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Sample records for established fixation techniques

  1. Biomechanical comparison of a new stand-alone anterior lumbar interbody fusion cage with established fixation techniques – a three-dimensional finite element analysis

    PubMed Central

    Chen, Shih-Hao; Tai, Ching-Lung; Lin, Chien-Yu; Hsieh, Pang-Hsing; Chen, Weng-Pin

    2008-01-01

    Background Initial promise of a stand-alone interbody fusion cage to treat chronic back pain and restore disc height has not been realized. In some instances, a posterior spinal fixation has been used to enhance stability and increase fusion rate. In this manuscript, a new stand-alone cage is compared with conventional fixation methods based on the finite element analysis, with a focus on investigating cage-bone interface mechanics and stress distribution on the adjacent tissues. Methods Three trapezoid 8° interbody fusion cage models (dual paralleled cages, a single large cage, or a two-part cage consisting of a trapezoid box and threaded cylinder) were created with or without pedicle screws fixation to investigate the relative importance of the screws on the spinal segmental response. The contact stress on the facet joint, slip displacement of the cage on the endplate, and rotational angle of the upper vertebra were measured under different loading conditions. Results Simulation results demonstrated less facet stress and slip displacement with the maximal contact on the cage-bone interface. A stand-alone two-part cage had good slip behavior under compression, flexion, extension, lateral bending and torsion, as compared with the other two interbody cages, even with the additional posterior fixation. However, the two-part cage had the lowest rotational angles under flexion and torsion, but had no differences under extension and lateral bending. Conclusion The biomechanical benefit of a stand-alone two-part fusion cage can be justified. This device provided the stability required for interbody fusion, which supports clinical trials of the cage as an alternative to circumferential fixations. PMID:18559117

  2. Posterior Fixation Techniques in the Subaxial Cervical Spine

    PubMed Central

    Ghori, Ahmer; Makanji, Heeren; Cha, Thomas

    2015-01-01

    This article reviews the historical context, indications, techniques, and complications of four posterior fixation techniques to stabilize the subaxial cervical spine. Specifically, posterior wiring, laminar screw fixation, lateral mass fixation, and pedicle screw fixation are among the common methods of operative fixation of the subaxial cervical spine. While wiring and laminar screw fixation are now rarely used, both lateral mass and pedicle screw fixation are technically challenging and present the risk of significant complications if performed incorrectly. With a sound understanding of anatomy and rigorous preoperative evaluation of bony structures, both lateral mass and pedicle screw fixation provide a safe and reliable method for subaxial cervical spine fixation. PMID:26594602

  3. Porcine Intestinal Mast Cells. Evaluation of Different Fixatives for Histochemical Staining Techniques Considering Tissue Shrinkage

    PubMed Central

    Rieger, J.; Twardziok, S.; Huenigen, H.; Hirschberg, R.M.; Plendl, J.

    2013-01-01

    Staining of mast cells (MCs), including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF) has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkagedifferences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from data using different

  4. Porcine intestinal mast cells. Evaluation of different fixatives for histochemical staining techniques considering tissue shrinkage.

    PubMed

    Rieger, J; Twardziok, S; Huenigen, H; Hirschberg, R M; Plendl, J

    2013-01-01

    Staining of mast cells (MCs), including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF) has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkage-differences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from data using

  5. Sacroiliac screw fixation: A mini review of surgical technique

    PubMed Central

    Alvis-Miranda, Hernando Raphael; Farid-Escorcia, Hector; Alcalá-Cerra, Gabriel; Castellar-Leones, Sandra Milena; Moscote-Salazar, Luis Rafael

    2014-01-01

    The sacral percutaneous fixation has many advantages but can be associated with a significant exposure to X-ray radiation. Currently, sacroiliac screw fixation represents the only minimally invasive technique to stabilize the posterior pelvic ring. It is a technique that should be used by experienced surgeons. We present a practical review of important aspects of this technique. PMID:25336831

  6. Emerging Techniques for Posterior Fixation of the Lumbar Spine.

    PubMed

    Verma, Kushagra; Boniello, Anthony; Rihn, Jeffrey

    2016-06-01

    Pedicle screw fixation is the preferred method of posterior fusion in lumbar spinal surgery. The technique provides three-column support of the vertebrae, contributing to the biomechanical strength of the construct. However, open pedicle screw fixation often necessitates wide posterior exposure and dissection with soft-tissue disruption of the facet joint. Alternative posterior fixation techniques have been developed to reduce surgical time, soft-tissue dissection, disruption of the adjacent facet joint capsule, neurologic risk, and implant cost. Results of these techniques are comparable to those of standard pedicle screw fixation systems. Certain patients, especially those at a lower risk of nonunion or those who require posterior fixation only as an adjunct to anterior column support, may benefit from the shorter surgical time and limited posterior exposure of the alternative techniques. However, the decreased rigidity of these alternative constructs can result in excessive motion, which can lead to nonunion and early hardware failure. PMID:27077477

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

    PubMed

    Choi, Sungwook; Kang, Hyunseong; Bang, Hyeongsig

    2014-08-01

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

  8. Multicomponent analysis using established techniques

    NASA Astrophysics Data System (ADS)

    Dillehay, David L.

    1991-04-01

    Recent environmental concerns have greatly increased the need, application and scope of real-time continuous emission monitoring systems. New techniques like Fourier Transform Infrared have been applied with limited success for this application. However, the use of well-tried and established techniques (Gas Filter Correlation and Single Beam Dual Wavelength) combined with sophisticated microprocessor technology have produced reliable monitoring systems with increased measurement accuracy.

  9. Suture Bridge Fixation Technique for Posterior Cruciate Ligament Avulsion Fracture

    PubMed Central

    Lee, Kwang Won; Lee, Gyu Sang; Choy, Won Sik

    2015-01-01

    We presented a surgical technique including a suture bridge technique with relatively small incision for the reduction and fixation of posterior ligament avulsion fractures. A suture anchor was used to hold the avulsed fragment and a knotless anchor was used to continuously compress the bony fragment into the fracture site, thereby maintaining reduction during healing. PMID:26640635

  10. [Sacroiliac fixation: a new technique after pelvic trauma].

    PubMed

    Hoffmann, E; Levassor, N; Rillardon, L; Lavelle, G; Guigui, P

    2003-12-01

    We propose a new technique for sacroiliac fixation for the treatment of pelvic fracture with vertical and horizontal instability (Tile class C). This fixation technique allows control of vertical displacement while allowing, if needed, a certain degree of movement in the horizontal plane to facilitate reduction of anterior lesions. The technique involves insertion of two sacral screws, one in S1 and one in S2, and two iliac screws. The iliac screws are inserted in the posterior iliac crest through two sacroiliac connectors placed on a rod linking the two sacral screws. Vertical displacement is controlled by blocking the screw heads on the connecting rod. If needed, a certain degree of horizontal mobility of the half pelvis can be allowed by loosening the connectors on the rods. This technique was used for 4 patients. Anatomic reduction was achieved and no secondary movement of the osteosynthesis material nor secondary displacement were observed. The quality of the fixation allowed rapid weight bearing in the standing position and early walking without crutches. This type of fixation can only be used for type C12 fractures in the Tile classification. PMID:14726839

  11. Epidural catheter fixation. A comparison of subcutaneous tunneling versus device fixation technique

    PubMed Central

    Sharma, Ashima; Parasa, Sujay Kumar; Tejvath, Kiran; Ramachandran, Gopinath

    2016-01-01

    Background and Aims: The technique of securing the epidural catheter has a major bearing on the efficacy of epidural analgesia. Specific fixator devices, for e.g., Lockit epidural catheter clamp, which successfully prevents catheter migration, are available. The possibility of catheter snapping and surgical retrieval has been reported with tunneling of catheters. These techniques have not been compared for safety, efficacy and appropriateness of achieving secure epidural catheter fixation in the postoperative period. Material and Methods: A total of 200 patients who required postoperative epidural analgesia were included. They were randomized into two groups: Group I (n = 100) in whom epidural catheters were tunneled vertically in the paravertebral subcutaneous tissue and group II (n = 100) wherein a Lockit device was used to fix the catheter. Likert score was used to quantify patient's comfort during procedure. The techniques were compared for migration, catheter dislodgement, local trauma, catheter snapping and catheter obstruction. Results: 12% of tunneled catheters had migrated significantly outward. 22% of patients had erythema and 77% had significant procedural discomfort in group I. In group II, 3% catheters had kinked and 14% had erythema from device adhesive. Conclusion: Our results support the use of Lockit device as a safe and comfortable fixation device compared to subcutaneous tunneling of catheters. PMID:27006544

  12. Novel venting technique for intramedullary rod fixation of pathologic fractures.

    PubMed

    Wilkens, Kenneth J; Nicolaou, Daemeon A M; Lee, Mark A

    2011-10-01

    This article introduces a novel technique to vent the femur and potentially decrease the embolic load created by reaming during intramedullary rod fixation of impending pathologic femur fractures. We used readily available operating room equipment to create a distal femoral vent hole without interfering with standard intramedullary instrumentation and with minimal increase in surgical time. This technique can be used for the prophylactic intramedullary stabilization of impending pathologic femur fractures from metabolic bone disease, metastatic cancer, and bisphosphonate use. PMID:21956178

  13. Biomechanical evaluation of four different posterior screw and rod fixation techniques for the treatment of the odontoid fractures.

    PubMed

    Li, Lei; Liu, Wen-Fei; Jiang, Hong-Kun; Li, Yun-Peng

    2015-01-01

    Problems that screw cannot be inserted may occur in screw-rod fixation techniques such as Harms technique. We compared the biomechanical stability imparted to the C-2 vertebrae by four designed posterior screw and rod fixation techniques for the management of odontoid fractures. A three-dimensional finite element model of the odontoid fracture was established by subtracting several unit structures from the normal model from a healthy male volunteer. 4 different fixation techniques, shown as follows: ① C-1 lateral mass and C-2 pedicle screw fixation (Harms technique); ② C-1 lateral mass and unilateral C-2 pedicle screw fixation combined with ipsilateral laminar screw fixation; ③ Unilateral C-1lateral mass combined with ipsilateral C-1 posterior arch, and C-2 pedicle screw fixation; and ④ Unilateral C1 lateral mass screw connected with bilateral C2 pedicle screw fixation was performed on the odontoid fracture model. The model was validated for axial rotation, flexion, extension, lateral bending, and tension for 1.5 Nm. Changes in motion in flexion-extension, lateral bending, and axial rotation were calculated. The finite element model of the odontoid fracture was established in this paper. All of the four screw-rod techniques significantly decreased motion in flexion-extension, lateral bending, and axial rotation, as compared with the destabilized odontoid fracture complex (P<0.05). There was no statistically significant difference in stability among the four screw techniques. We concluded that the first three fixation techniques are recommended to be used as surgical intervention for odontoid fracture, while the last can be used as supplementary for the former three methods. PMID:26309508

  14. Biomechanical evaluation of four different posterior screw and rod fixation techniques for the treatment of the odontoid fractures

    PubMed Central

    Li, Lei; Liu, Wen-Fei; Jiang, Hong-Kun; Li, Yun-Peng

    2015-01-01

    Problems that screw cannot be inserted may occur in screw-rod fixation techniques such as Harms technique. We compared the biomechanical stability imparted to the C-2 vertebrae by four designed posterior screw and rod fixation techniques for the management of odontoid fractures. A three-dimensional finite element model of the odontoid fracture was established by subtracting several unit structures from the normal model from a healthy male volunteer. 4 different fixation techniques, shown as follows: ① C-1 lateral mass and C-2 pedicle screw fixation (Harms technique); ② C-1 lateral mass and unilateral C-2 pedicle screw fixation combined with ipsilateral laminar screw fixation; ③ Unilateral C-1lateral mass combined with ipsilateral C-1 posterior arch, and C-2 pedicle screw fixation; and ④ Unilateral C1 lateral mass screw connected with bilateral C2 pedicle screw fixation was performed on the odontoid fracture model. The model was validated for axial rotation, flexion, extension, lateral bending, and tension for 1.5 Nm. Changes in motion in flexion-extension, lateral bending, and axial rotation were calculated. The finite element model of the odontoid fracture was established in this paper. All of the four screw-rod techniques significantly decreased motion in flexion-extension, lateral bending, and axial rotation, as compared with the destabilized odontoid fracture complex (P<0.05). There was no statistically significant difference in stability among the four screw techniques. We concluded that the first three fixation techniques are recommended to be used as surgical intervention for odontoid fracture, while the last can be used as supplementary for the former three methods. PMID:26309508

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

    PubMed Central

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

    2008-01-01

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

  16. A biomechanical comparison of internal fixation techniques for ankle arthrodesis.

    PubMed

    Clifford, Craig; Berg, Scott; McCann, Kevin; Hutchinson, Byron

    2015-01-01

    The purpose of the present study was to compare the primary bending stiffness characteristics of 5 different ankle arthrodesis fixation techniques: 3 compression screws, an anterior locking plate, a lateral locking plate, an anterior locking plate with a compression screw, and a lateral locking plate with a compression screw. A total of 25 full-scale anatomic models consisting of fourth-generation composite tibiae and tali were tested using an Instron 4505 Universal Testing System. We hypothesized that the use of a compression screw with a locking plate would add considerable stiffness to the fixation construct compared with the use of a locking plate alone. The data have shown that an anterior or lateral plate with a compression screw provides significantly greater stiffness than both a plate and 3 compression screws used individually. No significant difference was seen between the anterior plate with a compression screw and the lateral plate with a compression screw. No significant differences were found among the use of an anterior plate, a lateral plate, or 3 compression screws. We have concluded that when using a locking plate in an anterior or lateral configuration, the addition of a compression screw will considerably increase the primary bending stiffness of ankle arthrodesis. PMID:25116232

  17. The use of augmentation techniques in osteoporotic fracture fixation.

    PubMed

    Kammerlander, Christian; Neuerburg, Carl; Verlaan, Jorrit-Jan; Schmoelz, Werner; Miclau, Theodore; Larsson, Sune

    2016-06-01

    There are an increasing number of fragility fractures, which present a surgical challenge given the reduced bone quality of underlying osteoporosis. Particularly in aged patients, there is a need for early weight bearing and mobilization to avoid further complications such as loss of function or autonomy. As an attempt to improve fracture stability and ultimate healing, the use of biomaterials for augmentation of osseous voids and fracture fixation is a promising treatment option. Augmentation techniques can be applied in various locations, and fractures of the metaphyseal regions such as proximal humerus, femur, tibia and the distal radius remain the most common areas for its use. The current review, based on the available mechanical and biological data, provides an overview of the relevant treatment options and different composites used for augmentation of osteoporotic fractures. PMID:27338226

  18. Minifragment screw fixation of oblique metacarpal fractures: a biomechanical analysis of screw types and techniques.

    PubMed

    Liporace, Frank A; Kinchelow, Tosca; Gupta, Salil; Kubiak, Erik N; McDonnell, Matthew

    2008-12-01

    The lag screw technique has historically been a successful and accepted way to treat oblique metacarpal fractures. However, it does take additional time and involve multiple steps that can increase the risk of fracture propagation or comminution in the small hand bones of the hand. An alternate fixation technique uses bicortical interfragmentary screws. Other studies support the clinical effectiveness and ease of this technique. The purpose of this study is to biomechanically assess the strength of the bicortical interfragmentary screw versus that of the traditional lag screw. Using 48 cadaver metacarpals, oblique osteotomies were created and stabilized using one of four methods: 1.5 mm bicortical interfragmentary (IF) screw, 1.5 mm lag technique screw, 2.0 mm bicortical IF screw, or 2.0 mm lag technique screw. Biomechanical testing was performed to measure post cyclic displacement and load to failure. Data was analyzed using one-way analysis of variance (ANOVA). There was no significant difference among the fixation techniques with regard to both displacement and ultimate failure strength. There was a slight trend for a higher load to failure with the 2.0 mm IF screw and 2.0 mm lag screw compared to the 1.5 mm IF and 1.5 mm lag screws, but this was not significant. Our results support previously established clinical data that bicortical interfragmentary screw fixation is an effective treatment option for oblique metacarpal fractures. This technique has clinical importance because it is an option to appropriately stabilize the often small and difficult to control fracture fragments encountered in metacarpal fractures. PMID:18780019

  19. Double-eyelid operation: orbicularis oculi-levator aponeurosis fixation technique.

    PubMed

    Park, Jung I; Park, Min S

    2007-08-01

    Incision techniques in the past focused on fixing the pretarsal skin to either the tarsal plate or to the levator aponeurosis. High relapse rate remains one of the main concerns in double-eyelid surgery. To address these issues, the author developed a pretarsal orbicularis oculi muscle-levator aponeurosis fixation technique. This technique results in better fixation between the skin and the levator aponeurosis by recruiting a bulky, pretarsal orbicularis oculi muscle in the fixation mechanism. This technique provides for a solidly fixed, tightly stretched pretarsal skin when the eyes are open with significantly reduced chances of relapse. PMID:17658427

  20. Treatment of Unstable Thoracolumbar Fractures through Short Segment Pedicle Screw Fixation Techniques Using Pedicle Fixation at the Level of the Fracture: A Finite Element Analysis

    PubMed Central

    Li, Changqing; Zhou, Yue; Wang, Hongwei; Liu, Jun; Xiang, Liangbi

    2014-01-01

    Objective To compare the von Mises stresses of the internal fixation devices among different short segment pedicle screw fixation techniques to treat thoracic 12 vertebral fractures, especially the mono-segment pedicle screw fixation and intermediate unilateral pedicle screw fixation techniques. Methods Finite element methods were utilised to investigate the biomechanical comparison of the four posterior short segment pedicle screw fixation techniques (S4+2: traditional short-segment 4 pedicle screw fixation [SPSF]; M4+2: mono-segment pedicle screw fixation; I6+2: intermediate bilateral pedicle screw fixation; and I5+2: intermediate unilateral pedicle screw fixation). Results The range of motion (ROM) in flexion, axial rotation, and lateral bending was the smallest in the I6+2 fixation model, followed by the I5+2 and S4+2 fixation models, but lateral bending was the largest in the M4+2 fixation model. The maximal stress of the upper pedicle screw is larger than the lower pedicle screw in S4+2 and M4+2. The largest maximal von Mises stress was observed in the upper pedicle screw in the S4+2 and M4+2 fixation models and in the lower pedicle screw in the I6+2 and I5+2 fixation models. The values of the largest maximal von Mises stress of the pedicle screws and rods during all states of motion were 263.1 MPa and 304.5 MPa in the S4+2 fixation model, 291.6 MPa and 340.5 MPa in the M4+2 fixation model, 182.9 MPa and 263.2 MPa in the I6+2 fixation model, and 269.3 MPa and 383.7 MPa in the I5+2 fixation model, respectively. Comparing the stress between different spinal loadings, the maximal von Mises stress of the implants were observed in flexion in all implanted models. Conclusion Additional bilateral pedicle screws at the level of the fracture to SPSF may result in a stiffer construct and less von Mises stress for pedicle screws and rods. The largest maximal von Mises stress of the pedicle screws during all states of motion were observed in the mono-segment pedicle

  1. Autologous Hamstring Anterior Cruciate Ligament Graft Failure Using the Anteromedial Portal Technique With Suspensory Femoral Fixation

    PubMed Central

    Galdi, Balazs; Reyes, Allan; Brabston, Eugene W.; Levine, William N.

