic proximal humerus fractures. Furthermore, a multidisciplinary approach to the evaluation and treatment of osteoporosis may be beneficial in these patients. PMID:26161759

  3. Dual locked plating of unstable bicondylar tibial plateau fractures.

    PubMed

    Ozkaya, Ufuk; Parmaksizoglu, Atilla Sancar

    2015-07-01

    The operative treatment of displaced bicondylar tibial plateau fractures is challenging. The displaced condyles must be reduced, depressed plateaus must be elevated and adequately supported and early rehabilitation must be encouraged in order to obtain good clinical results. This retrospective study was designed to evaluate the clinical outcomes of patients with bicondylar tibial plateau fractures treated with dual locked plates using raft screws with MIPO technique and autologous bone grafting. We hypothesized that in this group of patients dual locked plating reduces the complication rates by avoiding loss of reduction due to the accomplished rigid fixation. Twenty-two consecutive patients with bicondylar tibial plateau fractures (AO Type C) were included in this study. The mean follow up was 26 months. Bone healing was achieved in all patients with 3 cases of superficial and 1 case of deep infection. Secondary loss of reduction, secondary loss of alignment, early post-traumatic arthritis were not observed in this study. The Lysholm knee score showed an average of 80.5 points (range: 61.5-90) at the final follow up assessment. Optimal fixation of the fracture with dual locked plating which allows immediate motion and partial weight bearing may be an alternative concept to prevent secondary loss of reduction to obtain a good clinical outcome. PMID:26021666

  4. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique.

  5. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique. PMID:27454625

  6. TIBIOTARSAL COMPRESSION ARTHRODESIS USING A LATERAL LOCKING PLATE

    PubMed Central

    Coughlin, Michael J.; Nery, Caio; Baumfeld, Daniel; Jastifer, James

    2015-01-01

    Objectives: Tibiotalar (TT) arthrodesis is still a very important option in the treatment of primary or post-traumatic arthritis of the ankle but persists the controversy regarding the optimal method for the fixation of the arthrodesis site. No matter the implant used, the goal is to obtain a solid, healthy, pain-free fusion. The purpose of the current study is to present the preliminary results of a novel laterally based tibiotalar compression arthrodesis system using a locked plate. Methods: Thirteen consecutive patients with tibiotalar arthritis were submitted to an arthrodesis using a new lateral plating system. The average age was 59.7 years (range 36~72); nine patients were male and four female. Using a cutting guide, the remaining articular surfaces of the tibia and talus were removed. A compression device was applied to avoid malalignment of the ankle and a precontoured lateral locking plate was used to achieve the joint fusion. Results: Both the AOFAS ankle-hindfoot score and the VAS score improved with the surgery. All patients’ ankles fused by 6 months. In all patients we found a very good alignment in the sagittal, coronal and transverse planes. Conclusion: We believe that a combination of a bilateral compression, contoured bony cuts, and lateral locked plating offers a novel, accurate and useful technique for ankle arthrodesis. PMID:27047874

  7. Locking plates in proximal humerus fractures.

    PubMed

    Strohm, P C; Helwig, P; Konrad, G; Südkamp, N P

    2007-12-01

    It is well known that proximal humerus fractures are among the three most frequent fracture types. Epidemiological invetsigations show that in people elder than 60 years the fracture of the proximal humerus is more frequent than fractures of the hip region (17). Over the last decades several techniques have been applied for treatment of proximal humerus fractures. Widely accepted is the initiation of a conservative treatment regimen for undisplaced fractures, however, the standard treatment for displaced fractures, especially three and four part fractures, is still the center of scientific debate. Many different implants have been tested and investigated, thus demonstrating lack of sufficient results. Over the last years the development of angle stable, locking implants started and clinical studies demonstrated encouraging results. In our clinic the locking proximal humerus plate and the PHILOS plate advanced to the implant of choice for treatment of displaced proximal humerus fractures. There are still cases of implant failure and humerus head necrosis, but most of these complications were caused by the fracture type and not an implant specific problem. However the overall results with these new implants are encouraging. Key words: locking plates, proximal humerus fracture, humerus, humerus fracture, PHILOS, PHP.

  8. Construct Choice for the Treatment of Displaced, Comminuted Olecranon Fractures: are Locked Plates Cost Effective?

    PubMed Central

    DelSole, Edward M.; Egol, Kenneth A.; Tejwani, Nirmal C.

    2016-01-01

    Background Cost effective implant selection in orthopedic trauma is essential in the current era of managed healthcare delivery. Both locking and non-locking plates have been utilized in the treatment of displaced fractures of the olecranon. However, locking plates are often more costly and may not provide superior clinical outcomes. The primary aim of the present study is to assess the clinical and functional outcomes of olecranon fractures treated with locked and non-locking plate and screw constructs while providing insight into the cost of various implants. Methods We performed a retrospective chart review of a single institution database identifying Mayo IIB type olecranon fractures treated surgically from 2003 to 2012. All fractures were treated with either a locked plate or a one-third tubular hook plate construct. Clinical and radiographic outcomes were evaluated. Minimum 6-month follow-up was required. Outcomes were compared between fixation constructs, including rate of union, early failure, postoperative range of motion, and complication rates. Statistical analysis included Pearson’s Chi-squared and Fisher’s exact test for categorical variables, and the Student’s ttest for continuous variables. Results The one-third tubular construct was equivalent to locking plate constructs with respect to union, post-operative range of motion, and rates of complications. There were no early or late failures. Locking plates were associated with a relative cost increase of $1,263.50 compared to the one-third tubular hook plate per case. Conclusion Surgeons should consider the cost of implants when treating Mayo IIB olecranon fracture. In this cohort, one-third tubular plates provided equivalent outcomes to locked plates with a notable decrease in cost. PMID:27528837

  9. Distal radius fractures-Design of locking mechanism in plate system and recent surgical procedures.

    PubMed

    Inagaki, Katsunori; Kawasaki, Keikichi

    2016-05-01

    Recently, many studies have emphasized the importance of the comprehension of detailed functional anatomy of the distal forearm and wrist joint, and their biomechanics. A significant contribution which yields good functional outcomes of surgical treatment was the development of the locking plate technology; this technology has facilitated the improvement of the surgical technique for the fixation of fractures. This article reviews the locking mechanism and design of the fixation screws and plate, and the details of the surgical technique including the double-tired subchondral support procedure as it is applied to common fractures. Arthroscopic-assisted surgical procedures can be used to reduce the intra-articular fracture fragments after realignment of the distal radius with the locking plate. This technique is also useful at the time of fixation to assess soft tissue injury. The combination of arthroscopic-assisted reduction and locking plate fixation is now indicated for AO type C2 and C3 intra-articular comminuted fractures. PMID:27006135

  10. 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

  11. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures.

    PubMed

    Seybold, Dominik; Citak, Mustafa; Königshausen, Matthias; Gessmann, Jan; Schildhauer, Thomas A

    2011-10-01

    Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft für Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures.

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

    PubMed

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

    2014-02-01

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

  13. 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

  14. Four corner fusion using a multidirectional angular stable locking plate

    PubMed Central

    Chaudhry, Tahseen; Spiteri, Michelle; Power, Dominic; Brewster, Mark

    2016-01-01

    AIM To review the results of our experience with the Medartis Aptus plating system for four corner arthrodesis of the wrist, which uses a combination of compression screws and variable angle locking screws. METHODS We reviewed the results of 17 procedures in 16 patients that underwent scaphoid excision and four corner fusion using the Medartis Aptus system between May 2010 and June 2014. The primary outcome measure was radiographic and clinical union. RESULTS The mean clinical follow up time was 20.6 mo. The mean union time was 6 mo. Two non-unions required revision procedures. The mean disabilities of the arm, shoulder and hand score taken after union was 36. The mean final grip strength was 27 kg. The mean final range of movement was 30° flexion and 31° of extension. All patients had a restored scapholunate angle on postoperative radiographs. There were no incidences of dorsal impingement. CONCLUSION Overall our experience with the Aptus plating system shows comparable results to other methods of fixation for four corner fusion, in the short to medium term. PMID:27622151

  15. Four corner fusion using a multidirectional angular stable locking plate

    PubMed Central

    Chaudhry, Tahseen; Spiteri, Michelle; Power, Dominic; Brewster, Mark

    2016-01-01

    AIM To review the results of our experience with the Medartis Aptus plating system for four corner arthrodesis of the wrist, which uses a combination of compression screws and variable angle locking screws. METHODS We reviewed the results of 17 procedures in 16 patients that underwent scaphoid excision and four corner fusion using the Medartis Aptus system between May 2010 and June 2014. The primary outcome measure was radiographic and clinical union. RESULTS The mean clinical follow up time was 20.6 mo. The mean union time was 6 mo. Two non-unions required revision procedures. The mean disabilities of the arm, shoulder and hand score taken after union was 36. The mean final grip strength was 27 kg. The mean final range of movement was 30° flexion and 31° of extension. All patients had a restored scapholunate angle on postoperative radiographs. There were no incidences of dorsal impingement. CONCLUSION Overall our experience with the Aptus plating system shows comparable results to other methods of fixation for four corner fusion, in the short to medium term.

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

    PubMed

    Sabat, Dhananjaya; Dabas, Vineet; Dhal, Anil

    2014-07-01

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

  17. Arthroscopic Removal of Symptomatic Proximal Humerus Locking Plates With Bone-Void Filler Augmentation.

    PubMed

    Voleti, Pramod B; Camp, Christopher L; Sinatro, Alec L; Dines, Joshua S

    2016-04-01

    Open reduction internal fixation of proximal humerus fractures is often accomplished with proximal humerus locking plates. While these plates have a good track record, they can become symptomatic and require removal once the fracture has healed. Open hardware removal is associated with a number of additional risks to the patient, including infection, scarring, nerve damage, and blood loss. In addition, the recovery time after open hardware removal may be prolonged, thereby predisposing the patient to postoperative stiffness. The purpose of this article is to describe a technique for removing proximal humerus locking plates arthroscopically. Although technically demanding, the benefits of this technique include smaller incisions, quicker recovery time, decreased risk of infection, and reduced blood loss. Arthroscopy also provides the surgeon with the ability to address concomitant intra-articular pathology at the time of surgery. Additionally, we use a bone-void filler to reduce the risk of fracture through stress caused by previous screw holes. PMID:27462532

  18. Biomechanical testing of the LCP--how can stability in locked internal fixators be controlled?

    PubMed

    Stoffel, Karl; Dieter, Ulrich; Stachowiak, Gwidon; Gächter, André; Kuster, Markus S

    2003-11-01

    New plating techniques, such as non-contact plates, have been introduced in acknowledgment of the importance of biological factors in internal fixation. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability, e.g. fracture motion, and the risk of implant failure can best be controlled. The results of a study based on in vitro experiments with composite bone cylinders and finite element analysis using the Locking Compression Plate (LCP) for diaphyseal fractures are presented and recommendations for clinical practice are given. Several factors were shown to influence stability both in compression and torsion. Axial stiffness and torsional rigidity was mainly influenced by the working length, e.g. the distance of the first screw to the fracture site. By omitting one screw hole on either side of the fracture, the construct became almost twice as flexible in both compression and torsion. The number of screws also significantly affected the stability, however, more than three screws per fragment did little to increase axial stiffness; nor did four screws increase torsional rigidity. The position of the third screw in the fragment significantly affected axial stiffness, but not torsional rigidity. The closer an additional screw is positioned towards the fracture gap, the stiffer the construct becomes under compression. The rigidity under torsional load was determined by the number of screws only. Another factor affecting construct stability was the distance of the plate to the bone. Increasing this distance resulted in decreased construct stability. Finally, a shorter plate with an equal number of screws caused a reduction in axial stiffness but not in torsional rigidity. Static compression tests showed that increasing the working length, e.g. omitting the screws immediately adjacent to the fracture on both sides, significantly diminished the load causing plastic

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

    PubMed Central

    Zafra-Jimenez, Jose Alberto; Rodriguez Martin, Juan

    2010-01-01

    In recent years, the locked plating system has gained favour in the treatment of certain fractures in adults; however, there is not much information regarding its use in children. We think there could be some advantages and applications such as: an alternative to external fixation, the bridge plating technique, unicortical screws, removal of hardware, metadiaphyseal fractures, periarticular fractures, poor quality bone, and allograft fixation. However, there are some disadvantages to keep in mind and the final decision for using it should be based on the osteosynthesis method principle the surgeon would like to apply. In this review article we discuss the up-to-date possible clinical applications and issues of this system. PMID:20162415

  20. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures

    PubMed Central

    Seybold, Dominik; Citak, Mustafa; Königshausen, Matthias; Gessmann, Jan; Schildhauer, Thomas A.

    2011-01-01

    Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft für Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures. PMID:22223961

  1. A comparison of reversed locking compression-distal femoral plates and blade plates in osteotomies for young adult hip pathology.

    PubMed

    MacLean, Simon B M; Evans, Scott; O'Hara, John N

    2013-01-01

    The aim of this study was to compare fixation of proximal femoral osteotomies using reverse contralateral LCP-Distal Femoral Plates (LCP-DF) with the more traditional blade plate technique. This was a retrospective review over six years of a single surgeon's practice within a tertiary orthopaedic unit. Patient demographics were collected, along with indication for surgery. Radiological outcomes, fixation failures and the need for revision surgery were recorded. Forty-six patients were identified; 23 patients in the LCP-DF plate group (7 females, 16 males. Mean age 18.3 years old) and 23 patients in the blade plate group (6 females, 17 males. Mean age 19.1 years old). The patients' presenting conditions were; 26 Perthes'; eight hip dysplasia; 11 slipped capital femoral epiphysis; one fibrous dysplasia. Osteotomy type included; 13 Double osteotomy, 11 Imhauser; 13 pure valgus; eight valgus + rotation; There was one revision for implant failure in the LCP-DF group. In the blade plate group, there were four implant failures--three requiring revision operations (p = 0.155). In the LCP-DF group the mean neck-shaft angle difference compared to the contralateral side (if normal) or 135 degrees (if abnormal) was 0.58°. In the condylar plate group the mean difference was 4.37°. The use of a contralateral LCP-DF plate in the reverse contralateral position to stabilise proximal femoral osteotomies in our cohort confers advantages over blade plate technology. We have found that the plate is stiffer, is easier to use and provides increased screw placement options over standard proximal femoral locking plates.

  2. Volar locking distal radius plates show better short-term results than other treatment options: A prospective randomised controlled trial

    PubMed Central

    Drobetz, Herwig; Koval, Lidia; Weninger, Patrick; Luscombe, Ruth; Jeffries, Paula; Ehrendorfer, Stefan; Heal, Clare

    2016-01-01

    AIM To compare the outcomes of displaced distal radius fractures treated with volar locking plates and with immediate postoperative mobilisation with the outcomes of these fractures treated with modalities that necessitate 6 wk wrist immobilisation. METHODS A prospective, randomised controlled single-centre trial was conducted with 56 patients who had a displaced radius fracture were randomised to treatment either with a volar locking plate (n = 29), or another treatment modality (n = 27; cast immobilisation with or without wires or external fixator). Outcomes were measured at 12 wk. Functional outcome scores measured were the Patient-Rated Wrist Evaluation (PRWE) Score; Disabilities of the Arm, Shoulder and Hand and activities of daily living (ADLs). Clinical outcomes were wrist range of motion and grip strength. Radiographic parameters were volar inclination and ulnar variance. RESULTS Patients in the volar locking plate group had significantly better PRWE scores, ADL scores, grip strength and range of extension at three months compared with the control group. All radiological parameters were significantly better in the volar locking plate group at 3 mo. CONCLUSION The present study suggests that volar locking plates produced significantly better functional and clinical outcomes at 3 mo compared with other treatment modalities. Anatomical reduction was significantly more likely to be preserved in the plating group. Level of evidence: II. PMID:27795951

  3. Magnetically Operated Holding Plate And Ball-Lock Pin

    NASA Technical Reports Server (NTRS)

    Monford, Leo G., Jr.

    1992-01-01

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

  4. Fractured facial bone reduction and resorbable plate fixation using tapper.

    PubMed

    Kim, Chang Yeon; Kim, Kee Woong

    2011-07-01

    A resorbable fixation system has many advantages, but there are complicated procedures to be accomplished to fix a resorbable plate. The complicated procedures in the fixation of a resorbable plate make the operation for facial fractures more difficult and can result in extended operation time and incomplete reduction or fixation. For these reasons, we suggest a new way of using a tapper that can make the surgery more simple and accurate than before. After the resorbable plate is properly located above the fractured site, a hole on the fracture fragment is made by drill, and the tapper is inserted into the hole. When the tapper is inserted at the proper depth, the fracture fragment can be reduced to right place by handling the inserted tapper. Then, the tapper is inserted to the end, and the handle is split. While the inserted tapper acting as a temporary metal screw is placed, another hole is made at nearby site and the screw is inserted. Next, the inserted tapper acting as a temporary metal screw is removed, and another screw is inserted into the hole from which the tapper was removed. From October 2006 to April 2008, we applied this procedure to 106 facial bone fractures in 68 patients, and no major complications were noted. In conclusion, we tried to make the operation more simple and accurate by using the tapper as an instrument for reduction and fixation of fracture fragment.

  5. A Novel Fixation System for Acetabular Quadrilateral Plate Fracture: A Comparative Biomechanical Study

    PubMed Central

    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

  6. Fixation of zygomatic and mandibular fractures with biodegradable plates

    PubMed Central

    Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

    2013-01-01

    Context: In this prospective study, 13 randomly selected patients underwent treatment for zygomatic–complex fractures (2 site fractures) and mandibular fractures using 1.5 / 2 / 2.5-mm INION CPS biodegradable plates and screws. Aims: To assess the fixation of zygomatic-complex and mandibular fractures with biodegradable copolymer osteosynthesis system. Materials and Methods: In randomly selected 13 patients, zygomatic-complex and mandibular fractures were plated using resorbable plates and screws using Champy's principle. All the cases were evaluated clinically and radiologically for the type of fracture, need for the intermaxillary fixation (IMF) and its duration, duration of surgery, fixation at operation, state of reduction at operation, state of bone union after operation, anatomic reduction, paresthesia, occlusal discrepancies, soft tissue infection, immediate and late inflammatory reactions related to biodegradation process, and any need for the removal of the plates. Statistical Analysis Used: Descriptives, Frequencies, and Chi-square test were used. Results: In our study, the age group range was 5 to 55 years. Road traffic accidents accounted for the majority of patients six, (46.2%). Postoperative occlusal discrepancies were found in seven patients as mild to moderate, which resolved with IMF for 1-8 weeks. There were minimal complications seen and only as soft tissue infection. Conclusions: Use of biodegradable osteosynthesis system is a reliable alternative method for the fixation of zygomatic-complex and mandibular fractures. The biodegradable system still needs to be refined in material quality and handling to match the stability achieved with metal system. Biodegradable plates and screws is an ideal system for pediatric fractures with favorable outcome. PMID:23662255

  7. Reverse distal femoral locking compression plate a salvage option in nonunion of proximal femoral fractures

    PubMed Central

    Dumbre Patil, Sampat S; Karkamkar, Sachin S; Patil, Vaishali S Dumbre; Patil, Shailesh S; Ranaware, Abhijeet S

    2016-01-01

    Background: When primary fixation of proximal femoral fractures with implants fails, revision osteosynthesis may be challenging. Tracts of previous implants and remaining insufficient bone stock in the proximal femur pose unique problems for the treatment. Intramedullary implants like proximal femoral nail (PFN) or surface implants like Dynamic Condylar Screw (DCS) are few of the described implants for revision surgery. There is no evidence in the literature to choose one implant over the other. We used the reverse distal femur locking compression plate (LCP) of the contralateral side in such cases undergoing revision surgery. This implant has multiple options of fixation in proximal femur and its curvature along the length matches the anterior bow of the femur. We aimed to evaluate the efficacy of this implant in salvage situations. Materials and Methods: Twenty patients of failed primary proximal femoral fractures who underwent revision surgery with reverse distal femoral locking plate from February 2009 to November 2012 were included in this retrospective study. There were 18 subtrochanteric fractures and two ipsilateral femoral neck and shaft fractures, which exhibited delayed union or nonunion. The study included 14 males and six females. The mean patient age was 43.6 years (range 22–65 years) and mean followup period was 52.1 months (range 27–72 months). Delayed union was considered when clinical and radiological signs of union failed to progress at the end of four months from initial surgery. Results: All fractures exhibited union without any complications. Union was assessed clinically and radiologically. One case of ipsilateral femoral neck and shaft fracture required bone grafting at the second stage for delayed union of the femoral shaft fracture. Conclusions: Reverse distal femoral LCP of the contralateral side can be used as a salvage option for failed fixation of proximal femoral fractures exhibiting nonunion. PMID:27512218

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

    PubMed Central

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

    2012-01-01

    Background We conducted this radiographic study in the elderly population with proximal humeral fracture aiming to evaluate 1) the serial changes of neck-shaft angle after locking plate fixation and 2) find relationship between change in neck shaft angle and various factors such as age, fracture pattern, severity of osteoporosis, medial support and initial reduction angle. Methods Twenty-five patients who underwent surgical treatment for proximal humeral fracture with locking plate between September 2008 and August 2010 are included. True anteroposterior and axillary lateral radiographs were made postoperatively and at each follow-up visit. Measurement of neck shaft angle was done at immediate postoperative, 3 months postoperative and a final follow-up (average, 11 months; range, 8 to 17 months). Severity of osteoporosis was assessed using cortical thickness suggested by Tingart et al. Results The mean neck shaft angles were 133.6° (range, 100° to 116°) at immediate postoperative, 129.8° (range, 99° to 150°) at 3 months postoperative and 128.4° (range, 97° to 145°) at final follow-up. The mean loss in the neck-shaft angle in the first 3 months was 3.8° as compared to 1.3° in the period between 3 months and final follow-up. This was statistically significant (p = 0.002), indicating that most of the fall in neck shaft angle occurs in the first three months after surgery. Relationship between neck shaft angle change and age (p = 0.29), fracture pattern (p = 0.41), cortical thickness (p = 0.21), medial support (p = 0.63) and initial reduction accuracy (p = 0.65) are not statistically significant. Conclusions The proximal humerus locking plate maintains reliable radiographic results even in the elderly population with proximal humerus fracture. PMID:22949952

  9. Use of a Proximal Humeral Locking Plate for Complex Ankle and Hindfoot Fusion.

    PubMed

    Shearman, Alexander D; Eleftheriou, Kyriacos Iordanis; Patel, Akash; Pradhan, Rajib; Rosenfeld, Peter Francis

    2016-01-01

    Arthrodesis of the ankle and hindfoot in the setting of major deformity is challenging and associated with substantial risks. Patients often have significant comorbidities that lead to unforgiving soft tissues, poor vascularity, and poor bone quality. This creates the high-risk scenario of poor wound healing and poor implant fixation. Complications can be devastating, leading to loss of the limb and sepsis. The use of locking plate technology might provide biomechanical and operative technique advantages in such patients. We retrospectively assessed the results of the modified use of the PHILOS(™) (Synthes(®), Zuchwil, Switzerland) proximal humeral locking plate in 21 patients (11 males, 10 females; mean age 56.1 years, range 25 to 74 years) who had undergone complex fusions, including tibiotalar (n = 4), tibiocalcaneal (n = 7), or tibiotalocalcaneal (n =10) fusions. The average follow-up period was 14.6 (median 10, range 6 to 49) months. Of the 21 fusions, 18 achieved union (85.7%) at an average period of 4.8 (median 4.3, range 3 to 12) months. The overall deep infection rate was 14.3%. Overall, 17 of the 21 patients (81%) were satisfied with the result (good to excellent), 1 reported the result was fair (4.8%), and 3 patients developed nonunion and were dissatisfied with the procedure (14.3%). The present study is the largest series to date of patients undergoing complex ankle and hindfoot arthrodesis with the use of a proximal humeral locking plate and confirms previous findings that the technique is reliable with union, satisfaction, and complication rates comparable to those of other techniques.

  10. LCP distal ulna hook plate as alternative fixation for fifth metatarsal base fracture.

    PubMed

    Lee, Sang Ki; Park, Ju Sang; Choy, Won Sik

    2013-08-01

    Intramedullary screw fixation is the most common treatment for fifth metatarsal base fractures. Screw application does not achieve accurate reduction in fracture with small fragments, osteoporotic bone, or Lawrence zone 1 fractures, however. On the basis of similar anatomical architectures between the distal ulna and the fifth metatarsal base, the purpose of this study was to assess the results of a locking compression plate (LCP) distal ulna hook plate in stabilizing displaced zone 1 or 2 fifth metatarsal base fractures. Nineteen patients with Lawrence zone 1 (n = 12) or 2 (n = 7) fractures of the fifth metatarsal base were treated surgically with an LCP distal ulna hook plate. The patients were evaluated clinically and radiographically, and functional outcomes were graded by using the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot scoring system. Radiographic bony union was obtained in all patients, at an average of 7.4 weeks. The mean AOFAS midfoot score improved from 26 (range, 0-45) preoperatively to 94 (range, 72-100) points at the final follow-up. There were three patients with post-traumatic cubometatarsal arthrosis and one patient with sural nerve neuropraxia. In our experience, the distal ulna hook plate achieves a high rate of bony consolidation and anatomically suitable fixation in zone 1 or 2 fifth metatarsal base fractures. We also suggest that the LCP distal ulna hook plate should be considered as an alternative treatment in multifragmentary, osteoporotic, and tuberosity avulsion (zone 1) fifth metatarsal base fractures.

  11. Outcome of proximal humerus fractures treated by PHILOS plate internal fixation. Experience of a district general hospital.

    PubMed

    Shahid, Rizwan; Mushtaq, Abid; Northover, Julian; Maqsood, Mohammad

    2008-10-01

    Proximal humerus fractures have been a challenge to achieve stable fixation. PHILOS (Proximal Humerus internal locking system) is part of the latest generation of locking compression plates for proximal humeral fracture fixation. We aim to assess the clinical and functional outcome of proximal humeral fractures (2-part, 3-part and 4-part) treated with the PHILOS plate. We prospectively reviewed 50 patients who had a proximal humeral fracture treated with the PHILOS plate from September 2002 to September 2006 in our institution. Clinical outcome was measured using the patient-based Oxford shoulder and DASH scoring systems. Five patients died and four were lost to follow-up. Eleven patients had 2-part, eleven 3-part and eighteen 4-part fractures. Mean follow-up time was 21.7 months (range: 6-44 months). Radiological union was achieved within 8 weeks in 40/41 fractures; complications were noted in four cases. Better results were achieved in younger than in older patients, and in male than in female patients. The number of fracture fragments did not appear to affect the results, but associated dislocation of the humeral head was a pejorative factor. Our study has shown that the PHILOS plate is a reliable implant. A direct correlation was observed between Oxford shoulder and DASH scores.

  12. EVALUATION OF THE COMPLICATIONS OF SURGICAL TREATMENT OF FRACTURES OF THE PROXIMAL EXTREMITY OF THE HUMERUS USING A LOCKING PLATE

    PubMed Central

    Miyazaki, Alberto Naoki; Estelles, José Renato Depari; Fregoneze, Marcelo; Santos, Pedro Doneux; da Silva, Luciana Andrade; do Val Sella, Guilherme; Ishioka, Fábio Eduardo; Rosa, João Polydoro; Checchia, Sergio Luiz

    2015-01-01

    Objective: To evaluate the complications from surgical treatment using a locking plate among patients with fractures of the proximal extremity of the humerus. Methods: Between July 2004 and December 2009, 56 patients with fractures of the proximal extremity of the humerus were treated using the PHILOS® plate. There were 19 male patients and 37 female patients, with a mean age of 62 years (range: 30 to 92 years). All the cases had a mean postoperative followup period of 12 months. Thirteen fractures were classified as presenting in two parts, 28 as three, eight as four and seven as epiphyseal fractures. Results: Among the patients operated, 26 were considered to have achieved excellent results, twelve good, ten fair and eight poor, according to the UCLA score. Thirty complications occurred in 20 patients (35.7%), among which the most frequent complication was inadequate reduction of the fracture, which occurred in eight cases. Subacromial impact, caused by the plate, occurred in seven cases, while inadequate fixation occurred in six cases. Other complications such as pseudarthrosis, adhesive capsulitis, avascular necrosis, loss of varus reduction and infection were also seen. Conclusion: The functional results from treating fractures of the proximal extremity of the humerus using a locking plate depended on correct anatomical reduction of the fracture and stable fixation of the implant. Complications still occur frequently, particularly because of intraoperative technical difficulty, fracture severity and possible inexperience of the surgeon. PMID:27047867

  13. Surgical Treatment of Unstable Distal Radius Fractures With a Volar Variable-Angle Locking Plate: Clinical and Radiological Outcomes

    PubMed Central

    Khatri, Kavin; Sharma, Vijay; Farooque, Kamran; Tiwari, Vivek

    2016-01-01

    Background Unstable distal end radius fractures are difficult to manage and so various treatment modalities have been described. The use of variable-angle locking plates is promoted for the management of these fractures. Objectives This study aimed to evaluate the functional and radiological outcomes in unstable distal end radius fractures treated with variable-angle locking plates. Patients and Methods We reviewed 23 unstable distal end radius fractures that were treated at our institution with volar variable-angle locking plates. The mean age of the patients was 32.82 ± 11.81 years (range 19 to 62) and the mean duration of follow-up was 11.04 ± 2.47 months (range 6 to 15). All of the patients underwent open reduction and internal fixation with a variable-angle locking plate. Radiological parameters such as radial inclination, length, tilt, and ulnar variance were measured at six weeks and at the final follow-up. The functional evaluation was conducted by measuring the range of motion at the wrist joint as well as the grip strength. Gartland and Werley’s demerit scoring system was used to assess the final outcome. Results There were two cases of superficial infection that responded to oral antibiotics. One patient had developed a hypertrophic scar, while another had carpal tunnel syndrome that was conservatively managed. There was a significant improvement in the functional indices from six weeks to the final follow-up, while the radiological parameters were maintained. According to Gartland and Werley, excellent results were reported in 65.2% cases, while good results were present in 35% cases. Conclusions The use of variable-angle locking plates in treating unstable distal end radius fractures is associated with excellent to good functional outcomes with minimal complications.

  14. Surgical Treatment of Unstable Distal Radius Fractures With a Volar Variable-Angle Locking Plate: Clinical and Radiological Outcomes

    PubMed Central

    Khatri, Kavin; Sharma, Vijay; Farooque, Kamran; Tiwari, Vivek

    2016-01-01

    Background Unstable distal end radius fractures are difficult to manage and so various treatment modalities have been described. The use of variable-angle locking plates is promoted for the management of these fractures. Objectives This study aimed to evaluate the functional and radiological outcomes in unstable distal end radius fractures treated with variable-angle locking plates. Patients and Methods We reviewed 23 unstable distal end radius fractures that were treated at our institution with volar variable-angle locking plates. The mean age of the patients was 32.82 ± 11.81 years (range 19 to 62) and the mean duration of follow-up was 11.04 ± 2.47 months (range 6 to 15). All of the patients underwent open reduction and internal fixation with a variable-angle locking plate. Radiological parameters such as radial inclination, length, tilt, and ulnar variance were measured at six weeks and at the final follow-up. The functional evaluation was conducted by measuring the range of motion at the wrist joint as well as the grip strength. Gartland and Werley’s demerit scoring system was used to assess the final outcome. Results There were two cases of superficial infection that responded to oral antibiotics. One patient had developed a hypertrophic scar, while another had carpal tunnel syndrome that was conservatively managed. There was a significant improvement in the functional indices from six weeks to the final follow-up, while the radiological parameters were maintained. According to Gartland and Werley, excellent results were reported in 65.2% cases, while good results were present in 35% cases. Conclusions The use of variable-angle locking plates in treating unstable distal end radius fractures is associated with excellent to good functional outcomes with minimal complications. PMID:27679785

  15. Rupture of Flexor Pollicis Longus Tendon: A Complication of Volar Locking Plating of the Distal Radius.

    PubMed

    Rajeev, Aysha Sethunathan; Sreverthana, Shanaka; Harrison, John

    2010-08-01

    We report an unusual case of complete rupture of the flexor pollicis longus tendon following volar locking plating for a distal radius fracture. We believe that the prominence of a distal locking screw head predisposed to the rupture of the tendon. We highlight that correctly attaching the distal locking screws to the plate is essential for obtaining the correct biomechanics of the device and preventing flexor tendon rupture.

  16. Treatment of Midshaft Clavicle Fractures: Application of Local Autograft With Concurrent Plate Fixation.

    PubMed

    Slette, Erik L; Mikula, Jacob D; Turnbull, Travis Lee; Hackett, Thomas R

    2016-06-01

    Currently, open reduction-internal fixation using contoured plates or intramedullary nails is considered the standard operative treatment for midshaft clavicle fractures because of the immediate rigid stability provided by the fixation device. In addition, autologous iliac crest bone graft has proved to augment osteosynthesis during internal fixation of nonunion fractures through the release of osteogenic factors. The purpose of this article is to describe a surgical technique developed to reduce donor-site morbidity and improve functional and objective outcomes after open reduction-internal fixation with autologous bone graft placement through local autograft harvesting and concurrent plate fixation. PMID:27656378

  17. [Angle-fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study].