    2015-01-01

    Background: The anteromedial portal technique for drilling of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction has been advocated by many surgeons as allowing improved access to the anatomical footprint. Furthermore, suspensory fixation of soft tissue grafts has become popularized because of complications associated with cross-pin fixation. Concerns regarding the use of both have recently arisen. Purpose: To raise awareness of the increased risk of graft failure when using the anteromedial portal technique with suspensory femoral fixation during ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: From November 1998 to August 2012, a total of 465 primary ACL reconstructions were performed using quadrupled hamstring autograft tendons, with drilling of the femoral tunnel performed via the transtibial portal. Graft fixation on the femur was achieved with cross-pin fixation, while interference screw fixation was used on the tibia. From September 2012 to October 2013, there were 69 reconstructions performed through an anteromedial portal. While there was no change in graft choice, a change was made to using suspensory femoral fixation. No other surgical or postoperative rehabilitation changes were made. Results: During the 14-year period in which ACL reconstructions were performed via the transtibial portal and with cross-pin fixation, 2 graft failures (0.4% failure rate) were reported. After switching to the anteromedial portal with suspensory fixation, 7 graft failures (10.1% failure rate) were reported over a 13-month period. These were 5 male and 2 female patients, with a mean age of 18.8 years—all elite athletes. The same surgical technique was used in all patients, and all patients had at least an 8 mm–diameter graft. Patients were cleared to return to sport at an average of 8.4 months postoperatively, after completing functional performance tests. Of the 7 patients, 6 sustained a rerupture of the graft within

  2. Biomechanical comparison of four mandibular angle fracture fixation techniques.

    PubMed

    Muñante-Cardenas, Jose Luis; Passeri, Luis Augusto

    2015-06-01

    The aim of this study was to make a comparison of the biomechanical behavior of four different internal fixation systems for mandibular angle fractures. A total of 40 polyurethane mandible replicas were employed with different fixation methods: group 1SP, one 2.0-mm four-hole miniplate; group 2PPL, two 2.0-mm four-hole parallel miniplates; group 3DP, one 3D 2.0-mm four-hole miniplate; and group 3DPP, one 3D 2.0-mm eight-hole miniplate. Each group was subjected to incisal or homolateral molar region loading. The load resistance values were measured at load application causing tip displacement of 1, 3, and 5 mm, and at the time at which the system achieves its maximum strength (MS). Means and standard deviations were compared among groups using analysis of variance and the Tukey test. Group 2PPL showed higher strength for all the displacements. For incisal loading, no statistically significant differences were found between groups 1SP, 3DP, and 3DPP. For molar loading, group 1SP and 3DPP showed statistically significant differences. For MS testing, group 1SP and 2PPL showed statistically significant differences in incisal loading; group 1SP and 3DP showed no statistically significant differences; and group 3DPP showed lower values of strength. Two parallel miniplates provide the most favorable mechanical behavior under the conditions tested. PMID:26000083

  3. Biomechanical Comparison of Four Mandibular Angle Fracture Fixation Techniques

    PubMed Central

    Muñante-Cardenas, Jose Luis; Passeri, Luis Augusto

    2014-01-01

    The aim of this study was to make a comparison of the biomechanical behavior of four different internal fixation systems for mandibular angle fractures. A total of 40 polyurethane mandible replicas were employed with different fixation methods: group 1SP, one 2.0-mm four-hole miniplate; group 2PPL, two 2.0-mm four-hole parallel miniplates; group 3DP, one 3D 2.0-mm four-hole miniplate; and group 3DPP, one 3D 2.0-mm eight-hole miniplate. Each group was subjected to incisal or homolateral molar region loading. The load resistance values were measured at load application causing tip displacement of 1, 3, and 5 mm, and at the time at which the system achieves its maximum strength (MS). Means and standard deviations were compared among groups using analysis of variance and the Tukey test. Group 2PPL showed higher strength for all the displacements. For incisal loading, no statistically significant differences were found between groups 1SP, 3DP, and 3DPP. For molar loading, group 1SP and 3DPP showed statistically significant differences. For MS testing, group 1SP and 2PPL showed statistically significant differences in incisal loading; group 1SP and 3DP showed no statistically significant differences; and group 3DPP showed lower values of strength. Two parallel miniplates provide the most favorable mechanical behavior under the conditions tested. PMID:26000083

  4. Femoral neck fracture fixation: rigidity of five techniques compared.

    PubMed Central

    Mackechnie-Jarvis, A C

    1983-01-01

    Artificial cadaveric femoral neck fractures were internally fixed with five different devices and subjected to cyclical loading of 0-1.0 kilonewtons (approximately one body weight) whilst in an anatomical position. Displacement of the proximal fragment was detected by a transducer and charted. Bone strength was assessed by a preliminary control loading phase on the intact bone. Efficiency of each fracture fixator could then be directly compared by the relative movement in each case. Five specimens each were tested with Moore's Pins, Trifin Nail, Garden Screws and a sliding screw-plate (OEC Ltd). By the criteria of the experiment, which put a severe shearing load on the implant, none of these devices reliably bore the representative body weight. An extended barrel-plate, which supported the sliding screw almost up to the fracture line, was then made. This device, employing some of Charnley's concepts, tolerated body weight in four cases out of five. PMID:6887186

  5. C1-2 posterior arthrodesis technique with a left segmental and right transarticular fixation. A hybrid novel (Kotil) technique

    PubMed Central

    Kotil, Kadir; Muslumanoglu, Murat

    2014-01-01

    Introduction: The most commonly used techniques for C1-C2 posterior arthrodesis are Goel and Magerl fixation techniques. Due to the anatomical variations of the region, the prior determination of the surgical technique might be hard. Right side Magerl, left side Goel's C1-C2 posterior arthrodesis case is presented as a new surgical combination technique used due to anatomical difficulties. Materials and Methods: Posterior C1-C2 arthrodesis operation was indicated for a 56-year-old female patient for the treatment of atlanto-axial subluxation caused by os odontoideum. First it was fixed from the nondominant arterial side (right vertebral artery) with Magerl (transarticular) technique. The left side was not suitable for the anatomical transarticular fixation, and the contralateral Goel fixation technique (segmental) was performed. Eventually, right side transarticular left side segmental fixation techniques were combined in one patient for the first time and C1-C2 fusion combination technique was presented. Results: Both Goel and Magerl techniques of C1-C2 posterior fusion techniques were successfully used simultaneously. The operation was initiated with Magerl technique with one screw on the nondominant side. The contralateral side was not suitable for Magerl technique therefore we changed to Goel's technique. Although, fluoroscopy was used 3 times as much during the introduction of the Drill with Magerl technique, twice as much operative time was spent during hemostasis and bleeding, preparation of the C1 entry point, and the reconstruction of polyaxial screws for Goel technique. No neurovascular complications were occurred during both procedures. Discussion: Combination of two C1-C2 posterior fusion techniques, Goel and Magerl, in suitable cases caused by anatomical or other reasons appears to be an alternative surgical procedure that protects the patient from complications. For a collection of better data, other studies that include large numbers of patients with

  6. Four lateral mass screw fixation techniques in lower cervical spine following laminectomy: a finite element analysis study of stress distribution

    PubMed Central

    2014-01-01

    Background Lateral mass screw fixation (LSF) techniques have been widely used for reconstructing and stabilizing the cervical spine; however, complications may result depending on the choice of surgeon. There are only a few reports related to LSF applications, even though fracture fixation has become a severe complication. This study establishes the three-dimensional finite element model of the lower cervical spine, and compares the stress distribution of the four LSF techniques (Magerl, Roy-Camille, Anderson, and An), following laminectomy -- to explore the risks of rupture after fixation. Method CT scans were performed on a healthy adult female volunteer, and Digital imaging and communication in medicine (Dicom) data was obtained. Mimics 10.01, Geomagic Studio 12.0, Solidworks 2012, HyperMesh 10.1 and Abaqus 6.12 software programs were used to establish the intact model of the lower cervical spines (C3-C7), a postoperative model after laminectomy, and a reconstructive model after applying the LSF techniques. A compressive preload of 74 N combined with a pure moment of 1.8 Nm was applied to the intact and reconstructive model, simulating normal flexion, extension, lateral bending, and axial rotation. The stress distribution of the four LSF techniques was compared by analyzing the maximum von Mises stress. Result The three-dimensional finite element model of the intact C3-C7 vertebrae was successfully established. This model consists of 503,911 elements and 93,390 nodes. During flexion, extension, lateral bending, and axial rotation modes, the intact model’s angular intersegmental range of motion was in good agreement with the results reported from the literature. The postoperative model after the three-segment laminectomy and the reconstructive model after applying the four LSF techniques were established based on the validated intact model. The stress distribution for the Magerl and Roy-Camille groups were more dispersive, and the maximum von Mises stress

  7. 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

  8. Surgical technique for transscleral fixation of a foldable posterior chamber intraocular lens.

    PubMed

    Yepez, Juan B; de Yepez, Jazmin Cedeño; Valero, Alejandro; Arevalo, J Fernando

    2006-01-01

    The safety and efficacy of a modified technique for transscleral fixation of a foldable posterior chamber intraocular lens (IOL) for intracapsular aphakia (secondary IOL) or after complicated phacoemulsification was evaluated. All eyes had inadequate or no posterior capsular support. Follow-up was between 4 and 26 months (mean, 12 months). Uncorrected visual acuity improved (> 2 lines) in all patients. During follow-up, the IOL was correctly positioned in all cases. There were no major complications, such as endophthalmitis or suture erosion through the conjunctiva at the site of fixation. No patient required further surgical interventions. This modified technique of transscleral fixation of foldable posterior chamber IOL offers the advantages of a small incision and rapid visual rehabilitation, and minimizes the risk of intraoperative and postoperative complications. PMID:16749265

  9. Aerobic rice mechanization: techniques for crop establishment

    NASA Astrophysics Data System (ADS)

    Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

    2015-12-01

    Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.

  10. Percutaneous Pedicle Screw Fixation Technique in the Thoracic and Lumbar Spine-Tips and Tricks.

    PubMed

    Gazzeri, Roberto

    2016-04-01

    The need for spinal fixation in patients who cannot tolerate classical open surgery has led in recent years to the development of minimally invasive approaches. The use of percutaneous pedicle screw fixation offers several advantages, such as less blood loss and postoperative pain due to blunt separation of the muscles with reduction of soft tissue dissection. Medical records and demographic information, diagnosis, and preoperative pain levels of 63 patients who underwent percutaneous minimally invasive thoracolumbar spine stabilization using the Illico® Fixation System (Alphatec Spine, Carlsbad, California) were analysed: a total of 344 screws were implanted. Preoperative and postoperative clinical assessment of the patients were based on a visual analogue scale. Because percutaneous techniques do not allow gross visualization of the vertebra and erroneous placement of the screw may be high in the initial cases, we discuss the techniques for a safe implantation of pedicle screws using a single or double intraoperative fluoroscopy. We report tips and tricks for technical challenges including fixation in osteoporotic patients, percutaneous insertion of long rods, compression/distraction using multiaxial screws turning into monoaxial, and use of minimally invasive retractror for interbody fusion. Recently, indications for minimally invasive percutaneous fixation have expanded and my results support that it may be considered a safe and effective option for the treatment of degenerative and traumatic thoracolumbar spinal diseases. PMID:27121407

  11. Cortical and Standard Trajectory Pedicle Screw Fixation Techniques in Stabilizing Multisegment Lumbar Spine with Low Grade Spondylolisthesis

    PubMed Central

    İnceoğlu, Serkan

    2015-01-01

    Background Cortical screw (CS) fixation has been recently proposed as an alternative to the standard pedicle screw (PS) fixation technique. Biomechanical studies involving individual screw pullout and single level motion segment stabilization showed comparable performance of both techniques. However, whether this new fixation technique can be applied to the stabilization of multilevel lumbar segments with significant destabilization has been unclear. Purpose To compare stability of CS fixation to the traditional PS fixation in an unstable 3 level spondylolisthesis model. Study Design This is a biomechanical study comparing cortical trajectory pedicle screw fixation to traditional trajectory pedicle screw fixation in an unstable cadaveric model using nondestructive flexibility test. Methods Eight fresh frozen cadaveric lumbar spines (T12- S1) were obtained. After intact baseline testing, a 3-level lowgrade spondylolisthesis was simulated at the L1-4. Each specimen was instrumented with the PS and CS fixation systems. Standard nondestructive flexibility test was performed. Range of motion at each level was compared between the constructs during flexion-extension, lateral bending, and axial rotation. Results The destabilization model significantly increased the ROM in all planes (P<0.05). Both fixation techniques provided significant reduction in the ROM (P<0.05). There was no significant difference in ROM between the PS and CS groups in any of planes (P>0.05). Conclusions Cortical trajectory pedicle screw fixation provided stabilization to multilevel lumbar segment with low-grade spondylolisthesis comparable to the standard trajectory pedicle screw construct. PMID:26484009

  12. New two-point scleral-fixation technique for foldable intraocular lenses with four hollow haptics.

    PubMed

    Liu, He-Ting; Jiang, Zheng-Xuan; Tao, Li-Ming

    2016-01-01

    The study was to report a new two-point scleral-fixation technique for foldable intraocular lenses with four haptics. Lenses were slid into the anterior chamber from a 2.8 mm corneal incision and fixed under two sclera flaps at two opposite points. The postoperative best-corrected visual acuities (BCVAs) of all patients were significantly better than their preoperative BCVA. The results demonstrate that two-point, scleral fixations of foldable, intraocular lenses might be practicable and effective. PMID:27158623

  13. New two-point scleral-fixation technique for foldable intraocular lenses with four hollow haptics

    PubMed Central

    Liu, He-Ting; Jiang, Zheng-Xuan; Tao, Li-Ming

    2016-01-01

    The study was to report a new two-point scleral-fixation technique for foldable intraocular lenses with four haptics. Lenses were slid into the anterior chamber from a 2.8 mm corneal incision and fixed under two sclera flaps at two opposite points. The postoperative best-corrected visual acuities (BCVAs) of all patients were significantly better than their preoperative BCVA. The results demonstrate that two-point, scleral fixations of foldable, intraocular lenses might be practicable and effective. PMID:27158623

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

    PubMed

    Shuker, Sabri T

    2013-07-01

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

  15. A Novel Technique for Closed Reduction and Fixation of Paediatric Calcaneal Fracture Dislocation Injuries

    PubMed Central

    Faroug, Radwane; Stirling, Paul; Ali, Farhan

    2013-01-01

    Paediatric calcaneal fractures are rare injuries usually managed conservatively or with open reduction and internal fixation (ORIF). Closed reduction was previously thought to be impossible, and very few cases are reported in the literature. We report a new technique for closed reduction using Ilizarov half-rings. We report successful closed reduction and screwless fixation of an extra-articular calcaneal fracture dislocation in a 7-year-old boy. Reduction was achieved using two Ilizarov half-ring frames arranged perpendicular to each other, enabling simultaneous application of longitudinal and rotational traction. Anatomical reduction was achieved with restored angles of Bohler and Gissane. Two K-wires were the definitive fixation. Bony union with good functional outcome and minimal pain was achieved at eight-weeks follow up. ORIF of calcaneal fractures provides good functional outcome but is associated with high rates of malunion and postoperative pain. Preservation of the unique soft tissue envelope surrounding the calcaneus reduces the risk of infection. Closed reduction prevents distortion of these tissues and may lead to faster healing and mobilisation. Closed reduction and screwless fixation of paediatric calcaneal fractures is an achievable management option. Our technique has preserved the soft tissue envelope surrounding the calcaneus, has avoided retained metalwork related complications, and has resulted in a good functional outcome. PMID:23819090

  16. 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

  17. Tram-Track Suture Technique for Pupillary Capture of a Scleral Fixated Intraocular Lens

    PubMed Central

    Kim, Sung In; Kim, Kiseok

    2016-01-01

    Purpose To report a new technique using tram-track suture for pupillary capture of a scleral fixated posterior chamber intraocular lens (PC-IOL) to reposition the tilted IOL. Methods In this prospective interventional case series, we describe a tram-track suture for pupillary capture of a scleral fixated PC-IOL. A long straight needle with double-armed 10-0 polypropylene is passed behind the iris and just above the optic portion (tilted forward) of the IOL. The other straight needle with double-armed 10-0 polypropylene is passed just below the optic portion (tilted backward) of the IOL. After the IOL is repositioned properly, the polypropylene sutures are gently pulled and tied. Results Four eyes of 4 patients underwent tram-track suture for pupillary capture of a scleral fixated PC-IOL. No intra- or postoperative complications were noted, and no pupillary captures were detected during the follow-up period. Conclusions The tram-track suture technique provides good centration and stability of a PC-IOL. This technique is an easy and effective way to reposition pupillary capture of an IOL. Further, it is also minimally invasive as it maintains a closed system. PMID:27462257

  18. Technique and nuances of an S-2 alar iliac screw for lumbosacral fixation in patients with transitional and normal anatomy.