    PubMed

    Hessmann, Martin H; Korner, Jan; Hofmann, Alexander; Sternstein, Werner; Rommens, Pol M

    2008-06-01

    Internal fixation of fractures of the proximal humerus needs a high stability of fixation to avoid secondary loss of fixation. This is especially important in osteoporotic bone. In an experimental study, the biomechanical properties of the angle-fixed Philos plate (internal fixator) and a double-plate osteosynthesis using two one-third tubular plates were assessed. The fracture model was an unstable three-part fracture (AO type B2). Eight pairs of human cadaveric humeri were submitted to axial load and torque. In the first part of the study, it was assessed to which degree the original stiffness of the humeri could be restored after the osteotomy by the osteosynthesis procedure. Subsequently, subsidence during 200 cycles of axial loading and torque was analysed. During axial loading, the Philos plate was significantly stiffer and showed less irreversible deformation. Two double-plate fixations, but none of the Philos plate osteosynthesis, failed. During torsion, there were no significant differences between the two implants. From the biomechanical point of view, the angle-fixed Philos plate represents the implant of choice for the surgical fixation of highly unstable three-part fractures of the proximal humerus, as the internal fixator system is characterised by superior biomechanical properties.

  18. 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 < 0.001). Dynamic 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.

  19. OSTEOSYNTHESIS OF PROXIMAL HUMERAL END FRACTURES WITH FIXED-ANGLE PLATE AND LOCKING SCREWS: TECHNIQUE AND RESULTS

    PubMed Central

    Cohen, Marcio; Amaral, Marcus Vinicius; Monteiro, Martim; Brandão, Bruno Lobo; Motta Filho, Geraldo Rocha

    2015-01-01

    Describe the results of proximal humeral fractures surgically treated with the Philos locking plate system. Method: Between March 2003 and October 2004 we prospectively reviewed 24 of 26 patients with proximal humerus fractures treated with a Philos plate. The mean follow-up time was 12 months and the mean age of patients was 57 years. Six patients had four-part proximal humerus fractures, 11 patients had three-part proximal humerus fractures, and nine patients had two-part proximal humerus fractures. Clinical evaluation was performed using the University of California at Los Angeles (UCLA) criteria. Results: The mean UCLA score was 30 points (17-34). All fractures showed union. Three patients showed fracture union at varus position. The mean UCLA score for these patients was 27 points. Conclusion: Osteosynthesis with Philos plate provides a stable fixation method with good functional outcome. PMID:26998460

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

    PubMed Central

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

    2009-01-01

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

  1. Locked META intramedullary nailing fixation for tibial fractures via a suprapatellar approach

    PubMed Central

    Fu, Beigang

    2016-01-01

    Background: Intramedullary nailing is an effective approach for treatment of diaphyseal tibial fractures. However, infrapatellar intramedullary nailing can easily cause angulation and rotation displacement at the fracture ends and increase risk of postoperative infection. Intramedullary nailing via the suprapatellar approach was proved with good reduction and fixation. We used locked intramedullary nailing for the treatment of tibial fractures via a suprapatellar approach in this study. Materials and Methods: 23 patients undergoing tibial fractures fixation by locked META intramedullary nailing via a suprapatellar approach were enrolled between June 2012 and October 2013. There were 18 males and 5 females. The average age was 35.5 years (range 18-60 years). The intraoperative data including operative time and blood loss and postoperative data consisting of hospital stays, fluoroscopy time, fracture healing time and complications were all recorded. Results: The average operative time, blood loss, fluoroscopy time and hospital stay were 78.2 ± 9.1 min, 90.4 ± 23.4 mL, 38.5 ± 6.5 s and 11 ± 3.4 days respectively. The mean followup period in all the patients was 15.5 months. Callus appeared in the patients at average 8 weeks after surgery. The mean knee and ankle range of motion were significantly improved at the last followup (P < 0.05). The average Hospital for Special Surgery and Olerud–Molander scores was 92 ± 4.3 points and 93.6 ± 3.9 points, respectively. No complications were observed. Conclusion: Locked META intramedullary nail fixation via a suprapatellar approach is safe and effective for patients suffering from tibial fractures and earlier functional recovery. PMID:27293289

  2. Comminuted olecranon fracture fixation with pre-contoured plate: Comparison of composite and cadaver bones

    PubMed Central

    Hamilton Jr, David A; Reilly, Danielle; Wipf, Felix; Kamineni, Srinath

    2015-01-01

    AIM: To determine whether use of a precontoured olecranon plate provides adequate fixation to withstand supraphysiologic force in a comminuted olecranon fracture model. METHODS: Five samples of fourth generation composite bones and five samples of fresh frozen human cadaveric left ulnae were utilized for this study. The cadaveric specimens underwent dual-energy X-ray absorptiometry (DEXA) scanning to quantify the bone quality. The composite and cadaveric bones were prepared by creating a comminuted olecranon fracture and fixed with a pre-contoured olecranon plate with locking screws. Construct stiffness and failure load were measured by subjecting specimens to cantilever bending moments until failure. Fracture site motion was measured with differential variable resistance transducer spanning the fracture. Statistical analysis was performed with two-tailed Mann-Whitney-U test with Monte Carlo Exact test. RESULTS: There was a significant difference in fixation stiffness and strength between the composite bones and human cadaver bones. Failure modes differed in cadaveric and composite specimens. The load to failure for the composite bones (n = 5) and human cadaver bones (n = 5) specimens were 10.67 nm (range 9.40-11.91 nm) and 13.05 nm (range 12.59-15.38 nm) respectively. This difference was statistically significant (P ˂ 0.007, 97% power). Median stiffness for composite bones and human cadaver bones specimens were 5.69 nm/mm (range 4.69-6.80 nm/mm) and 7.55 nm/mm (range 6.31-7.72 nm/mm). There was a significant difference for stiffness (P ˂ 0.033, 79% power) between composite bones and cadaveric bones. No correlation was found between the DEXA results and stiffness. All cadaveric specimens withstood the physiologic load anticipated postoperatively. Catastrophic failure occurred in all composite specimens. All failures resulted from composite bone failure at the distal screw site and not hardware failure. There were no catastrophic fracture failures in the cadaveric

  3. Effect of Off-Axis Screw Insertion, Insertion Torque, and Plate Contouring on Locked Screw Strength

    PubMed Central

    Gallagher, Bethany; Silva, Matthew J.; Ricci, William M.

    2015-01-01

    Objectives This study quantifies the effects of insertion torque, off-axis screw angulation, and plate contouring on the strength of locking plate constructs. Methods Groups of locking screws (n = 6–11 screws) were inserted at 50%, 100%, 150%, and 200% of the manufacturer-recommended torque (3.2 Nm) into locking compression plates at various angles: orthogonal (control), 5-degree angle off-axis, and 10-degree angle off-axis. Screws were loaded to failure by a transverse force (parallel to the plate) either in the same (“+”) or opposite direction (“−”) of the initial screw angulation. Separately, locking plates were bent to 5 and 10-degree angles, with the bend apex at a screw hole. Locking screws inserted orthogonally into the apex hole at 100% torque were loaded to failure. Results Orthogonal insertion resulted in the highest average load to failure, 2577 ± 141 N (range, 2413–2778 N), whereas any off-axis insertion significantly weakened constructs (165–1285 N, at 100% torque) (P < 0.05). For “+” loading, torque beyond 100% did not increase strength, but 50% torque reduced screw strength (P < 0.05). Loading in the “−” direction consistently resulted in higher strengths than “+” loading (P < 0.05). Plate contouring of 5-degree angle did not significantly change screw strength compared with straight plates but contouring of 10-degree angle significantly reduced load to failure (P < 0.05). Conclusions To maximize the screw plate interface strength, locking screws should be inserted without cross-threading. The mechanical stability of locked screws is significantly compromised by loose insertion, off-axis insertion, or severe distortion of the locking mechanism. PMID:24343255

  4. The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review.

    PubMed

    Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-02-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950's, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation.

  5. The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review

    PubMed Central

    Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-01-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950’s, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation. PMID:26889439

  6. 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 < 0.001). Dynamic 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

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

    PubMed

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

    2012-11-01

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

  8. Extraperiosteal Dual Plate Fixation of Acute Mid-Shaft Clavicle Fractures: A Technical Trick.

    PubMed

    Shannon, Steven F; Chen, Xiaobin; Torchia, Michael; Schoch, Bradley

    2016-10-01

    Historically, surgical treatment of acute mid-shaft clavicle fractures has excellent outcomes with low rates of nonunion. More complex fracture patterns with significant comminution may limit the fixation that can be obtained with a single plate. The authors describe the surgical technique and case series of patients treated with extraperiosteal dual plating for acute mid-shaft clavicle fractures.

  9. 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

  10. Fixation of 3- and 4-part proximal humerus fractures using the PHILOS plate: mid-term results.

    PubMed

    Gaheer, Rajinder Singh; Hawkins, Amanda

    2010-09-07

    Treatment of unstable, displaced, and comminuted fractures of the proximal humerus remains challenging, and optimal treatment continues to be controversial. Fifty-six patients with displaced 3- and 4-part fractures of the proximal humerus had open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate (Synthes, Stratec Medical Ltd, Mezzovico, Switzerland). Data were collected retrospectively, and clinical and radiological outcomes were assessed. Mean follow-up was 40 months (range, 18-62 months). The study shows that the PHILOS plate gives good results in the treatment of displaced 3- and 4-part fractures of the proximal humerus. Good fracture stability can be achieved early, allowing early mobilization without compromising fracture union. Most importantly, it requires minimal soft tissue dissection, does not need contouring, and gives good stability. No differences were observed in the functional outcomes of patients younger and older than 65 years. Few complications were associated with the plate, and the number of ≥2 surgeries was minimal. The complications noted were 1 case each of superficial wound infection, failure of the plate, and persistent stiffness. One patient had screw perforation of the humeral head articular surface, and 1 had subacromial impingement. Of the 32 patients who had been in active employment before the injury, 28 returned to their previous occupation.

  11. 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

  12. UK Fixation of Distal Tibia Fractures (UK FixDT): protocol for a randomised controlled trial of ‘locking’ plate fixation versus intramedullary nail fixation in the treatment of adult patients with a displaced fracture of the distal tibia

    PubMed Central

    Achten, Juul; Parsons, Nicholas R; McGuinness, Katie R; Petrou, Stavros; Lamb, Sarah E; Costa, Matthew L

    2015-01-01

    Introduction The treatment of displaced, extra-articular fractures of the distal tibia remains controversial. These injuries are difficult to manage due to limited soft tissue cover, poor vascularity of the area and proximity to the ankle joint. Surgical treatment options are expanding and include locked intramedullary nails, plate and screw fixation and external fixator systems. The nail and plate options are most commonly used in the UK, but controversy exists over which treatment is most clinically and cost-effective. In this multicentre randomised controlled trial we aim to assess ratings of disability 6 months postinjury in patients who have sustained a distal tibia fracture treated with either an intramedullary nail or plate and locking screw fixation. Methods and analysis Adult patients presenting at trial centres with an acute fracture of the distal tibia will be considered for inclusion. A total of 320 patients will provide 90% power to detect a difference of 8 points in Disability Rating Index (DRI) score at 6 months at the 5% level. The randomisation sequence is stratified by trial centre and age, and administered via web-based service with 1:1 treatment allocation. Baseline demographic and pre-injury functional data and radiographs will be collected using the DRI, Olerud and Molander, and EuroQol EQ-5D questionnaire. Clinical assessment, early complications and radiographs will be recorded at 6–8 weeks. Functional outcome, health-related quality of life and resource use will be collected at 3, 6 and 12 months postoperatively. The main analysis will investigate differences in DRI 6 months postsurgery, between the two treatment groups, on an intention-to-treat basis. Tests will be two-sided and considered to provide evidence for a significant difference if p values are <0.05. Ethics and dissemination NRES Committee West-Midlands, 6/11/2012 (ref:12/WM/0340). The results of the trial will be disseminated via peer-reviewed publications and

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

    PubMed

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

    2015-01-01

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

  14. Locking, mass flux and topographic response at convergent plate boundaries - the Chilean case

    NASA Astrophysics Data System (ADS)

    Oncken, Onno

    2016-04-01

    On the long term, convergent plate boundaries have been shown to be controlled by either accretion/underplating or by subduction erosion. Vertical surface motion is coupled to convergence rate - typically with an uplift rate of the coastal area ranging from 0 to +50% of convergence rate in accretive systems, and -20 to +30% in erosive systems. Vertical kinematics, however, are not necessarily linked to horizontal strain mode, i.e. upper plate shortening or extension, in a simple way. This range of kinematic behaviors - as well as their acceleration where forearcs collide with oceanic ridges/plateau - is well expressed along the Chilean plate margin. Towards the short end of the time scale, deformation appears to exhibit a close correlation with the frictional properties and geodetic locking at the plate interface. Corroborating analogue experiments of strain accumulation during multiple earthquake cycles, forearc deformation and uplift focus above the downdip and updip end of seismic coupling and slip and are each related to a particular stage of the seismic cycle, but with opposite trends for both domains. Similarly, barriers separating locked domains along strike appear to accumulate most upper plate faulting interseismically. Hence, locking patters are reflected in topography. From the long-term memory contained in the forearc topography the relief of the Chilean forearc seems to reflect long term stability of the observed heterogeneity of locking at the plate interface. This has fundamental implications for spatial and temporal distribution of seismic hazard. Finally, the nature of locking at the plate interface controlling the above kinematic behavior appears to be strongly controlled by the degree of fluid overpressuring at the plate interface suggesting that the hydraulic system at the interface takes a key role for the forearc response.

  15. Biomechanical Evaluation of Plate Versus Lag Screw Only Fixation of Distal Fibula Fractures.

    PubMed

    Misaghi, Amirhossein; Doan, Josh; Bastrom, Tracey; Pennock, Andrew T

    2015-01-01

    Traditional fixation of unstable Orthopaedic Trauma Association type B/C ankle fractures consists of a lag screw and a lateral or posterolateral neutralization plate. Several studies have demonstrated the clinical success of lag screw only fixation; however, to date no biomechanical comparison of the different constructs has been performed. The purpose of the present study was to evaluate the biomechanical strength of these different constructs. Osteotomies were created in 40 Sawbones(®) distal fibulas and reduced using 1 bicortical 3.5-mm stainless steel lag screw, 2 bicortical 3.5-mm lag screws, 3 bicortical 3.5-mm lag screws, or a single 3.5-mm lag screw coupled with a stainless steel neutralization plate with 3 proximal cortical and 3 distal cancellous screws. The constructs were tested to determine the stiffness in lateral bending and rotation and failure torque. No significant differences in lateral bending or rotational stiffness were detected between the osteotomies fixed with 3 lag screws and a plate. Constructs fixed with 1 lag screw were weaker for both lateral bending and rotational stiffness. Osteotomies fixed with 2 lag screws were weaker in lateral bending only. No significant differences were found in the failure torque. Compared with lag screw only fixation, plate fixation requires larger incisions and increased costs and is more likely to require follow-up surgery. Despite the published clinical success of treating simple Orthopaedic Trauma Association B/C fractures with lag screw only fixation, many surgeons still have concerns about stability. For noncomminuted, long oblique distal fibula fractures, lag screw only fixation techniques offer construct stiffness similar to that of traditional plate and lag screw fixation. PMID:25990534

  16. Biomechanical Evaluation of Plate Versus Lag Screw Only Fixation of Distal Fibula Fractures.

    PubMed

    Misaghi, Amirhossein; Doan, Josh; Bastrom, Tracey; Pennock, Andrew T

    2015-01-01

    Traditional fixation of unstable Orthopaedic Trauma Association type B/C ankle fractures consists of a lag screw and a lateral or posterolateral neutralization plate. Several studies have demonstrated the clinical success of lag screw only fixation; however, to date no biomechanical comparison of the different constructs has been performed. The purpose of the present study was to evaluate the biomechanical strength of these different constructs. Osteotomies were created in 40 Sawbones(®) distal fibulas and reduced using 1 bicortical 3.5-mm stainless steel lag screw, 2 bicortical 3.5-mm lag screws, 3 bicortical 3.5-mm lag screws, or a single 3.5-mm lag screw coupled with a stainless steel neutralization plate with 3 proximal cortical and 3 distal cancellous screws. The constructs were tested to determine the stiffness in lateral bending and rotation and failure torque. No significant differences in lateral bending or rotational stiffness were detected between the osteotomies fixed with 3 lag screws and a plate. Constructs fixed with 1 lag screw were weaker for both lateral bending and rotational stiffness. Osteotomies fixed with 2 lag screws were weaker in lateral bending only. No significant differences were found in the failure torque. Compared with lag screw only fixation, plate fixation requires larger incisions and increased costs and is more likely to require follow-up surgery. Despite the published clinical success of treating simple Orthopaedic Trauma Association B/C fractures with lag screw only fixation, many surgeons still have concerns about stability. For noncomminuted, long oblique distal fibula fractures, lag screw only fixation techniques offer construct stiffness similar to that of traditional plate and lag screw fixation.

  17. Assessment of carbon fibre composite fracture fixation plate using finite element analysis.

    PubMed

    Saidpour, Seyed H

    2006-07-01

    In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress shielding in the layer of bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. In this study a novel forearm internal fracture fixation plate made from short carbon fibre reinforced plastic (CFRP) was used in an attempt to address the problem. Accordingly, it has been possible to analyse the stress distribution in the composite plates using finite-element modelling. A three-dimensional, quarter-symmetric finite element model was generated for the plate system. The stress state in the underlying bone was examined for several loading conditions. Based on the analytical results the composite plate system is likely to reduce stress-shielding effects at the fracture site when subjected to bending and torsional loads. The design of the plate was further optimised by reducing the width around the innermost holes.

  18. 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.

  19. Callus Formation and Mineralization after Fracture with Different Fixation Techniques: Minimally Invasive Plate Osteosynthesis versus Open Reduction Internal Fixation.

    PubMed

    Xu, Haitao; Xue, Zichao; Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

    Minimally invasive plate osteosynthesis(MIPO) has been considered as an alternative for fracture treatment. Previous study has demonstrated that MIPO technique has the advantage of less soft tissue injury compared with open reduction internal fixation (ORIF). However, the comparison of callus formation and mineralization between two plate osteosynthesis methods remains unknown. In this experiment, ulna fracture model was established in 42 beagle dogs. The fractures underwent reduction and internal fixation with MIPO or ORIF. Sequential fluorescent labeling and radiographs were applied to determine new callus formation and mineralization in two groups after operation. At 4, 8 and 12 weeks postoperatively, the animals were selected to be sacrificed and the ulna specimens were analyzed by Micro-CT. The sections were also treated with Masson staining for histological evaluation. More callus formation was observed in MIPO group in early stage of fracture healing. The fracture union rate has no significant difference between two groups. The results indicate that excessive soft tissue stripping may impact early callus formation. As MIPO technique can effectively reduce soft tissue injury with little incision, it is considered to be a promising alternative for fracture fixation.

  20. Callus Formation and Mineralization after Fracture with Different Fixation Techniques: Minimally Invasive Plate Osteosynthesis versus Open Reduction Internal Fixation

    PubMed Central

    Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

    Minimally invasive plate osteosynthesis(MIPO) has been considered as an alternative for fracture treatment. Previous study has demonstrated that MIPO technique has the advantage of less soft tissue injury compared with open reduction internal fixation (ORIF). However, the comparison of callus formation and mineralization between two plate osteosynthesis methods remains unknown. In this experiment, ulna fracture model was established in 42 beagle dogs. The fractures underwent reduction and internal fixation with MIPO or ORIF. Sequential fluorescent labeling and radiographs were applied to determine new callus formation and mineralization in two groups after operation. At 4, 8 and 12 weeks postoperatively, the animals were selected to be sacrificed and the ulna specimens were analyzed by Micro-CT. The sections were also treated with Masson staining for histological evaluation. More callus formation was observed in MIPO group in early stage of fracture healing. The fracture union rate has no significant difference between two groups. The results indicate that excessive soft tissue stripping may impact early callus formation. As MIPO technique can effectively reduce soft tissue injury with little incision, it is considered to be a promising alternative for fracture fixation. PMID:26444295

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

    PubMed Central

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

    2014-01-01

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

  2. 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

  3. Analysis of Sternal Fixation Results According to Plate Type in Sternal Fracture

    PubMed Central

    Byun, Chun Sung; Park, Il Hwan; Hwang, Wan Jin; Lee, Yeiwon; Cho, Hyun Min

    2016-01-01

    Background Sternal fractures are relatively rare, and caused mainly by blunt anterior chest wall trauma. In most cases, sternal fractures are treated conservatively. However, if the patient exhibits problematic symptoms such as intractable chest wall pain or bony crepitus due to sternal instability, surgical correction is indicated. But no consensus exists regarding the most appropriate surgical method. We analyzed the results of surgical fixation in cases of sternal fracture in order to identify which surgical method led to the best outcomes. Methods We retrospectively reviewed the medical records of patients with sternal fractures from December 2008 to December 2011, and found 19 patients who underwent open reduction and internal fixation of the sternum with a longitudinal plate (L-group) or a T-shaped plate (T-group). We investigated patients’ characteristics, clinical details regarding each case of chest trauma, the presence of other associated injuries, the type of open reduction and fixation, whether a combined operation was performed, and postoperative complications. Results Of the 19 patients, 10 patients (52.6%) were male, and their average age was 56.8 years (range, 32 to 82 years). Seven patients (36.8%) had isolated sternal fractures, while 12 (63.2%) had other associated injuries. Seven patients (36.8%) were in the L-group and 12 patients (63.2%) were in the T-group. Three patients in the L-group (42.9%) showed a loosening of the fixation. In all patients in the T-group, the fracture exhibited stable alignment. Conclusion Open reduction and internal fixation with a T-shaped plate in sternal fractures is a safer and more efficient treatment method than treatment with a longitudinal plate, especially in patients with a severely displaced sternum or anterior flail chest, than a longitudinal plate. PMID:27733996

  4. Effect of in vitro aging on the stiffness of bioabsorbable fixation plates.

    PubMed

    Zinelis, Spiros; Venetis, Gregory; Eliades, Theodoros; Dimitrakopoulos, Ioannis; Eliades, Georgios

    2011-01-01

    The purpose of this study was to investigate the effect of in vitro aging on the stiffness of bioabsorbable fixation plates. Twenty-four polylactic/polyglycolic acid plates (LactoSorb; Lorenz, Jacksonville, FL) were divided in 3 groups of 8 specimens each. Group A served as control, and groups B and C were immersed in 0.1 M lactic acid for 15 and 30 days, respectively. All specimens were subjected to a 3-point bending test, using a universal testing machine, and the stiffness of each specimen was estimated. When analyzed with one-way analysis of variance, no difference was observed for the control and in vitro-aged specimens with regard to stiffness. Long-term (30 d) in vitro aging of poly-L-lactic acid bioabsorbable fixation plates does not seem to significantly affect the stiffness of the material as derived from a 3-point bending test.

  5. Novel Longitudinal Plate-Fixation Technique after Gross Resection of the Sternum

    PubMed Central

    Tasoglu, Irfan; Lafci, Gokhan

    2012-01-01

    Herein, we describe a plate-fixation technique as an alternative method to close a fragile or fractured sternum. A 69-year-old obese woman with diabetes mellitus and chronic obstructive pulmonary disease underwent coronary artery bypass grafting. One week postoperatively, sternal instability was detected, and traditional rewiring was performed. A week later, because of multiple sternal fractures, we performed sternal resection, with use of longitudinally affixed titanium plates and figure-8 steel wires for the anterior chest wall. The procedure was uneventful, and, on short-term follow-up, the anterior chest wall was stable. This longitudinal plate-fixation technique can be tailored to each patient. We think that the technique is safe, effective, economical, and easy to implement, and it is readily reproducible. To evaluate any associated risks, long-term follow-up in additional patients is warranted. PMID:22740734

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

    PubMed Central

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

    2005-01-01

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

  7. Close Intramedullary Interlocking Nailing Versus Locking Compression Plating In the Treatment of Closed Fracture Shaft of the Tibia.

    PubMed

    Kundu, I K; Datta, N K; Chowdhury, A Z; Das, K P; Tarik, M M; Faisal, M A

    2016-07-01

    Fracture of tibial shaft is the commonest site of long bone fractures due to its superficial location involving young or middle-age people. Proper management is an important issue regarding the future effective movements. In this study patients were grouped in closed Intra medullary interlocking nailing and locking compression plating. Post-operative follow up at 2 weeks, 6 weeks, 12 weeks and 3 months thereafter up to 6 months were done. Each of the patients was evaluated clinically and radiologically by tucker criteria of Tuker et al. Patients were assessed for pain on full weight bearing and kneeling, shortening and range of motion of knee and ankle joints. Radiological assessment for union of fracture, alignment of fracture and angulations and position of nail and screws and infection were observed during follow up. A total number of 32 patients were selected but only 27 patients were available for follow up for a period of 6 months. They were grouped into Group A, consisting of 15 patients who took the treatment in the form of closed intramedullary interlocking nailing and Group B, consisting of 12 patients those underwent ORIF with locking compression plating. In both of the groups Motor Vehicle Accident was the main mechanism of trauma. Fracture involving the middle 3rd of the tibia is common in both the groups. During post-operative follow up, four patients in Group A complained anterior knee pain, one patient in Group B had superficial infection, most of the patients had no restriction of movement in the ankle and knee joints and a single patient in Group B showed 1.5cm shortening of the lower limb. Period of hospital stay and fracture union time were less in Group A, which was statistically significant. Both groups showed excellent result with minimum complications. So this study permits to conclude that close IM interlocking nailing and open reduction and internal fixation by locking compression plating is equally effective for the management of close

  8. The use of short carbon fibre reinforced thermoplastic plates for fracture fixation.

    PubMed

    Gillett, N; Brown, S A; Dumbleton, J H; Pool, R P

    1985-03-01

    Thermoplastic plates of Nylon 6-10 and Polybutylene terephthalate reinforced with 30% short randomly oriented carbon fibres were tested for internal fixation of canine femoral transverse midshaft fractures. The elastic modulus of the plates was one-half that of bone: however, ultimate strength and strain in bending were comparable to bone. The fractures healed with moderate callus formation which was completely remodelled by 8 to 12 wk post surgery. Although a moderate inflammatory reaction to occasional particulate debris was noted, the materials appeared to possess the proper elastic moduli to allow sufficient support for the healing fracture without protecting the remodelling process.

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

    PubMed Central

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

    2014-01-01

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

  10. Plating versus intramedullary fixation for mid-shaft clavicle fractures: a systemic review and meta-analysis.

    PubMed

    Gao, Yan; Chen, Wei; Liu, Yue-Jv; Li, Xu; Wang, Hai-Li; Chen, Zhao-Yu

    2016-01-01

    Background. Plate fixation and intramedullary fixation are the most commonly used surgical treatment options for mid-shaft clavicle fractures; the latter method has demonstrated better performance in some studies. Objectives. Our aim was to critically review and summarize the literature comparing the outcomes of mid-shaft clavicle fracture treatment with plate fixation or intramedullary fixation to identify the better approach. Search Methods. Potential academic articles were identified from the Cochrane Library, MEDLINE (1966-2015.5), PubMed (1966-2015.5), EMBASE (1980-2015.5) and ScienceDirect (1966-2015.5). Gray studies were identified from the references of the included literature. Selection Criteria. Randomized controlled trials (RCTs) and non-RCTs comparing plate fixation and intramedullary fixation for mid-shaft clavicle fracture were included. Data Collection and Analysis. Two reviewers performed independent data abstraction. The I (2) statistic was used to assess heterogeneity. A fixed- or random-effects model was used for the meta-analysis. Results. Six RCTs and nine non-RCTs were retrieved, including 513 patients in the intramedullary fixation group and 521 patients in the plating group. No significant differences in terms of the union rate and shoulder function were found between the groups. Patients in the intramedullary fixation group had a shorter operative time, less blood loss, smaller wound size, and shorter union time than those in the plating group. With respect to complications, significant differences were identified for all complications and major complications (wound infection, nonunion, implant failures, transient brachial plexopathy, and pain after 6 months). Similar secondary complications (symptomatic hardware, hardware irritation, prominence, numbness, hypertrophic callus) were observed in both groups. Conclusions. Intramedullary fixation may be superior to plate fixation in the treatment of mid-shaft clavicle fractures, with similar

  11. Stoppa Approach for Anterior Plate Fixation in Unstable Pelvic Ring Injury

    PubMed Central

    Choo, Suk Kyu; Kim, Jung-Jae; Lee, Mark

    2016-01-01

    Background The Stoppa (intrapelvic) approach has been introduced for the treatment of pelvic-acetabular fractures; it allows easy exposure of the pelvic brim, where the bone quality is optimal for screw fixation. The purpose of our study was to investigate the surgical outcomes of unstable pelvic ring injuries treated using the Stoppa approach for stable anterior ring fixation. Methods We analyzed 22 cases of unstable pelvic ring injury treated with plate fixation of the anterior ring with the Stoppa approach. We excluded cases of nondisplaced rami fracture, simple symphyseal diastasis, and parasymphyseal fractures, which can be easily treated with other techniques. The average age of the study patients was 41 years (range, 23 to 61 years). There were 10 males and 12 females. According to the Young and Burgess classification, there were 12 lateral compression, 4 anteroposterior compression, and 6 vertical shear fracture patterns. The fracture location on the anterior ring was near the iliopectineal eminence in all cases and exposure of the pelvic brim was required for plate fixation. All patients were placed in the supine position. For anterior plate fixation, all screws were applied to the anterior ramus distally and directed above the hip joint proximally. Radiologic outcomes were assessed by union time and quality of reduction by Matta method. The Merle d'Aubigne-Postel score was used to evaluate the functional results. Results The average radiologic follow-up period was 16 months (range, 10 to 51 months). All fractures united at an average of 3.5 months (range, 3 to 5 months). According to the Matta method, the quality of reduction was classified as follows: 16 anatomical (73%) and 6 nearly anatomical (27%) reductions. There were no cases of screw or implant loosening before bone healing. The functional results were classified as 7 excellent (32%), 12 good (55%), and 3 fair (13%) by the Merle d'Aubigne-Postel score. There were no wound complications

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

    PubMed

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

    2014-03-01

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

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

    PubMed Central

    2011-01-01

    Background With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws ('calcar screw') has increasingly been discussed. The purpose of this study was to investigate the influence of calcar screws on secondary loss of reduction and on the occurrence of complications. Methods Patients with a proximal humeral fracture who underwent angular stable plate fixation between 01/2007 and 07/2009 were included. On AP views of the shoulder, the difference in height between humeral head and the proximal end of the plate were determined postoperatively and at follow-up. Additionally, the occurrence of complications was documented. Patients with calcar screws were assigned to group C+, patients without to group C-. Results Follow-up was possible in 60 patients (C+ 6.7 ± 5.6 M/C- 5.0 ± 2.8 M). Humeral head necrosis occurred in 6 (C+, 15.4%) and 3 (C-, 14.3%) cases. Cut-out of the proximal screws was observed in 3 (C+, 7.7%) and 1 (C-, 4.8%) cases. In each group, 1 patient showed delayed union. Implant failure or lesions of the axillary nerve were not observed. In 44 patients, true AP and Neer views were available to measure the head-plate distance. There was a significant loss of reduction in group C- (2.56 ± 2.65 mm) compared to C+ (0.77 ± 1.44 mm; p = 0.01). Conclusions The placement of calcar screws in the angular stable plate fixation of proximal humeral fractures is associated with less secondary loss of reduction by providing inferomedial support. An increased risk for complications could not be shown. PMID:21943090

  14. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation.

    PubMed

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-01-01

    BACKGROUND This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. MATERIAL AND METHODS We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. RESULTS All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. CONCLUSIONS Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement. PMID:26681388

  15. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation

    PubMed Central

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-01-01

    Background This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. Material/Methods We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. Results All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. Conclusions Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement. PMID:26681388

  16. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation.

    PubMed

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-12-18

    BACKGROUND This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. MATERIAL AND METHODS We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. RESULTS All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. CONCLUSIONS Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement.

  17. Biomechanical Concepts for Fracture Fixation.

    PubMed

    Bottlang, Michael; Schemitsch, Christine E; Nauth, Aaron; Routt, Milton; Egol, Kenneth A; Cook, Gillian E; Schemitsch, Emil H

    2015-12-01

    Application of the correct fixation construct is critical for fracture healing and long-term stability; however, it is a complex issue with numerous significant factors. This review describes a number of common fracture types and evaluates their currently available fracture fixation constructs. In the setting of complex elbow instability, stable fixation or radial head replacement with an appropriately sized implant in conjunction with ligamentous repair is required to restore stability. For unstable sacral fractures with vertical or multiplanar instabilities, "standard" iliosacral screw fixation is not sufficient. Periprosthetic femur fractures, in particular Vancouver B1 fractures, have increased stability when using 90/90 fixation versus a single locking plate. Far cortical locking combines the concept of dynamization with locked plating to achieve superior healing of a distal femur fracture. Finally, there is no ideal construct for syndesmotic fracture stabilization; however, these fractures should be fixed using a device that allows for sufficient motion in the syndesmosis. In general, orthopaedic surgeons should select a fracture fixation construct that restores stability and promotes healing at the fracture site, while reducing the potential for fixation failure.