    PubMed

    Ohya, Junichi; Vogel, Todd D; Dhall, Sanjay S; Berven, Sigurd; Mummaneni, Praveen V

    2016-07-01

    S-2 alar iliac (S2AI) screw fixation has recently been recognized as a useful technique for pelvic fixation. The authors demonstrate two cases where S2AI fixation was indicated: one case was a sacral insufficiency fracture following a long-segment fusion in a patient with a transitional S-1 vertebra; the other case involved pseudarthrosis following lumbosacral fixation. S2AI screws offer rigid fixation, low profile, and allow easy connection to the lumbosacral rod. The authors describe and demonstrate the surgical technique and nuances for the S2AI screw in a case with transitional S-1 anatomy and in a case with normal S-1 anatomy. The video can be found here: https://youtu.be/Sj21lk13_aw . PMID:27364429

  19. Two-Tension-Band Technique in Revision Surgery for Fixation Failure of Patellar Fractures.

    PubMed

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

    2016-01-01

    BACKGROUND Failed patellar fracture fixation is rare, and is usually attributed to technical errors. There are no specific details available on how to address this problem. We present our two-tension-band technique for fixing patellar fractures. MATERIAL AND METHODS Between March 2010 and March 2013, 4 men and 2 women with failed fixation patellar fractures were treated in our department. Their average age was 34 years (range 23-49 years). The initial fracture type was C1 in 3, C2 in 1, and C3 in 2, according to the AO classification. The initial fracture patterns included 3 transverse and 3 comminuted fractures. There were no open fractures. All patients underwent internal fixation with a modified anterior tension band (MATB) supplemented with cerclage wiring. All failures were caused by tension bands sliding past the tip of the Kirschner wires. The mean time between the primary and revision operations was 16.2 months (range 2-63 months). We revised the fractures by two-separate-tension-band technique. RESULTS The mean follow-up was 52 months (range 31-67 months). All patients healed radiographically without complications at an average of 14.7 weeks (range 8-20 weeks). The Bostman knee score was excellent in 3 and good in 3. All patients regained full extension and the mean range of flexion was 147.5° (135-155°). CONCLUSIONS Use of this two-tension-band technique can avoid technical errors and provide more secure fixation. We recommend it for both primary and revision surgery of patellar fractures. PMID:27485104

  20. Two-Tension-Band Technique in Revision Surgery for Fixation Failure of Patellar Fractures

    PubMed Central

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

    2016-01-01

    Background Failed patellar fracture fixation is rare, and is usually attributed to technical errors. There are no specific details available on how to address this problem. We present our two-tension-band technique for fixing patellar fractures. Material/Methods Between March 2010 and March 2013, 4 men and 2 women with failed fixation patellar fractures were treated in our department. Their average age was 34 years (range 23–49 years). The initial fracture type was C1 in 3, C2 in 1, and C3 in 2, according to the AO classification. The initial fracture patterns included 3 transverse and 3 comminuted fractures. There were no open fractures. All patients underwent internal fixation with a modified anterior tension band (MATB) supplemented with cerclage wiring. All failures were caused by tension bands sliding past the tip of the Kirschner wires. The mean time between the primary and revision operations was 16.2 months (range 2–63 months). We revised the fractures by two-separate-tension-band technique. Results The mean follow-up was 52 months (range 31–67 months). All patients healed radiographically without complications at an average of 14.7 weeks (range 8–20 weeks). The Bostman knee score was excellent in 3 and good in 3. All patients regained full extension and the mean range of flexion was 147.5° (135–155°). Conclusions Use of this two-tension-band technique can avoid technical errors and provide more secure fixation. We recommend it for both primary and revision surgery of patellar fractures. PMID:27485104

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

    PubMed

    Marie, Cronskär

    2015-08-01

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

  2. Technique tip: percutaneous fixation of partial incongruous Lisfranc injuries in athletes.

    PubMed

    Bleazey, Scott T; Brigido, Stephen A; Protzman, Nicole M

    2013-06-01

    Open reduction with screw fixation is considered the standard surgical approach for injuries of the Lisfranc complex in athletes. However, multiple incisions are required, which increase the risk for postoperative complications. We present a novel percutaneous reduction and solid screw fixation technique that may be a viable option to address partial incongruous injuries of the Lisfranc complex in athletes. At our institution, no intraoperative or postoperative complications have been encountered. Screw breakage did not occur. Reduction of the second metatarsal was considered anatomic across all patients. All patients have returned to their respective sport without limitation. The percutaneous approach appears to decrease complications while the targeting-reduction guide appears to precisely reduce the injury. Consequently, outcomes have been more consistent and predictable. The authors note that this percutaneous approach is specific to partial incongruous injuries of the Lisfranc complex. When presented with more extensive injuries, the authors advocate an open approach. PMID:23631892

  3. Sutureless, Glueless, Scleral Fixation of Single-Piece and Toric Intraocular Lens: A Novel Technique

    PubMed Central

    Kelkar, Aditya; Shah, Rachana; Kelkar, Jai; Kelkar, Shreekant; Arora, Ekta

    2015-01-01

    Sutureless, glueless, scleral fixation of an intraocular lens is a known technique of fixing a lens in the scleral pockets. However, this technique is applied to single-piece and toric lenses instead of 3-piece lenses, allowing the advantage of the use of premium lenses in patients with poor capsular support. Favourable results without complications of pigment dispersion, iris transillumination defects, dysphotopsia, elevated intraocular pressure, intraocular hemorrhage and cystoid macular edema with a well-centered, stable intraocular lens have been observed in the 3-month postoperative period in both cases. PMID:26327909

  4. Assessment of sagittal split ramus osteotomy rigid internal fixation techniques using a finite element method.

    PubMed

    Albougha, S; Darwich, K; Darwich, M A; Albogha, M H

    2015-07-01

    In this study, finite element analysis (FEA) was used to evaluate nine rigid internal fixation techniques for sagittal split ramus osteotomy. To achieve this, a computed tomography (CT) scan of a healthy patient was obtained and used to generate the geometry of a half-mandible. The geometries of bicortical screws, miniplates, and monocortical screws were designed and combined with the mandible in nine models simulating various techniques. Four models used bicortical screws in various arrangements and four used miniplates of various designs. One model represented a hybrid technique. A load of 500 N was applied to the posterior teeth and FEA was applied. The most stable techniques were the hybrid technique and a single straight miniplate, presenting the least displacement among all models. Bicortical screws, while presenting reasonable stability, showed high strain areas near the anterior ramus ridge, superoposterior to the screws, implying a risk of bone fracture in this area. On the other hand, the T-shaped and double Y-shaped miniplates were associated with high von Mises stresses that would impair their rigidity, especially where angles appeared in their designs. We recommend the use of a single straight miniplate because it provides sufficient stable fixation with minimal risks or disadvantages. PMID:25766461

  5. The RIVET: a novel technique involving absorbable fixation for hydroxyapatite osteosynthesis.

    PubMed

    Shido, Hirokazu; Sakamoto, Yoshiaki; Miwa, Tomoru; Ohira, Takayuki; Yoshida, Kazunari; Kishi, Kazuo

    2013-05-01

    Cranioplasty using custom-made hydroxyapatite (HAP) ceramic implants is a common procedure for the repair of skull defects. The advantages of using HAP are that it is nonmetallic, unlike titanium; biocompatible; and osteoconductive. Furthermore, it can be molded to any complex shape that may be needed. A disadvantage is that titanium screws and plates are in development for its fixation. We developed a technique for implant fixation using bioabsorbable screws and plates, and named this technique RIVET: resorbable immobilization for vacuolar en bloc technique.Before each operation, the implant was customized for the patient in question on the basis of models prepared using computed tomography data. The bioabsorbable plates were attached to the implant by drilling, tapping, and screwing, as shown in the video (http://links.lww.com/SCS/A43). The interior portion of the screw was then melted to flatten it against the internal surface of the implant, forming a rivet to join the plate and HAP implant.We used this technique for cranial reconstruction in 2 patients, with satisfying and functional results. We did not encounter any complications.In conclusion, the technique described here allows surgeons to fix implants and plates together more rigidly, giving a better result than possible with previous methods. PMID:23714917

  6. Long-term results following polydioxanone sling fixation technique in unstable lateral clavicle fracture.

    PubMed

    Teoh, Kar H; Jones, Sian A; Robinson, Juan D; Pritchard, Mark G

    2016-04-01

    Neer type II (Edinburgh type 3B) fractures of the lateral clavicle are unstable fractures. The optimal management of these fractures remains controversial with many surgical techniques described in the literature. Our study reports the long-term results of a modified suture (1.5-mm polydioxanone cord) and sling technique for these fractures to avoid complications associated with current techniques in the literature. Over a 5-year period, 23 patients who were (12 males, 11 females; 14 left, 9 right) with a mean age of 42 years were treated with this technique. At last follow-up, the mean Oxford score was 45.1 (range 36-48); the mean SPADI score was 7.4 (range 0-32.3); and the mean Constant score was 91.5 (range 71-100). There were one non-union and no malunion. All patients in our series, except one, returned to their pre-injury activity level. This modified suture fixation technique is safe, technically simple to perform and cheap. It achieves excellent rates of fracture union without the complications associated with other fixation methods in the literature. PMID:26794324

  7. Bicondylar tibial plateau fractures managed with the Sheffield Hybrid Fixator. Biomechanical study and operative technique.

    PubMed

    Ali, A M; Yang, L; Hashmi, M; Saleh, M

    2001-12-01

    The two main challenges in the management of bicondylar tibial plateau fractures are: Firstly, the compromised skin and soft tissue envelope which invite a high rate of complications following attempted open reduction and dual plating. Secondly, poor bone quality and comminuted fracture patterns, which create difficulty in achieving stable fixation. Although dual plating is considered to be the best mechanical method of stabilizing these complex fractures, there remains concern regarding the high rate of complications associated with extensive soft tissue dissection, required for the insertion of these plates in an already compromised knee. The Sheffield Hybrid fixator (SHF) technique offers a solution to the two main problems of these difficult fractures by minimizing soft tissue dissection, since bone fragments are reduced and fixed percutaneously, and providing superior cancellous bone purchase with beam loading stabilization for comminuted fractures. Our biomechanical testing showed the SHF with four tensioned wires to be as strong as dual plating and able to provide adequate mechanical stability in the fixation of bicondylar tibial plateau fractures. This was confirmed clinically by a prospective review of the use of the SHF at our centre, for managing complex and high-energy tibial plateau fractures with a good final outcome and no cases of deep infection or septic arthritis. PMID:11812481

  8. Biomechanical Evaluation of All-Polyethylene Pegged Bony Ingrowth Glenoid Fixation Techniques on Implant Micromotion.

    PubMed

    Wiater, Brett P; Moravek, James E; Kurdziel, Michael D; Baker, Kevin C; Wiater, J Michael

    2016-01-01

    Newer glenoid components that allow for hybrid cement fixation via traditional cementation of peripheral pegs and bony ingrowth into an interference-fit central peg introduce the possibility of long-term biological fixation. However, little biomechanical work has been done on the initial stability of these components and the various fixation options. We conducted a study in which all-polyethylene glenoid components with a centrally fluted peg were implanted in polyurethane blocks with interference-fit, hybrid cement, and fully cemented fixation (5 per fixation group). Biomechanical evaluation of glenoid loosening, according to ASTM Standard F-2028-12, subjected the glenoids to 50,000 cycles of rim loading, and glenoid component motion was recorded with 2 differential variable reluctance transducers fixed to each glenoid prosthesis. Fully cemented fixation exhibited significantly less mean distraction in comparison with interference-fit fixation (P < .001) and hybrid cement fixation (P < .001). Hybrid cement fixation exhibited significantly less distraction (P < .001), more compression (P < .001), and no significant difference in glenoid translation (P = .793) in comparison with interference-fit fixation. Fully cemented fixation exhibited the most resistance to glenoid motion in comparison with hybrid cement fixation and interference-fit fixation. However, hybrid cement fixation and interference-fit fixation exhibited equivocal motion. Given these results, cementation of peripheral pegs may confer no additional initial stability over that provided by uncemented interference-fit fixation. PMID:27327928

  9. Lumbosacral fixation using sacroiliac buttress screws: a modification to the Jackson technique with intrasacral rods

    PubMed Central

    2014-01-01

    Background The use of intrasacral rods has been previously reported for posterior lumbosacral fixation. However, problems associated with this technique include poor stability of the rod in the sacrum, difficulty in contouring the rod to fit the lateral sacral mass, and the complicated assembly procedure for the rod and pedicle screws in the thoracolumbar segments after insertion of the rod into the sacrum. Methods We used a screw with a polyaxial head instead of an intrasacral rod, which was inserted into the lateral sacral mass and assembled to the rod connected cephalad to pedicle screws. The dorsal side of the screw was stabilized by the sacral subchondral bone at the sacroiliac joint with iliac buttress coverage, and the tip of the screw was anchored by the sacral cortex. Results Three different cases were used to illustrate lumbosacral fixation using intrasacral screws as an anchor for the spinal instrumentation. Effective resistance of flexural bending moment and fusion were achieved in these patients at the lumbosacral level. Conclusions An intrasacral screw can be stabilized by subchondral bone with iliac buttress coverage at the dorsal and ventral sacral cortex. Posterior spinal fusion with this screw technique enables easier assembly of the instrumentation and presents better stabilization than that provided by the previously reported intrasacral rod technique for correction and fusion of thoracolumbar kyphoscoliosis. PMID:25050132

  10. 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

  11. Secondary Upper Lid Blepharoplasty: A Clinical Series Using the Tarsal Fixation Technique

    PubMed Central

    Mendelson, Bryan C.