  18. Comparison of outcome of tibial plafond fractures managed by hybrid external fixation versus two-stage management with final plate fixation

    PubMed Central

    Cisneros, Luis Natera; Gómez, Mireia; Alvarez, Carlos; Millán, Angélica; De Caso, Julio; Soria, Laura

    2016-01-01

    Background: Tibial platfond fractures are usually associated with massive swelling of the foot and ankle, as well as with open wounds. This swelling may cause significant decrease of the blood flow, so the state of the soft tissue is determinant for the surgical indication and the type of implant. This retrospective study compares the union times in cases of tibial plafond fractures managed with a hybrid external fixation as a definitive procedure versus those managed with a two stage strategy with final plate fixation. Materials and Methods: A retrospective study in a polytrauma referral hospital was performed between 2005 and 2011. Patients with a tibial plafond fracture, managed with a hybrid external fixation as a definitive procedure or managed with a two stage strategy with the final plate fixation were included in the study. Postoperative radiographs were evaluated by two senior surgeons. Fracture healing was defined as callus bridging of one cortex, seen on both lateral and anteroposterior X-ray. The clinical outcome was evaluated by means of 11 points Numerical Rating Scale for pain and The American Orthopedic Foot and Ankle Society ankle score, assessed at the last followup visit. Thirteen patients had been managed with a hybrid external fixation and 18 with a two-stage strategy with the final plate fixation. There were 14 males and 17 females with a mean age of 48 years (range 19–82 years). The mean followup was 24 months (range 24–70 months). Results: The mean time from surgery to weight bearing was 7 ± 6.36 days for the hybrid fixation group and 57.43 ± 15.46 days for the plate fixation group (P < 0.0001); and the mean time from fracture to radiological union was 133.82 ± 37.83) and 152.8 ± 72.33 days respectively (P = 0.560). Conclusion: Besides the differences between groups regarding the baseline characteristics of patients, the results of this study suggest that in cases of tibial plafond fractures, the management with a hybrid external

  19. Fixation of Intertrochanteric Valgus Osteotomy with T Plate in Treatment of Developmental Coxa Vara

    PubMed Central

    Khairy, Hosam Mohamed

    2016-01-01

    Background Although the valgus subtrochanteric osteotomy is considered as a standard surgical treatment for coxa vara, there is no consensus on the optimal method of fixation and osteotomy technique. Fixation of the osteotomy has been achieved by various methods including external fixation and internal fixation with pins and cerclage and a variety of plates. The aim of this study is the evaluation of the results of developmental coxa treated by Y intertrochanteric valgus osteotomy fixed with a T-buttress plate compared with other methods of fixation in the literature. Methods Eighteen corrective valgus intertrochanteric femoral osteotomies were performed in 18 patients (18 hips) for treatment of unilateral developmental coxa vara deformity and fixed with a T plate. There were 12 males and 6 females. The right hip was affected in 10 patients and the left hip in 8 patients. Clinically, patients were evaluated by Larson hip score. Radiographically, anteroposterior view of the pelvis and frog leg lateral views of the affected hip were taken preoperatively and compared with the findings at the final follow-up. Results The average follow-up was 29 months (range, 24 to 36 months). Clinical results showed improvement of the mean Larson hip score from 57.8 to 97.0 (p < 0.001). Radiological results showed that all osteotomies were completely united in 2.4 months (range, 2 to 3 months) with the achievement of the planned correction angle. The average correction of Hilgenreiner's epiphyseal angle improved from 78.2° to 27.8° (p < 0.001) at the final follow-up. The femoral neck shaft angle was improved from 93.7° to 129.9° (p < 0.001) at the final follow-up. Shortening of the affected limb was corrected from 2.8 cm to 1.3 cm (p < 0.001) at the last follow-up. No major serious complications were recorded in the present study. Conclusions Intertrochanteric valgus osteotomy of the proximal femur fixed with a T plate may be efficient for treatment of developmental coxa vara

  20. Biomechanical comparison of straight and helical compression plates for fixation of transverse and oblique bone fractures: Modeling and experiments.

    PubMed

    Sezek, Sinan; Aksakal, Bunyamin; Gürger, Murat; Malkoc, Melih; Say, Y

    2016-08-12

    Total deformation and stability of straight and helical compression plates were studied by means of the finite element method (FEM) and in vitro biomechanical experiments. Fixations of transverse (TF) and oblique (45°) bone (OF) fractures have been analyzed on sheep tibias by designing the straight compression (SP) and Helical Compression Plate (HP) models. The effects of axial compression, bending and torsion loads on both plating systems were analyzed in terms of total displacements. Numerical models and experimental models suggested that under compression loadings, bone fracture gap closures for both fracture types were found to be in the favor of helical plate designs. The helical plate (HP) fixations provided maximum torsional resistance compared to the (SP) fixations. The fracture gap closure and stability of helical plate fixation for transverse fractures was determined to be higher than that found for the oblique fractures. The comparison of average compression stress, bending and torsion moments showed that the FEM and experimental results are in good agreement and such designs are likely to have a positive impact in future bone fracture fixation designs.

  1. Biomechanical comparison of straight and helical compression plates for fixation of transverse and oblique bone fractures: Modeling and experiments.

    PubMed

    Sezek, Sinan; Aksakal, Bunyamin; Gürger, Murat; Malkoc, Melih; Say, Y

    2016-08-12

    Total deformation and stability of straight and helical compression plates were studied by means of the finite element method (FEM) and in vitro biomechanical experiments. Fixations of transverse (TF) and oblique (45°) bone (OF) fractures have been analyzed on sheep tibias by designing the straight compression (SP) and Helical Compression Plate (HP) models. The effects of axial compression, bending and torsion loads on both plating systems were analyzed in terms of total displacements. Numerical models and experimental models suggested that under compression loadings, bone fracture gap closures for both fracture types were found to be in the favor of helical plate designs. The helical plate (HP) fixations provided maximum torsional resistance compared to the (SP) fixations. The fracture gap closure and stability of helical plate fixation for transverse fractures was determined to be higher than that found for the oblique fractures. The comparison of average compression stress, bending and torsion moments showed that the FEM and experimental results are in good agreement and such designs are likely to have a positive impact in future bone fracture fixation designs. PMID:27567775

  2. 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

  3. A C1-2 locked facet in a child with atlantoaxial rotatory fixation. Case report.

    PubMed

    Missori, Paolo; Miscusi, Massimo; Paolini, Sergio; DiBiasi, Claudio; Finocchi, Vannina; Peschillo, Simone; Delfini, Roberto

    2005-12-01

    Conservative treatment is reported in a child with atlantoaxial rotatory fixation. Three-dimensional (3D) computerized tomography (CT) and magnetic resonance (MR) imaging demonstrated the degree of dislocation and alar ligament damage. A rigid cervical collar and muscle relaxant agents without any traction allowed full recovery. Control 3D CT scanning and MR imaging findings are reported.

  4. Conceptual finite element study for comparison among superior, anterior, and spiral clavicle plate fixations for midshaft clavicle fracture.

    PubMed

    Huang, Teng-Le; Chen, Wen-Chuan; Lin, Kun-Jhih; Tsai, Cheng-Lun; Lin, Kang-Ping; Wei, Hung-Wen

    2016-10-01

    Open reduction internal fixation technique has been generally accepted for treatment of midshaft clavicle fractures. Both superior and anterior clavicle plates have been reported in clinical or biomechanical researches, while presently the spiral clavicle plate design has been introduced improved biomechanical behavior over conventional designs. In order to objectively realize the multi-directional biomechanical performances among the three geometries for clavicle plate designs, a current conceptual finite element study has been conducted with identical cross-sectional features for clavicle plates. The conceptual superior, anterior, and spiral clavicle plate models were constructed for virtual reduction and fixation to an OTA 15-B1.3 midshaft transverse fracture of clavicle. Mechanical load cases including cantilever bending, axial compression, inferior bending, and axial torsion have been applied for confirming the multi-directional structural stability and implant safety in biomechanical perspective. Results revealed that the anterior clavicle plate model represented lowest plate stress under all loading cases. The superior clavicle plate model showed greater axial compressive stiffness, while the anterior clavicle plate model performed greater rigidity under cantilever bending load. Three model represented similar structural stiffness under axial torsion. Played as a transition structure between superior and anterior clavicle plate, the spiral clavicle plate model revealed comparable results with acceptable multi-directional biomechanical behavior. The concept of spiral clavicle plate design is worth considering in practical application in clinics. Implant safety should be further investigated by evidences in future mechanical tests and clinical observations. PMID:27423702

  5. Inherent Strength of the osteo-WEDGE(™) Bone Plate Locking System for Arthrodesis of the First Metatarsocuneiform Joint: A Biomechanical Study.

    PubMed

    Graham, Michael E; Chikka, Avanthi; Goel, Vijay K

    2016-01-01

    First metatarsocuneiform joint arthrodesis with a locking bone plate and screw system has been effectively used to correct metatarsus primus varus and instability of the first ray. The goal of the present cadaveric biomechanical study was to quantify and compare the inherent strength of the first metatarsocuneiform joint and surrounding bones fixated with the osteo-WEDGE(™) bone plate locking system (OW) with that of intact specimens. Fourteen fresh-frozen adult human cadaveric foot specimens consisting of the first metatarsal and medial cuneiform bones with intact joint capsules and ligaments were used. The OW was implanted in 7 of these specimens at the first metatarsal cuneiform joint (MCJ), and the remaining 7 specimens were left intact. Each of the specimens was then subjected to axial force to simulate dorsiflexion of the first metatarsal using a cantilever bending test setup. Load was applied on the plantar aspect of the first metatarsal head until failure of the construct. The mean load and bending moment on the first MCJ at failure for the implanted specimens were 119.98 ± 56.76 N and 5.57 ± 2.71 Nm, respectively. For the intact specimens, the mean load and bending moment on the first MCJ at failure were 107.93 ± 60.90 N and 6.07 ± 3.18 Nm, respectively. None of the specimens showed catastrophic failure within the physiologic loading limits. These results imply that the mechanical strength of the OW is comparable to that of intact specimens. Thus, the first MCJ and surrounding bones fixated with an OW should be able to effectively withstand the vertical ground reaction forces the same as intact specimens. PMID:26884262

  6. Opening wedge osteotomies for correction of hallux valgus: a review of wedge plate fixation.

    PubMed

    Smith, W Bret; Hyer, Christopher F; DeCarbo, William T; Berlet, Gregory C; Lee, Thomas H

    2009-12-01

    Osteotomy of the proximal metatarsal for the correction of moderate to severe hallux valgus deformity is commonly performed. The purpose of this study is to review the early results of a technique for the correction of hallux valgus, an opening wedge osteotomy of the proximal first metatarsal with opening wedge plate fixation. A review was performed of the results of 47 patients (49 feet) who underwent correction of hallux valgus with proximal metatarsal opening wedge osteotomy. All osteotomies were secured with plate fixation on the medial side. Evaluation consisted of preoperative and postoperative radiographic as well as clinical evaluations. Mean corrections of 7 degrees were achieved for the 1-2 intermetatarsal angles. Fourteen complications occurred, 6 of which involved mild hardware irritation and did not affect outcome. Four nonunions or delayed unions were identified. The authors find the opening wedge osteotomy of the proximal first metatarsal to be a technically straightforward procedure for correcting moderate to severe hallux valgus. The correction obtained is comparable to other described techniques. PMID:20400425

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

    PubMed Central

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

    2015-01-01

    Plate fixation remains one of the most popular surgical procedures for treating proximal humeral fractures (PHFx); however, substantial rates of complications have been reported in the literature. The objectives of the study were to examine how medial calcar support (MCS) affects the radiographic outcomes and to determine the prognostic factors predicting treatment failure. We performed a retrospective cohort study of 89 adult patients who had PHFx and were treated with plate fixation at our institution in 2007–2011. The enrolled patients were separated into two groups according to disruption of medial calcar. Our results revealed an increased rate of poor radiographic outcomes in patients with disrupted medial calcar. Osteonecrosis of the humeral head and redisplacement were the two radiographic outcomes which had a positive causality with disruption of medial calcar (P = 0.008 and 0.050, resp.). Deficient medial calcar, inadequate reduction, diabetes mellitus, chronic kidney disease, and chronic liver disease were all significant predictors for the development of osteonecrosis in patients after PHFx surgery. Inadequate reduction was also a predictor for redisplacement. We confirmed that the restoration of medial calcar as well as comorbid conditions plays key roles in treatment of patients having PHFx with disrupted medial calcar. PMID:25692132

  8. Biomechanical Study of the Fixation Strength of Anteromedial Plating for Humeral Shaft Fractures

    PubMed Central

    Zheng, Yin-Feng; Zhou, Jun-Lin; Wang, Xiao-Hong; Shan, Lei; Liu, Yang

    2016-01-01

    Background: Open reduction and internal fixation with plate and screws are the gold standard for the surgical treatment of humeral shaft fractures, this study was to compare the mechanical properties of anteromedial, anterolateral, and posterior plating for humeral shaft fractures. Methods: A distal third humeral shaft fracture model was constructed using fourth-generation sawbones (#3404, composite bone). A total of 24 sawbones with a distal third humeral shaft fracture was randomly divided into three Groups: A, B, and C (n = 8 in each group) for anteromedial, anterolateral, and posterior plating, respectively. All sawbones were subjected to horizontal torsional fatigue tests, horizontal torsional and axial compressive fatigue tests, four-point bending fatigue tests in anteroposterior (AP) and mediolateral (ML) directions and horizontal torsional destructive tests. Results: In the horizontal torsional fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 6.12°, 6.53°, and 6.81°. In horizontal torsional and axial compressive fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 5.66°, 5.67°, and 6.36°. The mean plate displacement amplitude was 0.05 mm, 0.08 mm, and 0.10 mm. Group A was smaller than Group C (P < 0.05). In AP four-point bending fatigue tests, the mean plate displacement amplitude was 0.16 mm, 0.13 mm, and 0.20 mm. Group B was smaller than Group C (P < 0.05). In ML four-point bending fatigue tests, the mean plate displacement amplitude were 0.16 mm, 0.19 mm, and 0.17 mm. In horizontal torsional destructive tests, the mean torsional rigidity in Groups A, B, and C was 0.82, 0.75, and 0.76 N·m/deg. The yielding torsional angle was 24.50°, 25.70°, and 23.86°. The mean yielding torque was 18.46, 18.05, and 16.83 N·m, respectively. Conclusions: Anteromedial plating was superior to anterolateral or posterior plating in all mechanical tests except in AP four-point bending fatigue tests compared to the

  9. Mid-Calcaneal Length After Evans Calcaneal Osteotomy: A Retrospective Comparison of Wedge Locking Plates and Tricortical Allograft Wedges.

    PubMed

    Protzman, Nicole M; Wobst, Garrett M; Storts, Eric C; Mulhern, Jennifer L; McCarroll, Raymond E; Brigido, Stephen A

    2015-01-01

    Evans calcaneal osteotomy remains a cornerstone in the correction of the flexible flatfoot. Although multiple techniques have been used to maintain the length of the lateral column, a low profile wedge locking plate was recently introduced as an alternative to the traditional tricortical allograft wedge. We hypothesized that the wedge locking plate would better maintain the mid-calcaneal length compared with the tricortical allograft wedge. To test this hypothesis, after Evans osteotomy, the mid-calcaneal length was measured in the immediate postoperative period and again at 3 and 6 months. A total of 24 patients met the inclusion criteria. The mean patient age was 48.1 years (range 11 to 66). Of the 24 patients, 9 (37.5%) were treated with a tricortical allograft wedge and 15 (62.5%) with a wedge locking plate. At 3 months postoperatively, the mean decrease in mid-calcaneal length was similar for the tricortical allograft wedge group (1.3 ± 1.9 mm) and the wedge locking plate group (0.5 ± 0.9 mm, p = .275). At 6 months postoperatively, however, the mean decrease in mid-calcaneal length was greater for the tricortical allograft wedge group (2.8 ± 1.7 mm) than for the wedge locking plate group (0.6 ± 0.7 mm, p = .004). The 2 groups demonstrated a similar incidence of dorsally displaced distal calcaneal fragments throughout the study endpoint (p ≥ .052). These results suggest that the wedge locking plate better maintains the mid-calcaneal length over time compared with the tricortical allograft wedge.

  10. Plate selection for fixation of extra-articular distal humerus fractures: a biomechanical comparison of three different implants.

    PubMed

    Scolaro, John A; Hsu, Jason E; Svach, David J; Mehta, Samir

    2014-12-01

    Operative fixation of extra-articular distal humerus using a single posterolateral column plate has been described but the biomechanical properties or limits of this technique is undefined. The purpose of this study was to evaluate the mechanical properties of distal humerus fracture fixation using three standard fixation constructs. Two equal groups were created from forty sawbones humeri. Osteotomies were created at 80mm or 50mm from the tip of the trochlea. In the proximal osteotomy group, sawbones were fixed with an 8-hole 3.5mm LCP or with a 6-hole posterolateral plate. In the distal group, sawbones were fixed with 9-hole medial and lateral 3.5mm distal humerus plates and ten sawbones were fixed with a 6-hole posterolateral plate. Biomechanical testing was performed using a servohydraulic testing machine. Testing in extension as well as internal and external rotation was performed. Destructive testing was also performed with failure being defined as hardware pullout, sawbone failure or cortical contact at the osteotomy. In the proximal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than with the 3.5mm LCP. In the distal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than the 3.5mm LCP. In extension testing, the yield strength was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. The yield strength of specimens in axial torsion was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. Limited biomechanical data to support the use of a pre-contoured posterolateral distal humerus LCP for fixation of extra-articular distal humerus exists. We have found that this implant provided significantly greater

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

    PubMed Central

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

    2013-01-01

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

  12. Treatment of Humeral Shaft Fractures: Minimally Invasive Plate Osteosynthesis Versus Open Reduction and Internal Fixation

    PubMed Central

    Esmailiejah, Ali Akbar; Abbasian, Mohammad Reza; Safdari, Farshad; Ashoori, Keyqobad

    2015-01-01

    Background: The optimal technique for operative fixation of humeral shaft fractures remains controversial and warrants research. Objectives: The purpose of the current study was to compare the functional and clinical outcomes of conventional open reduction and internal fixation (ORIF) with minimally invasive plate osteosynthesis (MIPO) in patients with fractures in two-third distal humeral shaft. Patients and Methods: In the current prospective case-control study, 65 patients with humeral shaft fractures were treated using ORIF (33 patients) or MIPO (32 patients). Time of surgery, time of union, incidence of varus deformity and complications were compared between the two groups. Also, the university of California-Los Angeles (UCLA) shoulder rating scale and Mayo Elbow performance score (MEPS) were used to compare the functional outcomes between the two groups. Results: The median of union time was shorter in the MIPO group (4 months versus 5 months). The time of surgery and functional outcomes based on the UCLA and MEPS scores were the same. The incidence of varus deformity was more than 5° and was higher and the incidence of nonunion, infection and iatrogenic radial nerve injury were lower in the MIPO group; however, the differences were not significant. Conclusions: Due to the shorter union time, to some extent less complication rate and comparable functional and clinical results, the authors recommend to use the MIPO technique in treating the mid-distal humeral shaft fracture. PMID:26543844

  13. First metatarsophalangeal arthrodesis: a biomechanical comparison of three fixation constructs.

    PubMed

    Foote, Kristopher M; Teasdall, Robert D; Tanaka, Martin L; Scott, Aaron T

    2012-01-01

    First metatarsophalangeal joint arthrodesis is utilized in the treatment of severe arthritis and hallux valgus. Successful fusion relies on limiting motion at the fusion site and may be achieved through numerous methods. Use of locking plates has recently generated considerable interest, but whether they provide any biomechanical advantage over other available constructs is unclear. Utilizing cyclic loading intended to mimic early weight bearing, the stiffness of three fixation methods for first metatarsophalangeal arthrodesis was compared using Sawbones. The one-third tubular plate completed 1.8 and 2.4 times more cycles before failure than the X-type locking plate or crossed screws, respectively. No difference was detected in cycles to failure between the X-type locking plate and crossed screws. One-third tubular plate mean stiffness was 49% greater than crossed screws at all cycles and greater than X-type locking plate by an average of 25%, beginning at cycle 50.

  14. Biomechanical comparison of three fixation techniques used for four-corner arthrodesis.

    PubMed

    Kraisarin, J; Dennison, D G; Berglund, L J; An, K N; Shin, A Y

    2011-09-01

    Clinical results following four-corner arthrodesis vary and suggest that nonunion may be related to certain fixation techniques. The purpose of our study was to examine the displacement between the lunate and capitate following a simulated four-corner arthrodesis with the hypothesis that three types of fixation (Kirschner wires, dorsal circular plate, and a locked dorsal circular plate) would allow different amounts of displacement during simulated wrist flexion and extension. Cadaver wrists with simulated four-corner arthrodeses were loaded cyclically either to implant failure or until the lunocapitate displacement exceeded 1 mm. The locked dorsal circular plate group was significantly more stable than the dorsal circular plate and K-wire groups (p = 0.018 and p = 0.006). While these locked dorsal circular plates appear to be very stable our results are limited only to the biomechanical behavior of these fixation techniques within a cadaver model. PMID:21636620

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

    PubMed Central

    2013-01-01

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

  16. In vivo biomechanical evaluation of nail-plate fixation of femoral neck fractures of rehabilitated patients.

    PubMed

    Mizrahi, J; Kantarovski, A; Najenson, T; Susak, Z

    1985-01-01

    A major advantage of internal fixation of intertrochanteric fractures is that it can normally be followed by early and fast rehabilitation of the patient, finding expression in weight bearing and locomotion abilities of the patients. Complications which nevertheless occur, are mostly of mechanical origin. The purpose of our study was to evaluate the biomechanical performance of rehabilitated patients treated with four different types of nail-plates. Forty nine patients (12 men and 37 women) with walking ability, and with an average age of 70.5 years, were tested on a 10 m walkway, instrumented for the monitoring of the time distance parameters of the stride. This method of evaluation is especially suitable for pathological gait, free or supported, as it does not impose any constraints on the natural and individual walking trend of the patient. The average time elapsed between the actual fracture and the locomotor test was 764 days, implying that the investigated patients formed a homogeneous, well-rehabilitated group. The main average stride results were as follows: contact time 1.25 sec, double contact time 0.41 sec, stride length 68.2 cm, velocity 51.39 cm/sec and symmetry 0.51. No significant differences were found in these parameters between the subgroups of patients using different nail-plates. These results show that while the biomechanical performance of the patients with their implants was satisfactory (good walking symmetry) this group can be characterized by its smaller stride and slower gait, compared to those of a healthy population of the same age.

  17. Endovascular treatment of anterior tibial artery pseudoaneurysm following locking compression plating of the tibia.

    PubMed

    van Hensbroek, P Boele; Ponsen, K J; Reekers, J A; Goslings, J C

    2007-04-01

    Less invasive surgery and interventional radiology are relatively new techniques. This case report describes a patient with a distal tibial fracture that was stabilized using minimally invasive osteosynthesis consisting of a precontoured metaphyseal Locking Compression Plate (LCP). Postoperative radiographs showed good alignment of the bone, and the initial postoperative course was uneventful. At the sixth-week follow-up visit after surgery, the patient presented with a pulsating and tender mass on the lower leg that was palpable subcutaneously. Arteriography showed a pseudoaneurysm of the anterior tibial artery. At the same procedure an endovascular stent was placed, thereby excluding the pseudoaneurysm from the main circulation while keeping the vessel lumen patent. At the time of the last visit, 6 months after the operation, the patient was fully weightbearing with normal function of the ankle but with a nonhealing fracture on the x-ray. The dorsalis pedis pulse was equally strong as on the right side. Endovascular treatment with a covered stent proved to be an effective treatment for the described posttraumatic pseudoaneurysm of the anterior tibial artery. This case illustrates a risk of less invasive fracture surgery and at the same time underlines the value of a multidisciplinary approach to complications in trauma surgery. PMID:17414557

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  19. Retrospective study of two fixation methods for 4-corner fusion: Shape-memory staple vs. dorsal circular plate.

    PubMed

    Le Corre, A; Ardouin, L; Loubersac, T; Gaisne, E; Bellemère, P

    2015-12-01

    The purpose of this study was to compare the results of two groups of patients with four-corner fusion, one group fixed with shape-memory staples and the other with locked circular plates. This retrospective study compared 52 wrists operated for scaphoid excision and four-corner fusion between 2005 and 2011. The arthrodesis was ensured by a shape-memory quadripodal staple (4Fusion(®), Memometal™) in 37 cases and a locking dorsal circular plate (Xpode(®), Biotech Ortho™) in 15 cases. In the staple group, the mean age was 58.5 years and the average follow-up was 4.3 years. In the circular plate group, the mean age was 58.6 years and the average follow-up was 3.1 years. Pain, range of motion, grip strength, functional scores (QuickDASH and PWRE), fusion of the midcarpal joint, complications (implant fracture and reoperation) and patients' satisfaction were used as outcome measures. There was no pain in 43% of patients in the staple group and 40% of patients in the circular plate group at the follow-up; range of motion and functional scores were similar in both groups. Seventy-five percent of patients in the staple group were satisfied or very satisfied versus 60% in the circular plate group. The implant broke in 24.3% of cases in the staple group and 60% in the circular plate group. Reoperation was needed in 18% of the staple cases and 14% of the plate cases. There was no difference between the implants in terms of pain, range of motion, functional scores and patient satisfactory. The implant fracture rate in the plate group was high. This study brings into question implant reliability for the four-corner fusion procedure.

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

    PubMed

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

    2013-10-01

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

  1. Biomechanical study in polyurethane mandibles of different metal plates and internal fixation techniques, employed in mandibular angle fractures.

    PubMed

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

    2014-11-01

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

  2. Distal third humeri fractures treated using the Synthes™ 3.5-mm extra-articular distal humeral locking compression plate: clinical, radiographic and patient outcome scores

    PubMed Central

    Lewis, James; Rao, Prasad; Parfitt, Dan; Mohanty, Khitish; Ghandour, Adel

    2014-01-01

    Background Conventional management protocols for distal humeral extra-articular fractures (e.g. conservative, double columnar plating) are often associated with complications. We aimed to describe our experience of using the Synthes™ 3.5-mm extra-articular distal humeral locking compression plate for treatment of extra-articular distal humeral fractures. Methods We prospectively studied 23 consecutive patients who underwent fixation, in a tertiary trauma centre, over 2 years. Data, including patient demographics, duration of follow-up, patient satisfaction, visual analogue score (VAS), Oxford Elbow Score, and final outcome on discharge, were collected and analyzed. Results Of the 23 patients (12 males, 11 females; mean age 47.5 years; range 18 years to 89 years), all fractures united radiologically and clinically after the index procedure, with a mean time to fracture union of 15.7 weeks (range 9 weeks to 34 weeks) and a mean time to discharge of 17.8 weeks (range 13 weeks to 34 weeks). Oxford Elbow Score was 36.5 (range 11 to 48) at 4.6 months postoperatively; at 20 months follow-up, it was 40 (range 14 to 48) and the VAS was 8.5 (range 5 to 10). One patient had radial nerve neuropraxia pre-operatively, and one postoperatively, and both recovered uneventfully 3 months postoperatively. Neither superficial, nor deep infections were observed in this cohort. Conclusions The present study reports satisfactory outcome with the usage of the Synthes plate for extra-articular fracture management. It has become the technique of choice in our centre because it provides excellent results. PMID:27582964

  3. A Novel Murine Model of Established Staphylococcal Bone Infection in the Presence of a Fracture Fixation Plate to Study Therapies Utilizing Antibiotic-laden Spacers after Revision Surgery

    PubMed Central

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

    2014-01-01

    Mice are the small animal model of choice in biomedical research due to the low cost and availability of genetically engineered lines. However, the devices utilized in current mouse models of implant-associated bone infection have been limited to intramedullary or trans-cortical pins, which are not amenable to treatments involving extensive debridement of a full-thickness bone loss and placement of a segmental antibiotic spacer. To overcome these limitations, we developed a clinically faithful model that utilizes a locking fracture fixation plate to enable debridement of an infected segmental bone defect (full-thickness osteotomy) during a revision surgery, and investigated the therapeutic effects of placing an antibiotic-laden spacer in the segmental bone defect. To first determine the ideal time point for revision following infection, a 0.7 mm osteotomy in the femoral mid-shaft was stabilized with a radiolucent PEEK fixation plate. The defect was inoculated with bioluminescent Staphylococcus aureus, and the infection was monitored over 14 days by bioluminescent imaging (BLI). Osteolysis and reactive bone formation were assessed by X-ray and micro-computed tomography (micro-CT). The active bacterial infection peaked by 5 days post-inoculation, however the stability of the implant fixation became compromised by 10–14 days post-inoculation due to osteolysis around the screws. Thus, day 7 was defined as the ideal time point to perform the revision surgery. During the revision surgery, the infected tissue was debrided and the osteotomy was widened to 3 mm to place a poly-methyl methacrylate spacer, with or without vancomycin. Half of the groups also received systemic vancomycin for the remaining 21 days of the study. The viable bacteria remaining at the end of the study were measured using colony forming unit assays. Volumetric bone changes (osteolysis and reactive bone formation) were directly measured using micro-CT image analysis. Mice that were treated with

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

    PubMed Central

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

    2015-01-01

    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

  5. 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.

  6. Internal fixation of fractures of the shaft of the humerus by dynamic compression plate or intramedullary nail: A prospective study

    PubMed Central

    Raghavendra, S; Bhalodiya, Haresh P

    2007-01-01

    Background: The indications for surgical management of fractures of the shaft of the humerus are clear, but selecting the right implant for internal fixation of humeral fractures has been a dilemma. Materials and Methods: Thirty-six patients (mean age 40.53 years) with fractures of the shaft of the humerus were followed for 12 to 24 months in a prospective study. Eighteen patients each underwent open reduction and internal fixation with compression plating and ante grade interlock nailing. Clinical and radiographic outcome measures included fracture healing, shoulder and elbow functions, need for additional procedures and any complication such as infection and recovery of radial nerve palsy. The results were analyzed statistically using the SPSS 11.5 software, with parametric and nonparametric tests. Results: Nine of the fractures treated with compression plating and seven of those treated with interlock nailing achieved union within six months. Though there was no significant difference in union time between the treatment groups, patients operated with interlock nailing underwent more number of secondary bone grafting procedures to obtain union (six against two). There were 12 patients (66.6%) with excellent and good results in the plating group compared to four patients (25%) in the nailing group. Interlock nailing was associated with significant reduction in shoulder function (P=0.03) and in overall results (P=0.02). Conclusion: Though there was no significant difference between plating or nailing in terms of time to union, compression plating is the preferred method in the majority of fractures of the shaft of the humerus with better preservation of joint function and lesser need for secondary bone grafting for union. PMID:21139747

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

    PubMed Central

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

    2013-01-01

    Aims: One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. Materials and Methods: A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. Results: The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P < 0.01). Discussion: To our knowledge, there are no studies in literature that show the causes of coracoid bone graft osteolysis after Latarjet procedure. Conclusion: Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level of Evidence: Level 4. Clinical Relevance: Prospective case series, Treatment study. PMID:23858288

  8. Computer-assisted preoperative simulation for positioning of plate fixation in Lefort I osteotomy: A case report.

    PubMed

    Suenaga, Hideyuki; Taniguchi, Asako; Yonenaga, Kazumichi; Hoshi, Kazuto; Takato, Tsuyoshi

    2016-06-01

    Computed tomography images are used for three-dimensional planning in orthognathic surgery. This facilitates the actual surgery by simulating the surgical scenario. We performed a computer-assisted virtual orthognathic surgical procedure using optically scanned three-dimensional (3D) data and real computed tomography data on a personal computer. It helped maxillary bone movement and positioning and the titanium plate temporary fixation and positioning. This simulated the surgical procedure, which made the procedure easy, and we could perform precise actual surgery and could forecast the postsurgery outcome. This simulation method promises great potential in orthognathic surgery to help surgeons plan and perform operative procedures more precisely.

  9. The use of a T-shaped contoured unilocking titanium radial plate for prophylactic internal fixation of the radial osteocutaneous donor site.

    PubMed

    Avery, C M E; Parmar, S; Martin, Tim

    2010-12-01

    The radial osteocutaneous flap retains a limited role in reconstructive maxillofacial surgery The application of prophylactic internal fixation, using straight 3.5 mm plates, has become established to substantially reduce the incidence of fracture at the radial donor site. New lower profile T-shaped 2.4 mm plates and anatomically contoured 3.5 mm plates are now available, both with unilocking screw fixation systems. These plates are easy to apply and allow the removal of up to 50% of the circumference of the radial bone, including the maximum amount of good quality bone from the distal radius. Although there have been no reports of complications as a result of a stress shielding effect with larger plates these refinements in plate design should lessen any remaining concerns.

  10. Serological diagnosis of brucellosis in water buffaloes (Bubalus bubalis): comparison among complement fixation, serum agglutination and rose bengal plate test.

    PubMed

    Mathias, L A; Pinto, A A

    1983-12-01

    The results of a comparative study among complement fixation (CFT), plate agglutination (PAT), tube agglutination (TAT) and Rose Bengal plate tests ( RBPT ) to the serodiagnosis of brucellosis in Indian buffaloes are reported. Sera from 212 buffaloes unvaccinated against brucellosis were examined and the CFT was able to reveal significant titres in sera with low agglutinating titres. From 109 sera which did not show agglutination titres in the PAT, four showed complement fixing titre greater than 1 in 200. All the positive sera to the RBPT gave complement fixing titre equal to or greater than 1 in 20. In sera that showed negative result to the RBPT the CFT was able to reveal relatively high titres. From 131 sera negative to the RBPT five showed complement fixing titres greater than 1 in 60.

  11. Radial shaft stress fracture after internal fixation using a titanium plate.

    PubMed

    Nagoshi, Narihito; Yamanaka, Kazuyoshi; Sasaki, Takashi

    2015-05-20

    A 22-year-old man, a boxer, presented with acute right forearm pain after striking a punch mitt. The patient had sustained a diaphyseal fracture of the right radius 19 months previously and was treated by minimally invasive plate osteosynthesis using a titanium reconstruction plate. Radiography revealed stress fractures beneath a proximal screw hole of the plate. The forearm was protected in a splint for 6 weeks and the fracture healed. Titanium plates are superior to stainless steel plates, due to various properties of titanium including corrosion resistance and biocompatibility. Removal of such plates is not routinely performed in our hospital, but plate removal may be warranted for patients who actively participate in certain sports.