    2015-01-01

    Background: One hundred consecutive secondary upper lid blepharoplasties were reviewed retrospectively to determine the lid characteristics of patients undergoing secondary blepharoplasty and the outcomes of all the procedures, which were performed using a tarsal fixation technique performed by one surgeon. Methods: The median age of the patients was 54 years, and 99 percent of the patients were women. The median time since primary blepharoplasty was 8.7 years (range, 2 to 22 years). At surgery, no additional skin was removed in 37 percent, and the median amount excised in the remainder was only 2 mm. Revision surgery was performed in 13 percent, mainly for incomplete correction of asymmetry (5 percent) or ptosis (4 percent). Nonsurgical complications were mainly ocular (8 percent). There were no cases of persistent postoperative lagophthalmos or dry eyes. Results: The term “postblepharoplasty look” was introduced to describe the different aging changes that follow primary blepharoplasty, mainly dermatochalasis (70 percent), with a high or absent and often poorly defined lid fold, with fat distribution irregularities. The tarsal fixation technique is advantageous in secondary blepharoplasty, as its benefit does not depend on further skin removal, minimizing the risk of lagophthalmos and dry eye syndrome. Lipoinfiltration for volume contouring is another major advance. The higher revision rate in secondary blepharoplasty reflects the incidence of asymmetry, lid ptosis, and scar from the original blepharoplasty, and from ongoing aging. Conclusions: The postblepharoplasty look of patients undergoing secondary upper lid blepharoplasty differs from the lid appearance of patients presenting for primary blepharoplasty. Tarsal fixation and lipoinfiltration are major advances in secondary upper lid blepharoplasty. PMID:25719715

  12. COMPLICATIONS OF THE SCREW/WASHER TIBIAL FIXATION TECHNIQUE FOR KNEE LIGAMENT RECONSTRUCTION

    PubMed Central

    Almeida, Alexandre; Roveda, Gilberto; Valin, Márcio Rangel; Almeida, Nayvaldo Couto de; Sartor, Vanderlei; Alves, Soraya Melina

    2015-01-01

    To evaluate the presence of pain at the site of the surgical incision and the need to remove the tibial fixation screw in anterior cruciate ligament (ACL) reconstruction, in relation to sex and body mass index (BMI). Methods: A group of 265 patients who underwent ACL reconstruction with ipsilateral flexor tendon grafts from the thigh in which the tibial fixation technique consisted of using a cortical screw and metal washer, between July 2000 and November 2007, were evaluated. Results: 176 patients were evaluated for an average of 33.3 ± 19.5 months; median of 29.5 months; IIQ: 17-45 months; minimum of 8 and maximum of 87 months. There was no statistical difference regarding complaints of pain at the site of the screw (p = 0.272) and the need to remove the tibial screw (p = 0.633) between sexes. There was no statistical difference regarding complaints of pain at the site of the screw (p = 0.08) and the need to remove the tibial screw (p = 0.379) according to BMI. Conclusion: The pain complaint rate at the screw site from the screw and metal washer method used for tibial fixation in ACL reconstruction was of the order of 25%, and the screw had to be removed in 10.8% of the cases. There was no predominance of pain complaints at the surgical wound between the sexes. There was a greater tendency to complain about pain among patients with BMI < 25. There was no predominance of screw and washer removal between the sexes or between individuals with different BMIs. PMID:27022587

  13. Novel Intramedullary-Fixation Technique for Long Bone Fragility Fractures Using Bioresorbable Materials

    PubMed Central

    Nishizuka, Takanobu; Kurahashi, Toshikazu; Hara, Tatsuya; Hirata, Hitoshi; Kasuga, Toshihiro

    2014-01-01

    Almost all of the currently available fracture fixation devices for metaphyseal fragility fractures are made of hard metals, which carry a high risk of implant-related complications such as implant cutout in severely osteoporotic patients. We developed a novel fracture fixation technique (intramedullary-fixation with biodegradable materials; IM-BM) for severely weakened long bones using three different non-metallic biomaterials, a poly(l-lactide) (PLLA) woven tube, a nonwoven polyhydroxyalkanoates (PHA) fiber mat, and an injectable calcium phosphate cement (CPC). The purpose of this work was to evaluate the feasibility of IM-BM with mechanical testing as well as with an animal experiment. To perform mechanical testing, we fixed two longitudinal acrylic pipes with four different methods, and used them for a three-point bending test (N = 5). The three-point bending test revealed that the average fracture energy for the IM-BM group (PLLA + CPC + PHA) was 3 times greater than that of PLLA + CPC group, and 60 to 200 times greater than that of CPC + PHA group and CPC group. Using an osteoporotic rabbit distal femur incomplete fracture model, sixteen rabbits were randomly allocated into four experimental groups (IM-BM group, PLLA + CPC group, CPC group, Kirschner wire (K-wire) group). No rabbit in the IM-BM group suffered fracture displacement even under full weight bearing. In contrast, two rabbits in the PLLA + CPC group, three rabbits in the CPC group, and three rabbits in the K-wire group suffered fracture displacement within the first postoperative week. The present work demonstrated that IM-BM was strong enough to reinforce and stabilize incomplete fractures with both mechanical testing and an animal experiment even in the distal thigh, where bone is exposed to the highest bending and torsional stresses in the body. IM-BM can be one treatment option for those with severe osteoporosis. PMID:25111138

  14. Phalangeal Lengthening Techniques for Brachydactily and Posttraumatic Digital Stumps With the Use of a Modified External Mini-Fixator.

    PubMed

    Danilkin, Mikhail Y

    2016-06-01

    Distraction osteogenesis has become the most used method for bone lengthening and deformity correction including the bones of the hand and foot. The principle techniques used for hand bone lengthening in posttraumatic and congenital conditions using available external fixators are based on this method. We present the technical specifications and surgical techniques with the use of a mini-fixator that was specially designed for short tubular bones. The surgical techniques of lengthening and web space skin stock creation for future web-pasty are supplied with the diagrams of their application to phalanges and illustrative clinical cases. Between 1999 and 2012, this mini-fixator was used for lengthening of 223 finger segments at our hospital and provided improvement of the hand esthetics and functions. PMID:27043289

  15. Biomechanical Comparison Between Bashti Bone Plug Technique and Biodegradable Screw for Fixation of Grafts in Ligament surgery

    PubMed Central

    Bashti, Kaveh; Tahmasebi, Mohammad N; Kaseb, Hasan; Farahmand, Farzam; Akbar, Mohammad; Mobini, Amir

    2015-01-01

    Background: Ligament reconstruction is a common procedure in orthopedic surgery. Although several popular techniques are currently in use, new methods are proposed for secure fixation of the tendon graft into the bone tunnel. Purposes: We sought to introduce our new technique of Bashti bone plug for fixation of soft tissue graft in anterior cruciate ligament (ACL) reconstruction and to compare its biomechanical features with conventional absorbable interference screw technique in a bovine model. Methods: Twenty pairs of bovine knees were harvested after death. Soft tissue was removed and the Achilles tendon was harvested to be used as an ACL graft. It was secured into the bone tunnel on the tibial side via two different methods: Bashti Bone Plug technique and conventional screw method. Biomechanical strength was measured using 200 N and 300 N cyclic loading on the graft. Pull out strength was also tested until the graft fails. Results: No graft failure was observed after 200 N and 300 N cyclic loading in either fixation methods. When testing for pull out failure, 21 tendons (53%) were torn and 19 tendons (48%) slipped out. No fixation failure occurred, which did not reveal a significant difference between the bone plug or interference screw group (P=0.11). The mean pull out force until failure of the graft was 496±66 N in the screw group and 503±67 N in the bone plug group (P=0.76). Conclusions: Our suggested fixation technique of Bashti bone plug is a native, cheap, and feasible method that provides comparable biomechanical strength with interference screw when soft tissue fixation was attempted in bovine model. PMID:25692166

  16. Combined use of Ilizarov external fixation and Papineau technique for septic pseudoarthrosis of the distal tibia in a patient with diabetes mellitus

    PubMed Central

    Koutsostathis, Stefanos D.; Lepetsos, Panagiotis; Polyzois, Vasilios D.; Pneumaticos, Spyros G.; Macheras, George A.

    2014-01-01

    The surgical treatment of open pilon fractures has a high complication rate especially in diabetic patients. In this article, we present a case of an infected tibial non-union after an open reduction and internal fixation in a diabetic patient, treated with Ilizarov external fixation combined with Papineau technique. Combined use of external fixation and Papineau technique can provide an alternative option for the treatment of septic pseudoarthrosis of the distal tibia. PMID:24563728

  17. Combined use of Ilizarov external fixation and Papineau technique for septic pseudoarthrosis of the distal tibia in a patient with diabetes mellitus.

    PubMed

    Koutsostathis, Stefanos D; Lepetsos, Panagiotis; Polyzois, Vasilios D; Pneumaticos, Spyros G; Macheras, George A

    2014-01-01

    The surgical treatment of open pilon fractures has a high complication rate especially in diabetic patients. In this article, we present a case of an infected tibial non-union after an open reduction and internal fixation in a diabetic patient, treated with Ilizarov external fixation combined with Papineau technique. Combined use of external fixation and Papineau technique can provide an alternative option for the treatment of septic pseudoarthrosis of the distal tibia. PMID:24563728

  18. A Technique of Superficial Medial Collateral Ligament Reconstruction Using an Adjustable-Loop Suspensory Fixation Device.

    PubMed

    Deo, Shaneel; Getgood, Alan

    2015-06-01

    This report describes superficial medial collateral ligament reconstruction of the knee using a novel method of graft fixation with the ACL Tightrope RT (Arthrex, Naples, FL). After tibial fixation with either a standard interference screw or staple, femoral fixation of the semitendinosus tendon is performed with the adjustable-loop suspensory fixation device, which allows for both initial graft tensioning and re-tensioning after cyclical knee range of motion. This provides the ability for the graft to accommodate for resultant soft-tissue creep and stress relaxation, thereby allowing for optimal soft-tissue tension and reduction in laxity at the end of the procedure. PMID:26258041

  19. A Technique of Superficial Medial Collateral Ligament Reconstruction Using an Adjustable-Loop Suspensory Fixation Device

    PubMed Central

    Deo, Shaneel; Getgood, Alan

    2015-01-01

    This report describes superficial medial collateral ligament reconstruction of the knee using a novel method of graft fixation with the ACL Tightrope RT (Arthrex, Naples, FL). After tibial fixation with either a standard interference screw or staple, femoral fixation of the semitendinosus tendon is performed with the adjustable-loop suspensory fixation device, which allows for both initial graft tensioning and re-tensioning after cyclical knee range of motion. This provides the ability for the graft to accommodate for resultant soft-tissue creep and stress relaxation, thereby allowing for optimal soft-tissue tension and reduction in laxity at the end of the procedure. PMID:26258041

  20. Reduction and fixation of the avulsion fracture of the tibial eminence using mini-open technique.

    PubMed

    Lu, Xiong-Wei; Hu, Xiao-Peng; Jin, Chen; Zhu, Tong; Ding, Yong; Dai, Li-Yang

    2010-11-01

    The purpose of this prospective study is to present and evaluate a new technique using suture anchors for the treatment of the avulsion fractures of the tibial eminence. Twenty-three consecutive patients with the displaced avulsion fracture of the tibial attachment of anterior cruciate ligament were treated using mini-open technique with suture anchors between 2005 and 2008. According to the classification of Meyers and McKeever, there were 5 type II, 13 type III, and 5 type IV fractures. The median follow-up period was 18 months (range, 12-32 months). The patient assessment included Lysholm score, Tegner score, IKDC score, and radiographic evaluation. The median Lysholm score improved from 32 (range, 28-48) preoperatively to 98 (range, 85-100) postoperatively. The median preoperative Tegner score was 3 (range, 2-5), and the median postoperative Tegner score was 7 (range, 5-9). The global IKDC objective score was normal (A) in 21 knees and nearly normal (B) in 2 knees. At final follow-up, the Lachman test and anterior drawer test were negative. The results showed that mini-open reduction and fixation of avulsion fracture of the tibial eminence with suture anchors have achieved satisfactory results. We suggest the use of this technique for treating avulsion fractures of the tibial eminence. PMID:20127313

  1. 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

  2. In vitro biomechanical evaluation of four fixation techniques for distractive–flexion injury stage 3 of the cervical spine

    PubMed Central

    Henriques, Thomas; Cunningham, Bryan W.; Mcafee, Paul C.

    2015-01-01

    Purpose Anterior plate fixation has been reported to provide satisfactory results in cervical spine distractive flexion (DF) injuries stages 1 and 2, but will result in a substantial failure rate in more unstable stage 3 and above. The aim of this investigation was to determine the biomechanical properties of different fixation techniques in a DF-3 injury model where all structures responsible for the posterior tension band mechanism are torn. Methods The multidirectional three-dimensional stiffness of the subaxial cervical spine was measured in eight cadaveric specimens with a simulated DF-3 injury at C5–C6, stabilized with four different fixation techniques: anterior plate alone, anterior plate combined with posterior wire, transarticular facet screws, and a pedicle screw–rod construct, respectively. Results The anterior plate alone did not improve stability compared to the intact spine condition, thus allowing considerable range of motion around all three cardinal axes (p > 0.05). The anterior plate combined with posterior wire technique improved flexion–extension stiffness (p = 0.023), but not in axial rotation and lateral bending. When the anterior plate was combined with transarticular facet screws or with a pedicle screws–rod instrumentation, the stability improved in flexion–extension, lateral bending, and in axial rotation (p < 0.05). Conclusions These findings imply that the use of anterior fixation alone is insufficient for fixation of the highly unstable DF-3 injury. In these situations, the use of anterior fixation combined with a competent posterior tension band reconstruction (e.g. transarticular screws or a posterior pedicle screws–rod device) improves segmental stability. PMID:25742755

  3. “Two-step” technique with OsiriX™ to evaluate feasibility of C2 pedicle for surgical fixation

    PubMed Central

    Marques, Luis Miguel Sousa; d’Almeida, Gonçalo Neto; Cabral, José

    2016-01-01

    Background: Surgical treatment of craniovertebral junction pathology has evolved considerably in recent decades with the implementation of short atlanto-axial fixation techniques, notwhithstanding increasing neurovascular risks. Also, there is strong evidence that fixation of C2 anatomical pedicle has the best biomechanical profile of the entire cervical spine. However, it is often difficult and misleading, to evaluate anatomical bony and vascular anomalies using the three orthogonal planes (axial, coronal, and sagittal) of CT. Objectives: The authors describe an innovative and simple technique to evaluate the feasibility of C2 pedicle for surgical screw fixation using preoperative planning with the free DICOM (Digital Imaging and Communications in Medicine) software OsiriX™. Materials and Methods: The authors report the applicatin of this novel technique in 5 cases (3 traumatic, 1 Os Odontoideum, and 1 complex congenital malformation) collected from our general case series of the Department in the last 5 years. Results: In this proof of concept study, the pre-operative analysis with the two-step tecnique was detrimental for choosing the surgical tecnique. Detailed post-operative analysis confirmed correct position of C2 screws without cortical breach. There were no complications or mortality reported. Conclusion: This two-step technique is an easy and reliable way to determine the feasibility of C2 pedicle for surgical fixation. The detailed tridimensional radiological preoperative evaluation of craniovertebral junction anatomy is critical to the sucess and safety of this surgeries, and can avoid, to certain degree, expensive intra-operative tridimensional imaging facilities. PMID:27217652

  4. Soft tissue fixation with a cortical button and interference screw: a novel technique in foot and ankle surgery.

    PubMed

    Shinabarger, Andrew B; Manway, Jeffrey M; Nowak, Jessica; Burns, Patrick R

    2015-02-01

    Tendon transfers are commonly performed procedures in the foot and ankle. They have been described for multiple tendons and a myriad of pathologies. One issue with these procedures has always been inadequate fixation with several methods available to the surgeon. In this report, we describe a novel technique in foot and ankle surgery using a cortical button and an interference screw. PMID:25534315

  5. Use of Ilizarov Fixator for Grade III B Open Olecranon Fracture: a Case Report and Surgical Technique

    PubMed Central

    Sharad Nemade, Pradip; Dash, Kumar Kaushik; Patwardhan, Tanvi Yeshwant; Londhe, Pravin Vasant

    2015-01-01

    Introduction: External fixator application can be difficult for olecranon fractures in presence of large degloving injuries. We describe use of simple Ilizarov ring fixator construct for grade IIIB open olecranon fracture management. Case Report: A 45-year-old female with Grade III B open comminuted olecranon fracture (30*15cm degloving area) and ulnar nerve palsy was treated with a novel ring fixator construct. Two cut-end olive wires were passed from the proximal olecranon across the fracture site in intramedullary fashion exiting dorsally at mid-ulnar level through healthy skin and were attached to an Ilizarov half ring secured by perpendicular wires. The olive wires were tensioned, achieving compression and stability. Range of motion (ROM) exercises could be started quickly as the elbow was not spanned. Wound healed after skin grafting and at one-year follow-up the patient has good functional results (PRE 7, DASH 9.48), elbow ROM 10°-130°, 75° pronation and 85° supination. The patient returned to pre-injury occupational activities and had no pain. At three-year follow-up, the x-ray and CT showed union of olecranon fragment with well-maintained congruency. Conclusion: Internal fixation in most cases may be precluded by the soft tissue trauma and risk of infection. In addition, the small proximal fragment precludes a stable external fixation. In this technique, the hardware is kept away from the open wound allowing better wound inspection and care. The intramedullary olive wires provide compression and stability, and thus allow early ROM. Ilizarov half-ring and olive wire fixation can be an useful option for management of high grade open olecranon fractures because of its advantages, viz. stable fixation, minimal internal hardware, optimal wound care, immediate initiation of range of motion, and good outcome. PMID:27299012

  6. Evaluation of a Chemical Fixation Technique for Remediation of Soils Contaminated with Arsenic Trioxide

    NASA Astrophysics Data System (ADS)

    Donahoe, R. J.; Yang, L.; Graham, E. Y.; Redwine, J. C.

    2004-12-01

    The results of an experimental study designed to test a chemical fixation technique for remediation of arsenic-contaminated soils are reported. Soil samples were collected from two industrial sites where herbicide application contaminated the soil with arsenic trioxide. Weathering has redistributed and changed the speciation of the arsenic and caused contamination of soil water and groundwater. Remediation techniques requiring excavation of the affected soil are impractical due to the lack of site access for heavy equipment and the large area impacted. To address these concerns, an in situ treatment method was developed and tested in laboratory experiments. Column experiments were conducted to evaluate the effectiveness of the soil treatment method. Homogenized soil samples from each site were packed into duplicate 4"x18" Plexiglas columns and treated with ferrous sulfate solution using a flow rate of 2 ml/min until iron breakthrough was achieved. Another pair of packed columns was leached with DDI water to provide baseline data for the effect of the treatment solution matrix on arsenic mobility. All soil column effluents showed an initial spike of arsenic after onset of fluid flow; however, the soils undergoing treatment leached less than one half the amount of arsenic leached from the soil by DDI water. When the soil became saturated with the ferrous sulfate treatment solution, effluent solution arsenic concentrations fell below detectable levels. After breakthrough of the treatment solution was achieved, the treated soil columns were allowed to drain and cure for 7 days. One treated soil column and one untreated soil column were then continuously leached with EPA Method 1312 SPLP fluid to observe the effect of treatment on the mobility of arsenic. The second set of treated and untreated soil columns was also leached with SPLP fluid, but in a manner designed to simulate periodic rainfall events. Preliminary experimental results show that ferrous sulfate treatment

  7. Orthopedic prosthesis fixation.

    PubMed

    Park, J B

    1992-01-01

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

  8. The chopstick-noodle twist: an easy technique of percutaneous patellar fixation in minimally displaced patellar fractures.