  12. Intramedullary Nailing Versus Plate Fixation for the Treatment Displaced Midshaft Clavicular Fractures: A Systematic Review and Meta-Analysis

    PubMed Central

    Hussain, Nasir; Sermer, Corey; Prusick, Parker J.; Banfield, Laura; Atrey, Amit; Bhandari, Mohit

    2016-01-01

    The two commonly performed surgical techniques used to repair displaced midshaft clavicle fractures are plate fixation or intramedullary nailing; however, despite recent evidence, the optimal method to treat such fractures remains a continued topic of debate. A meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate long term function, complications, and operative duration in adult patients receiving intramedullary nailing in comparison to plating. Seven RCTs and three quasi-randomized trials were included. No significant difference was found in long-term function between the two groups (MD: −0.66, 95% CI: −2.03 to 0.71, I2 = 62%, p = 0.34). Patients who received plating had a 2.19 times increased risk of treatment failure, but this failed to reach significance (95% CI: 0.93 to 5.15, I2 = 0%, p = 0.07). The risk of non-operative complications was 2.11 times higher in patients who received plating and this reached statistical significance (95% CI: 1.38 to 3.23, I2 = 53%, p = 0.0006). Finally, plating significantly prolonged operative duration by 20.16 minutes (95% CI: 16.87 to 23.44, I2 = 56%, p < 0.00001). Our results suggest that intramedullary nailing and plating provide equivalent long-term functional outcomes; however, plating may lead to a higher risk of treatment failure and non-operative complications. PMID:27762393

  13. SURGICAL TREATMENT OF DISTAL RADIUS FRACTURES WITH A VOLAR LOCKED PLATE: CORRELATION OF CLINICAL AND RADIOGRAPHIC RESULTS

    PubMed Central

    Xavier, Claudio Roberto Martins; Dal Molin, Danilo Canesin; dos Santos, Rafael Mota Marins; dos Santos, Roberto Della Torre; Neto, Julio Cezar Ferreira

    2015-01-01

    Objectives: To analyze and correlate the clinical and radiographic results from patients with distal radius fractures who underwent surgical treatment with a fixed-angle volar locked plate. Methods: Sixty-four patients with distal radius fractures were evaluated. They all underwent surgical treatment with a volar locked plate for the distal radius, with a minimum of six months of postoperative follow-up. They underwent a physical examination that measured range of motion and grip strength, answered the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and underwent radiographic examination. Results: In the physical examination on the patients, all the range-of-motion measurements were reduced. Grip strength measured in kgf was on average 85.8% of the strength on the unaffected side. The mean DASH score was 15.99. A significant relationship was found between lower DASH scores and losses of extension and grip strength. On the radiographs, the mean values in relation to the unfractured side were 84.0% for radial inclination, 85.4% for radial length and 86.8% for volar deviation of the radius. Loss of radial length was correlated with losses of extension and grip strength. PMID:27027046

  14. PHILOS humerus plate for a distal tibial fracture.

    PubMed

    Twaij, Haider; Damany, Dev

    2013-01-04

    This report discusses the use of an alternative implant in the emergency fixation of a distal tibial fracture. We planned to fix the shear-type medial malleolar fracture in a closed, tri-malleolar fracture with a locking distal tibial plate. Intra-operatively, it was noted that the required plate was unavailable. A PHILOS humeral plate seemed to fit the contours of the distal tibia. The broad end of the PHILOS, when placed distally, gave options to place locking screws in the medial malleolar fragment. The fracture was stable after fixation. The patient made a full post-operative recovery and follow-up at 4 months was satisfactory. Despite adequate planning, there will be instances where one has to improvise. An understanding of the principles of fracture management can aid in finding solutions. PHILOS humeral plate may be used to stabilize a distal tibial fracture if an appropriate distal tibial locking plate is not available.

  15. 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. PMID:26167493

  16. Minimally invasive proximal interphalangeal joint arthrodesis using a locking compression plate and tissue engineering in horses: A pilot study

    PubMed Central

    Seo, Jong-pil; Yamaga, Takashi; Tsuzuki, Nao; Yamada, Kazutaka; Haneda, Shingo; Furuoka, Hidefumi; Tabata, Yasuhiko; Sasaki, Naoki

    2014-01-01

    This pilot study assessed the efficacy of 2 minimally invasive techniques for proximal interphalangeal (PIP) joint arthrodesis in horses. The PIP joints of both forelimbs (n = 6) were stabilized with locking compression plates (LCP) using a minimally invasive technique (LCP technique). Subsequently, for 1 randomly selected PIP joint of each horse, surgical drilling (SurD) was performed and tissue engineering (TE) was applied (LCP/SurD/TE technique). Minimally invasive PIP joint arthrodesis with LCP demonstrated low postoperative infection rates. Gross and histological evaluations revealed considerable destruction of the articular cartilage in the LCP/SurD/TE-treated joints. In contrast, almost no destruction of the cartilage was observed in the LCP-treated joints. Our results suggest that the LCP technique alone is not sufficient for PIP joint arthrodesis and that the LCP/SurD/TE technique may be useful for PIP joint arthrodesis in horses. PMID:25392547

  17. Lateral fixation of AO type-B2 ankle fractures in the elderly: the Knowles pin versus the plate

    PubMed Central

    Huang, Hui-Ling; Lo, Ting-Ying; Huang, Chien-Rae

    2006-01-01

    The study was a retrospective evaluation and comparison. Seventy-five elderly patients (>50 years) with AO type-B2 ankle fractures were treated by open reduction and internal fixation. All patients were followed up retrospectively for at least 12 months. The 75 patients were divided into two groups, based on the method of treatment. The Knowles pin (KP) group included 45 patients with an average age of 62.7 years. The tubular plate (TP) group included 30 patients with an average age of 60.0 years. The clinical results were compared between the two groups. Both of the groups were similar in respect to the injury mechanisms, fracture pattern, open fracture grade, compounding medical conditions, and ankle score (all P values <0.28). However, the KP group had significantly smaller wound incisions, shorter surgery time, shorter hospital stay, less meperidine use, less symptomatic hardware, and lower complication rates than the TP group (all P values <0.03). In conclusion, lateral fixation of AO type-B2 ankle fractures in the elderly by the Knowles pin is recommended due to its simplicity, efficacy and low complication rate. PMID:17043861

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

    PubMed

    Wang, Da-xing; Xiong, Ying; Deng, Hong; Jia, Fu; Gu, Shao; Liu, Bai-lian; Li, Qun-hui; Pu, Qi; Zhang, Zhong-Zi

    2014-09-01

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

  19. Compression-plate fixation of femoral shaft fractures in children aged 8 to 12 years.

    PubMed

    Fyodorov, I; Sturm, P F; Robertson, W W

    1999-01-01

    Twenty-one patients between the ages of 8 and 12 years with 23 femoral-shaft fractures underwent dynamic compression plating (DCP) between August 1993 and February 1996. Eleven patients had isolated femoral-shaft fractures, five had associated long-bone injuries, and five had multiple organ injuries. A 4.5-mm DCP plate was used in each case. Patients were kept non-weight bearing with crutches for an average of 8 weeks. Hardware failure occurred in two patients at 6 weeks. One was treated with revision plating, and the other, with spica casting. Both healed uneventfully. No other complications occurred. All patients were radiographically and clinically healed at last follow-up.

  20. Comparison of nail-plate fixation and Ender's nailing for intertrochanteric fractures.

    PubMed

    Hall, G; Ainscow, D A

    1981-02-01

    Two comparable groups of patients with fractures of the trochanteric region of the femur were studied. One hundred and sixty-five fractures had been fixed with conventional nail-plates and 132 with Ender's nails. Ender's nails gave superior results in the treatment of trochanteric fractures. The operation was quicker and less traumatic than that using conventional nail-plates and both the mortality rate and the time in hospital were reduced. More patients in the group with Ender's nails who were initially independent returned to an independent existence.

  1. Distal Radius Volar Rim Fracture Fixation Using DePuy-Synthes Volar Rim Plate.

    PubMed

    Kachooei, Amir Reza; Tarabochia, Matthew; Jupiter, Jesse B

    2016-03-01

    Background To assess the results of distal radius fractures with the involvement of the volar rim fixed with the DePuy-Synthes Volar Rim Plate. Case Description We searched for the patients with volar rim fracture and/or volar rim fractures as part of a complex fracture fixed with a volar rim plate. Ten patients met the inclusion criteria: three patients with type 23B3, six patients with type 23C, and one patient with very distal type 23A. The mean follow-up was 14 months (range: 2-26). Fractures healed in all patients. Of the three patients with isolated volar rim fractures (type 23B3), two patients had no detectable deficits in motion. These patients had an average Gartland and Werley score of 9 (range: 2-14). Of the other seven patients (six with type 23C and one with type 23A fracture), three patients healed with full range of motion and four had some deficits in range of motion. Two patients had excellent results, three had good results, and two had fair results using the Gartland and Werley categorical rating. One patient healed with a shortened radius and ulnar impingement requiring a second surgery for ulnar head resection arthroplasty. Literature Review Results after nonoperative treatment of volar rim fractures are not satisfactory and often require subsequent corrective osteotomy. Satisfactory outcomes are achieved when the fragments are well reduced and secured regardless of the device type. Clinical Relevance Volar rim plates give an adequate buttress of the volar radius distal to volar projection of the lunate facet and do not interfere with wrist mobility. Furthermore, the dorsal fragments can be fixed securely through the volar approach eliminating the need for a secondary posterior incision. However, patients should be informed of the potential problems and the need to remove the plate if symptoms develop.

  2. 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. PMID:26101659

  3. [Humerus varus: correction by proximal valgus osteotomy with precontourned plate fixation in children].

    PubMed

    Tallón-López, J; Domínguez-Amador, J J; Andrés-García, J A

    2014-01-01

    Varus deformity of the proximal humerus in children is a little known pathology due to its low incidence of presentation. Progress has been made in recent years in understanding the possible etiology and pathophysiological causes. Radiological criteria for diagnosis and functional impairment that occurs have also been defined. However, there are few reports in the literature about the surgical treatment of this deformity in children. In this paper we present a case of surgical treatment of this deformity by corrective osteotomy fixed with precontoured external maleolar plate osteosynthesis.

  4. Variation of plate fixation for mandibular advancement with intraoral vertical ramus osteotomy using endoscopically assisted intraoral rigid or semi-rigid internal fixation: Case series study: Postoperative condylar seating control for mandibular advancement.

    PubMed

    Hara, Shingo; Mitsugi, Masaharu; Tatemoto, Yukihiro

    2015-12-01

    The purpose of the present study was to evaluate the safety and efficacy associated with mandibular advancement by intraoral vertical ramus osteotomy (IVRO) with endoscopically assisted intraoral rigid or semi-rigid internal fixation. The study sample included all patients who had undergone an mandibular advancement by IVRO procedure with endoscopically assisted intraoral plate fixation from September 2008 to May 2012. An mandibular advancement by IVRO with endoscopically assisted intraoral rigid or semi-rigid internal fixation was used for mandibular advancement. The patients were analyzed prospectively, with more than 2 years of follow-up, and were evaluated in terms of functional results, postoperative complications, and skeletal stability. A total of 14 patients (bilateral, 7 patients with class II; unilateral, 7 patients with asymmetry) were included in the present study. The average degree of mandibular advancement was 5.5 ± 1.9 mm (range, 3-9 mm). Both the occlusal relationship and facial appearance in all patients were significantly improved by the surgical-orthodontic treatment, with no major harmful clinical symptoms. In addition, one-screw semi-rigid fixation could control postoperative passive condylar seating. This study showed that mandibular advancement by IVRO with endoscopically assisted, intraoral semi-rigid internal fixation offers a promising treatment alternative for patients with skeletal class II malocclusion or facial asymmetry. PMID:26610634

  5. The use of rigid internal fixation in the surgical management of cervical spondylosis.

    PubMed

    Kwon, Brian K; Vaccaro, Alexander R; Grauer, Jonathan N; Beiner, John M

    2007-01-01

    In the surgical management of cervical spondylosis, the application of rigid internal fixation can enhance the immediate stability of the cervical spine. The sophistication of such internal fixation systems and the indications for their use are continuously evolving. A sound understanding of regional anatomy, biomechanics, and kinematics within the cervical spine is essential for the safe and effective application of internal fixation. Numerous options currently exist for anterior cervical plating systems; some lock the screws to the plate rigidly (constrained), whereas others allow for some rotational or translational motion between the screw and plate (semiconstrained). The role of anterior fixation in single and multilevel fusions is still the subject of some controversy. Long anterior cervical reconstructions may require additional posterior fixation to reliably promote fusion. Rigid fixation in the posterior cervical spine can be achieved with lateral mass screws or pedicle screws. Although lateral mass screws provide excellent fixation within the subaxial cervical spine, the regional anatomy of C2 and C7 often make it difficult to place such screws, and pedicle screws at these levels are advocated. Pedicle screws achieve fixation into both the anterior and posterior column and are arguably the most stable form of rigid internal fixation within the cervical spine. Familiarity with these internal fixation techniques can be an extremely valuable tool for the spine surgeon managing these degenerative disorders of the cervical spine.

  6. Double plate fixation for correction of the malunited distal ulna fracture: a case report.

    PubMed

    Bessho, Yuki; Okazaki, Masato; Nakamura, Toshiyasu

    2011-01-01

    A 62-year-old woman visited our hospital one year after a motor vehicle accident complaining of ulnar wrist pain and restricted pronation and supination. Radiographs showed a 35° angular deformity at the ulnar neck. Closing wedge osteotomy was performed using two plates for stabilization. Twenty-four months postoperatively, the osteotomy site united without correction loss and the patient gained adequate pronation and supination. To the best of our knowledge, this represents the first report of corrective osteotomy for the treatment of malunited ulnar neck fracture. Although salvage operations such as ulnar head resection and the Sauvé-Kapandji procedure may provide reasonable results, anatomical repair can be considered as an option. PMID:22072470

  7. [Investigation on biomechanics behavior using three-dimensional finite element analysis for femur shaft fracture treated with locking compression plate].

    PubMed

    He, Qinli; Jiang, Wei; Luo, Jiaoming

    2014-08-01

    Based on the CT data and the structure characteristics of the femoral fractures during different healing stages, medical FE models of fractured femur treated with locking compression plate (LCP)were built. Under the physiological load of a standard body weight (70 kg) and the constraint condition, the stress distributions of LCP and fractured femur during healing were calculated by means of three-dimensional finite element analysis (3D-FEA). The results showed that the stress distribution in the LCP and the fractured femur was similar, during the initial stage which there was no newly formed bone or soft tissue in fracture site. The maximum von Mises stress (371.23,272.76 MPa) in the fractured femur was much higher than that in natural femur, and the intensive stress was concentrated mainly in the proximal area of the fractured femur. With the growth of bony callus bone in fracture site, the intensity of stress in proximal femur decreased. Contrasted to the two cases mentioned above, the value of the maximum von Mises stress (68. 17 MPa) in bony callus bone stage decreased significantly, and was lower than the safe strength of natural bone. Therefore, appropriate training which is benefitial for the growth to new bone could be arranged for the better rehabilitation.

  8. Open reduction and internal fixation of osteoporotic acetabular fractures through the ilio-inguinal approach: use of buttress plates to control medial displacement of the quadrilateral surface.

    PubMed

    Peter, Robin E

    2015-01-01

    The number of acetabular fractures in the geriatric population requiring open reduction and internal fixation is increasing. Fractures with medial or anterior displacement are the most frequent types, and via the ilio-inguinal approach buttress plates have proved helpful to maintain the quadrilateral surface or medial acetabular wall. Seven to ten hole 3.5 mm reconstruction plates may be used as buttress plates, placed underneath the usual pelvic brim plate. This retrospective study presents our results with this technique in 13 patients at a minimum follow-up of 12 months (average, 31 months). 85% of the patients had a good result. The early onset of post-traumatic osteoarthritis necessitated total hip arthroplasty in two patients (15%) at 12 and 18 months follow-up, respectively. This treatment option should be considered in the surgeon's armamentarium when fixing these challenging cases.

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

    PubMed

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

    2015-04-01

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

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

    PubMed

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

    2015-04-01

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

  11. [Theoretical analysis and numerical simulation of effect of steel plate positions on steel plate rigidity in internal fixation of bone surgery].

    PubMed

    Chen, Bingzhi; Gu, Yuanxian; Lü, Decheng; Lü, Xuemin

    2003-09-01

    In this study we calculate theoretically and use FEM to simulate the effect of plate position relative to bending direction on the overall bending stiffness of the composite system plate-bone. The results show that for different bending directions the effect of the modulus of elasticity of the plate is negligible. Changing the position of a plate will often alter the stress obviously. During the operation, the steel plate should be assigned onto the tension side of the bone. PMID:14565005

  12. Comparison of stability of 2.0 mm standard and 2.0 mm locking miniplate/screws for the fixation of sagittal split ramus osteotomy on sheep mandibles.

    PubMed

    Oguz, Yener; Saglam, Haci; Dolanmaz, Dogan; Uckan, Sina

    2011-03-01

    Ten unembalmed adult sheep mandibles were used. The mandibles were sectioned in the midline, followed by sagittal split ramus osteotomies to obtain 20 hemimandibles. Each distal segment was advanced 5mm on each hemimandible. Ten of the specimens were fixed with 4-hole extended 2.0 mm titanium miniplates and screws and the other 10 were fixed with 4-hole extended 2.0 mm locking miniplates/screws. Each fixed specimen was mounted on a servo-hydraulic testing unit with the fixation device, and was tested to a range of forces of 0-140 N. The displacement values (mm) under 20, 60, 120, and 140 N were compared with the help of the Mann-Whitney U-test, and there were no significant differences between them at any force tested. Locking miniplate/screws and standard miniplate/screws showed similar displacement values at the range of forces tested. PMID:20226575

  13. Plating of proximal humeral fractures.

    PubMed

    Martetschläger, Frank; Siebenlist, Sebastian; Weier, Michael; Sandmann, Gunther; Ahrens, Philipp; Braun, Karl; Elser, Florian; Stöckle, Ulrich; Freude, Thomas

    2012-11-01

    The optimal treatment for proximal humeral fractures is controversial. Few data exist concerning the influence of the surgical approach on the outcome. The purpose of this study was to evaluate the clinical and radiological outcomes of proximal humeral fractures treated with locking plate fixation through a deltopectoral vs an anterolateral deltoid-splitting approach. Of 86 patients who met the inclusion criteria, 70 were available for follow-up examination. Thirty-three patients were treated through a deltopectoral approach and 37 through an anterolateral deltoid-splitting approach. In all cases, open reduction and internal fixation with a PHILOS locking plate (Synthes, Umkirch, Germany) was performed. Clinical follow-up included evaluation of pain, shoulder mobility, and strength. Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score were assessed. A clinical neurological examination of the axillary nerve was also performed. Consolidation, reduction, and appearance of head necrosis were evaluated radiographically. After a mean follow-up of 33 months, Constant scores, DASH scores, and American Shoulder and Elbow Surgeons scores showed no significant differences between the groups. Clinical neurologic examination of the axillary nerve revealed no obvious damage to the nerve in either group. Deltopectoral and anterolateral detoid-splitting approaches for plate fixation of proximal humeral fractures are safe and provide similar clinical outcomes. The results of this study suggest that the approach can be chosen according to surgeon preference.

  14. Comparison of functional outcomes of total elbow arthroplasty vs plate fixation for distal humerus fractures in osteoporotic elbows.

    PubMed

    Egol, Kenneth A; Tsai, Peter; Vazques, Oscar; Tejwani, Nirmal C

    2011-02-01

    Treating intra-articular fractures about the osteoporotic distal humerus poses a significant challenge. The purpose of this retrospective study was to evaluate functional outcomes for distal humeral fractures treated with total elbow arthroplasty (TEA) or open reduction and internal fixation (ORIF) in a nonarthritic elderly population with osteoporosis. We reviewed the records of all women older than age 60 who had undergone surgical treatment for intraarticular distal humerus fractures (Orthopaedic Trauma Association types 13B and 13C) by 1 of 2 surgeons. Demographic and operative data were obtained, charts were reviewed, and patients were asked to have their outcomes evaluated with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the Mayo Elbow Performance Index (MEPI). Twenty-two patients (23 elbows) were identified, and 2 of these (3 elbows) were excluded. Of the remaining 20 patients, 9 had undergone cemented, semiconstrained TEA as initial treatment, and 11 had undergone ORIF. These 2 groups were compared. Mean follow-up was 14.8 months (range, 6-38 months). There were no significant differences between the TEA and ORIF groups with respect to demographic factors. Final elbow range of motion was 92° flexion-extension arc (arthroplasty group) and 98° (fixation group). Two patients in the arthroplasty group and 2 in the fixation group died. For the remaining patients, mean DASH scores were 30.2 (arthroplasty) and 32.1 (fixation), and mean MEPI scores were 79 (arthroplasty) and 85 (fixation). These differences were not statistically significant. Four TEAs developed radiographic loosening by a mean of 15 months, and 1 of these underwent revision with good outcome. Ten of the 11 fractures in the fixation group healed radiographically; the 1 nonunion with collapse continued to be asymptomatic. Two patients in the fixation group underwent contracture release after union for limited elbow range of motion. Many factors come into play in the

  15. Comparison of functional outcomes of total elbow arthroplasty vs plate fixation for distal humerus fractures in osteoporotic elbows.

    PubMed

    Egol, Kenneth A; Tsai, Peter; Vazques, Oscar; Tejwani, Nirmal C

    2011-02-01

    Treating intra-articular fractures about the osteoporotic distal humerus poses a significant challenge. The purpose of this retrospective study was to evaluate functional outcomes for distal humeral fractures treated with total elbow arthroplasty (TEA) or open reduction and internal fixation (ORIF) in a nonarthritic elderly population with osteoporosis. We reviewed the records of all women older than age 60 who had undergone surgical treatment for intraarticular distal humerus fractures (Orthopaedic Trauma Association types 13B and 13C) by 1 of 2 surgeons. Demographic and operative data were obtained, charts were reviewed, and patients were asked to have their outcomes evaluated with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the Mayo Elbow Performance Index (MEPI). Twenty-two patients (23 elbows) were identified, and 2 of these (3 elbows) were excluded. Of the remaining 20 patients, 9 had undergone cemented, semiconstrained TEA as initial treatment, and 11 had undergone ORIF. These 2 groups were compared. Mean follow-up was 14.8 months (range, 6-38 months). There were no significant differences between the TEA and ORIF groups with respect to demographic factors. Final elbow range of motion was 92° flexion-extension arc (arthroplasty group) and 98° (fixation group). Two patients in the arthroplasty group and 2 in the fixation group died. For the remaining patients, mean DASH scores were 30.2 (arthroplasty) and 32.1 (fixation), and mean MEPI scores were 79 (arthroplasty) and 85 (fixation). These differences were not statistically significant. Four TEAs developed radiographic loosening by a mean of 15 months, and 1 of these underwent revision with good outcome. Ten of the 11 fractures in the fixation group healed radiographically; the 1 nonunion with collapse continued to be asymptomatic. Two patients in the fixation group underwent contracture release after union for limited elbow range of motion. Many factors come into play in the

  16. The biomechanics of plate fixation of periprosthetic femoral fractures near the tip of a total hip implant: cables, screws, or both?

    PubMed

    Shah, S; Kim, S Y R; Dubov, A; Schemitsch, E H; Bougherara, H; Zdero, R

    2011-09-01

    Femoral shaft fractures after total hip arthroplasty (THA) remain a serious problem, since there is no optimal surgical repair method. Virtually all studies that examined surgical repair methods have done so clinically or experimentally. The present study assessed injury patterns computationally by developing three-dimensional (3D) finite element (FE) models that were validated experimentally. The investigation evaluated three different constructs for the fixation of Vancouver B1 periprosthetic femoral shaft fractures following THA. Experimentally, three bone plate repair methods were applied to a synthetic femur with a 5 mm fracture gap near the tip of a total hip implant. Repair methods were identical distal to the fracture gap, but used cables only (construct A), screws only (construct B), or cables plus screws (construct C) proximal to the fracture gap. Specimens were oriented in 15 degrees adduction to simulate the single-legged stance phase of walking, subjected to 1000 N of axial force, and instrumented with strain gauges. Computationally, a linearly elastic and isotropic 3D FE model was developed to mimic experiments. Results showed excellent agreement between experimental and FE strains, yielding a Pearson linearity coefficient, R2, of 0.92 and a slope for the line of best data fit of 1.06. FE-computed axial stiffnesses were 768 N/mm (construct A), 1023 N/mm (construct B), and 1102 N/mm (construct C). FE surfaces stress maps for cortical bone showed Von Mises stresses, excluding peaks, of 0-8 MPa (construct A), 0-15 MPa (construct B), and 0-20 MPa (construct C). Cables absorbed the majority of load, followed by the plates and then the screws. Construct A yielded peak stress at one of the empty holes in the plate. Constructs B and C had similar bone stress patterns, and can achieve optimal fixation. PMID:22070022

  17. Dynamic Hip Screw with Trochanteric Stablization Plate Fixation of Unstable Inter-Trochanteric Fractures: A Prospective Study of Functional and Radiological Outcomes

    PubMed Central

    Shetty, Ashwin; Sadasivan, Anand Kumar; Hegde, Anoop

    2016-01-01

    Introduction Management of unstable intertrochanteric fractures have posed a unique challenge to orthopaedicians over years. Several surgical techniques and implants have been developed for the same. Fractures of the lateral wall have been considered as the major cause of femoral medialization after fixation by Dynamic Hip Screw (DHS). Studies have shown that supplementation of trochanteric stabilization plate reduces the incidence of femoral medialization. Aim To assess the radiological union and hip function after fixation of unstable intertrochanteric fractures with DHS and Trochanteric Stabilization Plate (TSP). Materials and Methods A prospective study was conducted with a total of 32 patients between age groups of 30-70 years with Evan Jensen unstable and very unstable type of intertrochanteric fractures, between August 2013 to March 2015 in the Department of Orthopaedics ARS Hospital, Tirupur, Tamil Nadu, India. They underwent open reduction and DHS and TSP fixation. They were started on full weight bearing mobilization on post op day three. They were reviewed at post-op weeks 3,6,12 and 24. Hip mobilization and rehabilitation exercises were instituted during course of reviews. Radiographs were taken to assess fracture union and hip function was evaluated during follow-ups. At the end of 24 weeks, degree of radiographic union was scored as per Radiological Union Score for Hip (RUSH). Hip function was scored with Harris hip score. Analyses were done using frequency and proportions. Chi-square tests were used to assess the test of association. Results Fifteen patients had RUSH scores between 10-20 and 17 patients had scores between 20-30 points. RUSH score had mean of 21.03+/- 2.132 points. 9 of 32 patients had excellent results as per Harris hip score, 10 had good, nine had fair and four had poor. On comparison of Harris hip score with RUSH score: Interval between 10-20 points, of 15 patients; two had excellent results, five had good, five had fair and three

  18. [Internal fixation of radial shaft fractures: Anatomical and biomechanical principles].

    PubMed

    Bartoníček, J; Naňka, O; Tuček, M

    2015-10-01

    Radius is a critical bone for functioning of the forearm and therefore its reconstruction following fracture of its shaft must be anatomical in all planes and along all axes. The method of choice is plate fixation. However, it is still associated with a number of unnecessary complications that were not resolved even by introduction of locking plates, but rather the opposite. All the more it is surprising that discussions about anatomical and biomechanical principles of plate fixation have been reduced to minimum or even neglected in the current literature. This applies primarily to the choice of the surgical approach, type of plate, site of its placement and contouring, its working length, number of screws and their distribution in the plate. At the same time it has to be taken into account that a plate used to fix radius is exposed to both bending and torsion stress. Based on our 30-year experience and analysis of literature we present our opinions on plate fixation of radial shaft fractures:We always prefer the volar Henry approach as it allows expose almost the whole of radius, with a minimal risk of injury to the deep branch of the radial nerve.The available studies have not so far found any substantial advantage of LCP plates as compared to 3.5mm DCP or 3.5mm LC DCP plates, quite the contrary. The reason is high rigidity of the locking plates, a determined trajectory of locking screws which is often unsuitable, mainly in plates placed on the anterior surface of the shaft, and failure to respect the physiological curvature of the radius. Therefore based on our experience we prefer "classical" 3.5mm DCP plates.Volar placement of the plate, LCP in particular, is associated with a number of problems. The volar surface covered almost entirely by muscles, must be fully exposed which negatively affects blood supply to the bone. A straight plate, if longer, either lies with its central part partially off the bone and overlaps the interosseous border, or its ends

  19. Periprosthetic femoral fracture--a biomechanical comparison between Vancouver type B1 and B2 fixation methods.

    PubMed

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

    2014-03-01

    Current clinical data suggest a higher failure rate for internal fixation in Vancouver type B1 periprosthetic femoral fracture (PFF) fixations compared to long stem revision in B2 fractures. The aim of this study was to compare the biomechanical performance of several fixations in the aforementioned fractures. Finite element models of B1 and B2 fixations, previously corroborated against in vitro experimental models, were compared. The results indicated that in treatment of B1 fractures, a single locking plate can be without complications provided partial weight bearing is followed. In case of B2 fractures, long stem revision and bypassing the fracture gap by two femoral diameters are recommended. Considering the risk of single plate failure, long stem revision could be considered in all comminuted B1 and B2 fractures. PMID:24035619

  20. Teleseismic receiver and transfer function modeling of OBS data: Resolving plate structure in the locked zone of Cascadia

    NASA Astrophysics Data System (ADS)

    Audet, P.

    2015-12-01

    Teleseismic receiver function studies in the forearc of the Cascadia subduction zone have resolved structures associated with deep fluid cycling, such as the basalt-to-eclogite reaction and overpressure of the subducting oceanic crust, as well as the serpentinization of the forearc mantle wedge. Unfortunately, the updip extent of the overpressured zone and its possible control on the transition from episodic slow slip to seismic slip occur offshore and are not resolved in those studies. The Cascadia Initiative has provided an opportunity to extend our capabilities to study the locked zone using teleseismic receiver functions from the deployment of a dense line of ocean-bottom seismograph (OBS) stations offshore of Washington State, from the trench to the coastline. However, high quality receiver functions using OBS data are notoriously difficult to obtain and to interpret due to the presence of a water column that produces P-wave reverberation above the recording stations. Here we model receiver functions for a variety of oceanic lithospheric structures to investigate the possibilities and limitations of receiver functions using OBS data. These modeling results indicate that receiver functions from OBS data are difficult to interpret in the presence of marine sediments, but shallow-water sites in subduction zone forearcs are suitable for constraining various crustal elements around the locked megathrust fault. We also propose using a complementary approach based on transfer function modeling that bypasses receiver functions altogether and estimates crustal properties directly from the waveforms. Using real data examples from the Cascadia Initiative, we show how calculated receiver and transfer functions can be used to constrain seismic properties of the crust in both shallow (Cascadia forearc) and deep (Juan de Fuca Ridge) ocean settings. Interestingly, the elevated P-to-S velocity ratio of the downgoing oceanic crust interpreted as high pore-fluid pressure extends

  1. The 2014 Iquique Chile earthquake: Preparatory breaking processes of a locked asperity and natural constraints for fluid migration along the plate interface

    NASA Astrophysics Data System (ADS)

    Moreno, M.; Li, S.; Angiboust, S.; Schurr, B.; Bedford, J. R.; Oncken, O.

    2015-12-01

    Variations in pore fluid pressure are of paramount importance in controlling fault stability. Recent studies have focused on investigating the underlying causes of pore fluid pressure, but natural constraints for lateral fluid migration have not yet been described. Here, we investigate the evolution of the plate interface kinematics and fluid pressure migration leading up to the Mw 8.1 Iquique earthquake. We present the deformation evolution of the last decade from a combination of ~40 continuous and ~70 survey-type GPS. The slip distribution of Iquique event covered areas that were previously intermediately to highly locked and enclosed by creeping interface zones. The seismicity recorded in the years before the mainshock tended to encircle the central locked patch (~40 km length asperity), which itself exhibited a low amount of seismicity. This earthquake was preceded by a series of foreshocks and transient deformation that was initiated by an Mw=6.7 event and which lasted for 16 days. The observed transient GPS signals can be explained by deformation due to foreshocks, indicating that slow slip was not a dominant factor in the stress build up that led to the mainshock. Foreshocks initiated at the edge of the asperity and migrated along the plate interface towards the mainshock hypocentre. The spatial and temporal proximity to the mainshock, as well as the migration pattern of events suggest that the foreshocks and mainshock were mechanically coupled. We suggest that the Mw 6.7 (that likely occurred on a splay fault) is responsible for a transient pore fluid pressure increase in the plate interface region, hence diminishing the effective normal stress on the interface. This segment of the plate interface, presumably mechanically weakened by near-lithostatic pore fluid pressures, was subsequently subjected to a propagation of foreshocks. We propose that the 16-days seismicity swarm could represent the lateral propagation of a fluid front through the place

  2. [Comparative serology in typhoid fever in children. II. Comparison of a microhemagglutination plate technic with Ruiz-Castañeda surface fixation].

    PubMed

    Alvarado-Alemán, F; González-Quijano, M; Rodríguez-Solis, B; Ramírez-Vidals, A; Isibasi, A; Kumate, J

    1989-02-01

    Two lipopolysaccharide antigens that differ by the technique of preparation from S. typhi, one named crude is easily extracted, the other one is water-phenol extracted. Both were adsorbed by papain and cysteine to lamb erythrocyte surfaces, fixed then by glutaraldehyde and used in a plate microhemagglutination test (MHA). The MHA test was done with 30 sera from children with S. typhi blood isolates. The same number of control sera were tested for comparison. The crude LPS antigen showed better sensitivity: 73% versus 53% of the water-phenol extracted one despite a high index correlation (r = 0.88). The latest one was evaluated in a prospective study, using it during a six-month period in an emergency room with S. typhi blood isolated sera. The MHA test was compared with the surface fixation test. Both assays showed similar sensitivity and a specificity of 91 and 100%, respectively.

  3. Proximal Humerus Fracture Plating Through the Extended Anterolateral Approach.

    PubMed

    Gardner, Michael J

    2016-08-01

    Several approaches to the proximal humerus for fracture fixation are possible. The traditional utilitarian approach to the shoulder, the deltopectoral, has distinct disadvantages when performing fracture reduction and locked plating. The anterolateral acromial approach exploits the intermuscular plane between the anterior and middle heads of the deltoid. After identifying the position of the axillary nerve as it crosses this interval, fracture reduction and fixation is performed. Direct access to both the greater and the lesser tuberosities is facilitated. The cancellous surface of the humeral head fragment provides an excellent surface for direct manipulation without further endangering the extraosseous soft tissue attachments. PMID:27441923

  4. Plate on plate osteosynthesis for the treatment of nonhealed periplate fractures.

    PubMed

    Arealis, Georgios; Nikolaou, Vassilios S; Lacon, Andrew; Ashwood, Neil; Hamlet, Mark

    2014-01-01

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

  5. Plate on Plate Osteosynthesis for the Treatment of Nonhealed Periplate Fractures

    PubMed Central

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

    2014-01-01

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

  6. Development of a Titanium Plate for Mandibular Angle Fractures with a Bone Defect in the Lower Border: Finite Element Analysis and Mechanical Test

    PubMed Central

    Goulart, Douglas Rangel; Kemmoku, Daniel Takanori; Noritomi, Pedro Yoshito

    2015-01-01

    ABSTRACT Objectives The aim of the present study was to develop a plate to treat mandibular angle fractures using the finite element method and mechanical testing. Material and Methods A three-dimensional model of a fractured mandible was generated using Rhinoceros 4.0 software. The models were exported to ANSYS®, in which a static application of displacement (3 mm) was performed in the first molar region. Three groups were assessed according to the method of internal fixation (2 mm system): two non-locking plates; two locking plates and a new design locking plate. The computational model was transferred to an in vitro experiment with polyurethane mandibles. Each group contained five samples and was subjected to a linear loading test in a universal testing machine. Results A balanced distribution of stress was associated with the new plate design. This plate modified the mechanical behavior of the fractured region, with less displacement between the fractured segments. In the mechanical test, the group with two locking plates exhibited greater resistance to the 3 mm displacement, with a statistically significant difference when compared with the new plate group (ANOVA, P = 0.016). Conclusions The new plate exhibited a more balanced distribution of stress. However, the group with two locking plates exhibited greater mechanical resistance. PMID:26539287

  7. Open reduction and internal fixation of proximal humerus fractures.

    PubMed

    Drosdowech, Darren S; Faber, Kenneth J; Athwal, George S

    2008-10-01

    Open reduction of proximal humeral fractures has the advantage of providing direct control over each fracture fragment and permitting anatomic reduction and fixation with advanced devices. Modern fixed-angle locking plates designed specifically for proximal humerus fractures have allowed the expansion of surgical indications permitting surgeons to address more complicated fractures. Advanced preoperative imaging and fluoroscopy allow a better understanding of fracture patterns and permit the surgeon to use this knowledge intraoperatively. Research is required to further validate fracture classification systems, to develop surgical guidelines for decision making, and to compare the outcomes of the various treatments options for proximal humerus fractures.

  8. Limb lengthening with submuscular plate stabilization: a case series and description of the technique.

    PubMed

    Iobst, Christopher A; Dahl, Mark T

    2007-01-01

    Combining a circular fixator with a percutaneously inserted locking plate has all of the same advantages that lengthening over an intramedullary nail provides but eliminates the concern with regard to creating a deep infection in the medullary canal. It also can be applied to virtually any bone in any age group of patients without any concern with regard to causing avascular necrosis, fat embolism, or physeal injury. The design of the locking plate prevents loss of fixation and protects against bending of the regenerate bone after frame removal. This study represents a description of the surgical technique and a retrospective examination of the first 6 patients treated using this technique. The average age of the patients is 7.6 years, and the average duration of follow-up is 10 months. All 6 patients achieved solid union of the lengthening site and full, unassisted weight bearing with excellent range of motion. The mean lengthening was 3.52 cm, which represents an average of 14.6% of the overall bone length. The mean duration of external fixation was 45 days, and the mean external fixation index was 0.42 mo/cm. The mean distraction rate was 0.85 mm/d. There were 3 serious and 2 severe complications noted. The serious complications included the development of a premature consolidation and a translational deformity of the regenerate in 1 patient, requiring a revision corticotomy, and a fall of a second patient 3 months after fixator removal, causing a fracture at the superior edge of his locking plate. The 2 severe complications were an 11-degree and an 18-degree residual procurvatum deformity that developed during lengthening. In conclusion, lengthening with the assistance of a percutaneously inserted locking plate provides an alternative method to lengthening over an intramedullary nail, applicable to children with open physes.

  9. EVALUATION OF PATIENTS UNDERGOING FIXATION OF DIAPHYSEAL HUMERAL FRACTURES USING THE MINIMALLY INVASIVE BRIDGE-PLATE TECHNIQUE

    PubMed Central

    Superti, Mauro José; Martynetz, Fábio; Falavinha, Ricardo Sprenger; Fávaro, Rodrigo Caldonazzo; Boas, Luis Felipe Villas; Filho, Salim Mussi; Martynetz, Juliano; Ribas, Bruno

    2015-01-01

    Objective: The aim was to describe the experience of our group in treating humeral shaft fractures using the bridge–plate technique via an anterior approach. Methods: Seventeen patients with acute diaphyseal humeral fractures with an indication for surgical treatment who were operated in 2006–2010 were evaluated. The AO and Gustilo & Anderson classifications were used. All the patients were operated using the anterior bridge-plate technique and completed a follow–up period of at least twelve months. Results: Sixteen men and one woman were treated. Their mean age was 31.8 years (18–52). Among the injury mechanisms found were: five motorcycle accidents, four car accidents, three fractures due to firearm projectiles, two falls to the ground and finally, with one case each, assault, crushing and being run over. Eight patients had open fractures: two grade I, one grade II, four grade IIIa and one grade IIIb, according to the Gustilo-Anderson classification. In relation to the AO classification, we found: one 12A1, three 12A2, four 12A3, one 12B1, four 12 B2, three 12B3 and one 12C2. The mean postoperative follow-up was 25 months (12–48). As complications, two patients had pain in the elbow and a ROM deficit and one had deep infection. The mean time taken to achieve consolidation was 17.5 weeks. There was no loss of reduction, pseudarthrosis or malunion in this series of patients. Conclusion: The authors believe that the technique described has low rates of complications and morbidity, with good initial results, although the series is limited by the small sample. PMID:27042639

  10. A biomechanical comparison of four different fixation methods for midshaft clavicle fractures.

    PubMed

    Chen, Yang; Yang, Yang; Ma, Xinlong; Xu, Weiguo; Ma, Jianxiong; Zhu, Shaowen; Ma, Baoyi; Xing, Dan

    2016-01-01

    Clavicle fractures may occur in all age groups, and 70%-80% of clavicle fractures occur in the midshaft. Many methods for treating midshaft clavicular fractures have been reported and remain controversial. To provide some guidance for clinical treatment, 30 artificial polymethyl methacrylate models of the clavicle were sewn obliquely at the midshaft to simulate the most common type of clavicular fractures, and the fracture models were divided into five groups randomly and were fixed as follows: the reconstruction plates were placed at the superior position of the fracture model (R-S group), the reconstruction plates were placed at the anteroinferior position of the fracture model (R-AI group), the locking plates were placed at the superior position (L-S group), the locking plates were placed at the anteroinferior position (L-AI group); and the control models were unfixed (control group). The strain gauges were attached to the bone surface near the fracture fragments, and then, the biomechanical properties of the specimens were measured using the compression test, torsion test and three-point bending test. The results showed that plate fixation can provide a stable construct to help with fracture healing and is the preferred method in the treatment of clavicle fractures. The locking plate provides the best biomechanical stability when placed at the anteroinferior position, and this surgical method can reduce the operation time and postoperative complications; thus, it would be a better choice in clinical practice.

  11. Evaluating formability of LCP plate for sacral fractures with one step inverse forming finite element analysis.

    PubMed

    Li, Xiaoda; Zhang, Xiangkui; Hu, Ping; Liu, Weijie; Shen, Guozhe; Zhan, Xianghui

    2015-01-01

    The locking compression plate fixation treatment for the unstable sacral fractures is simple and effective, with less trauma and complications. Some locking compression plate parts have been made of high-strength Plate manufactured by hot stamping process since the demand for lightweight biomedical materials. Finite Element (FE) method of One-Step inverse forming based on deformation theory is the tool to evaluate the formability of locking compression plate panel quickly in initial design for reducing costs and development cycle of Plate. But current one-step inverse forming methods are all suitable for cold stamping, not hot-stamping. This paper proposed one-step inverse forming method and workflow for hot-stamping of locking compression Plate. And the B pillar of a sacral bone was simulated and its computing result was compared with experimental value. The result shows that the proposed method in this paper can quickly evaluate high temperature formability of high-strength Plate. And the method is proposed to be used in initial design. PMID:26405951

  12. What is new in distal femur periprosthetic fracture fixation?

    PubMed

    Tosounidis, Theodoros H; Giannoudis, Peter V

    2015-12-01

    Distal femoral periprosthetic fractures are on the rise. Increased mortality of these injuries is also evident from recent data. Their incidence and risk factors have been extensively reported in the past but new data are being available that merit attention. The increased incidence and the even higher projected incidence should direct the focus of future strategies to the education of surgeons, relevant capacity of hospital and reconfiguration of health care resources. New and potentially modifiable risk factors should be taken into consideration to the informed consent process and new studies should be developed to clarify the causative relationship of the new risk factors such as the peptic ulcer disease and the COPD. The main internal fixation techniques remain the lateral locking plating and the retrograde intramedullary nailing. New techniques in plating are the supplementary medial plate in selected cases and the far cortical locking. Nailing is considered a valid option especially in fractures located well above the anterior flange of the femoral component of the arthroplasty. Results and outcomes from good quality studies are still sparse regarding the comparison between plating and nailing. Interprosthetic fractures constitute an entity that is lately gaining considerable attention. The best method of management of these injuries is still evolving with considerable amount of work being done in the clinical and biomechanical level.

  13. Treating Tibia Fractures With Far Cortical Locking Implants.

    PubMed

    Rice, Christopher; Christensen, Thomas; Bottlang, Michael; Fitzpatrick, Dan; Kubiak, Erik

    2016-01-01

    Compared with conventional plating, the relatively new technology of far cortical locking (FCL) allows for more flexible fixation. Increased flexibility of FCL constructs is thought to better stimulate secondary osteosynthesis and lead to improved healing for certain fracture patterns. We conducted a study to compare healing rates and complications of tibial fractures treated with FCL or standard plating techniques. Twenty-two patients with fractures of the tibia (Orthopaedic Trauma Association 41ABC, 42C, 43C) were included in the study. Twelve tibia fractures were treated with FCL and 10 with standard plating (locking or nonlocking). Mean follow-up was 47 weeks in the FCL group and 41 weeks in the control group. The fracture healing rate was 92% in the FCL group and 100% in the control group (difference not statistically significant). Of note, there were 2 open fractures in the FCL group and 0 in the control group. The groups had similar complication rates. Our study data suggest FCL implants are not inferior to conventional plating techniques. Given that FCL-treated fractures tended to be more complex, the groups' similar fracture healing rates may indicate improved fracture healing with FCL technology, but this possibility requires further investigation. PMID:26991582

  14. Radioscapholunate arthrodesis using low-profile dorsal pi plate.

    PubMed

    Galvis, Elkin J; Kumar, Kannan K; Özyurekoglu, Tuna

    2013-06-01

    Radioscapholunate arthrodesis is a desirable method to treat isolated radiolunate arthritis or ulnar translocation of the carpal bones. An intact midcarpal joint is a prerequisite for functional range of motion. Previously, high rates of nonunion were observed with these procedures, as rigid fixation was difficult to obtain with simple Kirschner wires and screws. A successful outcome depends on bringing the scaphoid, lunate, and the radius to an anatomic alignment, and rigid fixation of the arthrodesis. We describe a technique for the arthrodesis of the radioscapholunate joint from the dorsal side using a low-profile locking Pi plate. We observed the advantages of an easy approach, better visualization of the joint, and easier manipulation of the carpal bones. The Pi plate fits on the scaphoid, lunate, and the radius with minimal adjustment. It is not necessary to remove the Lister's tubercle. Pi plate allows for rigid fixation and compression between the scaphoid, lunate, and the radius by 1 compression and 1 locking screw in scaphoid and lunate, and by 2 eccentric compression screws in the radius. Rectangular retinacular flaps were used under and over the extensor tendons. We performed these arthrodeses in patients with lunate fossa arthritis after a distal radius fracture, and with ulnar translocation of the carpus. We have observed excellent clinical results with about 50% of wrist motion preserved and no cases of nonunion or delayed union.

  15. Locking mechanism

    DOEpatents

    Williams, Gary L.; Goin, Jr., Jesse L.; Kirby, Patrick G.; McKenna, John P.

    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.

  16. Complications of rigid internal fixation.

    PubMed

    Campbell, Chris A; Lin, Kant Y

    2009-03-01

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

  17. Retrospective study of mandibular angle fractures treated with three different fixation systems

    PubMed Central

    Bhatt, Krushna; Arya, Satyavrat; Bhutia, Ongkila; Pandey, Sandeep; Roychoudhury, Ajoy

    2015-01-01

    Aim: To evaluate the outcomes of mandibular angle fractures treated with metal 2.0 mm locking, metal 2.0 mm nonlocking, and 2.5 mm resorbable systems. Study Design: Retrospective cohort study. Materials and Methods: Trauma records were screened for linear angle fractures treated with open-reduction and internal semi-rigid fixation with single metal/bioresorbable plates, and baseline variables were tabulated. The outcome variable was the presence or absence of any complication. Statistical Analysis Used: The Fisher's exact test and analysis of covariance (ANCOVA) using STATA 11. Results: A total of 60 case records of over four years were included. The mean age of the patients was 27.4 (SD 9.7) years. Fifty-five were male and five female. There were 20 nonlocking and 16 locking metal miniplates and 24 bioresorbable plates. In 55 (91.6%) cases there was a third molar in the fracture line. In 51/55 (92.7%) cases the third molar was retained. In seven patients postoperative complications were seen. There was no difference between the complication rates of the three treatment groups. Infection was the most common complication followed by delayed union and hardware failure. Conclusions: This retrospective study found no difference in the complication rate when fractures of the mandibular angle were treated with locking or nonlocking miniplates or bioresorbable plates. PMID:26668450

  18. Comment to: Haque S, Khan A, Sharma A, Sundararajan S: Technical tip: tightrope fixation of neer type II distal clavicle fracture supported by a case series. Pol Orthop Traumatol, 2014; 79: 19-22.

    PubMed

    Gökkuş, Kemal; Saylik, Murat; Aydin, Ahmet Turan

    2014-04-15

    Additional suture anchor fixation to coracoclaviculer area with precountered distal clavicle locking plate allows an anatomic reduction with bone-bone contact and gives additional neutralisation effect with coracoclavicular suture anchor fixation against the trapezius muscle pulling effect .Event though the effeciency of this technique reported by other authors,still there is a few articles and cases reported.In the terms of proving the efficiency of the combination technique we would like to stress to contribute the published article by Haque et al.

  19. Resistance and Stress Finite Element Analysis of Different Types of Fixation for Mandibular Orthognathic Surgery.

    PubMed

    Stringhini, Diego José; Sommerfeld, Ricardo; Uetanabaro, Lucas Caetano; Leonardi, Denise Piotto; Araújo, Melissa Rodrigues; Rebellato, Nelson Luís Barbosa; Costa, Delson João da; Scariot, Rafaela

    2016-01-01

    The aim of this study was to evaluate the stress and dislodgement resistance by finite element analysis of different types of fixation in mandibular orthognathic surgery. A 3D solid finite element model of a hemi-mandible was obtained. A bilateral sagittal split osteotomy was simulated and the distal segment was advanced 5 mm forward. After the adjustment and superimposing of segments, 9 different types of osteosynthesis with 2.0 miniplates and screws were simulated: A, one 4-hole conventional straight miniplate; B, one 4-hole locking straight miniplate; C, one 4-hole conventional miniplate and one bicortical screw; D, one 4-hole locking miniplate and 1 bicortical screws; E, one 6-hole conventional straight miniplate; F, one 6-hole locking miniplate; G, two 4-hole conventional straight miniplates; H, two 4-hole locking straight miniplates; and I, 3 bicortical screws in an inverted-L pattern. In each model, forces simulating the masticatory muscles were applied. The values of stress in the plates and screws were checked. The dislodgement resistance was checked at the proximal segment since the distal segment was stable because of the screen at the occlusal tooth. The regions with the lowest and highest displacement were measured. The offset between the osteotomized segments was verified by millimeter intervals. Inverted-L with bicortical screws was the model that had the lowest dislodgment and the model with the lowest tension was the one with two conventional plates. The results suggest that the tension was better distributed in the locking miniplates, but the locking screws presented higher concentration of tension.

  20. Resistance and Stress Finite Element Analysis of Different Types of Fixation for Mandibular Orthognathic Surgery.

    PubMed

    Stringhini, Diego José; Sommerfeld, Ricardo; Uetanabaro, Lucas Caetano; Leonardi, Denise Piotto; Araújo, Melissa Rodrigues; Rebellato, Nelson Luís Barbosa; Costa, Delson João da; Scariot, Rafaela

    2016-01-01

    The aim of this study was to evaluate the stress and dislodgement resistance by finite element analysis of different types of fixation in mandibular orthognathic surgery. A 3D solid finite element model of a hemi-mandible was obtained. A bilateral sagittal split osteotomy was simulated and the distal segment was advanced 5 mm forward. After the adjustment and superimposing of segments, 9 different types of osteosynthesis with 2.0 miniplates and screws were simulated: A, one 4-hole conventional straight miniplate; B, one 4-hole locking straight miniplate; C, one 4-hole conventional miniplate and one bicortical screw; D, one 4-hole locking miniplate and 1 bicortical screws; E, one 6-hole conventional straight miniplate; F, one 6-hole locking miniplate; G, two 4-hole conventional straight miniplates; H, two 4-hole locking straight miniplates; and I, 3 bicortical screws in an inverted-L pattern. In each model, forces simulating the masticatory muscles were applied. The values of stress in the plates and screws were checked. The dislodgement resistance was checked at the proximal segment since the distal segment was stable because of the screen at the occlusal tooth. The regions with the lowest and highest displacement were measured. The offset between the osteotomized segments was verified by millimeter intervals. Inverted-L with bicortical screws was the model that had the lowest dislodgment and the model with the lowest tension was the one with two conventional plates. The results suggest that the tension was better distributed in the locking miniplates, but the locking screws presented higher concentration of tension. PMID:27224561

  1. Locking support for nuclear fuel assemblies

    DOEpatents

    Ledin, Eric

    1980-01-01

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

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

    PubMed

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

    1989-04-01

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

  3. Staged Columnar Fixation of Bicondylar Tibial Plateaus: A Cheaper Alternative to External Fixation.

    PubMed

    Perdue, Aaron; Greenberg, Sarah E; Sathiyakumar, Vasanth; Thakore, Rachel V; Mir, Hassan R; Obremskey, William T; Sethi, Manish K

    2016-01-01

    The objective of this study was to compare complication rates and costs of staged columnar fixation (SCF) to external fixation for bicondylar tibial plateau fractures. Patients who received SCF or temporary external fixation across a 3-year period at a major level I trauma center underwent a retrospective chart review for associated complications. Fisher's exact analysis was used to determine any statistical difference in complication rates between both groups. However, there was no significant difference in complication rates between the SCF and external fixator groups. Average medial plate costs for SCF were $2131 compared with an average external fixator cost of $4070 (p < .0001). Given that all patients with external fixation undergo eventual medial and lateral plating, savings with SCF include $4070 plus operative costs for removing the fixator. As our health care system focuses on cost-cutting efforts, orthopaedic trauma surgeons must explore cheaper and equally effective treatment alternatives. PMID:27082883

  4. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

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

    PubMed Central

    Park, Chang-Min; Kim, Jae-Do

    2013-01-01

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

  6. Titanium plate artefact mimicking popliteal artery dissection on digital subtraction CT angiography.

    PubMed

    Woodacre, Timothy; Wienand-Barnett, Sophie

    2013-04-05

    Titanium plates used for the internal fixation of long bone fractures cause significant artefact on CT scans but have not been reported to affect digital subtraction CT angiography. We present a patient with clinical suspicion of popliteal artery injury following a high tibial osteotomy. The osteotomy was stabilised with a titanium locking plate. During the digital subtraction process used to produce reconstruction CT angiography, removal of artefact caused by the titanium plate produced CT images mimicking the appearance of a popliteal artery dissection. The imaging inaccuracy was realised prior to the patient undergoing further intervention. We highlight the potential error caused by titanium plates on digital subtraction CT angiography and recommend careful analysis of such images prior to further treatment.

  7. 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.

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

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

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

  9. Surgical Management of Tibial Plateau Fractures With 3.5 mm Simple Plates

    PubMed Central

    Bagherifard, Abolfazl; Jabalameli, Mahmoud; Hadi, Hosseinali; Rahbar, Mohammad; Minator Sajjadi, Mohammadreza; Jahansouz, Ali; Karimi Heris, Hossein

    2016-01-01

    Background Tibial plateau fractures can be successfully fixed utilizing 3.5 mm locking plates. However, there are some disadvantages to using these plates. Objectives In the current prospective study, we investigated the outcome of treating different types of tibial plateau fractures with 3.5 mm simple plates which, to our knowledge, has not been evaluated in previous studies. Materials and Methods Between 2011 and 2013, 32 patients aged 40 ± 0.2 years underwent open reduction and internal fixation for tibial plateau fractures with 3.5 mm simple plates. The patients were followed for 16.14 ± 2.1 months. At each patient’s final visit, the articular surface depression, medial proximal tibial angle, and slope angle were measured and compared with measurements taken early after the operation. The functional outcomes were measured with the WOMAC and Lysholm knee scores. Results The mean union time was 13 ± 1.2 weeks. The mean knee range of motion was 116.8° ± 3.3°. The mean WOMAC and Lysholm scores were 83.5 ± 1.8 and 76.8 ± 1.6, respectively. On the early postoperative and final X-rays, 87.5% and 84% of patients, respectively, had acceptable reduction. Medial proximal tibial and slope angles did not change significantly by the last visit. No patient was found to have complications related to the type of plate. Conclusions In this case series study, the fixation of different types of tibial plateau fractures with 3.5 mm simple non-locking and non-precontoured plates was associated with acceptable clinical, functional, and radiographic outcomes. Based on the advantages and costs of these plates, the authors recommend using 3.5 mm simple plates for different types of tibial plateau fractures. PMID:27626010

  10. Preoperative Planning of Virtual Osteotomies Followed by Fabrication of Patient Specific Reconstruction Plate for Secondary Correction and Fixation of Displaced Bilateral Mandibular Body Fracture.

    PubMed

    Thor, Andreas

    2016-06-01

    This paper describes the course of treatment of a severely diplaced bilateral mandibular body fracture, where the first osteosynthesis failed. The subject developed an open bite due to a posterior rotation of the distal part of the mandible and anterior rotation of the proximal parts of the mandible. This situation was evaluated with CBCT and the facial skeleton was segmented using computer software. Correct occlusion was virtually established by bilateral virtual osteotomies in the fracture areas of the mandible. After segmentation, the mandible was virtually rotated back into position and the open bite was closed. A patient specific mandibular reconstruction plate was outlined and fabricated from the new virtual situation and the plate was thereafter installed utilizing the preoperative plan. Osteotomy- and drill-guides was used and thus simplified the surgery resulting in uneventful healing. Virtual planning and patient specific implants and guides were valuable in this case of secondary reconstructive trauma surgery. PMID:27162581

  11. Analysis of residual stress and hardness in regions of pre-manufactured and manual bends in fixation plates for maxillary advancement.

    PubMed

    Araújo, Marcelo Marotta; Lauria, Andrezza; Mendes, Marcelo Breno Meneses; Claro, Ana Paula Rosifini Alves; Claro, Cristiane Aparecida de Assis; Moreira, Roger William Fernandes

    2015-12-01

    The aim of this study was to analyze, through Vickers hardness test and photoelasticity analysis, pre-bent areas, manually bent areas, and areas without bends of 10-mm advancement pre-bent titanium plates (Leibinger system). The work was divided into three groups: group I-region without bend, group II-region of 90° manual bend, and group III-region of 90° pre-fabricated bends. All the materials were evaluated through hardness analysis by the Vickers hardness test, stress analysis by residual images obtained in a polariscope, and photoelastic analysis by reflection during the manual bending. The data obtained from the hardness tests were statistically analyzed using ANOVA and Tukey's tests at a significance level of 5 %. The pre-bent plate (group III) showed hardness means statistically significantly higher (P < 0.05) than those of the other groups (I-region without bends, II-90° manually bent region). Through the study of photoelastic reflection, it was possible to identify that the stress gradually increased, reaching a pink color (1.81 δ / λ), as the bending was performed. A general analysis of the results showed that the bent plate region of pre-bent titanium presented the best results.

  12. MECHANICAL STUDY ON DORSAL STABILITY OF INTRAMEDULLARY OSTEOSYNTHESIS ASSOCIATED WITH EXTERNAL FIXATION (ULSON'S METHOD)

    PubMed Central

    Sardenberg, Trajano; Muller, Sérgio Swain; Medeiros, Daniel Ricardo; Baptistão, Pablo Luiz

    2015-01-01

    Objective: To evaluate the Ulson intramedullary fixation method, with external fixation in which the level of the external locking of the Kirschner wires is varied, and without external fixation. Methods: Eighteen porcine tibias were used. Transverse osteotomy was performed in the region of the tuberosity, and two intramedullary Kirschner wires were inserted into each specimen, using three different assembly patterns: Group I: locking with external minifixator at a height of 3.0 cm; Group II: locking at a height of 4.5 cm; Group III: without external locking. Mechanical shear tests were then conducted, to determine the maximum load, proportionality limit and coefficient of rigidity. Results: There were no significant differences in maximum load or proportionality limit between the groups. The coefficient of rigidity was higher in Group II. Conclusion: The locking height for the Kirschner wires in Ulson's method, within the limits evaluated, did not harm the stability of the fracture fixation system. PMID:27027069

  13. Automatic locking orthotic knee device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

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

  14. Early results for treatment of three- and four-part fractures of the proximal humerus using the PHILOS plate system.

    PubMed

    Moonot, P; Ashwood, N; Hamlet, M

    2007-09-01

    Secure fixation of displaced proximal fractures of the humerus is a challenging problem. A total of 32 patients with acutely displaced three- or four-part proximal fractures of the humerus were treated by open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate. There were 23 women and nine men with a mean age of 59.9 years (18 to 87). Data were collected prospectively and the outcomes were assessed using the Constant score. The mean follow-up was for 11 months (3 to 24). In 31 patients (97%) the fracture united clinically and radiologically at a mean of 10 weeks (8 to 24). The mean Constant score at final review was 66.5 (30 to 92). There was no significant difference in outcome when comparing patients aged more than 60 years (18 patients) with those aged less than 60 years (14 patients) (t-test, p = 0.8443). There was one case each of nonunion, malunion and a broken screw in the elderly population. This plate provides an alternative method of fixation for fractures of the proximal humerus. It provides a stable fixation in young patients with good-quality bone sufficient to permit early mobilisation. Failure of the screws to maintain fixation in the elderly remains a problem.

  15. Periprosthetic fracture fixation in osteoporotic bone.

    PubMed

    Lenz, Mark; Lehmann, Wolfgang; Wähnert, Dirk

    2016-06-01

    Fixation techniques of periprosthetic fractures are far from ideal although the number of this entity is rising. The presence of an intramedullary implant generates its own fracture characteristics since stiffness is altered along the bone shaft and certain implant combinations affect load resistance of the bone. Influencing factors are cement fixation of the implant, intramedullary locking and extramedullary or intramedullary localization of the implant and the cortical thickness of the surrounding bone. Cerclage wires are ideally suited to fix radially displaced fragments around an intramedullary implant but they are susceptible to axial and torsional load. Screws should be added if these forces have to be neutralized. Stability of the screw fixation itself can be enhanced by embracement configuration around the intramedullary implant. Poor bone stock quality, often being present in metaphyseal areas limits screw fixation. Cement augmentation is an attractive option in this field to enhance screw purchase. PMID:27338227

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

  17. An electronically instrumented internal fixator for the assessment of bone healing

    PubMed Central

    Kowald, B.; Seide, K.; Aljudaibi, M.; Faschingbauer, M.; Juergens, C.; Gille, J.

    2016-01-01

    Objectives The monitoring of fracture healing is a complex process. Typically, successive radiographs are performed and an emerging calcification of the fracture area is evaluated. The aim of this study was to investigate whether different bone healing patterns can be distinguished using a telemetric instrumented femoral internal plate fixator. Materials and Methods An electronic telemetric system was developed to assess bone healing mechanically. The system consists of a telemetry module which is applied to an internal locking plate fixator, an external reader device, a sensor for measuring externally applied load and a laptop computer with processing software. By correlation between externally applied load and load measured in the implant, the elasticity of the osteosynthesis is calculated. The elasticity decreases with ongoing consolidation of a fracture or nonunion and is an appropriate parameter for the course of bone healing. At our centre, clinical application has been performed in 56 patients suffering nonunion or fracture of the femur. Results A total of 39 cases of clinical application were reviewed for this study. In total, four different types of healing curves were observed: fast healing; slow healing; plateau followed by healing; and non-healing. Conclusion The electronically instrumented internal fixator proved to be valuable for the assessment of bone healing in difficult healing situations. Cost-effective manufacturing is possible because the used electronic components are derived from large-scale production. The incorporation of microelectronics into orthopaedic implants will be an important innovation in future clinical care. Cite this article: B. Kienast, B. Kowald, K. Seide, M. Aljudaibi, M. Faschingbauer, C. Juergens, J. Gille. An electronically instrumented internal fixator for the assessment of bone healing. Bone Joint Res 2016;5:191–197. DOI: 10.1302/2046-3758.55.2000611. PMID:27226357

  18. Technique of Open Reduction and Internal Fixation of Comminuted Proximal Humerus Fractures With Allograft Femoral Head Metaphyseal Reconstruction.

    PubMed

    Parada, Stephen A; Makani, Amun; Stadecker, Monica J; Warner, Jon J P

    2015-10-01

    Proximal humerus fractures are common injuries that can require operative treatment. Different operative techniques are available, but the hallmark of fixation for 3- and 4-part fractures is a locking-plate-and-screw construct. Despite advances in this technology, obtaining anatomical reduction and fracture union can be difficult, and complications (eg, need for revision) are not uncommon. These issues can be addressed by augmenting the fixation with an endosteally placed fibular allograft. Although biomechanical and clinical results have been good, the technique can lead to difficulties in future revision to arthroplasty, a common consequence of failed open reduction and internal fixation. The technique described, an alternative to placing a long endosteal bone graft, uses a trapezoidal, individually sized pedestal of allograft femoral head to facilitate the reduction and healing of the humeral head and tuberosity fragments in a displaced 3- or 4-part fracture of the proximal humerus. It can be easily incorporated with any plate-and-screw construct and does not necessitate placing more than 1 cm of bone into the humeral intramedullary canal, limiting the negative effects on any future revision to arthroplasty.

  19. 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.

  20. Safety lock-out device for electrical appliances

    DOEpatents

    Cliff, Jr., Paul L.

    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.

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

    PubMed

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

    2013-11-01

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

  2. Acetabular liner fixation by cement.

    PubMed

    Jiranek, William A

    2003-12-01

    Many situations in revision THA require the exchange of a PE liner in the setting of a well-fixed cementless acetabular shell. Unfortunately, a replacement liner is not always available, the locking mechanism of the metal shell may be damaged or incompatible with the desired liner, or the shell is malpositioned. Revision of a well-fixed cementless acetabular shell has been associated with considerable morbidity. This raises several questions: can a new PE liner be fixed in the existing shell using bone cement, and if so, which techniques can improve the end result, and in which patients should they be used? Biomechanical testing of cemented PE liners has shown initial fixation strengths that exceed conventional locking mechanisms. It is not known during what period this initial fixation will fail, but clinical reports with followup of as many as 6 years have shown survival in approximately 90% of cases. These studies have shown the importance of proper patient selection, accurate sizing of the PE liner, careful preparation of the substrate of the liner and the shell, and good cement technique. The potential advantages of this technique are less surgical morbidity, more rapid surgery and patient recovery, the ability to incorporate antibiotics in the cement, and more liner options.