    PubMed

    Muzaffar, Nasir; Ahmad, Nawaz; Ahmad, Aejaz; Ahmad, Nissar

    2012-01-01

    We report six cases of minimally displaced two-part patellar fractures with skin injury over the patella that were treated with percutaneous K wire fixation and compression applied using stainless steel (SS) wire. This technique makes it possible to perform early operative treatment in cases where unhealthy skin is not amenable to conventional tension band wiring. The technique employs two K wires inserted through the two fracture fragments under local or regional anaesthesia. They are then compressed using simple SS wire knots at the two ends - making it look like noodles at the end of two chopsticks. The fixation is subsequently augmented with a cylindrical plaster-of-Paris cast. The technique is simple, cheap and does not cause soft tissue injury. PMID:22290109

  9. Comparison of Hallux Interphalangeal Joint Arthrodesis Fixation Techniques: A Retrospective Multicenter Study.

    PubMed

    Thorud, Jakob C; Jolley, Tyler; Shibuya, Naohiro; Lew, Eric; Britt, Matthew; Butterfield, Ted; Boike, Alan; Hardy, Mark; Brancheau, Steven P; Motley, Travis; Jupiter, Daniel C

    2016-01-01

    Few studies have investigated the complications that occur after hallux interphalangeal joint arthrodesis. The present study evaluated complications in 152 patients aged 18 to 80 years from 2005 to 2012 from 4 different academic institutions after hallux interphalangeal joint arthrodesis. Overall, 65.8% of the patients had ≥1 complication. Infections occurred in 16.5%, dehiscence in 12.5%, and reoperations in 27.0%. The clinical nonunion rate was ≥17.8%, and the radiographic nonunion rate was ≥13.8%. After logistic regression analysis, only the study site and peripheral neuropathy were associated with having ≥1 complication (p < .01 and p < .05, respectively). Single screw fixation compared with other fixation did not have a statistically significant influence on the postoperative complications. However, when fixation was expanded to 4 categories, single screw fixation had lower infection and reoperation rates than either crossed Kirschner wires or other fixation category but not compared with crossed screws on multivariate logistic regression analysis. Although additional studies are warranted, the findings from the present study might aid in both the prognosis of complications and the support of the use of a single screw over crossed Kirchner wire fixation in hallux interphalangeal joint arthrodesis. PMID:25960055

  10. Malik`s Technique of Single Loop Fixation of Posterior Chamber Intraocular Lens in Presence of Partial Capsular Support

    PubMed Central

    Singh Malik, Krishan Pal; Goel, Ruchi; Kishore, Divya; Nagpal, Smriti

    2015-01-01

    Single loop fixation of posterior chamber intraocular lens in the presence of partial capsular support is usually performed by creation of additional scleral flap or tunnel. This extra port may expose the suture holding the intraocular lens or the tucked-in lens haptics to the outside environment thereby increasing the risk of endophthalmitis. We describe a technique of single loop fixation where the scleral tunnel is created adjacent to the site with the absent capsule, the leading haptic is placed on the capsular scaffold, the trailing haptic is tied to 9-0 polypropylene, and the suture is then secured to the inner edge of the scleral lip with enough tension to center the optics and the wound is then closed. The suture knot gets buried within the scleral tunnel with no external communication and does not require a separate port. It is an easy, safe, fast and reproducible technique with a lens tilt of less than 2°. PMID:26962380

  11. Free vascularized fibular grafts for femoral head osteonecrosis: alternative technique utilizing a buttress plate for graft fixation.

    PubMed

    Woodhouse, Andrew G; Drake, Matthew L; Lee, Gwo Chin; Levin, L Scott; Tintle, Scott M

    2015-01-01

    Core decompression with free vascularized fibular grafting is an effective hip preservation treatment for osteonecrosis of the femoral head. This procedure has traditionally utilized a single Kirschner wire to secure the fibular strut within the femoral neck. While this method has proven effective, migration of the Kirschner wire remains the most common recipient site complication. Additionally the presence of the Kirschner wire traversing the intramedullary canal can also complicate future hip arthroplasty. Therefore, this article describes a simple graft fixation technique utilizing a buttress plate that obviates migration problems. Ten patients are presented with at least 6 months of follow-up who have been treated with this technique without complications. This fixation method is simple and eliminates a major potential complication and allows for easier conversion to total hip arthroplasty. PMID:25988699

  12. Minimally invasive field abomasopexy techniques for correction and fixation of left displacement of the abomasum in dairy cows.

    PubMed

    Newman, Kenneth D; Harvey, Denis; Roy, Jean-Philippe

    2008-07-01

    To reduce the potential drawbacks associated with laparotomy techniques for correction and fixation of left displaced abomasums (LDA), minimally invasive techniques have been developed. This chapter reviews the toggle pin suture (TPS) and the laparoscopic abomasopexy procedures used in the field for correction and fixation of the abomasum for correction of left-displacement of the abomasum in dairy cows. The importance of case selection cannot be overestimated. By combining laparoscopy with the principle of the TPS procedure, the lack of visual control associated with the TPS procedure is eliminated, while the advantage of the speed of completion and minimal invasiveness provided by both procedures are maintained. Successful LDA treatment includes not only early detection and treatment of the LDA, but also the prevention of secondary ketosis and aggressive treatment of concurrent disease. PMID:18471576

  13. 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. PMID:26447409

  14. Arthroscopic Labral Reconstruction of the Hip Using Iliotibial Band Allograft and Front-to-Back Fixation Technique

    PubMed Central

    White, Brian J.; Herzog, Mackenzie M.

    2016-01-01

    Labral repair has been shown to be an effective treatment option with excellent early outcomes; however, in cases of severe labral damage or when the labral tissue is too large or diminutive, labral repair may be less effective. The purpose of this article is to present a modified technique for hip labral reconstruction using iliotibial band allograft tissue and a front-to-back fixation technique. The described technique is modified from the original report of a technique for arthroscopic labral reconstruction. The front-to-back technique allows the surgeon to make a graft that is longer than necessary and cut excess graft after front-to-back fixation, resulting in the correct graft size and a reproducible procedure. Allograft tissue offers several advantages, including the ability to control graft thickness and length, as well as the ability to eliminate donor-site morbidity. This procedure adds to the available techniques for treatment of labral pathology by providing a labral reconstruction technique using allograft tissue. PMID:27073784

  15. Technique for rapid establishment of American lotus in remediation efforts

    SciTech Connect

    Ryon, M. G.; Jett, R. T.; McCracken, M. K.; Morris, G. W.; Roy, W. K.; Fortner, A. M.; Goins, K. N.; Riazi, A. S.

    2013-03-01

    A technique for increasing the establishment rate of American lotus (Nelumbo lutea) and simplifying planting was developed as part of a pond remediation project. Lotus propagation techniques typically require scarification of the seed, germination in heated water, and planting in nursery containers. Then mature (~ 1 yr) nursery-grown stock is transferred to planting site or scarified seed are broadcast applied. Mature plants should grow more quickly, but can be sensitive to handling, require more time to plant, and cost more. Scarified seeds are easier to plant and inexpensive, but have a lag time in growth, can fail to germinate, and can be difficult to site precisely. We developed an intermediate technique using small burlap bags that makes planting easier, provides greater germination success, and avoids lag time in growth. Data on survival and growth from experiments using mature stock, scarified seeds, and bag lotus demonstrate that bag lotus grow rapidly in a variety of conditions, have a high survival rate, can be processed and planted easily and quickly, and are very suitable for a variety of remediation projects

  16. Radiological Evaluation of the Initial Fixation between Cortical Bone Trajectory and Conventional Pedicle Screw Technique for Lumbar Degenerative Spondylolisthesis

    PubMed Central

    Iwatsuki, Koichi; Ohnishi, Yu-Ichiro; Yoshimine, Toshiki

    2016-01-01

    Study Design Retrospective study. Purpose To compare initial fixation using the cortical bone trajectory (CBT) technique versus conventional pedicle screws (PS) in radiographs of postsurgical lumbar degenerative spondylolisthesis. Overview of Literature Few reports have documented the holding strength of CBT technique for spondylolisthesis cases. Methods From October 2009 to June 2014, 21 cases of degenerative spondylolisthesis were surgically treated in our institution. Ten were treated with conventional PS technique and 11 of with CBT technique. Mean lumbar lordosis and percent slippage were evaluated preoperatively, immediately after surgery, and 6 months and 1 year postoperatively using radiographs. We also investigated percent loss of slip reduction. Results There were statistically significant differences between preoperative percent slippage and postoperative slippage in both PS and CBT procedures over 1 year, and both techniques showed good slip reduction. On the other hand, lumbar lordosis did not change significantly in either the PS or CBT groups over 1 year. Conclusions CBT technique showed similarly good initial fixation compared with the PS procedure in the treatment of lumbar degenerative spondylolisthesis. PMID:27114765

  17. An Effective and Feasible Method, “Hammering Technique,” for Percutaneous Fixation of Anterior Column Acetabular Fracture

    PubMed Central

    Zhang, Lihai; Zhang, Wei; Li, Tongtong; Li, Jiantao; Chen, Hua

    2016-01-01

    Objective. The objective of this study was to evaluate the effectiveness and advantages of percutaneous fixation of anterior column acetabular fracture with “hammering technique.” Materials and Methods. We retrospectively reviewed 16 patients with percutaneous fixation of anterior column acetabular fracture with “hammering technique.” There were 11 males and 5 females with an average age of 38.88 years (range: 24–54 years) in our study. Our study included 7 nondisplaced fractures, 6 mild displaced fractures (<2 mm), and 5 displaced fractures (>2 mm). The mean time from injury to surgery was 4.5 days (range: 2–7 days). Results. The average of operation time was 27.56 minutes (range: 15–45 minutes), and the mean blood loss was 55.28 mL (range: 15–100 mL). The mean fluoroscopic time was 54.78 seconds (range: 40–77 seconds). The first pass of the guide wire was acceptable without cortical perforation or intra-articular perforation in 88.89% (16/18) of the procedures, and the second attempt was in 11.11% (2/18). Conclusion. Our study suggested that percutaneous fixation of anterior column acetabular fracture with “hammering technique” acquired satisfying surgical and clinical outcomes. It may be an alternative satisfying treatment for percutaneous fixation of anterior column acetabular fracture by 2D fluoroscopy using a C-arm with less fluoroscopic time. PMID:27493962

  18. A comparison of techniques for fixation of the quadriceps muscle-tendon complex for in vitro biomechanical testing of the knee joint in sheep.

    PubMed

    Schöttle, Philip; Goudakos, Ioannis; Rosenstiel, Nikolaus; Hoffmann, Jan-Erik; Taylor, William R; Duda, Georg N; Heller, Markus O

    2009-01-01

    Whilst in vitro testing can contribute to a better understanding of the biomechanical interactions at the knee joint, the application of physiological-like muscle forces in vitro remains challenging. One main difficulty seems to be the adequate fixation of the muscle-tendon complex to the mechanical apparatus that provides the forces in vitro. The goal of this study was to compare the ability of different muscle-tendon fixation mechanisms, including a new technique developed to optimise the interface grip of the soft tissues, to reliably transmit physiological in vivo loads through the muscle-tendon complex to the attached bone. The fixations of three quadriceps components in 16 right knees of skeletally mature female merino sheep were loaded to failure using four different fixation techniques (aluminium clamp, freeze clamp, suture technique and a new extension hull technique). Each technique was tested 12 times: 4 times on each individual quadriceps component. A factorial analysis for repeated measurements was undertaken to examine differences between the different fixation techniques. The extension hull technique and the aluminium clamp performed similarly, exceeding the computationally determined physiological forces in all but one trial and achieved higher failure loads than the suture technique. Although the freeze clamp reached the highest mean load to failure, it also failed more often than the extension hull technique. This comparison of the fixation techniques suggests that the new extension hull technique is a suitable fixation method for applying physiological-like muscle loading in an in vitro set-up. It cannot only be handled in a very simple manner, but also possesses a compact, lightweight construction, providing the possibility for the application of more complex loading conditions that include, e.g. the action of multiple muscles of the knee flexor and extensor group concurrently. PMID:18539516

  19. Least Possible Fixation Techniques of 4-Part Valgus Impacted Fractures of the Proximal Humerus: A Systematic Review

    PubMed Central

    Panagopoulos, Andreas; Tatani, Irini; Ntourantonis, Dimitrios; Seferlis, Ioannis; Kouzelis, Antonis; Tyllianakis, Minos

    2016-01-01

    The valgus-impacted (VI) 4-part fractures are a subset of fractures of the proximal humerus with a unique anatomic configuration characterized by a relatively lower incidence of avascular necrosis after operative intervention. We systematically reviewed clinical studies assessing the benefits and harms of least possible fixation techniques (LPFT) for this unique fracture type. Such information would be potentially helpful in developing an evidence-based approach in the management of these complex injuries. We performed analytic searches of PubMed, Embase, Web of Science, Google Scholar and the Cochrane Library, restricting it to the years 1991-2014. Included studies had to describe outcomes and complications after primary osteosynthesis with any type of LPFT apart from plate-screws and intramedullary nailing. Eligibility criteria were also included English language, more than 5 cases, minimum follow up of one year and report of clinical outcome using at least one relevant score (Constant, Neer or ASES). Based on 292 database hits we identified 12 eligible studies including 190 four-part valgus impacted fractures in 188 patients. All eligible studies were case series composed of min 8 to max 45 patients per study. The gender distribution was 60% (112) female and 40% (76) male. The average age of the patients at the time of injury was 54.5 years. In 8/12 studies an open reduction was used for fracture fixation using different surgical techniques including KW, cerclage wires, cannulated screws and osteosutures. Closed reduction and percutaneous fixation was used in 4 studies. Mean follow-up time ranged from 24 to 69 months. A good functional outcome (constant score >80) was reported in 9/12 studies. The most common complication was avascular necrosis of the humeral head with an overall incidence of 11% (range, 0-26.3%). Total avascular necrosis (AVN) was found in 15/188 patients (7.9%) and was more common in percutaneous techniques and partial AVN in 6/188 (3

  20. Simplified ab externo fixation technique to treat late dislocation of scleral-sutured polymethyl methacrylate intraocular lenses.

    PubMed

    Lyu, J; Zhao, P-Q

    2016-05-01

    PurposeWe report a simplified ab externo scleral fixation technique to manage the late dislocation of scleral-sutured polymethyl methacrylate (PMMA) intraocular lenses (IOLs) in the absence of capsule support.Materials and methodsThe technique was performed on five eyes of five patients. Symmetrical scleral pocket tunnels without conjunctival peritomy were created. An anterior vitrectomy via a limbal approach with an anterior chamber infusion or a 3-port pars plana vitrectomy was performed to rescue the dislocated IOL. A long straight suture needle and 23-gauge vitreoretinal forceps were used to conveniently reposition the IOL and loop sutures through the IOL positioning eyelets without externalizing IOL haptics. The outside suture knots were buried under the roof of the scleral tunnels.ResultsThe patients were followed for 5-14 months after surgery. All the operated eyes quickly recovered with negligible corneal endothelial cell loss and mild inflammation. Visual acuity improvement and IOL centration were achieved in all eyes with no major complications.ConclusionThe simplified ab externo scleral fixation technique offers an effective and minimally invasive surgical alternative to salvage dislocated previously scleral-sutured PMMA IOLs. PMID:26795420

  1. A Comparison of Open and Percutaneous Techniques in the Operative Fixation of Spinal Fractures Associated with Ankylosing Spinal Disorders

    PubMed Central

    Daffner, Scott D.; Obafemi-Afolabi, Abimbola; Gelb, Daniel; Ludwig, Steven; Emery, Sanford E.; France, John C.

    2016-01-01

    Background The operative care of patients with ankylosing spinal conditions such as ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) after a spine fracture is not well represented in the literature. This work seeks to determine the effect of minimally invasive techniques on patients with spinal fractures and ankylosing spinal conditions through a retrospective case-control analysis. Methods The operative logs from 1996-2013 of seven fellowship-trained spine surgeons from two academic, Level I trauma centers were reviewed for cases of operatively treated thoracic and lumbar spinal fractures in patients with ankylosing spinal disorders. Results A total of 38 patients with an ankylosing spinal condition and a spinal fracture were identified. The minimally invasive group demonstrated a statistically significant decrease in estimated blood loss, operative time, and need for transfusion when compared to either the hybrid or open group. There was no difference between the three subgroups in overall hospital stay or mortality. Conclusions Patients with ankylosing spinal conditions present unique challenges for operative fixation of spinal fractures. Minimally invasive techniques for internal fixation offer less blood loss, operative time, and need for transfusion compared to traditional techniques; however, no difference in hospital stay or mortality was reflected in this series of patients. Level of Evidence: 4. Clinical Relevance Ankylosing spinal disorders are increasingly common in an aging population. PMID:27441181

  2. The effects of guided tissue regeneration and fixation technique on osseous wound healing in rabbit zygomatic arch osteotomies.