  3. Optimizing Stability in Femoral Neck Fracture Fixation.

    PubMed

    Ye, Ye; Hao, Jiandong; Mauffrey, Cyril; Hammerberg, E Mark; Stahel, Philip F; Hak, David J

    2015-10-01

    Optimizing stability of femoral neck fracture fixation is important in obtaining a successful outcome. The mechanical problems and strategies for achieving optimal stability differ depending on patients' age and degree of osteoporosis. Femoral neck fractures in younger adults usually result from high-energy trauma and have a vertical fracture pattern. Strategies for optimizing fixation stability in this group include placing additional screws at right angles to the fracture plane and medial buttress plate augmentation. In elderly patients, screw position relative to the intact cortical femoral neck bone is of critical importance. Additional strategies for optimizing fixation stability in this group include the concept of length stable fixation, use of adjunctive calcium phosphate cement, and use of novel fixed angle fixation implants. PMID:26488776

  4. Reconstruction of multiplanar deformity of the hindfoot and midfoot with internal fixation techniques.

    PubMed

    Dreher, Thomas; Hagmann, Sebastién; Wenz, Wolfram

    2009-09-01

    Reconstruction surgery of the midand hindfoot is a demanding challenge for foot surgeons. Satisfactory results depend not only on surgical technique and skills but also on the knowledge of underlying disorders, pathomechanics, and indication criteria. The cavovarus foot, the planovalgus foot, and Charcot's foot are some of the most challenging foot deformities, requiring different surgical strategies for their correction. Most of the osteotomies and fusions in children and adults can be fixed with transcutaneous Kirschner wires, which are inexpensive and easy to use and remove. The use of alternative fixation systems such as cannulated screws, compression screws, or angle-stable locking plates depends on patient age, vascular situation, risk for nonunion, and underlying pathology.

  5. 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.

  6. Extra-platysma fixation of bisphosphonate-related mandibular fractures: a suggested technical solution.

    PubMed

    Biglioli, F; Pedrazzoli, M

    2013-05-01

    Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an evolving epidemic. Often the patients are in poor general condition and therefore the aim of surgical treatment is generally limited to pain control and restoration of feeding ability. We present a useful surgical technique for the stabilization of BRONJ-related mandibular fractures, including application of a reconstructive plate. With an extraoral approach, a 2.5-mm reconstructive locking plate is contoured and placed in the plane of dissection, superficial to the platysma. The fracture site is accessed through an intraoral approach, which limits surgery to curettage and rinsing of the surgical site. Since there is no removal of the periosteal support to the residual stumps, the blood supply to the affected mandible is maintained. Avoidance of direct contact of the infected fractured site with the reconstructive plate is another advantage of working in a surgical plane over the platysma muscle. Although fracture healing is not achieved, plate fixation with this technique is stable and painless and patients can easily eat; therefore, patients enjoy a great improvement in their quality of life. We consider this easy and effective procedure to be a reliable palliative solution in these patients. PMID:23490473

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

    PubMed

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

    2014-02-01

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

  8. 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

  9. Comparison of the Mechanical Characteristics of a Universal Small Biplane Plating Technique Without Compression Screw and Single Anatomic Plate With Compression Screw.

    PubMed

    Dayton, Paul; Ferguson, Joe; Hatch, Daniel; Santrock, Robert; Scanlan, Sean; Smith, Bret

    2016-01-01

    To better understand the mechanical characteristics of biplane locked plating in small bone fixation, the present study compared the stability under cyclic cantilever loading of a 2-plate locked biplane (BPP) construct without interfragmentary compression with that of a single-plate locked construct with an additional interfragmentary screw (SPS) using surrogate bone models simulating Lapidus arthrodesis. In static ultimate plantar bending, the BPP construct failed at significantly greater load than did the SPS construct (556.2 ± 37.1 N versus 241.6 ± 6.3 N, p = .007). For cyclic failure testing in plantar bending at a 180-N starting load, the BPP construct failed at a significantly greater number of cycles (158,322 ± 50,609 versus 13,718 ± 10,471 cycles) and failure load (242.5 ± 25.0 N versus 180.0 ± 0.0 N) than the SPS construct (p = .002). For cyclic failure testing in plantar bending at a 120-N starting load, the results were not significantly different between the BPP and SPS constructs for the number of cycles (207,646 ± 45,253 versus 159,334 ± 69,430) or failure load (205.0 ± 22.4 N versus 185.0 ± 33.5 N; p = .300). For cyclic testing with 90° offset loading (i.e., medial to lateral bending) at a 120-N starting load, all 5 BPP constructs (tension side) and 2 of the 5 SPS constructs reached 250,000 cycles without failure. Overall, the present study found the BPP construct to have superior or equivalent stability in multiplanar orientations of force application in both static and fatigue testing. Thus, the concept of biplane locked plating, using 2 low profile plates and unicortical screw insertion, shows promise in small bone fixation, because it provides consistent stability in multiplanar orientations, making it universally adaptable to many clinical situations.

  10. Latarjet Fixation

    PubMed Central

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

    2016-01-01

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

  11. Purge Lock Server

    2012-08-21

    The software provides a simple web api to allow users to request a time window where a file will not be removed from cache. HPSS provides the concept of a "purge lock". When a purge lock is set on a file, the file will not be removed from disk, entering tape only state. A lot of network file protocols assume a file is on disk so it is good to purge lock a file beforemore » transferring using one of those protocols. HPSS's purge lock system is very coarse grained though. A file is either purge locked or not. Nothing enforces quotas, timely unlocking of purge locks, or managing the races inherent with multiple users wanting to lock/unlock the same file. The Purge Lock Server lets you, through a simple REST API, specify a list of files to purge lock and an expire time, and the system will ensure things happen properly.« less

  12. Rod locking device

    SciTech Connect

    Troxell, J.N. Jr.

    1986-07-22

    A ram locking apparatus used on a blowout preventer is described having a housing, a ram, ram actuating means having a closing side and a retracted side and a tail rod having its inner end connected to the ram actuating means and its outer end engaged by the apparatus to lock the ram. The apparatus consists of: a lock housing having a closed end and a hollow interior connected to the exterior of the preventer housing in which the tail rod is positioned, a body positioned within the lock housing, a primary piston, a lost motion connection between the primary piston and the body, a lock piston associated with the primary piston and movable axially with respect to the primary piston, a tapered split locking ring interconnected to the lock piston, wedging means with the split locking ring, and means for supplying fluid under pressure into the lock housing for movement of the pistons, the initial pressure on the primary pistons causing movement of the body to engage the ram tail rod and subsequently moving the lock piston relative to the wedging means and to thereby wedge the split locking ring against the interior of the lock housing to lock the body therein against movement in the lock housing.

  13. 12. LOCK GATES AT THE SWAMP LOCKS, SEPARATING THE UPPER ...

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

    12. LOCK GATES AT THE SWAMP LOCKS, SEPARATING THE UPPER AND LOWER LOCK CHAMBERS, SHOWING PADDLE VALVES, LOOKING WEST: 1976 - Pawtucket Canal, Swamp Locks, Pawtucket & Merrimack Canals, Lowell, Middlesex County, MA

  14. 56. LOCK AND DAM NO. 26 (REPLACEMENT). AUXILIARY LOCK AND ...

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

    56. LOCK AND DAM NO. 26 (REPLACEMENT). AUXILIARY LOCK AND REMAINDER OF DAM -- CONCRETE MONOLITH PLAN AND WALL ELEVATIONS (WITH LOCK APPURTENANCES). Drawing V-601 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  15. Intramedullary nailing of the femur with an inflatable self-locking nail: comparison with locked nailing.

    PubMed

    Lepore, Luciano; Lepore, Stefano; Maffulli, Nicola

    2003-01-01

    We report a comparative study between an inflatable expandable nail and a traditional locked intramedullary implant in closed fractures of the femoral shaft. We matched each of 43 patients who had undergone intramedullary fixation with an inflatable expandable nail with a patient of the same sex, age (within 2 years), and fracture who had undergone statically locked intramedullary fixation with traditional nails. The mean duration of surgery was significantly shorter in the patients who were treated with the inflatable expandable nail. There were no differences in average blood loss, transfusion requirements, or hospitalization. Five of the patients who underwent traditional nailing required dynamization to achieve union. The inflatable expandable nail allows effective management of diaphyseal fractures of the femur. Interlocking is not necessary, operative times are reduced, and exposure to ionizing radiation is minimized. At present, however, the inflatable expandable nail used in the this investigation is markedly more expensive than traditional devices. PMID:14648267

  16. Retrospective comparison of percutaneous fixation and volar internal fixation of distal radius fractures.

    PubMed

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

    2008-06-01

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

  17. External Fixation of Open Humerus Factures

    PubMed Central

    Marsh, JL; Mahoney, Craig R; Steinbronn, Dave

    1999-01-01

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

  18. Bicondylar tibial fractures: Internal or external fixation?

    PubMed

    Kumar, Gunasekaran; Peterson, Nicholas; Narayan, Badri

    2011-03-01

    Bicondylar fractures of the tibia, representing the Schatzker V and VI fractures represent a challenging problem. Any treatment protocol should aim at restoring articular congruity and the metaphyseo-diaphsyeal dissociation (MDD)-both of these are equally important to long-term outcome. Both internal and external fixations have their proponents, and each method of treatment is associated with its unique features and complications. We review the initial and definitive management of these injuries, and the advantages and disadvantages of each method of definitive fixation. We suggest the use of a protocol for definitive management, using either internal or external fixation as deemed appropriate. This protocol is based on the fracture configuration, local soft tissue status and patient condition. In a nutshell, if the fracture pattern and soft tissue status are amenable plate fixation (single or double) is performed, otherwise limited open reduction and articular surface reconstruction with screws and circular frame is performed. PMID:21430865

  19. Fast flux locked loop

    DOEpatents

    Ganther, Jr., Kenneth R.; Snapp, Lowell D.

    2002-09-10

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

  20. 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.

  1. Overview of locking systems

    SciTech Connect

    Gee, K.T.; Scott, S.H.; Wilde, M.G.; Highland, S.E.

    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.

  2. No benefit to surgical fixation of flail chest injuries compared with modern comprehensive management: results of a retrospective cohort study

    PubMed Central

    Farquhar, Jaclyn; Almahrabi, Yahya; Slobogean, Gerard; Slobogean, Bronwyn; Garraway, Naisan; Simons, Richard K.; Hameed, S. Morad

    2016-01-01

    Background Chest wall trauma is a common cause of morbidity and mortality. Recent technological advances and scientific publications have created a renewed interest in surgical fixation of flail chest. However, definitive data supporting surgical fixation are lacking, and its virtues have not been evaluated against modern, comprehensive management protocols. Methods Consecutive patients undergoing rib fracture fixation with rib-specific locking plates at 2 regional trauma centres between July 2010 and August 2012 were matched to historical controls with similar injury patterns and severity who were managed nonoperatively with modern, multidisciplinary protocols. We compared short- and long-term outcomes between these cohorts. Results Our patient cohorts were well matched for age, sex, injury severity scores and abbreviated injury scores. The nonoperatively managed group had significantly better outcomes than the surgical group in terms of ventilator days (3.1 v. 6.1, p = 0.012), length of stay in the intensive care unit (3.7 v. 7.4 d, p = 0.009), total hospital length of stay (16.0 v. 21.9 d, p = 0.044) and rates of pneumonia (22% v. 63%, p = 0.004). There were no significant differences in long-term outcomes, such as chest pain or dyspnea. Conclusion Although considerable enthusiasm surrounds surgical fixation of flail chest injuries, our analysis does not immediately validate its universal implementation, but rather encourages the use of modern, multidisciplinary, nonoperative strategies. The role of rib fracture fixation in the modern era of chest wall trauma management should ultimately be defined by prospective, randomized trials. PMID:27438051

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

    PubMed

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

    2014-12-01

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

  4. Biomechanical Analysis of the Fixation System for T-Shaped Acetabular Fracture.

    PubMed

    Fan, Yanping; Lei, Jianyin; Zhu, Feng; Li, Zhiqiang; Chen, Weiyi; Liu, Ximing

    2015-01-01

    This study aims to evaluate the biomechanical mechanism of fixation systems in the most frequent T-shaped acetabular fracture using finite element method. The treatment of acetabular fractures was based on extensive clinical experience. Three commonly accepted rigid fixation methods (double column reconstruction plates (P × 2), anterior column plate combined with posterior column screws (P + PS), and anterior column plate combined with quadrilateral area screws (P + QS)) were chosen for evaluation. On the basis of the finite element model, the biomechanics of these fixation systems were assessed through effective stiffness levels, stress distributions, force transfers, and displacements along the fracture lines. All three fixation systems can be used to obtain effective functional outcomes. The third fixation system (P + QS) was the optimal method for T-shaped acetabular fracture. This fixation system may reduce many of the risks and limitations associated with other fixation systems.

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

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

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

  6. 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

  7. 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

  8. 37. VIEW OF AUXILIARY LOCK MITER GATE, WITH MAIN LOCK ...

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

    37. VIEW OF AUXILIARY LOCK MITER GATE, WITH MAIN LOCK UPSTREAM MITER GATE AND UPSTREAM GUIDE WALL IN BACKGROUND, LOOKING NORTHEAST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 4, Alma, Buffalo County, WI

  9. Triangular Fixation Technique for Bicolumn Restoration in Treatment of Distal Humerus Intercondylar Fracture

    PubMed Central

    Kang, Seung-Hoon; Jeong, Min; Lim, Hae-Seong

    2016-01-01

    Background Distal humerus intercondylar fractures are intra-articular and comminuted fractures involving soft tissue injury. As distal humerus is triangle-shaped, parallel plating coupled with articular fixation would be suitable for bicolumn restoration in treatment of distal humerus intercondylar fracture. Methods This study included 38 patients (15 males and 23 females) who underwent olecranon osteotomy, open reduction and internal fixation with the triangle-shaped cannulated screw and parallel locking plates (triangular fixation technique). Functional results were assessed with the visual analog scale (VAS) scores, Mayo elbow performance (MEP) scores and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaires. Anteroposterior and lateral elbow radiographs were assessed for reduction, alignment, fracture union, posttraumatic arthrosis, and heterotopic ossification, and computed tomography (CT) scans were used to obtain more accurate measurements of articular discrepancy. Results All fractures healed primarily with no loss of reduction. The mean VAS, MEP, and DASH scores of the affected elbow were not significantly different from those of the unaffected elbow (p = 0.140, p = 0.090, and p = 0.262, respectively). The mean degree of flexion was significantly lower in the affected elbow than in the unaffected elbow, but was still considered as functional (p = 0.001, > 100° in 33 of 38 patients). Two cases of articular step-offs (> 2 mm) were seen on follow-up CT scans, but not significantly higher in the affected elbow than in the unaffected elbow (p = 0.657). Binary logistic regression analysis revealed that only Association for Osteosynthesis (AO) type C3 fractures correlated with good/excellent functional outcome (p = 0.012). Complications occurred in 12 of the 38 patients, and the overall reoperation rate for complications was 10.5% (4 of 38 patients). Conclusions Triangular fixation technique for bicolumn restoration was an effective and reliable

  10. Adapter plate assembly for adjustable mounting of objects

    DOEpatents

    Blackburn, Robert S.

    1987-01-01

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

  11. Adapter plate assembly for adjustable mounting of objects

    DOEpatents

    Blackburn, R.S.

    1986-05-02

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

  12. 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.

  13. Rotatable stem and lock

    DOEpatents

    Deveney, Joseph E.; Sanderson, Stephen N.

    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.

  14. 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.

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

    PubMed

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

    2007-10-01

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

  16. 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

  17. Minimally invasive plate osteosynthesis in the treatment of proximal humeral fracture

    PubMed Central

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

    2006-01-01

    The management of fractures of the proximal shaft of the humerus has been evolving since the development of new techniques and new implants in recent years. It seems that this kind of fracture has an increasing incidence in the older, osteoporotic population. In the last 2 years, we have operated on 17 patients, with an average age of 65, who had proximal humeral shaft fractures treated by minimally invasive percutaneous osteosynthesis (MIPO) technique using the metaphyseal locking compression plate. Our study evaluated the surgical technique used and the outcome for these patients with regards to their range of movement and shoulder function. Our results showed that all the patients could achieve at least 140º of shoulder abduction in the first 6 months after the operation, except for three patients who had shoulder impingement. These patients had an average Constant score of 76.8. All fractures had bony union at 6 months, except one, which was probably due to poor reduction in the initial operation. Another complication that we encountered was radial nerve neuropraxia. The ways to prevent these complications are discussed. In conclusion, MIPO fixation using the metaphyseal locking compression plate is a good option for the management of proximal humeral shaft fractures. It provides early functional recovery, but we had to pay special attention to some of the surgical details in order to minimise complications. PMID:17033765

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

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

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

  19. Proximal Periprosthetic Femur Fractures: Strategies for Internal Fixation.

    PubMed

    Moloney, Gele B; Toro, Jose B; Helfet, David L; Wellman, David S

    2016-01-01

    As the number of patients living with total hip arthroplasty continues to rise, there will be an increase in periprosthetic fractures requiring surgical treatment. Treatment of periprosthetic femur fractures below a well-fixed hip arthroplasty stem presents a unique set of challenges. A review of the existing literature on surgical technique, including plate selection and configuration, proximal fixation options, and use of allograft, can serve to guide treatment of these challenging injuries. While not conclusive, the literature supports using soft tissue preserving techniques, bicortical proximal fixation, and fixation spanning the length of the femur. PMID:27327912

  20. Electronic door locking mechanism

    DOEpatents

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

    1997-10-21

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

  1. Electronic door locking mechanism

    DOEpatents

    Williams, Gary Lin; Kirby, Patrick Gerald

    1997-01-01

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

  2. Coal feed lock

    DOEpatents

    Pinkel, I. Irving

    1978-01-01

    A coal feed lock is provided for dispensing coal to a high pressure gas producer with nominal loss of high pressure gas. The coal feed lock comprises a rotor member with a diametral bore therethrough. A hydraulically activated piston is slidably mounted in the bore. With the feed lock in a charging position, coal is delivered to the bore and then the rotor member is rotated to a discharging position so as to communicate with the gas producer. The piston pushes the coal into the gas producer. The rotor member is then rotated to the charging position to receive the next load of coal.

  3. ''Old'' locked inflation

    SciTech Connect

    Liu, Yang; Piao, Yun-Song; Si, Zong-Guo E-mail: yspiao@gucas.ac.cn

    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.

  4. Arthroscopic Fixation of Tibial Spine Avulsion Fracture in Open Physis

    PubMed Central

    Chouhan, Varun

    2016-01-01

    Introduction: Arthroscopic fixation of tibial spine fracture in patients with open physis without damaging the growth plate is very important. We have described a very simple and effective technique for the first time in this article. Case report: A 16-year-old boy sustained avulsion fractures of tibial spine while playing. He was treated arthroscopically with excellent results. Conclusion: Arthroscopic fixation of tibial spine fracture in patients with open physis with two cannulated screws perpendicular to each other is a very simple technique providing strong construct, and allowing early mobilization without risk of damage to the growth plate. PMID:27703945

  5. Experimental quantum data locking

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Cao, Zhu; Wu, Cheng; Fukuda, Daiji; You, Lixing; Zhong, Jiaqiang; Numata, Takayuki; Chen, Sijing; Zhang, Weijun; Shi, Sheng-Cai; Lu, Chao-Yang; Wang, Zhen; Ma, Xiongfeng; Fan, Jingyun; Zhang, Qiang; Pan, Jian-Wei

    2016-08-01

    Classical correlation can be locked via quantum means: quantum data locking. With a short secret key, one can lock an exponentially large amount of information in order to make it inaccessible to unauthorized users without the key. Quantum data locking presents a resource-efficient alternative to one-time pad encryption which requires a key no shorter than the message. We report experimental demonstrations of a quantum data locking scheme originally proposed by D. P. DiVincenzo et al. [Phys. Rev. Lett. 92, 067902 (2004), 10.1103/PhysRevLett.92.067902] and a loss-tolerant scheme developed by O. Fawzi et al. [J. ACM 60, 44 (2013), 10.1145/2518131]. We observe that the unlocked amount of information is larger than the key size in both experiments, exhibiting strong violation of the incremental proportionality property of classical information theory. As an application example, we show the successful transmission of a photo over a lossy channel with quantum data (un)locking and error correction.

  6. Locke and botany.

    PubMed

    Anstey, Peter R; Harris, Stephen A

    2006-06-01

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

  7. Photographic fixative poisoning

    MedlinePlus

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

  8. Pressure locking test results

    SciTech Connect

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D.

    1996-12-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.{close_quotes} Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; the authors will publish the results of their thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions.

  9. Pressure locking test results

    SciTech Connect

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D.

    1996-06-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.{close_quotes} Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; we will publish the results of our thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions.

  10. 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.

  11. Healing of fractures with freeze-dried cortical bone plates. Comparison with compression plating.

    PubMed

    Malinin, T; Latta, L L; Wagner, J L; Brown, M D

    1984-11-01

    The healing of fractures of the radius with internal fixation by stainless-steel compression plates was compared with fractures fixed with freeze-dried bone-plate allografts. Fractures fixed with metallic plates gained slightly less than half the biomechanical strength of the contralateral control bone and healed without noticeable external callus formation. Bone-plated fractures regained three-fourths of the biomechanical strength of controls and healed by forming an external callus. Bone-plate allografts were eventually incorporated in the host bone. Allograft plates were vascularized and remodeled into cancellous bone in the process of incorporation in the host bones.

  12. A Mindlin-Reissner variational principle to analyze the behavior of moderately thick plates

    SciTech Connect

    Carnicer, R.S. ); Alliney, S. )

    1989-11-01

    In the present work a method to solve the plate behavior under the assumption of the Mindlin plate theory is analyzed by means of finite element techniques, avoiding the tendency of the thin element to lock when the thickness of the plates becomes very small. A different formulation is developed from the Mindlin-Reissner principle for general boundary conditions. Numerical examples to evaluate the noninfluence of locking on clamped and simple support plates are calculated.

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

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

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

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

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

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

  15. Lock 1 (Savannah River Lock), Elevation of North Wall, Detail ...

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

    Lock 1 (Savannah River Lock), Elevation of North Wall, Detail of Wall Foundation, Detail of Gate Pocket - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  16. Lock 6 (Ogeechee River Lock), Plan, Elevation of North Wall, ...

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

    Lock 6 (Ogeechee River Lock), Plan, Elevation of North Wall, Cap Stone for Gate Hinge, Brick Patterns - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

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

    PubMed Central

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

    2014-01-01

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

  18. [Multifunctional external fixator compatible with the Zespol system and Schanz pins].

    PubMed

    Molski, K; Molski, K

    1995-01-01

    The construction and use of new external fixator broadening the use and increasing efficacy of Zespol system is presented. The apparatus may be used primarily or may replace Zespol plate. It enables controlled interfragmental compression, limb elongation, correction of angular and translational dislocations. After bony union occurs the fixator may be replaced with Zespol plate and reapplied to another patient. It is also compatible with Schanz pins. PMID:8620776

  19. Self Locking Fasteners

    NASA Technical Reports Server (NTRS)

    1987-01-01

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

  20. Improving carbon fixation pathways

    SciTech Connect

    Ducat, DC; Silver, PA

    2012-08-01

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

  1. Management of Postoperative Spondylodiscitis with and without Internal Fixation.

    PubMed

    Wang, Xiang; Tao, Hairong; Zhu, Yanhui; Lu, Xiongwei; Hu, Xiaopeng

    2015-01-01

    Postoperative spondylodiscitis is relatively uncommon. This complication is associated with increased cost, and long-term of inability to work, and even morbidity. Although the majority of postoperative spondylodiscitis cases can be well managed by conservative treatment, postoperative spondylodiscitis after internal fixation and those cases that are unresponsive to the conservative treatment present challenges to the surgeon. Here, a review was done to analyze the treatment of postoperative spondylodiscitis with/without internal fixation. This review article suggested that majority of postoperative spondylodiscitis without internal fixation could be cured by conservative treatment. Either posterior or anterior debridement can be used to treat postoperative spondylodiscitis without internal fixation when conservative treatment fails. In addition, minimally invasive debridement and drainage may also be an alternative treatment. In case of postoperative spondylodiscitis after internal fixation, surgical treatment was required. In the cervical spine, it can be well managed by anterior debridement, removal of internal fixation, and reconstruction of the spinal stability by using bone grafting/cage/anterior plate. Postoperative spondylodiscitis after internal fixation is successfully managed by combined anterior debridement, fusion with posterior approach and removal of pedicle screw or extension of pedicle screw beyond the lesion site, in the thoracic and lumbar spine. PMID:26242325

  2. Biomechanical Study of Acetabular Tridimensional Memoryalloy Fixation System

    NASA Astrophysics Data System (ADS)

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

    2011-07-01

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

  3. Positioning and locking apparatus

    DOEpatents

    Hayward, Milton L.; Harper, William H.

    1987-01-01

    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.

  4. Positioning and locking apparatus

    DOEpatents

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

    1987-06-30

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

  5. 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.

  6. Lock for Gantry Trolley

    NASA Technical Reports Server (NTRS)

    Newberg, H. F.

    1982-01-01

    Single operator on ground controls trolley-locking mechanism on portable gantry. Mechanism prevents trolley and load from moving along track when gantry is wheeled from one location to another. A downward pull on chain withdraws brakeshoes from trolley wheels. When operator releases chain, brakeshoes reengage to wheels.

  7. 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.

  8. Plate motion

    SciTech Connect

    Gordon, R.G. )

    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.

  9. Carbon-fibre reinforced plates for problem fractures.

    PubMed

    Pemberton, D J; McKibbin, B; Savage, R; Tayton, K; Stuart, D

    1992-01-01

    We report our experience with carbon-fibre reinforced plastic (CFRP) plates in the management of 19 problem fractures complicated by either infection, nonunion, comminution or contamination. The combination offers secure fixation without inhibition of callus formation.

  10. Fixation produced by conflict.

    PubMed

    Karsh, E B

    1970-05-15

    All rats given a choice between a rewarded alternative and a conflict alternative (rewarded and punished) developed position fixations when the position of the alternatives was reversed. In contrast, all animals given one rewarded alternative and another nonrewarded (or punished and nonrewarded) alternative learned to choose the rewarded side during 25 successive reversals.

  11. 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)

  12. 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,…

  13. Fixation produced by conflict.

    PubMed

    Karsh, E B

    1970-05-15

    All rats given a choice between a rewarded alternative and a conflict alternative (rewarded and punished) developed position fixations when the position of the alternatives was reversed. In contrast, all animals given one rewarded alternative and another nonrewarded (or punished and nonrewarded) alternative learned to choose the rewarded side during 25 successive reversals. PMID:5444066

  14. Shaft Fractures of Both Forearm Bones: The Outcomes of Surgical Treatment with Plating Only and Combined Plating and Intramedullary Nailing

    PubMed Central

    Kim, Sang Bum; Yi, Jin Woong; Lee, Jung Bum; Lim, Byoung Gu

    2015-01-01

    Background Plate fixation is the most commonly used technique for the treatment of shaft fractures of both forearm bones (SFBFBs). However, all fractures are difficult to treat with plate fixation because of soft tissue injuries, fracture patterns, or the patient's condition. The purpose of this study is to compare the functional results of plate fixation only and combined plate and intramedullary (IM) nail fixation in SFBFBs. Methods Fifty-nine cases of SFBFBs that were surgically treated from June 2007 to July 2012 were retrospectively reviewed. In this study, 47 cases that were followed up for more than 12 months were included. All SFBFBs were divided into two groups according to the methods used for internal fixation: plate fixation only (group A) and combined plate and IM nail fixation (group B). The fixation methods were determined intraoperatively. Plate fixation was considered as the first option in all cases, but combined plate and IM nail fixation was selected as the second option if it was difficult to be fixed with plate only. Groups A and B comprised of 31 and 16 cases, respectively. The functional results were evaluated by the Grace and Eversmann rating system and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. Results In groups A and B, a radiologic union was achieved in 30/31 and 14/16 cases and average union time was 11.1 and 17.8 weeks, respectively. According to the Grace and Eversmann rating system, group A had excellent results in 15 cases, good in 14, acceptable in one, and unacceptable in one. Group B had excellent results in three cases, good in nine, acceptable in two, and unacceptable in two. The average DASH score was 7.1 points (range, 0 to 19.2 points) in group A and 15.1 points (range, 0 to 29.6 points) in group B. Three cases of nonunion with unacceptable results achieved a bony union by additional procedures and the functional results of these cases improved to good or excellent. Conclusions The functional

  15. Experimental study in order to assess the effects of limited periosteum stripping on the fracture healing and to compare osteosynthesis using plates and screws with intramedullary Kirschner wire fixation.

    PubMed

    Neagu, Tiberiu Paul; Enache, Valentin; Cocoloş, Ion; Ţigliş, Mirela; Cobilinschi, Cristian; Ţincu, Radu

    2016-01-01

    There are many studies that investigate indirect and direct fracture healing but few mention the effect of periosteum stripping on consolidation of fractures. Most of these studies use only one method of osteosynthesis for each group. Therefore, we reported a new developed murine model in order to assess if limited periosteum stripping influence significantly the quality of the fracture healing process by comparing two different osteosynthesis methods to reduce simultaneously bilateral femur fractures. We applied the experimental protocol for a number of 12 rats. We used plates and screws to reduce femoral osteotomy for the right hind limb and intramedullary Kirschner wire for the left hind limb. Clinical, radiological and histological assessments were made for a period of eight weeks. The absence of a healthy hind limb led to a slower healing process based on the histological findings and to implant failure based on radiological findings. In summary, complete fracture healing was not achieved during this experimental study. Therefore, we consider that future studies are needed for a better understanding of the effects of periosteum removal on the fracture healing process. PMID:27516016

  16. 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.

  17. 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.

  18. External Fixation: Principles and Applications.

    PubMed

    Bible, Jesse E; Mir, Hassan R

    2015-11-01

    The modularity and ease of application of modern external fixation has expanded its potential use in the management of fractures and other musculoskeletal conditions. In fracture care, it can be used for provisional and definitive fixation. Short-term provisional applications include "damage control" and periarticular fracture fixation. The risk:benefit ratio of added stability needs to be assessed with each fixator. Soft-tissue management is critical during pin insertion to lessen the risk of loosening and infection. Although provisional fixation is safe for early conversion to definitive fixation, several factors affect the timing of definitive surgery, including the initial injury, external fixator stability, infection, and the physiologic state of the patient. PMID:26306568

  19. The Mechanics of External Fixation

    PubMed Central

    Rozbruch, S. Robert

    2006-01-01

    External fixation has evolved from being used primarily as a last resort fixation method to becoming a main stream technique used to treat a myriad of bone and soft tissue pathologies. Techniques in limb reconstruction continue to advance largely as a result of the use of these external devices. A thorough understanding of the biomechanical principles of external fixation is useful for all orthopedic surgeons as most will have to occasionally mount a fixator throughout their career. In this review, various types of external fixators and their common clinical applications are described with a focus on unilateral and circular frames. The biomechanical principles that govern bony and fixator stability are reviewed as well as the recommended techniques for applying external fixators to maximize stability. Additionally, we have illustrated methods for managing patients while they are in the external frames to facilitate function and shorten treatment duration. PMID:18751766

  20. Data port security lock

    DOEpatents

    Quinby, Joseph D.; Hall, Clarence S.

    2008-06-24

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

  1. 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.

  2. 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.

  3. 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

  4. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  5. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  6. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  7. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  9. Intra-ply shear locking

    NASA Astrophysics Data System (ADS)

    ten Thije, R. H. W.; Akkerman, R.

    2007-04-01

    Intra-ply shear locking results in unrealistic fibre stresses and spurious wrinkling in composite forming simulations. Three remedies are investigated: aligning the mesh, applying reduced integration and using multi-field elements. The bias extension simulation is used to test several triangular and quadrilateral elements on their capability to avoid locking. Their performance under large deformations is tested as well. The new multi-field element seems to be the best locking free element in random meshes.

  10. Safe-haven locking device

    DOEpatents

    Williams, J.V.

    1984-04-26

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

  11. Backlash-Free Locking Hinge

    NASA Technical Reports Server (NTRS)

    Wessekski, Clarence J.

    1987-01-01

    Tight joints achieved without precisely machined parts. Hinge for foldable structures locked with minimum force by human operator. Once locked, hinge makes strong, tight joint. Loose fit, or joint slop, common to commercial locking hinges eliminated. Despite tight fit, new hinge concept does not impose close tolerances on manufacture of its parts. Developed for erecting unfoldable structures in space, hinge used on collapsible scaffolds and similar terrestrial structures.

  12. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity.

    PubMed

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang

    2015-01-01

    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves.

  13. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity.

    PubMed

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang

    2015-01-01

    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves. PMID:26431525

  14. Bacterial alternative nitrogen fixation systems.

    PubMed

    Joerger, R D; Bishop, P E

    1988-01-01

    The introduction briefly reviews some of the salient features of the well-characterized conventional molybdo-enzyme system for N2 fixation. This is followed by a brief account of the discovery of an alternative N2 fixation system that does not require molybdenum in the N2-fixing bacterum Azotobacter vinelandii. The next section cites observations from the early literature on N2 fixation suggesting may not always require molybdenum. Next, recent evidence for an alternative N2 fixation system in A. vinelandii is discussed. A brief description of our discovery of an alternative nitrogenase which is not a molybdenum or vanadium enzyme is presented, followed by a summary of recent papers describing an alternative vanadium-containing nitrogenase. Available information on the genetics and regulation of alternative N2 fixation systems is discussed. Finally, the possible/probable presence of alternative N2 fixation systems in bacteria other than Azotobacter species is covered.

  15. Robust Photon Locking

    SciTech Connect

    Bayer, T.; Wollenhaupt, M.; Sarpe-Tudoran, C.; Baumert, T.

    2009-01-16

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

  16. Chronic unilateral locked facet joint with spinal cord injury in a 26-month-old child: A case report

    PubMed Central

    Wu, Ai-Min; Wang, Xiang-Yang; Luo, Peng; Xu, Hua-Zi; Chi, Yong-Long

    2015-01-01

    Objectives This study presents the successful posterior surgical reduction and fusion on a 26-month-old child with chronic unilateral locked facet joint and spinal cord injury (SCI). Methods A 26-month-old child with chronic unilateral locked facet joint and SCI treated by posterior surgical reduction and fusion. Plaster external fixation was applied and rehabilitation exercise was trained post-operatively. Results Chronic unilateral locked facet joint was reduced successfully and bone fusion of C4/5 was achieved 3 months after surgery. The function of both lower limbs was improved 1 year after surgery, aided with physical rehabilitation. Conclusion Unilateral locked facet joint in pediatric population is rare. Few clinical experiences were found in the literature. Non-surgical treatment has advantages of not being invasive and is preferred for acute patients; however, it may not be suitable for chronic unilateral locked facet joint with SCI, in which surgical intervention is needed. PMID:24673578

  17. Nitrogen fixation apparatus

    DOEpatents

    Chen, Hao-Lin

    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.

  18. Multistability and hysteresis phenomena in passively mode-locked fiber lasers

    SciTech Connect

    Komarov, Andrey; Leblond, Herve; Sanchez, Francois

    2005-05-15

    A passively mode-locked fiber laser is theoretically investigated. The mode locking is achieved using the nonlinear polarization technique. We consider the practical case of the ytterbium-doped fiber laser operating in the normal dispersion regime. The effect of the phase plates is explicitly taken into account. The resulting model reduces to one iterative equation for the optical Kerr nonlinearity, the phase plates and the polarizer, and one partial differential equation for the gain and the dispersion. Numerical simulations allow us to describe several features observed in passively mode-locked fiber lasers such as bistability between the mode lock and the continuous regime, multiple pulse behavior, hysteresis phenomena. The dynamics of the number of pulses as a function of the pumping power is also reported. Pump power hysteresis is demonstrated.

  19. Five cases of failure of the tibial polyethylene insert locking mechanism in one design of constrained knee arthroplasty.

    PubMed

    Rapuri, Venkata R; Clarke, Henry D; Spangehl, Mark J; Beauchamp, Christopher P

    2011-09-01

    We describe 5 cases of failure of the locking mechanism of the polyethylene insert and tibial base-plate in one design of constrained condylar knee prosthesis due to disengagement of the locking screw. Loosening of the screw is believed to occur because of a counterclockwise torque created by the axial rotation of the femur on the tibia that occurs as the knee extends during gait. This torque is transmitted via the highly rotationally constrained femoral housing and tibial post to the locking screw. These failures suggest that an alternative locking mechanism should be considered for this prosthesis.

  20. [An experimental study of the effects of stress-relaxation plate on bone remodeling].

    PubMed

    Dai, M; Dai, K; Qui, S

    1995-11-01

    An ideal bone plate would provide rigid fixation to ensure stabilization of bone fragments at the early stage after fracture, while at the late stage osteoporosis induced by stress shielding effect of the plate should be prevented. However, there is no report of such a plate that could meet with all these requirements. Twenty-eight adult New Zealand rabbits were used in this experiment. Ordinary stainless-steel plate (no washer plate) and similar plate padded with ultrahigh molecular polyethylene washers in its screw holes (washer plate) were fixed respectively on mid-shelf of each side of tibiae. The animals were killed at 2, 4, 8, 12, 16, 20 and 24 weeks after operation, and the fixed bone segments of both tibiae were removed for light microscopy, polarized light microscopy and fluoroscopy. The results showed that the tibiae fixed with plate fixation both appeared bone resorption, but there was more severe resorption in bone with no washer plate fixation than that with washer plate fixation. Cancelization of cortical bone was seen in the former but not in the latter at 12 weeks postopertively. This demonstrated that the washer might creep and damage with fixation time, resulting in gradual decrease in the rigidity of the plate-screw system and thus reducing bone resorption as caused by stress shielding. PMID:8731919

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

    PubMed

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

    2013-06-01

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

  2. 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.

  3. 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.

  4. TIBIOTARSAL COMPRESSION ARTHRODESIS USING A LATERAL LOCKING PLATE.

    PubMed

    Coughlin, Michael J; Nery, Caio; Baumfeld, Daniel; Jastifer, James

    2012-01-01

    Objetivos: A artrodese tibiotársica (TT) continua sendo uma importante opção no tratamento da artrose primária ou pós-traumática do tornozelo mas persiste ainda a controvérsia sobre o melhor método de fixação do foco de artrodese. Independentemente do tipo de material utilizado, o objetivo maior é a obtenção da fusão articular sólida, saudável e indolor. O propósito do presente estudo é apresentar os resultados preliminares de um novo sistema de placa bloqueada lateral compressiva para a artrodese do tornozelo. Método: Treze pacientes consecutivos portadores de artrose tibiotársica foram submetidos à artrodese do tornozelo nove pacientes eram homens e quatro mulheres. Com o auxílio de um guia, as superfícies articulares do talo e da tíbia foram decorticadas. Um sistema de compressão foi aplicado para evitar o alinhamento indesejável dos segmentos e uma placa bloqueada pré-moldada lateral foi utilizada para obter a fusão articular. Resultados: Tanto o escore AOFAS quanto o VAS melhoraram com a cirurgia. Todos os tornozelos operados consolidaram dentro do prazo de seis meses. Em todos os pacientes, foi obtido um ótimo alinhamento nos planos sagital, coronal e transverso. Conclusão: Acreditamos que a combinação de compressão bilateral, cortes ósseos com contornos pré-demarcados e placa lateral bloqueada, constitui uma técnica moderna, segura e útil para a artrodese do tornozelo.

  5. Modeling and minimizing interference from corneal birefringence in retinal birefringence scanning for foveal fixation detection

    PubMed Central

    Irsch, Kristina; Gramatikov, Boris; Wu, Yi-Kai; Guyton, David

    2011-01-01

    Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates (“wave-plate-enhanced RBS”) that allows foveal fixation detection essentially independently of corneal birefringence. The RBS computer model, and in particular the optimization algorithm, were verified with experimental human data using an available monocular RBS-based eye fixation monitor. Fixation detection using wave-plate-enhanced RBS is adaptable to less cooperative subjects, including young children at risk for developing amblyopia. PMID:21750772

  6. Modeling and minimizing interference from corneal birefringence in retinal birefringence scanning for foveal fixation detection.

    PubMed

    Irsch, Kristina; Gramatikov, Boris; Wu, Yi-Kai; Guyton, David

    2011-07-01

    Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates ("wave-plate-enhanced RBS") that allows foveal fixation detection essentially independently of corneal birefringence. The RBS computer model, and in particular the optimization algorithm, were verified with experimental human data using an available monocular RBS-based eye fixation monitor. Fixation detection using wave-plate-enhanced RBS is adaptable to less cooperative subjects, including young children at risk for developing amblyopia.

  7. Definition of Locked-up Stresses around a Rectilinear Welding Seam

    NASA Astrophysics Data System (ADS)

    Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

    2016-04-01

    In article one of the ways of modelling of the locked-up stresses caused by imposing of a welding seam in a plate is described. These stresses are caused by residual deformations of welding seams. In the settlement scheme the welding seam is presented in the form of an element by the thickness equal to the thickness of a plate, inserted in it with a longitudinal and cross-section tightness. The field of locked-up stresses around the welding seam experiences longitudinal and cross-section shrinkage under cooling and it is defined in work with the use of complex potentials of the theory of elasticity.

  8. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus...

  9. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus...

  10. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus...

  11. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus...

  12. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus...

  13. 49 CFR 236.336 - Locking bed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking bed. 236.336 Section 236.336 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Instructions § 236.336 Locking bed. The various parts of the locking bed, locking bed supports, and tappet...

  14. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall...

  15. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall...

  19. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  20. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  1. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  2. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  3. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  4. Cavity-locked ring down spectroscopy

    DOEpatents

    Zare, Richard N.; Paldus, Barbara A.; Harb, Charles C.; Spence, Thomas

    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.

  5. Toward FRP-Based Brain-Machine Interfaces-Single-Trial Classification of Fixation-Related Potentials.

    PubMed

    Finke, Andrea; Essig, Kai; Marchioro, Giuseppe; Ritter, Helge

    2016-01-01

    The co-registration of eye tracking and electroencephalography provides a holistic measure of ongoing cognitive processes. Recently, fixation-related potentials have been introduced to quantify the neural activity in such bi-modal recordings. Fixation-related potentials are time-locked to fixation onsets, just like event-related potentials are locked to stimulus onsets. Compared to existing electroencephalography-based brain-machine interfaces that depend on visual stimuli, fixation-related potentials have the advantages that they can be used in free, unconstrained viewing conditions and can also be classified on a single-trial level. Thus, fixation-related potentials have the potential to allow for conceptually different brain-machine interfaces that directly interpret cortical activity related to the visual processing of specific objects. However, existing research has investigated fixation-related potentials only with very restricted and highly unnatural stimuli in simple search tasks while participant's body movements were restricted. We present a study where we relieved many of these restrictions while retaining some control by using a gaze-contingent visual search task. In our study, participants had to find a target object out of 12 complex and everyday objects presented on a screen while the electrical activity of the brain and eye movements were recorded simultaneously. Our results show that our proposed method for the classification of fixation-related potentials can clearly discriminate between fixations on relevant, non-relevant and background areas. Furthermore, we show that our classification approach generalizes not only to different test sets from the same participant, but also across participants. These results promise to open novel avenues for exploiting fixation-related potentials in electroencephalography-based brain-machine interfaces and thus providing a novel means for intuitive human-machine interaction.

  6. Toward FRP-Based Brain-Machine Interfaces—Single-Trial Classification of Fixation-Related Potentials

    PubMed Central

    Finke, Andrea; Essig, Kai; Marchioro, Giuseppe; Ritter, Helge

    2016-01-01

    The co-registration of eye tracking and electroencephalography provides a holistic measure of ongoing cognitive processes. Recently, fixation-related potentials have been introduced to quantify the neural activity in such bi-modal recordings. Fixation-related potentials are time-locked to fixation onsets, just like event-related potentials are locked to stimulus onsets. Compared to existing electroencephalography-based brain-machine interfaces that depend on visual stimuli, fixation-related potentials have the advantages that they can be used in free, unconstrained viewing conditions and can also be classified on a single-trial level. Thus, fixation-related potentials have the potential to allow for conceptually different brain-machine interfaces that directly interpret cortical activity related to the visual processing of specific objects. However, existing research has investigated fixation-related potentials only with very restricted and highly unnatural stimuli in simple search tasks while participant’s body movements were restricted. We present a study where we relieved many of these restrictions while retaining some control by using a gaze-contingent visual search task. In our study, participants had to find a target object out of 12 complex and everyday objects presented on a screen while the electrical activity of the brain and eye movements were recorded simultaneously. Our results show that our proposed method for the classification of fixation-related potentials can clearly discriminate between fixations on relevant, non-relevant and background areas. Furthermore, we show that our classification approach generalizes not only to different test sets from the same participant, but also across participants. These results promise to open novel avenues for exploiting fixation-related potentials in electroencephalography-based brain-machine interfaces and thus providing a novel means for intuitive human-machine interaction. PMID:26812487

  7. John Locke on Personal Identity**

    PubMed Central

    Nimbalkar, Namita

    2011-01-01

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

  8. John locke on personal identity.

    PubMed

    Nimbalkar, Namita

    2011-01-01

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

  9. Biomechanical and biological aspects of defect treatment in fractures using helical plates.

    PubMed

    Perren, S M; Regazzoni, P; Fernandez, A A D

    2014-01-01

    The clinical case of figure 1 through figure 11 shows a series of impressive failures of plate fixation. The plates were repeatedly applied bridging a comminuted bone segment in a heavy patient. The biomechanical analysis elaborates why this happened and proposes an unconventional procedure to prevent this failure with a minimally invasive procedure. A plate bridging an open gap or a defect in a long bone diaphysis is exposed to full functional load. According to clinical observations such plate application often fails even without external load such as weight bearing. The plate risks to break through fatigue when exposed during a long time to cyclic loading. This type of failure has been observed even with broad plates as well in femoral as in tibiae. The first option to avoid such failure consists in protecting the plate by installing load sharing between plate and either bone or an additional implant. This reduces the load carried by the plate to a safe level. Load sharing with bone may be installed at surgery by establishing solid mechanical bridge between the two main fragments of the fractured bone. The optimal load sharing relies on a solid compressed contact between the main fragments. It can be established because the bone is able to take a large load which results in optimal protection of the plate. In the case of an extended comminuted bone segment it may be very difficult, traumatizing and inefficient to reconstruct the bone. In the present case it was impossible to establish load sharing through the bone. The second option protecting the plate is provided by callus bridging of the gap or defect. The formation of a solid callus bridge takes time but the fatigue failure of the plate also takes time. Therefore, the callus bridge may prevent a late fatigue failure. The surgeon may select one of several options: - Replacing the lack of bone support using a second plate which immediately alleviates plate loading. The drawback of application of a second

  10. The Josephson locked synthesizer

    NASA Astrophysics Data System (ADS)

    Jeanneret, Blaise; Overney, Frédéric; Rüfenacht, Alain

    2012-12-01

    This paper reviews the development of a Josephson locked synthesizer (JoLoS) where a calibrator is used as a sine wave generator whose output is controlled by the calculable fundamental of the stepwise sinusoidal wave generated by a programmable Josephson junction array. Such a system combines the versatility of a calibrator with the stability and accuracy of the Josephson voltage standard. The accuracy of the JoLoS was confirmed by a high precision comparison with a pulse-driven Josephson voltage standard. This comparison showed agreement between the two systems of 0.3 μV V-1 at a frequency of 500 Hz and an rms amplitude of 100 mV. As an example of the calibration ability of the JoLoS, the calibration of a thermal transfer standard (TTS) is reported. This calibration is in good agreement with a calibration performed against a multi-junction thermal converter for voltages below 1 V and frequencies below 1 kHz. The agreement between the JoLoS and the calibrated TTS is better than 1 μV V-1 at 1 V. On the lowest voltage ranges, the uncertainties measured with the JoLoS are significantly smaller than the calibration uncertainties of the TTS. This result demonstrates the present potential of the JoLoS at voltages up to 1 V and frequencies up to 1 kHz.

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

    PubMed

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

    2011-01-01

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

  12. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fixation device. 886.1290 Section 886.1290 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for use as a fixation target for the patient...

  13. Stereotactic atlantoaxial transarticular screw fixation.

    PubMed

    Laherty, R W; Kahler, R J; Walker, D G; Tomlinson, F H

    2005-01-01

    Atlantoaxial stabilisation can be performed using a variety of surgical techniques. Developments in spinal instrumentation and stereotactic technology have been incorporated into these procedures. We have recently adopted frameless stereotaxy to assist in such operations. A retrospective study of patients treated by the authors and using frameless stereotaxy from 2001 to 2002 was performed. Each patient underwent pre-operative fine-cut CT in the position of fixation. Using these images, screw trajectory was planned. Stereotaxis and fluoroscopy was utilised during fixation. A post-operative CT was performed. There were nine patients. Bilateral screw placement was achieved in eight. In the remaining case stereotactic planning predicted the single screw fixation. There were no post-operative complications. Post-operative CT showed screw placement corresponding to the planned trajectory in all 17 screws. Stabilisation was achieved in all. Stereotactic atlantoaxial screw fixation is an accessible, safe and accurate method for the management of C1-2 instability. PMID:15639416

  14. Internal fixation: a historical review.

    PubMed

    Greenhagen, Robert M; Johnson, Adam R; Joseph, Alison

    2011-08-01

    Internal fixation has become a pillar of surgical specialties, yet the evolution of these devices has been relatively short. The first known description of medical management of a fracture was found in the Edwin Smith Papyrus of Ancient Egypt (circa 2600 bc). The first description of internal fixation in the medical literature was in the 18th century. The advancement of techniques and technology over the last 150 years has helped to preserve both life and function. The pace of advancement continues to accelerate as surgeons continue to seek new technology for osseous fixation. The authors present a thorough review of the history of internal fixation and the transformation into a multibillion dollar industry. PMID:21944395

  15. Molecular Biology of Nitrogen Fixation

    ERIC Educational Resources Information Center

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

    1975-01-01

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

  16. [Intra-articular fracture of the distal radius: results following osteosynthesis with a support plate].

    PubMed

    Ferguson, G A; Leutenegger, A; Mark, G; Breiter, H; Rüedi, T

    1989-01-01

    The treatment of comminuted intra-articular fractures of the distal radius often requires an operative fixation. Beside the recently recommended external fixator, the support plate fixation offers a helpful alternative to treatment. Between 1980 and 1986, 30 wrists in 29 patients with intra-articular fractures of the distal radius were stabilized with a buttress plate an the Kantonsspital Chur, Switzerland. The mean follow-up-time was 15 months. These follow-ups showed that the buttress plate in treatment of complicated intra-articular fractures allows a satisfactory reduction and stabilization with restoration of the articular congruity and the possibility for early active assisted motion. Buttress plate fixation still remains a demanding technique, which in complicated cases, should be reserved for the experienced surgeon. PMID:2500786

  17. Hamate hook nonunion treated with a hook plate: case report and surgical technique.

    PubMed

    Taleb, Chihab; Murachowsky, Joel; Ruggiero, Gustavo M

    2012-12-01

    Despite of its rarity, hamate hook nonunion can cause several complications like tendon rupture or loss of grip strength. Admitted treatments in the literature are excision of the bone fragment or its open reduction and internal fixation. We report a clinical case of a high-level baseball player with hamate hook nonunion treated with an original technique of fixation using a hook plate.

  18. [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.

  19. Medicine in John Locke's philosophy.

    PubMed

    Sanchez-Gonzalez, M A

    1990-12-01

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

  20. The healing philosopher: John Locke's medical ethics.

    PubMed

    Short, Bradford William

    2004-01-01

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

  1. 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.

  2. Lock detection in Costas loops

    NASA Astrophysics Data System (ADS)

    Mileant, A.; Hinedi, S.

    1992-03-01

    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.

  3. GPS constraints on interplate locking within the Makran subduction zone

    NASA Astrophysics Data System (ADS)

    Frohling, E.; Szeliga, W.

    2016-04-01

    The Makran subduction zone is one of the last convergent margins to be investigated using space-based geodesy. While there is a lack of historical and modern instrumentation in the region, a sparse sampling of continuous and campaign measurements over the past decade has allowed us to make the first estimates of convergence rates. We combine GPS measurements from 20 stations located in Iran, Pakistan and Oman along with hypocentral locations from the International Seismological Centre to create a preliminary 3-D estimate of the geometry of the megathrust, along with a preliminary fault-coupling model for the Makran subduction zone. Using a convergence rate which is strongly constrained by measurements from the incoming Arabia plate along with the backslip method of Savage, we find the Makran subduction zone appears to be locked to a depth of at least 38 km and accumulating strain.We also find evidence for a segmentation of plate coupling, with a 300 km long section of reduced plate coupling. The range of acceptable locking depths from our modelling and the 900 km along-strike length for the megathrust, makes the Makran subduction zone capable of earthquakes up to Mw = 8.8. In addition, we find evidence for slow-slip-like transient deformation events on two GPS stations. These observations are suggestive of transient deformation events observed in Cascadia, Japan and elsewhere.

  4. Locking mechanism for orthopedic braces

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  5. Circuit breaker lock out assembly

    DOEpatents

    Gordy, Wade T.

    1984-01-01

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

  6. Locked-wrap fuel rod

    DOEpatents

    Kaplan, Samuel; Chertock, Alan J.; Punches, James R.

    1977-01-01

    A method for spacing fast reactor fuel rods using a wire wrapper improved by orienting the wire-wrapped fuel rods in a unique manner which introduces desirable performance characteristics not attainable by previous wire-wrapped designs. Use of this method in a liquid metal fast breeder reactor results in: (a) improved mechanical performance, (b) improved rod-to-rod contact, (c) reduced steel volume, and (d) improved thermal-hydraulic performance. The method produces a "locked wrap" design which tends to lock the rods together at each of the wire cluster locations.

  7. Automatic locking knee brace joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce (Inventor)

    1995-01-01

    This invention is an apparatus for controlling the pivotal movement of a knee brace comprising a tang-and-clevis joint that has been uniquely modified. Both the tang and the clevis have a set of teeth that, when engaged, can lock the tang and the clevis together. In addition, the tang is biased away from the clevis. Consequently, when there is no axial force (i.e., body weight) on the tang, the tang is free to pivot within the clevis. However, when an axial force is exerted on the tang, the tang is pushed into the clevis, both sets of teeth engage, and the tang and the clevis lock together.

  8. Intraocular lens fixation with dacron.

    PubMed

    Peyman, G A; Koziol, J E

    1978-10-01

    To overcome the problem of postoperative lens dislocation, we evaluated a new means of lens fixation. Our experimental studies in rabbits and primates demonstrated that Dacron polyethylene terephtalate induced a cellular reaction from either the anterior or posterior iris surface when placed in contact with the iris, thereby establishing a bond between the Dacron fibers and the iris. Dacron mesh can be attached to the distal portion of either the anterior or posterior loops of a Binkhorst iris clip (4-loop) lens. In the rabbit eye, lens fixation occurred within five days; in the primate eye, 30 days. When combined with silk, Dacron produced tissue ingrowth in the primate eye within 14 days. No unwanted reaction occurred in any animal with the Dacron and silk combination. Being biodegradable, the silk induced faster cellular ingrowth than the Dacron. However, Dacron, which is not biodegradable, provided a permanent means of fixation. PMID:155053

  9. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  10. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  11. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  12. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  13. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  14. Mechanical properties of Indonesian-made narrow dynamic compression plate.

    PubMed

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

    2012-09-01

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

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

    PubMed

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

    2004-09-01

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

  16. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  17. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  18. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  19. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  20. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  1. 49 CFR 236.767 - Locking, route.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Locking, route. Electric locking, effective when a train passes a signal displaying an aspect for it to... within the route entered. It may be so arranged that as a train clears a track section of the route,...

  2. 49 CFR 236.767 - Locking, route.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Locking, route. Electric locking, effective when a train passes a signal displaying an aspect for it to... within the route entered. It may be so arranged that as a train clears a track section of the route,...

  3. 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-L

  4. A survey of current practices and preferences for internal fixation of displaced olecranon fractures

    PubMed Central

    Wood, Thomas; Thomas, Katie; Farrokhyar, Forough; Ristevski, Bill; Bhandari, Mohit; Petrisor, Bradley

    2015-01-01

    Background Olecranon fractures represent 10% of upper extremity fractures. There is a growing body of literature to support the use of plate fixation for displaced olecranon fractures. The purpose of this survey was to gauge Canadian surgeons’ practices and preferences for internal fixation methods for displaced olecranon fractures. Methods Using an online survey tool, we administered a cross-sectional survey to examine current practice for fixation of displaced olecranon fractures. Results We received 256 completed surveys for a response rate of 31% (95% confidence interval [CI] 30.5–37.5%). The preferred treatment was tension band wiring (78.5%, 95% CI 73–83%) for simple displaced olecranon fractures (Mayo IIA) and plating (81%, 95% CI 75.5–85%) for displaced comminuted olecranon fractures (Mayo IIB). Fracture morphology with a mean impact of 3.31 (95% CI 3.17–3.45) and comminution with a mean impact of 3.34 (95% CI 3.21–3.46) were the 2 factors influencing surgeons’ choice of fixation method the most. The major deterrent to using tension band wiring for displaced comminuted fractures (Mayo IIB) was increased stability obtained with other methods described by 75% (95% CI 69–80%) of respondents. The major deterrent for using plating constructs for simple displaced fractures (Mayo IIA) was better outcomes with other methods. Hardware prominence was the most commonly perceived complication using either method of fixation: 77% (95% CI 71.4–81.7%) and 76.2% (95% CI 70.6–81.0%) for tension band wiring and plating, respectively. Conclusion Divergence exists with current literature and surgeon preference for fixation of displaced olecranon fractures. PMID:26204363

  5. Intraoperative Periprosthetic Femur Fracture: A Biomechanical Analysis of Cerclage Fixation.

    PubMed

    Frisch, Nicholas B; Charters, Michael A; Sikora-Klak, Jakub; Banglmaier, Richard F; Oravec, Daniel J; Silverton, Craig D

    2015-08-01

    Intraoperative periprosthetic femur fracture is a known complication of total hip arthroplasty (THA) and a variety of cerclage systems are available to manage these fractures. The purpose of this study was to examine the in situ biomechanical response of cerclage systems for fixation of periprosthetic femur fractures that occur during cementless THA. We compared cobalt chrome (CoCr) cables, synthetic cables, monofilament wires and hose clamps under axial compressive and torsional loading. Metallic constructs with a positive locking system performed the best, supporting the highest loads with minimal implant subsidence (both axial and angular) after loading. Overall, the CoCr cable and hose clamp had the highest construct stiffness and least reduction in stiffness with increased loading. They were not demonstrably different from each other.

  6. Theoretical analysis of the operating regime of a passively-mode-locked fiber laser through nonlinear polarization rotation

    SciTech Connect

    Komarov, Andrey; Leblond, Herve; Sanchez, Francois

    2005-12-15

    The dynamics of a fiber laser passively mode-locked through nonlinear polarization rotation is theoretically investigated. The model is based on an iterative equation for the nonlinear polarization rotation and the phase plates and on a scalar differential equation for the gain, the Kerr nonlinearity, and the dispersion. It is demonstrated that depending on the orientation of the phase plates, the laser can be continuous, mode-locked, or Q-switched. In the latter case, an additional equation for the gain dynamics must be taken into account. Hysteresis dependence of the operating regime versus the orientation angles of the phase plates is shown. A large bistability domain between the Q-switch and the continuous regimes is demonstrated. This model allows us to obtain the main features observed in passively-mode-locked fiber lasers.

  7. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Air locks. 154.345 Section 154.345 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Ship Arrangements § 154.345 Air locks. (a) An air lock may...

  8. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... mechanically ventilated to make the pressure in the space greater than that in the air lock; and (2) Has a... when the pressure in the space falls to or below the pressure in the air lock. ... 46 Shipping 5 2013-10-01 2013-10-01 false Air locks. 154.345 Section 154.345 Shipping COAST...

  9. 49 CFR 236.378 - Time locking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Time locking. 236.378 Section 236.378 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.378 Time locking. Time locking shall be tested when placed in service and...

  10. 49 CFR 236.768 - Locking, time.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, time. 236.768 Section 236.768... Locking, time. A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined...

  11. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall be...

  12. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall be...

  13. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall be...

  14. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall be...

  15. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall be...

  16. 75 FR 2129 - Lock+TM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... Energy Regulatory Commission Lock+ TM Hydro Friends Fund XXX, LLC; Notice of Preliminary Permit... January 6, 2010. On November 13, 2009, Lock+ TM Hydro Friends Fund XXX, LLC filed an application, pursuant...,018 megawatt-hours. Applicant Contact: Wayne F. Krouse, Lock+ TM Hydro Friends Fund XXX, LLC,...

  17. 49 CFR 236.769 - Locking, traffic.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, traffic. 236.769 Section 236.769... Locking, traffic. Electric locking which prevents the manipulation of levers or other devices for changing the direction of traffic on a section of track while that section is occupied or while a...

  18. 49 CFR 236.769 - Locking, traffic.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, traffic. 236.769 Section 236.769... Locking, traffic. Electric locking which prevents the manipulation of levers or other devices for changing the direction of traffic on a section of track while that section is occupied or while a...

  19. 49 CFR 236.381 - Traffic locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Traffic locking. 236.381 Section 236.381 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.381 Traffic locking. Traffic locking shall be tested when placed in service...

  20. 49 CFR 236.381 - Traffic locking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Traffic locking. 236.381 Section 236.381 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.381 Traffic locking. Traffic locking shall be tested when placed in service...

  1. 49 CFR 236.378 - Time locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Time locking. 236.378 Section 236.378 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.378 Time locking. Time locking shall be tested when placed in service and...

  2. 49 CFR 236.768 - Locking, time.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, time. 236.768 Section 236.768... Locking, time. A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined...

  3. 49 CFR 236.105 - Electric lock.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except...

  4. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Lock, electric. 236.757 Section 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, solenoid...

  5. 49 CFR 236.761 - Locking, electric.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, electric. 236.761 Section 236.761 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, electric. The combination of one or more electric locks and controlling circuits by means...

  6. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lock, electric. 236.757 Section 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, solenoid...

  7. 49 CFR 236.105 - Electric lock.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except...

  8. 49 CFR 236.761 - Locking, electric.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, electric. 236.761 Section 236.761 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, electric. The combination of one or more electric locks and controlling circuits by means...

  9. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Lock, electric. 236.757 Section 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, solenoid...

  10. 49 CFR 236.761 - Locking, electric.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking, electric. 236.761 Section 236.761 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, electric. The combination of one or more electric locks and controlling circuits by means...

  11. 49 CFR 236.105 - Electric lock.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except...

  12. 49 CFR 236.761 - Locking, electric.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking, electric. 236.761 Section 236.761 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, electric. The combination of one or more electric locks and controlling circuits by means...

  13. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Lock, electric. 236.757 Section 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, solenoid...

  14. 49 CFR 236.105 - Electric lock.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except...

  15. 49 CFR 236.105 - Electric lock.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except...

  16. 49 CFR 236.761 - Locking, electric.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, electric. 236.761 Section 236.761 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, electric. The combination of one or more electric locks and controlling circuits by means...

  17. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Lock, electric. 236.757 Section 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, solenoid...

  18. Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

  19. Surgical Treatment of Sternoclavicular Joint Dislocation Using a T-plate

    PubMed Central

    Hwang, Wan Jin; Lee, Yeiwon; Yoon, Yoo Sang; Kim, Young Jin; Ryu, Han Young

    2016-01-01

    A 22-year-old man was hospitalized with a sternoclavicular joint (SCJ) dislocation caused by a traffic accident. Surgical reduction and fixation of the SCJ were performed using a T-plate. SCJ dislocation is rare, accounting for less than 1% of all dislocations, and is usually treated conservatively, although severe cases may require surgery. Surgery typically involves joint reduction and fixation using an autologous tendon graft, but this has disadvantages such as the requirement for additional surgery to obtain autologous tissue and an extended operative time. To overcome these issues, here, we performed a simple SCJ reduction and fixation using a T-plate and achieved good results. PMID:27298805

  20. 75 FR 5068 - Lock + TM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Lock + \\TM\\ Hydro Friends Fund XXXIII, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications January 22, 2010. On January 8,...

  1. 75 FR 5071 - Lock + TM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    ..., Chairman and CEO, Hydro Green Energy, LLC., 5090 Richmond Avenue, Suite 290, Houston, TX 77056, (877) 556... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Lock + \\TM\\ Hydro Friends Fund XXXI, LLC; Notice of Preliminary...

  2. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  3. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  4. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  5. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  6. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  7. Missing nitrogen fixation in the Benguela region

    NASA Astrophysics Data System (ADS)

    Wasmund, Norbert; Struck, Ulrich; Hansen, Anja; Flohr, Anita; Nausch, Günther; Grüttmüller, Annett; Voss, Maren

    2015-12-01

    Opposing opinions on the importance of nitrogen fixation in the northern Benguela upwelling region provoked us to investigate the magnitude of nitrogen fixation in front of northern Namibia and southern Angola. Measurements of nitrogen fixation rates using the 15N method at 66 stations during seven cruises from 2008 to 2014 showed that, in general, the 15N content in the biomass did not increase after tracer incubation with 15N2, indicating that no nitrogen fixation occurred. Correspondingly, the filamentous nitrogen-fixing cyanobacterium Trichodesmium was almost not present. The abundant picocyanobacteria did obviously not perform nitrogen fixation to a significant degree. The artificial improvement of conditions for nitrogen fixation in mesocosm experiments, including phosphate and iron additions and a warmer temperature, failed to induce nitrogen fixation. A plausible explanation of these findings is a lack of conditioned cells for nitrogen fixation in the Benguela region.

  8. First metatarsophalangeal joint arthrodesis: current fixation options.

    PubMed

    Moon, Jared L; McGlamry, Michael C

    2011-04-01

    This article reviews the current literature on first metatarsophalangeal joint arthrodesis rates using various forms of fixation, as well as reviewing biomechanical studies comparing the strengths of the different fixation options that are available.