    PubMed

    Mooney, M P; Mundell, R D; Stetzer, K; Ochs, M W; Milch, E A; Buckley, M J; Siegel, M I

    1996-01-01

    The development of fibrous nonunions after craniofacial surgery is thought to result from an interaction of biomechanical stress and the differential migration of various tissue types into the wound site during healing. The present study is designed to test this hypothesis through the manipulation of guided tissue regeneration and osteotomy fixation techniques in an experimental rabbit model. Bilateral, critical size (5 mm), vertical osteotomies (n = 32) were produced in the zygomatic arches of eight adult rabbits. The mobile bony segments were fixed rigidly or nonrigidly using bone microplates and screws or osteosynthetic wires. The defects were then covered with a resorbable collagen membrane or left uncovered. The rabbits were followed for 4 weeks with serial dorsoventral cephalographs and the zygomatic arches harvested for histological analysis. Cephalometric results revealed significantly (p < 0.001) increased bone growth in the margins of the defects covered with the collagen membrane; however, no significant (p > 0.05) differences were noted between fixation techniques. Histological analysis revealed that defects fixed rigidly and covered by the membrane showed the most rapid and organized osseous wound healing, followed by the defects that were fixed nonrigidly and membrane covered. The defects not covered by the collagen membrane showed invasion by fibroblasts resulting in fibrous nonunions. These results demonstrate the efficacy of guided tissue regeneration with a resorbable collagen membrane in preventing fibrous tissue ingrowth in large bony defects. The addition of rigid fixation at a potentially mobile site appeared to enhance bony trabecular organization but not the osteogenic rate in this rabbit model. PMID:9086901

  3. Photoelastic stress analysis of internal fixation techniques for femur shaft crack

    NASA Astrophysics Data System (ADS)

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

    2001-06-01

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

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

    PubMed

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

    2015-11-01

    Rigid external distraction device is often indicated for superior midfacial advancement in pediatric syndromic craniosynostosis patients. Even though the technique is proven reliable to treat the functional issues related to the craniofacial deformity, major complications associated with its fixation, such as intracranial pin perforation and migration have been reported. We report a novel technique of using a customized headgear to prevent intracranial pin perforation over a very thin temporal bone region in an 8-month-old infant with Crouzon syndrome who underwent monobloc Le Fort III distraction osteogenesis using a combination of bilateral internal and a rigid external distraction device. The customized headgear provides a protective platform at the temporal region thus preventing intracranial pin perforation and allows stable fixation during the early phase of consolidation period to prevent central component relapse. The headgear can be used short term when rigid external distractor is indicated in infant patient but requires close monitoring because of risks of skin necrosis and temporal region indentation. PMID:26594993

  5. 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

  6. Treatment of tibial eminence fractures with arthroscopic suture fixation technique: a retrospective study

    PubMed Central

    Yuan, Yanhao; Huang, Xiaohan; Zhang, Yanjie; Wang, Zhanchao

    2015-01-01

    Aims: The present study aims to investigate the clinical outcomes of arthroscopic suture fixation in treating tibial eminence fracture with a retrospective study design of two years’ follow-up. Methods: A total of 33 patients with imaging evidence of tibial eminence avulsion fractures who underwent arthroscopic surgery between 2008 and 2012 were included in this study. The inclusion criteria for the study were a displaced tibial eminence avulsion fracture and anterior knee instability of grade II or higher inskeletally mature patients. These patients were treated with arthroscopic suture fixation and followed with a mean period of 24 months. Anteroposterior and lateral radiographs were obtained 3 months postoperatively to assess fracture healing. At 24 months after surgery, all patients were evaluated by an independent orthopaedic professor with clinical examination like anteroposterior laxity (Lachman-Noulis and anterior drawer tests) and Rolimeter knee tester (Aircast, Vista, CA). Knee range of motion was evaluated actively and passively with a goniometer. Knee function was evaluated by the Lysholm and International Knee Documentation Committee (IKDC) scores. Knee radiographs in standing anteroposterior, standing lateral, and Merchant views were examined for alignment, joint space narrowing, and degenerative knee changes. Results: No major complication like infection, deep venous thrombosis, or neurovascular deficit happened peri-operatively. At the final follow-up, there were no symptoms of instability and no clinical signs of ACL deficiency. Radiographs showed that all fractures healed 3 months post-operative, but at the last follow-up, there was one person with degenerative changes like joint space narrowing in radiographs. Anterior translation of the tibia was 0.47 mm on average (0 to 2.5 mm) compared with the uninjured side. Range-of-motion measurement showed a mean extension deficit of 1.5° (0° to 5°) and a mean flexion deficit of 2.7° (0° to 10

  7. Use of a Percutaneous Pointed Reduction Clamp Before Screw Fixation to Prevent Gapping of a Fifth Metatarsal Base Fracture: A Technique Tip.

    PubMed

    Tan, Eric W; Cata, Ezequiel; Schon, Lew C

    2016-01-01

    Intramedullary screw fixation has become widely accepted as the standard of care for operative treatment of Jones fractures, allowing not only accelerated rehabilitation but also reduction of the risk of repeat fracture. The unique anatomy of the fifth metatarsal--mainly its inherent lateral curvature--makes fixation technically challenging. In general, surgical fixation should be performed with the largest screw possible, in both diameter and length, which will provide the strongest possible construct. However, an increased screw length and width have been associated with complications, including lateral gapping and distraction of the fracture site and malreduction of the fracture. The use of a pointed reduction clamp is a simple, yet effective, method of preventing iatrogenic displacement and gapping at the fracture site during placement of an intramedullary screw. Percutaneous reduction and stabilization of the fracture using this technique could help limit the complications associated with large screw fixation of Jones fractures. PMID:26188626

  8. Wound Coverage Technologies in Burn Care: Established Techniques

    PubMed Central

    Jeschke, Marc G.; Shahrokhi, Shahriar; Finnerty, Celeste C.; Branski, Ludwik K.; Dibildox, Manuel

    2013-01-01

    Major advances in burn care have reduced post-burn morbidity and mortality. The development and incorporation of new wound healing modalities into the clinical arena have contributed to this improvement by allowing standard-of-care regimens to be established. These regimens range from early excision to the use of cultured epithelial autograft. Here, we review the wound care options that are now well established and used by many burn surgeons. PMID:24165670

  9. Open Versus Minimally Invasive Fixation Techniques for Thoracolumbar Trauma: A Meta-Analysis

    PubMed Central

    McAnany, Steven J.; Overley, Samuel C.; Kim, Jun S.; Baird, Evan O.; Qureshi, Sheeraz A.; Anderson, Paul A.

    2015-01-01

    Study Design Systematic literature review and meta-analysis of studies published in English. Objective This study evaluated differences in outcome variables between percutaneous and open pedicle screws for traumatic thoracolumbar fractures. Methods A systematic review of PubMed, Cochrane, and Embase was performed. The variables of interest included postoperative visual analog scale (VAS) pain score, kyphosis angle, and vertebral body height, as well as intraoperative blood loss and operative time. The results were pooled by calculating the effect size based on the standardized difference in means. The studies were weighted by the inverse of the variance, which included both within- and between-study error. Confidence intervals were reported at 95%. Heterogeneity was assessed using the Q statistic and I 2. Results After two-reviewer assessment, 38 studies were eliminated. Six studies were found to meet inclusion criteria and were included in the meta-analysis. The combined effect size was found to be in favor of percutaneous fixation for blood loss and operative time (p < 0.05); however, there were no differences in vertebral body height (VBH), kyphosis angle, or VAS scores between open and percutaneous fixation. All of the studies demonstrated relative homogeneity, with I 2 < 25. Conclusions Patients with thoracolumbar fractures can be effectively managed with percutaneous or open pedicle screw placement. There are no differences in VBH, kyphosis angle, or VAS between the two groups. Blood loss and operative time were decreased in the percutaneous group, which may represent a potential benefit, particularly in the polytraumatized patient. All variables in this study demonstrated near-perfect homogeneity, and the effect is likely close to the true effect. PMID:26933621

  10. Short-term Clinical Outcomes after Transscleral Fixation Using the Intrascleral Pocket Technique: A Retrospective Cohort Study Analysis

    PubMed Central

    Cho, Yong-Wun; Yoo, Woong-Sun; Chung, Inyoung; Seo, Seong-Wook; Yoo, Ji-Myong

    2016-01-01

    Purpose To compare the two transscleral fixation (TSF) techniques of intrascleral pocket and conventional scleral flap with conjunctival division techniques in terms of short-term clinical effects. Methods This retrospective cohort study included all consecutive patients with aphakia in Gyeongsang National University Hospital in Jinju, Korea, who underwent TSF between January 2012 and December 2014. The medical records of all patients were retrospectively reviewed, and the endothelial cell count (ECC), refraction, best-corrected visual acuity (BCVA), intraocular pressure, slit lamp, and fundus examination results before and 1 day and 6 months after surgery were recorded. The postoperative complications and visual outcomes were also recorded. Results The intrascleral pocket and conventional-flap groups did not differ significantly in terms of demographics, presurgical BCVA, or ECC. However, the intrascleral pocket group had a significantly lower BCVA at 1 day and 6 months after surgery compared to the conventional-flap group. The two groups did not differ in terms of ECC 6 months after surgery. The intrascleral pocket group had no postoperative complications, but five patients in the conventional-flap group complained of irritation. In both groups, the intraocular lens was well positioned without tilting or subluxation, and astigmatism was significantly reduced at 1 day and 6 months after surgery. Conclusions The intrascleral pocket technique of TSF does not involve conjunctival dissection and is a successful method of sulcus fixation. It stably corrects the intraocular lens and is easy to perform, which helps to reduce operation time. It also reliably yields rapid visual acuity recovery without complications. PMID:27051258

  11. A new technique for lag screw placement in the dynamic hip screw fixation of intertrochanteric fractures: decreasing radiation time dramatically

    PubMed Central

    Sheng, Wei-Chao; Li, Jia-Zhen; Chen, Sheng-Hua

    2008-01-01

    The goal of this study was to confirm the decrease in radiation time required for a new technique to place dynamic hip screws (DHS) in intertrochanteric fractures. Seventy-six patients were treated with DHS by either the new technique (NT) or the conventional technique (CT). The width of femoral shaft, the length of the hip screw to be implanted into the injured side, and the distance between the tip of the greater trochanter and the entry point of the guide wire were measured at the uninjured side on the anteroposterior pelvic radiograph preoperatively, and the actual width of the injured femoral shaft was measured intra-operatively. Finally, the entry point and the length of hip screw were obtained through an equation. Mean radiation time of the NT patients (24.57 ± 7.80 s) was significantly shorter than the CT patients (54.2 ± 18.26 s) (P  < 0.001). The new technique decreased radiation time dramatically in DHS fixation. PMID:18265981

  12. In vitro experiments with an injection technique for cup fixation in total hip arthroplasty.

    PubMed

    Somville, J M; Moldenaers, P F; Mulier, J C; Mewis, J J

    1987-01-01

    A new technique has been developed to position the cup rigidly into the acetabulum during total hip joint replacement. After positioning the flanged cup on the acetabulum by means of screws, a low-viscosity cement is injected through a hole in the rim of the cup. A comparison with the standard cementing technique was made on the basis of in vitro experiments. For this purpose a mold was constructed to produce castings simulating the human acetabulum. The distribution of the cement, the pressure developed in the acetabulum, and the penetration of the cement are compared for the two cementing techniques. PMID:3606358

  13. Establishment of reproducible osteosarcoma rat model using orthotopic implantation technique.

    PubMed

    Yu, Zhe; Sun, Honghui; Fan, Qingyu; Long, Hua; Yang, Tongtao; Ma, Bao'an

    2009-05-01

    In experimental musculoskeletal oncology, there remains a need for animal models that can be used to assess the efficacy of new and innovative treatment methodologies for bone tumors. Rat plays a very important role in the bone field especially in the evaluation of metabolic bone diseases. The objective of this study was to develop a rat osteosarcoma model for evaluation of new surgical and molecular methods of treatment for extremity sarcoma. One hundred male SD rats weighing 125.45+/-8.19 g were divided into 5 groups and anesthetized intraperitoneally with 10% chloral hydrate. Orthotopic implantation models of rat osteosarcoma were performed by injecting directly into the SD rat femur with a needle for inoculation with SD tumor cells. In the first step of the experiment, 2x10(5) to 1x10(6) UMR106 cells in 50 microl were injected intraosseously into median or distal part of the femoral shaft and the tumor take rate was determined. The second stage consisted of determining tumor volume, correlating findings from ultrasound with findings from necropsia and determining time of survival. In the third stage, the orthotopically implanted tumors and lung nodules were resected entirely, sectioned, and then counter stained with hematoxylin and eosin for histopathologic evaluation. The tumor take rate was 100% for implants with 8x10(5) tumor cells or more, which was much less than the amount required for subcutaneous implantation, with a high lung metastasis rate of 93.0%. Ultrasound and necropsia findings matched closely (r=0.942; p<0.01), which demonstrated that Doppler ultrasonography is a convenient and reliable technique for measuring cancer at any stage. Tumor growth curve showed that orthotopically implanted tumors expanded vigorously with time-lapse, especially in the first 3 weeks. The median time of survival was 38 days and surgical mortality was 0%. The UMR106 cell line has strong carcinogenic capability and high lung metastasis frequency. The present rat

  14. Arthroscopically Assisted Anatomic Coracoclavicular Ligament Reconstruction Technique Using Coracoclavicular Fixation and Soft-Tissue Grafts

    PubMed Central

    Millett, Peter J.; Warth, Ryan J.; Greenspoon, Joshua A.; Horan, Marilee P.

    2015-01-01

    Acromioclavicular joint injuries are common and are often seen in contact athletes. Good to excellent clinical results have been reported using soft-tissue grafts to reconstruct the coracoclavicular ligaments; however, complications remain. Some complications are unique to the surgical technique, particularly clavicle and coracoid fractures that are associated with drilling large or multiple bone tunnels. The described technique allows for an anatomic coracoclavicular reconstruction using a large soft-tissue graft while minimizing the risk of clavicle fracture by avoiding large bone tunnels. PMID:26900558

  15. Knee Osteochondritis Dissecans Treated by the AO Hook Fixation System: A Four Year Follow-Up of an Alternative Technique

    PubMed Central

    Pengas, Ioannis P; Assiotis, Angelos; Kokkinakis, Michail; Khan, Wasim S; Meyers, Paul; Arbuthnot, James; Mcnicholas, Michael J

    2014-01-01

    Surgical fixation is recommended for stable osteochondritis dissecans (OCD) lesions that have failed nonoperative management and for all unstable lesions. In this study we set out to describe and evaluate an alternative method of surgical fixation for such lesions. Five knees with unstable OCD lesions in four male adolescent patients with open physes were treated with the AO Hook Fixation System. The outcome was evaluated both clinically and with three separate outcome systems (IKDC 2000, KOOS, Lysholm) at one and a mean four year follow-up. We demonstrated excellent clinical results in all patients. At four years, all scoring systems demonstrated statistically significant improvement when compared to the preoperative status. Our study suggests that the AO Hook Fixation System is an alternative method of surgical intervention with comparable medium term results with other existing modes of fixation and the added biomechanical advantage of the absence of distracting forces during hardware removal. PMID:25067976

  16. A comparative study of pedicle screw fixation in dorsolumbar spine by freehand versus image-assisted technique: A cadaveric study

    PubMed Central

    Agarwal, Archit; Chauhan, Vijendra; Singh, Deepa; Shailendra, Raghuvanshi; Maheshwari, Rajesh; Juyal, Anil

    2016-01-01

    Background: New and expensive technology such as three-dimensional computer assisted surgery is being used for pedicle screw fixation in dorsolumbar spine. Their availability, expenses and amount of radiation exposure are issues in a developing country. On the contrary, freehand technique of pedicle screw placement utilizes anatomic landmarks and tactile palpation without fluoroscopy or navigation to place pedicle screws. The purpose of this study was to analyze and compare the accuracy of freehand and image-assisted technique to place pedicle screws in the dorsolumbar spine of cadavers by an experienced surgeon and a resident. Evaluation was done using dissection of pedicle and computed tomography (CT) imaging. Materials and Methods: Ten cadaveric dorsolumbar spines were exposed by a posterior approach. Titanium pedicle screws were inserted from D5 to L5 vertebrae by freehand and image-assisted technique on either side by an experienced surgeon and a resident. CT was obtained. A blinded radiologist reviewed the imaging. The spines were then dissected to do a macroscopic examination. Screws, having evidence of cortical perforation of more than 2 mm on CT, were considered to be a significant breach. Results: A total of 260 pedicle screws were placed. The surgeon and the resident placed 130 screws each. Out of 130 screws, both of them placed 65 screws each by freehand and image- assisted technique each. The resident had a rate of 7.69% significant medial and 10.76% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 9.23% significant lateral breach. The expert surgeon had a rate of 6.15% significant medial and 1.53% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 6.15% significant lateral breach on CT evaluation. Conclusion: Freehand technique is as good as the image-assisted technique. Under appropriate supervision, residents