  9. WRIST ARTHRODESIS WITH MINIMAL FIXATION PRESERVING THE CARPOMETACARPAL JOINTS

    PubMed Central

    Pardini, Arlindo Gomes; Pádua Gonçalves, Rodolfo Fonseca; Freitas, Afrânio Donato; Chaves, Antonio Barbosa

    2015-01-01

    Objective: Wrist arthrodesis is a surgical procedure that should always be considered in cases of pathological conditions in which anatomical and functional structures are altered. In general, the results are very satisfactory, particularly for pain relief, and in the majority of cases, there is considerable functional improvement. Various techniques have been described, with different methods of internal fixation, most of which include the carpometacarpal joints in the fusion. The objective of this study was to evaluate the results from wrist arthrodesis using a technique that is simpler, more biological, less expensive, and does not involve the carpometacarpal joints. Methods: Fifteen patients with wrist arthrodesis were evaluated (six with sequelae from trauma, four with rheumatoid arthritis, three with Kienbock grade IV, one with Preiser and one with panarthrosis). The technique consisted of using an iliac bone plate and internal fixation with Kirschner wires, avoiding the carpometacarpal joints. Results: The evaluation was based on consolidation time (93% in seven weeks); movements of the fingers and pronosupination; pinch and grasp strength; functional evaluation through the DASH, pain and patient satisfaction questionnaires. In general, the results were similar to those of other, more aggressive techniques, and the non-inclusion of the carpometacarpal joints did not affect the final result. Conclusion: Wrist arthrodesis with fixation using Kirschner wires and an iliac bone plate, preserving the carpometacarpal joints, gives good or excellent results that are not inferior to those of other techniques that have been described. However, it presents major advantages over other methods: it is less aggressive and cheaper, and does not have the inconvenience and complications associated with the use of plates and screws. PMID:27022522

  10. 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

  11. Understanding Nitrogen Fixation

    SciTech Connect

    Paul J. Chirik

    2012-05-25

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

  12. Options for acetabular fixation surfaces.

    PubMed

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

    2007-01-01

    Aseptic loosening is the most common cause for revision total hip arthroplasty (THA). Due to poor long-term results with cemented acetabular components, cementless implants that rely on biologic fixation became popular in the United States for both primary and revision procedures in the early 1980s. Cementless acetabular components used in THA have been reported to have superior radiographic performance compared with cemented fixation, although the optimal method of acetabular fixation remains controversial. Cementless acetabular components require initial implant stability to allow for bone ingrowth and remodeling into the acetabular shell, providing long-term durability of the prosthesis. Many improved implant materials are available to facilitate bone growth and remodeling, including the 3 most common surface treatments; fibermesh, sintered beads, and plasma spray coatings. Recently added to these are porous metal surfaces, which have increased porosity and optimal pore sizes when compared with titanium fibermesh. The most studied of these materials is the titanium fibermesh fixation surface, which has demonstrated a mechanical failure rate of 1% at 10 to 15 years. This technology utilizes the diffusion bonding process to attach fiber metal pads to a titanium substrate using heat and pressure. The sintered bead fixation surface offers a porous coating of various sizes of spherical beads, achieved by the sintering process, and has been shown to provide long-term fixation. While there are less long-term published data regarding the titanium plasma spray surface, its early results have provided evidence of its durability, even in the face of significant osteolysis. The most recently added alternative fixation surface is porous tantalum metal, which offers potentially greater bone ingrowth and bone graft incorporation due to its high porosity (80%) and low modulus of elasticity (3 MPa). Porous tantalum implants have shown early favorable clinical results and have

  13. Binocular Fixation Disparity in Single Word Displays

    ERIC Educational Resources Information Center

    Paterson, Kevin B.; Jordan, Timothy R.; Kurtev, Stoyan

    2009-01-01

    It has been claimed that the recognition of words displayed in isolation is affected by the precise location at which they are fixated. However, this putative role for fixation location has yet to be reconciled with the finding from reading research that binocular fixations are often misaligned and, therefore, more than 1 location in a word is…

  14. An eye fixation-related potentials analysis of the P300 potential for fixations onto a target object when exploring natural scenes.

    PubMed

    Devillez, Hélène; Guyader, Nathalie; Guérin-Dugué, Anne

    2015-01-01

    The P300 event-related potential has been extensively studied in electroencephalography with classical paradigms that force observers to not move their eyes. This potential is classically used to infer whether a target or a task-relevant stimulus was presented. Few researches have studied this potential through more ecological paradigms where observers were able to move their eyes. In this study, we examined with an ecological paradigm and an adapted methodology the P300 potential using a visual search task that involves eye movements to actively explore natural scenes and during which eye movements and electroencephalographic activity were coregistered. Averaging the electroencephalography signal time-locked to fixation onsets, a P300 potential was observed for fixations onto the target object but not for other fixations recorded for the same visual search or for fixations recorded during the free viewing without any task. Our approach consists of using control experimental conditions with similar eye movements to ensure that the P300 potential was attributable to the fact that the observer gazed at the target rather than to other factors such as eye movement pattern (the size of the previous saccade) or the "overlap issue" between the potentials elicited by two successive fixations. We also proposed to model the time overlap issue of the potentials elicited by consecutive fixations with various durations. Our results show that the P300 potential can be studied in ecological situations without any constraint on the type of visual exploration, with some precautions in the interpretation of results due to the overlap issue.

  15. Morbus-Locke's early essay on disease.

    PubMed

    Walmsley, J

    2000-01-01

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

  16. Open reduction and fixation of proximal humeral fractures and fracture-dislocations.

    PubMed

    Moda, S K; Chadha, N S; Sangwan, S S; Khurana, D K; Dahiya, A S; Siwach, R C

    1990-11-01

    Open reduction and internal fixation was employed in the treatment of 25 severely displaced fractures and fracture-dislocations of the proximal humerus. Our aims were accurate reduction and stable fixation to allow early mobilisation and to achieve full functional recovery. In 15 fractures an AO T-plate was used and in 10 a bent semitubular plate was employed as a blade plate. Excellent or satisfactory results were obtained in all six patients with two-part fractures involving the surgical neck; in four of the five patients with three-part fractures involving the surgical neck and tuberosities; in nine of the 11 patients with fracture-dislocation; and in two of the three patients with split fractures of the humeral head. Overall results were good or satisfactory in 21 of the 25 cases. Unsatisfactory results were associated with rotator cuff damage.

  17. Functional outcomes and cost estimation for extra-articular and simple intra-articular distal radius fractures treated with open reduction and internal fixation versus closed reduction and percutaneous Kirschner wire fixation

    PubMed Central

    Dzaja, Ivan; MacDermid, Joy C.; Roth, James; Grewal, Ruby

    2013-01-01

    Background We sought to compare direct costs and clinical and radiographic outcomes for distal radius fractures (DRF) treated with open reduction internal fixation with volar locking plates (VLP) versus closed reduction and percutaneous pinning (CRPP). Methods We identified patients with AO-type A and C1 DRFs from a prospective database. Outcomes were assessed at 6 weeks and at 3, 6 and 12 months, and surgical care costs were estimated. Results Twenty patients were treated with CRPP and 24 with VLP. There were no significant differences in patient-rated wrist evaluation (PRWE) scores between the 2 groups at any time point (mean 16.2 ± 23.1 in the CRPP group v. 21.5 ± 23.6 in the VLP group, p = 0.91). Overall alignment was maintained in both groups; however, there was a greater loss of radial height over time with CRPP than VLP (0.97 mm v. 0.25 mm, p = 0.018). The mean duration of surgery was longer for VLP than CRPP (113.9 ± 39.5 min v. 86.5 ± 7.8 min, p = 0.029), but there were fewer clinic visits (5.2 ± 1.4 v. 7.8 ± 1.3, p < 0.001) and fewer radiographs (7.4 ± 2.7 v. 9 ± 2.4, p = 0.031). The total cost per case was greater for VLP than CRPP ($1637.27 v. $733.91). Conclusion Based on PRWE scores, VLPs did not offer any significant advantage over CRPP in patients with simple fracture types between 3 and 12 months, but they were much more costly. Whether VLP offers any functional advantage earlier in recovery, thereby justifying their expense, requires further investigation in the form of a prospective randomized trial with a detailed cost analysis. PMID:24284144

  18. Performance of arm locking in LISA

    SciTech Connect

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

    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

  19. External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients.

    PubMed

    Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

    2016-01-01

    The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the "gross motor" category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

  20. External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients

    PubMed Central

    Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

    2016-01-01

    The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the “gross motor” category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

  1. Nonbridging external fixation of distal radius fractures.

    PubMed

    Eichenbaum, Matthew D; Shin, Eon K

    2010-08-01

    Surgical management of distal radius fractures continues to evolve because of their high incidence in an increasingly active elderly population. Traditional radiocarpal external fixation relies on ligamentotaxis for fracture reduction but has several drawbacks. Nonbridging external fixation has evolved to provide early wrist mobility in the setting of anatomic fracture reduction. Several studies of the nonbridging technique have demonstrated satisfactory results in isolated nonbridging external fixation series and in comparison with traditional spanning external fixation. Nonbridging external fixation for surgical treatment of distal radius fractures can be technically demanding and requires at least 1 cm of intact volar cortex in the distal fracture fragment for successful implementation.

  2. Self-locking threaded fasteners

    DOEpatents

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

    1996-01-16

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

  3. Locking mechanism for indexing device

    DOEpatents

    Lindemeyer, Carl W.

    1984-01-01

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

  4. 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.

  5. Locked nucleic acid molecular beacons.

    PubMed

    Wang, Lin; Yang, Chaoyong James; Medley, Colin D; Benner, Steven A; Tan, Weihong

    2005-11-16

    A novel LNA-MB (molecular beacon based on locked nucleic acid bases) has been designed and investigated. It exhibits very high melting temperature and is thermally stable, shows superior single base mismatch discrimination capability, and is stable against digestion by nuclease and has no binding with single-stranded DNA binding proteins. The LNA-MB will be widely useful in a variety of areas, especially for in vivo hybridization studies.

  6. 2010 Maule earthquake slip correlates with pre-seismic locking of Andean subduction zone.

    PubMed

    Moreno, Marcos; Rosenau, Matthias; Oncken, Onno

    2010-09-01

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

  7. Evolution of the Hoffmann Fixators.

    PubMed

    Seligson, David

    2015-09-01

    Dr. Raoul Hoffmann of Geneva, Switzerland with the collaboration of Henri Jaquet developed the original Hoffmann external fixateur as a system for treating broken bones without necessarily opening a fracture site to reposition the bone ends. This system has evolved to a more flexible, modular concept with input from surgeons and engineers. In this chapter the modifications of the Hoffmann family of fixators are traced and the important steps in the development of the concept and the instrumentation emphasized. PMID:26458297

  8. Fixation strategies for retinal immunohistochemistry.

    PubMed

    Stradleigh, Tyler W; Ishida, Andrew T

    2015-09-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons. PMID:25892361

  9. Fixation Strategies For Retinal Immunohistochemistry

    PubMed Central

    Stradleigh, Tyler W.; Ishida, Andrew T.

    2015-01-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons. PMID:25892361

  10. Hinged external fixation for complex fracture-dislocation of the elbow in elderly people.

    PubMed

    Maniscalco, P; Pizzoli, A L; Renzi Brivio, L; Caforio, M

    2014-12-01

    The authors report their experience of treating complex elbow fracture-dislocations in elderly people, using a minimally-invasive approach with a new articulated external fixator that is associated with minimal internal fixation. The clinical results for 19 patients are presented according to outcome factors, such as range of motion, pain and function, rate and type of complications, and reoperation rate. The results indicate that this treatment strategy should be considered as a good alternative to other treatment options reported in the literature, including conservative treatment, ORIF with angular stable plates and total elbow arthroplasty. PMID:25457320

  11. The effectiveness of standard povidone iodine surgical preparation in decontaminating external fixator components.

    PubMed

    Hak, David J; Wiater, Patrick J; Williams, Robert M; Pierson, Carl L

    2005-12-01

    The purpose of this study was to evaluate the effectiveness of standard iodine surgical scrubs to remove bacteria from external fixator components. Sterile adjustable external fixation clamps, Schanz pins, and carbon fibre rods were coated with a sterile protein solution and immersed in solution of coagulase negative Staphylococcus (10(3)organisms/ml). They were then decontaminated in standard fashion using a povidone iodine scrub and paint solution. After neutralisation the components were sonicated, serially diluted, plated on blood agar, and incubated for 24h. Unassembled external fixation components were examined individually, and as assembled pin-rod-clamp constructs with and without manipulation of the clamp. Of the three external fixation components (pins, rods, clamps) the highest number of bacterial colony forming units was seen on the external fixation clamps. Manipulation of the assembled construct significantly increased the mean bacterial colony counts compared to the assembled non-manipulated construct (p=0.0007). Standard surgical preparation does not remove all bacteria from external fixators during subsequent operative procedures.

  12. Finite Element Analysis of a New Pedicle Screw-Plate System for Minimally Invasive Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Zhou, Yue; Li, Changqing; Liu, Huan

    2015-01-01

    Purpose Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is increasingly popular for the surgical treatment of degenerative lumbar disc diseases. The constructs intended for segmental stability are varied in MI-TLIF. We adopted finite element (FE) analysis to compare the stability after different construct fixations using interbody cage with posterior pedicle screw-rod or pedicle screw-plate instrumentation system. Methods A L3–S1 FE model was modified to simulate decompression and fusion at L4–L5 segment. Fixation modes included unilateral plate (UP), unilateral rod (UR), bilateral plate (BP), bilateral rod (BR) and UP+UR fixation. The inferior surface of the S1 vertebra remained immobilized throughout the load simulation, and a bending moment of 7.5 Nm with 400N pre-load was applied on the L3 vertebra to recreate flexion, extension, lateral bending, and axial rotation. Range of motion (ROM) and Von Mises stress were evaluated for intact and instrumentation models in all loading planes. Results All reconstructive conditions displayed decreased motion at L4–L5. The pedicle screw-plate system offered equal ROM to pedicle screw-rod system in unilateral or bilateral fixation modes respectively. Pedicle screw stresses for plate system were 2.2 times greater than those for rod system in left lateral bending under unilateral fixation. Stresses for plate were 3.1 times greater than those for rod in right axial rotation under bilateral fixation. Stresses on intervertebral graft for plate system were similar to rod system in unilateral and bilateral fixation modes respectively. Increased ROM and posterior instrumentation stresses were observed in all loading modes with unilateral fixation compared with bilateral fixation in both systems. Conclusions Transforaminal lumbar interbody fusion augmentation with pedicle screw-plate system fixation increases fusion construct stability equally to the pedicle screw-rod system. Increased posterior

  13. Locked and loading megathrust linked to active subduction beneath the Indo-Burman Ranges

    NASA Astrophysics Data System (ADS)

    Steckler, Michael S.; Mondal, Dhiman Ranjan; Akhter, Syed Humayun; Seeber, Leonardo; Feng, Lujia; Gale, Jonathan; Hill, Emma M.; Howe, Michael

    2016-08-01

    The Indo-Burman mountain ranges mark the boundary between the Indian and Eurasian plates, north of the Sumatra-Andaman subduction zone. Whether subduction still occurs along this subaerial section of the plate boundary, with 46 mm yr-1 of highly oblique motion, is contentious. About 21 mm yr-1 of shear motion is taken up along the Sagaing Fault, on the eastern margin of the deformation zone. It has been suggested that the remainder of the relative motion is taken up largely or entirely by horizontal strike-slip faulting and that subduction has stopped. Here we present GPS measurements of plate motions in Bangladesh, combined with measurements from Myanmar and northeast India, taking advantage of a more than 300 km subaerial accretionary prism spanning the Indo-Burman Ranges to the Ganges-Brahmaputra Delta. They reveal 13-17 mm yr-1 of plate convergence on an active, shallowly dipping and locked megathrust fault. Most of the strike-slip motion occurs on a few steep faults, consistent with patterns of strain partitioning in subduction zones. Our results strongly suggest that subduction in this region is active, despite the highly oblique plate motion and thick sediments. We suggest that the presence of a locked megathrust plate boundary represents an underappreciated hazard in one of the most densely populated regions of the world.

  14. Brain potentials associated with eye fixations during visual tasks under different lighting systems.

    PubMed

    Yagi, A; Imanishi, S; Konishi, H; Akashi, Y; Kanaya, S

    1998-05-01

    The variations of eye fixation related potentials (EFRPs) were examined in two tasks under three lighting conditions for assessment of lighting environments. Sixteen subjects participated in two tasks; a difficult and an easy reading task under three lighting conditions: Spot light (S), General light (G) and Mixed light (M). EEG (Oz) and EOG were recorded. EEG epochs time-locked to onset of eye fixations were collected at random and averaged separately in two arrays to obtain a pair of EFRPs. Two wave forms under the S were similar, although those under the G showed the disparity, the largest disparity being in the easy task under the G. Under the S, wave forms of EFRPs were stable in the difficult task. The amplitude changed with the task load. The results suggested that EFRPs might be an index of the work load under lighting conditions.

  15. VIEW LOOKING WEST THROUGH LOCK 70. NOTE THE EXTANT HARDWARE ...

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

    VIEW LOOKING WEST THROUGH LOCK 70. NOTE THE EXTANT HARDWARE EMBEDED IN THE TOP OF THE LOCK WALLS, THE RECESSES IN THE LOCK WALLS, AND THE LATER-ERA CONCRETE WEIR APPROXIMATELY WHERE THE LOCK GATE SHOULD BE. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

  16. 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

  17. 49 CFR 236.780 - Plunger, facing point lock.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Plunger, facing point lock. 236.780 Section 236... § 236.780 Plunger, facing point lock. That part of a facing point lock which secures the lock rod to the plunger stand when the switch is locked....

  18. 49 CFR 236.780 - Plunger, facing point lock.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plunger, facing point lock. 236.780 Section 236... § 236.780 Plunger, facing point lock. That part of a facing point lock which secures the lock rod to the plunger stand when the switch is locked....

  19. 49 CFR 236.780 - Plunger, facing point lock.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Plunger, facing point lock. 236.780 Section 236... § 236.780 Plunger, facing point lock. That part of a facing point lock which secures the lock rod to the plunger stand when the switch is locked....

  20. 49 CFR 236.780 - Plunger, facing point lock.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Plunger, facing point lock. 236.780 Section 236... § 236.780 Plunger, facing point lock. That part of a facing point lock which secures the lock rod to the plunger stand when the switch is locked....

  1. 49 CFR 236.780 - Plunger, facing point lock.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Plunger, facing point lock. 236.780 Section 236... § 236.780 Plunger, facing point lock. That part of a facing point lock which secures the lock rod to the plunger stand when the switch is locked....

  2. An external fixation method and device to study fracture healing in rats.

    PubMed

    Mark, Hans; Bergholm, Jan; Nilsson, Anders; Rydevik, Björn; Strömberg, Lennart

    2003-08-01

    We wished to establish a reproducible model for fracture fixation to be used in fracture healing research and therefore developed an external fixation construct and surgical procedure adapted to Sprague-Dawley rats. We evaluated the mechanical properties of the construct in brass rods and rat bone, in an Instron test machine with axial and transverse loading, and the in vivo performance. We found that the mechanical properties of the construct in brass rods were predictable and could be repeated in rat femora. In all tests, the axial load was about 10 times the transverse for the same degree of deformation. The stiffness among fixators was uniform. 1 mm pins caused about 50% less stiffness than 1.2 mm pins in axial loading of rat bone (p < 0.001) and brass rods (p < 0.001) as well as in transverse loading of brass rods (p < 0.001). Loosening of 1 or 2 screws that lock the pins to the fixator reduced stiffness by about 50% in axial loading of rat bone (p = 0.009) and brass rods (p = 0.05). A change in the distance between the bone surface and the fixator was linearly related to the stiffness in axial loading of rat bone (p < 0.001) and brass rods (p < 0.001) and in transverse loading of brass rods (p < 0.001). If the bone ends touched each other, the axial stiffness of the construct increased almost 10 times (265 N/mm), as compared to a fracture gap size of 2 mm (31 N/mm). In vivo experiments had a complication rate of less than 10% when we used 1.2 mm pins, 6 mm offset and rats weighing 350-450 g. Our method and device for experimental external fixation of rat femora are reliable and the findings are reproducible. These can be used in bone repair and fracture healing research. PMID:14521302

  3. Interchangeable breech lock for glove boxes

    SciTech Connect

    Lemonds, David Preston

    2015-11-24

    A breech lock for a glove box is provided that may be used to transfer one or more items into the glove box. The breech lock can be interchangeably installed in place of a plug, glove, or other device in a port or opening of a glove box. Features are provided to aid the removal of items from the breech lock by a gloved operator. The breech lock can be reused or, if needed, can be replaced with a plug, glove, or other device at the port or opening of the glove box.

  4. Microcontroller-based locking in optics experiments

    SciTech Connect

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

    2014-12-15

    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.

  5. 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.

  6. Peer-to-Peer Magnetron Locking

    NASA Astrophysics Data System (ADS)

    Cruz, Edward Jeffrey

    The viability of coherent power combination of multiple high-efficiency, moderate power magnetrons requires a thorough understanding of frequency and phase control. Injection locking of conventional magnetrons, and other types of oscillators, employing a master-to-slave configuration has been studied theoretically and experimentally. This dissertation focuses on the peer-to-peer locking, where each oscillator acts as a master of and slave to all others, between two conventional magnetrons, where the general condition for locking was recently derived. The experiments performed on peer-to-peer locking of two 1-kW magnetrons verify the recently developed theory on the condition under which the two nonlinear oscillators may be locked to a common frequency and relative phase. This condition reduces to Adler's classical locking condition (master-slave) if the coupling is one way. Dependent on the degree of coupling, the frequency of oscillation when locking occurs was found to not necessarily lie between the two magnetrons' free running frequencies. Likewise, when the locking condition was violated, the beat of the spectrum was not necessarily found to be equal to the difference between the free running frequencies. The frequency of oscillation and relative phase between the two magnetrons when locking did occur were found to correspond to one of two solution modes given by the recent theory. The accessibility of the two possible modes is yet to be determined. This work was supported by ONR, AFRL, AFOSR, L-3 Communications Electron Devices Division and Northrop-Grumman Corporation.

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

    NASA Astrophysics Data System (ADS)

    Navarro-González, Rafael; McKay, Christopher P.; Mvondo, Delphine Nna

    2001-07-01

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

  8. Overcoming fixation with repeated memory suppression.

    PubMed

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

    2015-01-01

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

  9. Locking mechanism for orthopedic braces

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  10. Corrugated cover plate for flat plate collector

    DOEpatents

    Hollands, K. G. Terry; Sibbitt, Bruce

    1978-01-01

    A flat plate radiant energy collector is providing having a transparent cover. The cover has a V-corrugated shape which reduces the amount of energy reflected by the cover away from the flat plate absorber of the collector.

  11. Modeling fixation locations using spatial point processes.

    PubMed

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

    2013-10-01

    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.

  12. 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.

  13. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, Hao-Lin

    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.

  14. 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.

  15. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  16. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  17. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  18. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  19. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  20. 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

  1. 12. VIEW OF OUTLET LOCKS AND RARITAN RIVER, LOOKING NORTH ...

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

    12. VIEW OF OUTLET LOCKS AND RARITAN RIVER, LOOKING NORTH FROM APPROXIMATE SITE OF FORMER LOCK TENDER'S HOUSE - Delaware & Raritan Canal, Outlet Locks, Between State Route 18 & Raritan River, New Brunswick, Middlesex County, NJ

  2. 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

  3. 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

  4. Tidal Locking Of The Earth

    NASA Astrophysics Data System (ADS)

    Koohafkan, Michael

    2006-05-01

    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 Earth is slightly distorted into an egg-like shape, and the torque exerted by the Moon on our equatorial bulge slowly changes the tilt of our spin axis. How do effects such as these change as the Moon drifts away from Earth? I will examine gravitational interactions between Earth and Moon to learn how they contribute to the deceleration of the Earth's rotation. My goal is to determine the amount of time it would take for the Earth's rotational speed to decelerate until the period of a single rotation matches the period of the Moon's orbit around Earth -- when the Earth is ``tidally locked'' with the Moon. I aim to derive a general mathematical expression for the rotational deceleration of the Earth due to Moon's gravitational influences.

  5. Electron Locking in Current Drive

    NASA Astrophysics Data System (ADS)

    McCollam, K. J.; Jarboe, T. R.; Nelson, B. A.; Orvis, D. J.; Raman, R.; Redd, A. J.; Smith, R. J.; Nagata, M.; Uyama, T.

    2000-10-01

    The traveling n=1, m~= q_edge magnetic distortion observed in the Helicity Injected Torus (HIT-II) during coaxial helicity injection (CHI) is responsible for some current profile relaxation. A model for electromotive current drive, called the electron locking model, can account for the results of current drive experiments in both the HIT-II and the original HIT devices. The most relevant of these results involve the the frequencies and directions of the mode itself, the E× B drift, and the electric current drift. In spherical tokamaks with CHI, electrode and coil polarities can be changed to control the relative directions of these drifts. Results from HIT-II experiments with different polarities are shown. These point out the character n=1, m~= q_edge mode, and suggest its role in CHI current drive. The electron locking model is presented, and is also discussed in the context of mean field electrodynamics. This model might also be applied to other types of current drive, such as rotating magnetic field (RMF) current drive, oscillating field current drive (OFCD), steady inductive helicity injection (SIHI), or Ohmic current drive in a reversed field pinch (RFP). These examples are discussed.

  6. Comparative study of injection locked FET oscillators

    NASA Astrophysics Data System (ADS)

    Jacob, Arne

    1991-07-01

    A study of injection locked FET oscillators (ILO) is presented. Starting from large signal design considerations a comparison between reflection- and transmission-type injection locking is drawn. Bandwidth capabilities and the transfer of modulated signals are investigated by both experiments and computer simulations. In the examples studied the reflection type ILO shows superior preformances.

  7. 49 CFR 236.760 - Locking, approach.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.760 Locking, approach. Electric locking effective while a train is approaching, within a specified distance, a... time interval after such signal has been caused to display its most restrictive aspect, the movement...

  8. 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.

  9. Self-Injection Locking Of Diode Lasers

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1991-01-01

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

  10. Function Test of an Automatic Locking and Unlocking System for Passive Damper by using Parabolic Flight

    NASA Astrophysics Data System (ADS)

    Sakurai, M.; Yoshihara, S.; Ohnishi, M.; Watanabe, K.; Sekiya, T.

    2002-01-01

    existence of residual acceleration has been reported.The acceleration is called "g-jitter".In a lot of experiments carried out in space, the adverse influence of the g-jitter on their results has been found out.To understand the effect of g-jitter on fluid phenomena, we are making preparation to orbital experiment as a post-JUSTSAP. In the experiment, the information to understand the influence of the g-jitter on diffusion phenomena will be obtained by comparing diffusion process in two containers. One container is isolated from the g-jitter using a passive damper and the other is not. To avoid the strong accelerations during launch giving damage to the passive damper, an automatic locking and unlocking system for the passive damper must be applied to the experimental apparatus. To increase flight opportunity of the experiment, the apparatus is designed as a small, light, self-controlled and self-powered system.In order to test the function of the apparatus, we have carried out parabolic flight experiments as preparations for the orbital experiment. mol/l), ethanol (0.7%) and NaCl (0.02 mol/l) is set on the upper base plate, which has the passive damper and the locking-unlocking system.The other container is directly set on the lower base plate.The passive damper comprises of flexible membranes and thin-metal plate and connecting rods. The damping is performed under micro-gravity condition by utilizing the non-linear elasticity of flexible membranes. The CPU unit on the upper base plate has 8 channels of A/D converter to measure 3-dimensional vibrations and 8 relays to control all experimental procedures, that is, locking, unlocking, heating, recording and so on. The power unit provides electricity to the CPU unit, the locking-unlocking system and heaters. A digital camera records diffusion of color in both cells simultaneously. color between pH8.3 and pH10. airplane vibrations were directly translated to the experimental container.During a parabolic flight, a

  11. Commonwealth Edison Company pressure locking test report

    SciTech Connect

    Bunte, B.D.; Kelly, J.F.

    1996-12-01

    Pressure Locking is a phenomena which can cause the unseating thrust for a gate valve to increase dramatically from its typical static unseating thrust. This can result in the valve actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the actuator capability exceeds the valve structural limits. For these reasons, a proper understanding of the conditions which may cause pressure locking and thermal binding, as well as a methodology for predicting the unseating thrust for a pressure locked or thermally bound valve, are necessary. This report discusses the primary mechanisms which cause pressure locking. These include sudden depressurization of piping adjacent to the valve and pressurization of fluid trapped in the valve bonnet due to heat transfer. This report provides a methodology for calculating the unseating thrust for a valve which is pressure locked. This report provides test data which demonstrates the accuracy of the calculation methodology.

  12. Cheek drooping in 2 patients with maxillary fractures after rigid fixation with bioabsorbable mesh.

    PubMed

    Oh, Seung Hyun; Kim, Chung Hun; Choi, Hyun Gon; Hwang, Euna

    2014-03-01

    Bioabsorbable plate-screw systems are commonly used for the internal fixation of facial bone fractures. The anterior maxilla has a unique curved shape, and fractured bony fragments tend to be small and fragile; therefore, more effective rigid fixation can be achieved using a molded bioabsorbable mesh rather than a bioabsorbable plate. Herein, we describe 2 patients with cheek drooping after a rigid fixation of comminuted maxillary fracture using bioabsorbable meshes and screws.The postoperative courses were uneventful, but both showed soft tissue bulging in the cheek area of the operation site for 12 to 13 months after the operation. No other symptom or sign related to inflammation or foreign body reaction was noted.In comminuted maxillary fractures, bone fragments are more conveniently fixed with a 1-piece molded bioabsorbable mesh. However, it is believed that a single large mesh may interfere with adhesion between the maxillary surface and the overlying soft tissue. Therefore, we recommend using the least amount of mesh to fixate maxillary bone fragments.

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

    PubMed

    Gagnon, Katie; Chadwell, C David; Norabuena, Edmundo

    2005-03-10

    The subduction zone off the west coast of South America marks the convergence of the oceanic Nazca plate and the continental South America plate. Nazca-South America convergence over the past 23 million years has created the 6-km-deep Peru-Chile trench, 150 km offshore. High pressure between the plates creates a locked zone, leading to deformation of the overriding plate. The surface area of this locked zone is thought to control the magnitude of co-seismic release and is limited by pressure, temperature, sediment type and fluid content. Here we present seafloor deformation data from the submerged South America plate obtained from a combination of Global Positioning System (GPS) receivers and acoustic transponders. We estimate that the measured horizontal surface motion perpendicular to the trench is consistent with a model having no slip along the thrust fault between 2 and 40 km depth. A tsunami in 1996, 200 km north of our site, was interpreted as being the result of an anomalously shallow interplate earthquake. Seismic coupling at shallow depths, such as we observe, may explain why co-seismic events in the Peruvian subduction zone create large tsunamis. PMID:15758997

  14. Antegrade Unreamed Locked Intramedullary Nailing in Open Fractures of Shaft of Humerus

    PubMed Central

    Singh, Jasbir; Lal, Mukand; Chandel, Desh Raj

    2016-01-01

    Introduction Open fractures of shaft of humerus have been treated conservatively as well as operatively. Plate osteosynthesis has been considered as the gold standard treatment. Intramedullary nailing also has same success rate in closed fractures. The results of 30 open fractures of shaft humerus fixed with locked unreamed antegrade intramedullary nailing were evaluated. Aim The purpose of the study was to evaluate the role of locked intramedullary nailing in open fractures of shaft humerus in terms of bone union, secondary procedure required, complication, shoulder dysfunction and infection. Materials and Methods Of consecutive 365 humeral shaft fractures, 63 fractures were open. Thirty-two patients were operated with plate osteosynthesis, while 31 patients who were treated with locked unreamed intramedullary nails fulfilling the inclusion criteria entered the study. Results Twenty eight of thirty patients united in mean duration of 10.5 weeks. There were two non-unions both of them united with bone grafting and plate osteosynthesis. Seven patients had superficial infection which healed with antibiotic course, while two patients had deep infection, which healed with repeat debridement. Eleven patients had preoperative radial nerve palsy, nine of which healed completely in average of six months. Twenty eight patients had excellent functional outcome at final follow-up while two patients had good outcome. Conclusion Antegrade nailing is associated with good union rates and low infection rates and is a good option in open fractures and in polytrauma patients. PMID:27790533

  15. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fixation device. 886.1290 Section 886.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A...

  16. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fixation device. 886.1290 Section 886.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A...

  17. 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...

  18. Delayed Foreign Body Reaction Caused by Bioabsorbable Plates Used for Maxillofacial Fractures

    PubMed Central

    Jeon, Hong Bae; Gu, Ja Hea; Oh, Sang Ah

    2016-01-01

    Background Bioabsorbable plates and screws are commonly used to reduce maxillofacial bones, particularly in pediatric patients because they degrade completely without complications after bone healing. In this study, we encountered eight cases of a delayed foreign body reaction after surgical fixation with bioabsorbable plates and screws. Methods A total of 234 patients with a maxillofacial fracture underwent surgical treatment from March 2006 to October 2013, in which rigid fixation was achieved with the Inion CPS (Inion, Tampere, Finland) plating system in 173 patients and Rapidsorb (Synthes, West Chester, PA, USA) in 61 patients. Their mean age was 35.2 years (range, 15-84 years). Most patients were stabilized with two- or three-point fixation at the frontozygomatic suture, infraorbital rim, and anterior wall of the maxilla. Results Complications occurred in eight (3.4%) of 234 patients, including palpable, fixed masses in six patients and focal swelling in two patients. The period from surgical fixation to the onset of symptoms was 9-23 months. Six patients with a mass underwent secondary surgery for mass removal. The masses contained fibrous tissue with a yellow, grainy, cloudy fluid and remnants of an incompletely degraded bioabsorbable plate and screws. Their histological findings demonstrated a foreign body reaction. Conclusions Inadequate degradation of bioabsorbable plates caused a delayed inflammatory foreign body reaction requiring secondary surgery. Therefore, it is prudent to consider the possibility of delayed complications when using bioabsorbable plates and surgeons must conduct longer and closer follow-up observations. PMID:26848444

  19. Microsaccades counteract visual fading during fixation.

    PubMed

    Martinez-Conde, Susana; Macknik, Stephen L; Troncoso, Xoana G; Dyar, Thomas A

    2006-01-19

    Our eyes move continually, even while we fixate our gaze on an object. If fixational eye movements are counteracted, our perception of stationary objects fades completely, due to neural adaptation. Some studies have suggested that fixational microsaccades refresh retinal images, thereby preventing adaptation and fading. However, other studies disagree, and so the role of microsaccades remains unclear. Here, we correlate visibility during fixation to the occurrence of microsaccades. We asked subjects to indicate when Troxler fading of a peripheral target occurs, while simultaneously recording their eye movements with high precision. We found that before a fading period, the probability, rate, and magnitude of microsaccades decreased. Before transitions toward visibility, the probability, rate, and magnitude of microsaccades increased. These results reveal a direct link between suppression of microsaccades and fading and suggest a causal relationship between microsaccade production and target visibility during fixation.

  20. 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.