  17. The results of a press-fit-only technique for acetabular fixation in hip dysplasia.

    PubMed

    Takao, Masaki; Nakamura, Nobuo; Ohzono, Kenji; Sakai, Takashi; Nishii, Takashi; Sugano, Nobuhiko

    2011-06-01

    The purpose of the present study was to evaluate the 6- to 11-year follow-up results of hemispherical porous-coated cups implanted into dysplastic hips using press-fit technique without screws focusing on the amount of host bone coverage. There were 87 patients who underwent 98 primary total hip arthroplasties. Bony coverage was measured as the angle between the vertical line and the line drawn from the cup center to the lateral edge of the acetabulum, which was named the cup center-edge angle (cup-CE angle). All 98 cups were judged to be bone ingrown. The minimum cup-CE angle was 8.4° (mean, 26.3°). Bone-cup contact of more than 8.4° of the cup-CE angle was large enough for press-fit cups to resist superior directed loads during this follow-up period. PMID:20647158

  18. A modified cementing technique using BoneSource to augment fixation of the acetabulum in a sheep model

    PubMed Central

    Timperley, A John

    2010-01-01

    Background and purpose Our aim was to assess in an animal model whether the use of HA paste at the cement-bone interface in the acetabulum improves fixation. We examined, in sheep, the effect of interposing a layer of hydroxyapatite cement around the periphery of a polyethylene socket prior to fixing it using polymethylmethacrylate (PMMA). Methods We performed a randomized study involving 22 sheep that had BoneSource hydroxyapatite material applied to the surface of the acetabulum before cementing a polyethylene cup at arthroplasty. We studied the gross radiographic appearance of the implant-bone interface and the histological appearance at the interface. Results There were more radiolucencies evident in the control group. Histologically, only sheep randomized into the BoneSource group exhibited a fully osseointegrated interface. Use of the hydroxyapatite material did not give any detrimental effects. In some cases, the material appeared to have been fully resorbed. When the material was evident in histological sections, it was incorporated into an osseointegrated interface. There was no giant cell reaction present. There was no evidence of migration of BoneSource to the articulation. Interpretation The application of HA material prior to cementation of a socket produced an improved interface. The technique may be useful in humans, to extend the longevity of the cemented implant by protecting the socket interface from the effect of hydrodynamic fluid flow and particulate debris. PMID:20586703

  19. Biomechanical in vitro evaluation of three stable internal fixation techniques used in sagittal osteotomy of the mandibular ramus: a study in sheep mandibles

    PubMed Central

    de OLIVERA, Leandro Benetti; SANT'ANA, Eduardo; MANZATO, Antonio José; GUERRA, Fábio Luis Bunemer; ARNETT, G. William

    2012-01-01

    Among the osteotomies performed in orthognathic surgery, the sagittal osteotomy of the mandibular ramus (SOMR) is the most common, allowing a great range of movements and stable internal fixation (SIF), therefore eliminating the need of maxillomandibular block in the postoperative period. Objectives: The purpose of this study was to evaluate the biomechanical resistance of three national systems used for SIF in SOMR in sheep mandibles. Material and methods: The study was performed in 30 sheep hemi-mandibles randomly divided into 3 experimental groups, each containing 10 hemi-mandibles. The samples were measured to avoid discrepancies and then subjected to SOMR with 5-mm advancement. In group I, 2.0x12 mm screws were used for fixation, inserted in an inverted "L" pattern (inverted "L" group). In group II, fixation was performed with two 2.0x12 mm screws, positioned in a linear pattern and a 4-hole straight miniplate and four 2.0x6.0 mm monocortical screws (hybrid group). In group III, fixation was performed with two 4-hole straight miniplates and eight 2.0x6.0 mm monocortical screws (mini plate group). All materials used for SIF were supplied by Osteosin - SIN. The hemimandibles were subjected to vertical linear load test by Kratos K2000MP mechanical testing unit for loading registration and displacement. Results: All groups showed similar resistance during mechanical test for loading and displacement, with no statistically significant differences between groups according to analysis of variance. Conclusion: These results indicate that the three techniques of fixation are equally effective for clinical fixation of SOMR. PMID:23032203

  20. CT-based morphometric analysis of C1 laminar dimensions: C1 translaminar screw fixation is a feasible technique for salvage of atlantoaxial fusions

    PubMed Central

    Yew, Andrew; Lu, Derek; Lu, Daniel C.

    2015-01-01

    Background: Translaminar screw fixation has become an alternative in the fixation of the axial and subaxial cervical spine. We report utilization of this approach in the atlas as a salvage technique for atlantoaxial stabilization when C1 lateral mass screws are precluded. To assess the feasibility of translaminar fixation at the atlas, we have characterized the dimensions of the C1 lamina in the general adult population using computed tomography (CT)-based morphometry. Methods: A 46-year-old male with symptomatic atlantoaxial instability secondary to os odontoideum underwent bilateral C1 and C2 translaminar screw/rod fixation as C1 lateral mass fixation was precluded by an anomalous vertebral artery. The follow-up evaluation 2½ years postoperatively revealed an asymptomatic patient without recurrent neck/shoulder pain or clinical signs of instability. To better assess the feasibility of utilizing this approach in the general population, we retrospectively analyzed 502 consecutive cervical CT scans performed over a 3-month period in patients aged over 18 years at a single institution. Measurements of C1 bicortical diameter, bilateral laminar length, height, and angulation were performed. Laminar and screw dimensions were compared to assess instrumentation feasibility. Results: Review of CT imaging found that 75.9% of C1 lamina had a sufficient bicortical diameter, and 63.7% of C1 lamina had sufficient height to accept bilateral translaminar screw placement. Conclusions: CT-based measurement of atlas morphology in the general population revealed that a majority of C1 lamina had sufficient dimensions to accept translaminar screw placement. Although these screws appear to be a feasible alternative when lateral mass screws are precluded, further research is required to determine if they provide comparable fixation strength versus traditional instrumentation methods. PMID:26005585

  1. New Technique for C1 Double-Door Laminoplasty Using Allograft Spacers and Titanium Miniplate Screw Fixation: Technical Report.

    PubMed

    Kim, Seok Woo; Lee, Jae-Hoo; Lee, Ho-Won; Oh, Jae-Keun; Kwak, Yoon-Hae

    2016-03-01

    Although conventional C1 laminectomy is the gold standard for decompression at the atlas, it provides little space for the bone graft to fuse. The fusion area can be extended cranially up to the occipital bone, but it requires sacrificing the function of the craniocervical junction. To date, no reports have focused on surgical techniques for successful decompression and fusion without disruption of the posterior C1 arch while providing enough room for the bone graft to fuse. This study introduces a new technique for C1-C2 fusion and C1 double-door laminoplasty in patients with C1-C2 instability, canal stenosis, and cervical spondylotic myelopathy. A 66-year-old man who had undergone C1-C2 fusion at a local clinic 2 years earlier visited our hospital due to progressive myelopathy. A preoperative computed tomography (CT) scan showed the tip of the odontoid process, extending into the spinal canal. On the axial view of T2-weighted magnetic resonance images, the tip of the odontoid process significantly compressed the spinal cord on the left side. The atlantodental interval was 7 mm on radiography; however, C1-C2 instability was not evident on flexion-extension X-rays due to the previous screw fixation. The patient underwent C1-C2 decompression and fusion surgery with our new surgical technique. The segmental screws were repositioned at C1 and C2, and we performed C1 double-door laminoplasty augmented with an allograft spacer and a titanium miniplate. A marked reduction was seen at postoperative radiograph and CT scan. Neurologic symptoms were relieved dramatically after surgery without any discomfort. No complications were noted. We introduced a new surgical technique that allows bone grafting, decompression, and fusion to be performed without disruption of the posterior C1 arch in the event of C1-C2 canal stenosis combined with instability. This technique may be indicated for other conditions that cause instability and stenosis at the C1-C2 area. PMID:26689563

  2. Burnei’s “double X" internal fixation technique for supracondylar humerus fractures in children: indications, technique, advantages and alternative interventions

    PubMed Central

    Georgescu, I; Gavriliu, S; Pârvan, A; Martiniuc, A; Japie, E; Ghiță, R; Drăghici, I; Hamei, S; Ţiripa, I; El Nayef, T; Dan, D

    2013-01-01

    Background. The Study and Research Group in Pediatric Orthopedics-2012 initated this retrospective study due to the fact that in Romania and in other countries, the numerous procedures do not ensure the physicians a definite point of view related to the therapeutic criteria in the treatment of supracondylar fractures. That is why the number of complications and their severity brought into notice these existent deficiencies. In order to correct some of these complications, cubitus varus or valgus, Prof. Al. Pesamosca communicated a paper called "Personal procedure in the treatment of posttraumatic cubitus varus" at the County Conference from Bacău, in June 24, 1978. This procedure has next been made popular by Prof. Gh. Burnei and his coworkers by operating patients with cubitus varus or valgus due to supracondylar humeral fractures and by presenting papers related to the subject at the national and international congresses. The latest paper regarding this problem has been presented at the 29th Annual Meeting of the European Pediatric Orthopedic Society in Zagreb, Croatia, April 7-10, 2010, being titled “Distal humeral Z-osteotomy for posttraumatic cubitus varus or valgus", having as authors Gh. Burnei, Ileana Georgescu, Ştefan Gavriliu, Costel Vlad and Daniela Dan. As members of this group, based on the performed studies, we wish to make popular this type of osteosynthesis, which ensures a tight fixation, avoids complications and allows a rapid postoperative activity. Introduction. The acknowledged treatment for these types of fractures is the orthopedic one and it must be accomplished as soon as possible, in the first 6 hours, by reduction and cast immobilization or by closed or open reduction and fixation, using one of the several methods (Judet, Boehler, Kapandji, San Antonio, San Diego, Burnei’s double X technique). The exposed treatment is indicated in irreducible supracondylar humeral fractures, in reducible, but unstable type, in polytraumatized

  3. In vivo evaluation of a vibration analysis technique for the per-operative monitoring of the fixation of hip prostheses

    PubMed Central

    Pastrav, Leonard C; Jaecques, Siegfried VN; Jonkers, Ilse; Perre, Georges Van der; Mulier, Michiel

    2009-01-01

    Background The per-operative assessment of primary stem stability may help to improve the performance of total hip replacement. Vibration analysis methods have been successfully used to assess dental implant stability, to monitor fracture healing and to measure bone mechanical properties. The objective of the present study was to evaluate in vivo a vibration analysis-based endpoint criterion for the insertion of the stem by successive surgeon-controlled hammer blows. Methods A protocol using a vibration analysis technique for the characterisation of the primary bone-prosthesis stability was tested in 83 patients receiving a custom-made, intra-operatively manufactured stem prosthesis. Two groups were studied: one (n = 30) with non cemented and one (n = 53) with partially cemented stem fixation. Frequency response functions of the stem-femur system corresponding to successive insertion stages were compared. Results The correlation coefficient between the last two frequency response function curves was above 0.99 in 86.7% of the non cemented cases. Lower values of the final correlation coefficient and deviations in the frequency response pattern were associated with instability or impending bone fracture. In the cases with a partially cemented stem an important difference in frequency response function between the final stage of non cemented trial insertion and the final cemented stage was found in 84.9% of the cases. Furthermore, the frequency response function varied with the degree of cement curing. Conclusion The frequency response function change provides reliable information regarding the stability evolution of the stem-femur system during the insertion. The protocol described in this paper can be used to accurately detect the insertion end point and to reduce the risk for intra-operative fracture. PMID:19358703

  4. Comparison of modified Thiel embalming and ethanol-glycerin fixation in an anatomy environment: Potentials and limitations of two complementary techniques.

    PubMed

    Hammer, Niels; Löffler, Sabine; Bechmann, Ingo; Steinke, Hanno; Hädrich, Carsten; Feja, Christine

    2015-01-01

    Thiel-fixed specimens have outstandingly lifelike visual and haptic properties. However, the original Thiel method is expensive and requires an elaborate setup. It is therefore of principal interest to modify the Thiel method in order to make it available to a broader user group. A modified Thiel embalming method will be described in detail and compared to ethanol-glycerin fixation with the help of illustrative examples. The visual properties, haptic properties, the usability for performing histological investigations, costs and potential health aspects will be considered. Tissues fixed with the modified Thiel technique gave results similar to the original method, providing more realistic visual and haptic properties than ethanol-glycerin embalming. However, Thiel fixation is significantly more expensive and requires more precautions to minimize potential health hazards than ethanol-glycerin-fixed tissues. In contrast to ethanol-glycerin-fixed specimens, the Thiel-fixed specimens are not suitable for histological investigations. Both modes of fixation are inappropriate for biomechanical testing. Modified Thiel embalming simplifies the availability of body donors with lifelike properties and has cost-saving advantages to the original technique. Thiel-embalmed body donors are ideally suited for clinical workshops but have restrictions for student dissection courses in facilities with limited storage space, air circulation or technical staff. Vice versa, ethanol-glycerin-fixed body donors are well suited for student dissection courses in such an environment but are limited in their use for clinical workshops. Modified Thiel embalming therefore ideally complements ethanol-glycerin fixation in order to provide customized solutions for clinical workshops and student dissection courses in a wide range of applications. PMID:24706536

  5. Symbiotic N 2 -Fixation Estimated by the (15) N Tracer Technique and Growth of Pueraria phaseoloides (Roxb.) Benth. Inoculated with Bradyrhizobium Strain in Field Conditions.

    PubMed

    Sarr, Papa Saliou; Okon, Judith Wase; Begoude, Didier Aime Boyogueno; Araki, Shigeru; Ambang, Zachée; Shibata, Makoto; Funakawa, Shinya

    2016-01-01

    This field experiment was established in Eastern Cameroon to examine the effect of selected rhizobial inoculation on N2-fixation and growth of Pueraria phaseoloides. Treatments consisted of noninoculated and Bradyrhizobium yuanmingense S3-4-inoculated Pueraria with three replications each. Ipomoea batatas as a non-N2-fixing reference was interspersed in each Pueraria plot. All the twelve plots received 2 gN/m(2) of (15)N ammonium sulfate 10% atom excess. At harvest, dry matter yields and the nitrogen derived from atmospheric N2-fixation (%Ndfa) of inoculated Pueraria were significantly (P < 0.05) higher (81% and 10.83%, resp.) than those of noninoculated Pueraria. The inoculation enhanced nodule dry weight 2.44-fold. Consequently, the harvested N significantly (P < 0.05) increased by 83% in inoculated Pueraria, resulting from the increase in N2-fixation and soil N uptake. A loss of 55 to 60% of the N fertilizer was reported, and 36 to 40% of it was immobilized in soil. Here, we demonstrated that both N2-fixing potential of P. phaseoloides and soil N uptake are improved through field inoculations using efficient bradyrhizobial species. In practice, the inoculation contributes to maximize N input in soils by the cover crop's biomass and represent a good strategy to improve soil fertility for subsequent cultivation. PMID:26904363

  6. Symbiotic N2-Fixation Estimated by the 15N Tracer Technique and Growth of Pueraria phaseoloides (Roxb.) Benth. Inoculated with Bradyrhizobium Strain in Field Conditions

    PubMed Central

    Sarr, Papa Saliou; Okon, Judith Wase; Begoude, Didier Aime Boyogueno; Araki, Shigeru; Ambang, Zachée; Shibata, Makoto; Funakawa, Shinya

    2016-01-01

    This field experiment was established in Eastern Cameroon to examine the effect of selected rhizobial inoculation on N2-fixation and growth of Pueraria phaseoloides. Treatments consisted of noninoculated and Bradyrhizobium yuanmingense S3-4-inoculated Pueraria with three replications each. Ipomoea batatas as a non-N2-fixing reference was interspersed in each Pueraria plot. All the twelve plots received 2 gN/m2 of 15N ammonium sulfate 10% atom excess. At harvest, dry matter yields and the nitrogen derived from atmospheric N2-fixation (%Ndfa) of inoculated Pueraria were significantly (P < 0.05) higher (81% and 10.83%, resp.) than those of noninoculated Pueraria. The inoculation enhanced nodule dry weight 2.44-fold. Consequently, the harvested N significantly (P < 0.05) increased by 83% in inoculated Pueraria, resulting from the increase in N2-fixation and soil N uptake. A loss of 55 to 60% of the N fertilizer was reported, and 36 to 40% of it was immobilized in soil. Here, we demonstrated that both N2-fixing potential of P. phaseoloides and soil N uptake are improved through field inoculations using efficient bradyrhizobial species. In practice, the inoculation contributes to maximize N input in soils by the cover crop's biomass and represent a good strategy to improve soil fertility for subsequent cultivation. PMID:26904363

  7. Biomechanical Evaluation of Supplemental Percutaneous Lumbo-Sacro-iliac Screws For Spino-pelvic Fixation Following Total Sacrectomy

    PubMed Central

    Le, Vu H.; Heckmann, Nathanael; Jain, Nickul; Wang, Lawrence; Turner, Alexander W. L.; Lee, Thay Q.; Bederman, S. Samuel

    2015-01-01

    Study Design This is a cadaveric biomechanical study evaluating the biomechanical properties of a novel spino-pelvic fixation technique with percutaneous lumbo-sacro-iliac (LSI) screws in an unstable total sacrectomy model. Objective To compare standard posterior dual rod spino-pelvic fixation alone with dual rod fixation supplemented with LSI screw fixation. Summary of Background Data Primary or metastatic tumors of the sacrum requiring a total sacrectomy can result in spino-pelvic instability if inadequate fixation is achieved. Many fixation techniques have been proposed to address this instability. However, to date, an optimal fixation technique has not been established. Methods Ten fresh-frozen cadaveric spino-pelvic specimens were randomized according to bone mineral density (BMD) to either posterior rod fixation (control group) or posterior rod fixation with supplemental LSI screws (LSI group). Following fixation, a total sacrectomy of each specimen was performed. Specimens where then potted and axially loaded in a caudal direction. Stiffness, yield load, energy absorbed at yield load, ultimate load, and energy absorbed at ultimate load were computed. A students t-test was used for statistical analysis with significance set at p<0.05. Results The average age and BMD were not significantly different between the control and LSI groups (age, p=0.255; BMD, p=0.810). After normalizing for BMD, there were no significant differences detected for any of the biomechanical parameters measured between the two fixation techniques: stiffness (p=0.857), yield load (p=0.219), energy at yield load (p=0.293), ultimate load (p=0.407), and energy at ultimate load (p=0.773). However, both fixation techniques were able to withstand physiological loads. Conclusions Our study did not demonstrate any biomechanical advantage for supplemental LSI screw fixation in our axial loading model. However, given the theoretical advantage of this percutaneous technique, further studies are

  8. Coral surface area quantification-evaluation of established techniques by comparison with computer tomography

    NASA Astrophysics Data System (ADS)

    Naumann, M. S.; Niggl, W.; Laforsch, C.; Glaser, C.; Wild, C.

    2009-03-01

    The surface area of scleractinian corals represents an important reference parameter required for various aspects of coral reef science. However, with advancements in detection accuracy and novel approaches for coral surface area quantification, evaluation of established techniques in comparison with state-of-the-art technology gains importance to coral researchers. This study presents an evaluation of methodological accuracy for established techniques in comparison to a novel approach composed of computer tomography (CT) and 3-dimensional surface reconstruction. The skeleton surface area of reef corals from six genera representing the most common morphological growth forms was acquired by CT and subsequently measured by computer-aided 3-dimensional surface reconstruction. Surface area estimates for the same corals were also obtained by application of four established techniques: Simple and Advanced Geometry, Wax Coating and Planar Projection Photography. Comparison of the resulting area values revealed significant differences between the majority (82%) of established techniques and the CT reference. Genus-specific analysis assigned the highest accuracy to geometric approximations (Simple or Advanced Geometry) for the majority of assessed coral genera (maximum accuracy: 104%; Simple Geometry with Montipora sp.). The commonly used and invasive Wax Coating technique reached intermediate accuracy (47-74%) for the majority of genera, but performed outstanding in the measurement of branching Acropora spp. corals (maximum accuracy: 101%), while the Planar Projection Photography delivered genera-wide low accuracy (12-36%). Comparison of area values derived from established techniques and CT additionally yielded approximation factors (AFs) applicable as factors in the mathematical improvement of surface area estimates by established techniques in relation to CT reference accuracy.

  9. Mechanical evaluation of six techniques for stable fixation of the sagittal split osteotomy after counterclockwise mandibular advancement.

    PubMed

    De Oliveira, Leandro Benetti; Reis, Jose Mauricio Nunes; Spin-Neto, Rubens; Gabrielli, Marisa Aparecida Cabrini; Oguz, Yener; Pereira-Filho, Valfrido Antonio

    2016-06-01

    We have evaluated the resistance to displacement of six stable methods of fixation of a sagittal split ramus osteotomy (SSRO) in the mandibular advancement with counterclockwise rotation. We tested 60 synthetic hemimandibles in six groups of 10 each: Group I - fixation with a straight four-hole 2.0mm miniplate; Group II - a straight six-hole 2.0mm miniplate; Group III - two straight 2.0mm four-hole miniplates; Group IV - an eight-hole 2.0mm (grid plate); Group V - a 2.0mm four-hole straight miniplate and 2.0×12mm bicortical screw; and Group VI - a straight four-hole 2.0mm locking miniplate. We applied a linear force in the region between the canine and the first premolar using a universal testing machine (EMIC- DL2000) with a loading cell of 10 KN. The loads at 1, 3, and 5mm displacement were recorded (N) and the data transmitted from the load cell to a computer. Results were analysed using analysis of variance (ANOVA) (p<0.001) and the Tukey post-test for comparison of the significance of the differences between the groups. For the three degrees of displacement, fixation with two straight 2.0mm plates and with the grid plate gave higher load values. PMID:27068853

  10. A Simple Technique for the Positioning of a Patient with an above Knee Amputation for an Ipsilateral Extracapsular Hip Fracture Fixation

    PubMed Central

    Davarinos, N.; Ellanti, P.; McCoy, G.

    2013-01-01

    The positioning of the patient on the fracture table is critical to the successful reduction and operative fixation of hip fractures which are fixed using the dynamic hip screw system (DHS). There is a standard setup which is commonly used with relative ease. Yet the positioning of patients with amputations either above or below knee of the affected side can pose a significant challenge. We describe a novel positioning technique used on a 51-year old patient with a right above knee amputation who sustained an intertrochanteric extracapsular hip fracture. PMID:24416607

  11. Technique for Establishing Personnel Performance Standards (TEPPS). Volume III. Results of Navy User Test. Final Report.

    ERIC Educational Resources Information Center

    Smith, Russel L.; And Others

    The results of a test application of TEPPS (Technique for Establishing Personnel Performance Standards) by a Navy analyst team are described in this report. TEPPS is a general systems analysis tool which includes a mathematical model for evaluating man-machine systems. The test results are interpreted both by the system's developers and by the…

  12. Novel labeling technique illustrates transfer of 15N2 from Sphagnum moss to vascular plants via diazotrophic nitrogen fixation

    NASA Astrophysics Data System (ADS)

    Thorp, N. R.; Vile, M. A.; Wieder, R.

    2013-12-01

    We used 15N2 gas to trace nitrogen (N) from biological N2-fixation to vascular plant uptake in an Alberta bog in order to determine if neighboring bog plants acquire recently fixed N from diazotrophs associating with Sphagnum mosses. Recent evidence indicates high rates of N2-fixation in Sphagnum mosses of Alberta bogs (Vile et al. 2013). Our previous work has shown that mosses can assimilate fixed N from associated diazotrophs as evidenced by the high N content of mosses despite minimal inputs from atmospheric deposition, retranslocation, and N mineralization. Therefore, the potential exists for vascular plants to obtain N from ';leaky' tissues of live mosses, however, this phenomenon has not been tested previously. Here we document the potential for relatively rapid transfer to vascular plants of N fixed by Sphagnum moss-associated diazotrophs. We utilized the novel approach of incubating mosses in 15N2 to allow the process of diazotrophic N2-fixation to mechanistically provide the 15N label, which is subsequently transferred to Sphagnum mosses. The potential for vascular bog natives to tap this N was assessed by planting the vascular plants in the labeled moss. Sphagnum mosses (upper 3 cm of live plants) were incubated in the presence of 98 atom % 15N2 gas for 48 hours. Two vascular plants common to Alberta bogs; Picea mariana and Vaccinium oxycoccus were then placed in the labeled mosses, where the mosses served as the substrate. Tissue samples from these plants were collected at three time points during the incubation; prior to 15N2 exposure (to determine natural abundance 15N), and at one and two months after 15N2 exposure. Roots and leaves were separated and run separately on a mass spectrometer to determine 15N concentrations. Sphagnum moss capitula obtained N from N2-fixation (δ15N of -2.43 × 0.40, 122.76 × 23.78, 224.92 × 68.37, 143.74 × 54.38 prior to, immediately after, and at 1 and 2 months after exposure to 15N2, respectively). Nitrogen was

  13. Comparison of Surgical Outcomes Between Short-Segment Open and Percutaneous Pedicle Screw Fixation Techniques for Thoracolumbar Fractures.

    PubMed

    Fu, Zhiguo; Zhang, Xi; Shi, Yaohua; Dong, Qirong

    2016-01-01

    BACKGROUND This study aimed to compare the surgical outcomes between open pedicle screw fixation (OPSF) and percutaneous pedicle screw fixation (PPSF) for the treatment of thoracolumbar fractures, which has received scant research attention to date. MATERIAL AND METHODS Eight-four patients with acute and subacute thoracolumbar fractures who were treated with SSPSF from January 2013 to June 2014 at the Changzhou Hospital of Traditional Chinese Medicine (Changzhou, China) were retrospectively reviewed. The patients were divided into 4 groups: the OPSF with 4 basic screws (OPSF-4) group, the OPSF with 4 basic and 2 additional screws (OPSF-6) group, the PPSF with 4 basic screws (PPSF-4) group, and the PPSF with 4 basic and 2 additional screws (PPSF-6) group. The intraoperative, immediate postoperative, and over 1-year follow-up outcomes were evaluated and compared among these groups. RESULTS Blood loss in the PPSF-4 group and the PPSF-6 group was significantly less than in the OPSF-4 group and the OPSF-6 group (P<0.05). The OPSF-6 group exhibited significantly higher immediate postoperative correction percentage of anterior column height of fractured vertebra than the other 3 groups (P<0.05), and higher correction of sagittal regional Cobb angle and kyphotic angle of injured vertebra than in the PPSF-4 and -6 groups (P<0.05). In addition, there was no significant difference in the correction loss of percentage of anterior column height, and loss of sagittal Cobb angle and kyphotic angle of fractured vertebrae at final follow-up among the 4 groups (P>0.05). CONCLUSIONS OPSF with 6 screws had an advantage in the correction of injured vertebral height and kyphosis, and PPSF reduced the intraoperative blood loss of patients. PMID:27602557

  14. 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

  15. An Anterior Cruciate Ligament Reconstruction Technique With 4-Strand Semitendinosus Grafts, Using Outside-In Tibial Tunnel Drilling and Suspensory Fixation Devices.

    PubMed

    Colombet, Philippe; Graveleau, Nicolas

    2015-10-01

    We describe an anatomic single-bundle anterior cruciate ligament reconstruction using a 4-strand semitendinosus graft fixed with 2 Pullup adjustable suspensory fixation systems (SBM, Lourdes, France). Outside-in full tibial tunnel drilling represents a secure option for length management of the graft. The preferred graft choice is a 4-strand semitendinosus autologous graft. A special technique is used to stitch the graft with a figure-of-8 stitch to load the 4 strands. The Pullup adjustable loop is equipped with 2 buttons of different sizes: a small button for the standard Pullup system on the femoral side and a large button for the Pullup XL system on the tibial side. With this method, graft tension is equally distributed among the 4 strands and the graft cannot bottom out in the tibial tunnel in case of inadequate graft length. PMID:26697313

  16. An Anterior Cruciate Ligament Reconstruction Technique With 4-Strand Semitendinosus Grafts, Using Outside-In Tibial Tunnel Drilling and Suspensory Fixation Devices

    PubMed Central

    Colombet, Philippe; Graveleau, Nicolas

    2015-01-01

    We describe an anatomic single-bundle anterior cruciate ligament reconstruction using a 4-strand semitendinosus graft fixed with 2 Pullup adjustable suspensory fixation systems (SBM, Lourdes, France). Outside-in full tibial tunnel drilling represents a secure option for length management of the graft. The preferred graft choice is a 4-strand semitendinosus autologous graft. A special technique is used to stitch the graft with a figure-of-8 stitch to load the 4 strands. The Pullup adjustable loop is equipped with 2 buttons of different sizes: a small button for the standard Pullup system on the femoral side and a large button for the Pullup XL system on the tibial side. With this method, graft tension is equally distributed among the 4 strands and the graft cannot bottom out in the tibial tunnel in case of inadequate graft length. PMID:26697313

  17. Establishment of C6 brain glioma models through stereotactic technique for laser interstitial thermotherapy research

    PubMed Central

    Shi, Jian; Zhang, Ying; Fu, Wei-ming; Chen, Minjiang; Qiu, Zheng

    2015-01-01

    Objective: To establish C6 brain glioma models using stereotactic technique, and to study effects of laser interstitial thermotherapy (LITT) in rat models of glioma. Methods: C6 glioma cells were cultured in dulbecco's minimum essential medium (DMEM) cell culture medium. The in vitro C6 cell cultures were stereotaxically implanted into the right caudate nucleus of rat brain. Presence of tumor was confirmed with Factor VIII R, hematoxylin–eosin stain, staining of glial fibrillary acid protein, and S-100 immunohistochemistry. After magnetic resonance (MR) scanning and correction of tumor location, the models were divided into groups according to the treating time and laser power (2–10 W). Semiconductor laser optical fibers were inserted in tumors for LITT. Cortex's temperature conducted from the center target was measured using infrared thermograph, and deep-tissue temperature around the target was measured using a thermocouple. Results: Rat C6 gliomas were inoculated with optimized stereotactic technique. These gliomas resembled human glioma in terms of histopathological features. Such models are more reliable and reproducible, with 100% yield of intracranial tumor and no extracranial growth extension. The difference between cortex temperature conducted from center target and deep-tissue temperature around target was not statistically significant. Conclusion: The rat C6 brain glioma model established in the study was a perfect model to study LITT of glioma. Infrared thermograph technique measured temperature conveniently and effectively. The technique is noninvasive, and the obtained data could be further processed using software used in LITT research. To measure deep-tissue temperature, combining thermocouple with infrared thermograph technique would present better results. PMID:25883843

  18. Outcomes After Fixation of Proximal Humerus (OTA Type 11) Fractures in the Elderly Patients Using Modern Techniques

    PubMed Central

    Shulman, Brandon S.; Ong, Crispin C.; Lee, James H.; Karia, Raj; Zuckerman, Joseph D.; Egol, Kenneth A.

    2013-01-01

    Purpose To investigate the effects of age on the clinical, functional, and radiographic outcomes of patients with proximal humerus fractures treated operatively with locking plates. Methods Between February 2003 and July 2012, all patients who sustained a proximal humerus fracture who presented to our institution were enrolled into a database. Patients were followed up at 1, 6, 12, 26, and 52 weeks postoperatively with physical examination and radiographs. Validated functional outcomes scores were collected at 6 and 12 months. Complications were recorded as they occurred. Statistical analysis was conducted to assess for functional, physical, or radiographic differences between patients age younger than 65 and patients age 65 or older. Results Of the 147 consecutive patients treated operatively for a proximal humerus fracture, 115 (78%) patients with an average follow-up of 16 months met the inclusion criteria for this study. The young cohort (patients < 65) included 70 patients with an average age of 53, whereas the elderly cohort (patients ≥ 65) included 45 patients with an average age of 73. The older cohort had significantly more women (P = .04), but there was no statistical difference in fracture type between the age groups. There were no differences in the radiographic measures of screw penetration, humeral head height, and neck-shaft angle between the age groups. There were no differences in physical examination scores between the age groups. There were no significant differences in functional outcomes or complication rates between the age groups. Conclusion Treating proximal humerus fractures operatively with locked plates can overcome the challenges of poor bone quality that often occur with increasing age. Age should not play a significant role in the decision-making process for treating proximal humerus fractures that would otherwise be indicated for surgical fixation. PMID:23936736

  19. Vaginal Vault Suspension at Hysterectomy for Prolapse – Myths and Facts, Anatomical Requirements, Fixation Techniques, Documentation and Cost Accounting

    PubMed Central

    Graefe, F.; Marschke, J.; Dimpfl, T.; Tunn, R.

    2012-01-01

    Vaginal vault suspension during hysterectomy for prolapse is both a therapy for apical insufficiency and helps prevent recurrence. Numerous techniques exist, with different anatomical results and differing complications. The description of the different approaches together with a description of the vaginal vault suspension technique used at the Department for Urogynaecology at St. Hedwig Hospital could serve as a basis for reassessment and for recommendations by scientific associations regarding general standards. PMID:25278621

  20. Integrating conventional and CAD/CAM digital techniques for establishing canine protected articulation: A clinical report.

    PubMed

    El Kerdani, Tarek; Nimmo, Arthur

    2016-05-01

    Canine protected articulation is widely accepted for patients requiring extensive oral rehabilitation. Computer-aided design and computer-aided manufacturing (CAD/CAM) restorations have been primarily designed in occlusion at the maximum intercuspal position. Designing a virtual articulator that is capable of accepting excursive occlusal records and duplicating the mandibular movements is a challenge for CAD/CAM technology. Modifying tooth shape using composite resin trial restorations to produce esthetic results and later scanning the modified teeth to create milled crowns is becoming a popular use of the CAD/CAM technology. This report describes a technique that combines conventional and CAD/CAM prosthodontic techniques for milling crowns for canine teeth that are designed to establish or improve canine protected articulation. This technique involves designing and fabricating interim restorations based on diagnostic waxing, scanning the designs intraorally, and storing them in software as pretreatment digital records. The scanned designs are then applied to the digital representation of the prepared teeth to fabricate the definitive restorations. PMID:26774319

  1. Established and emerging ancillary techniques in management of microbial keratitis: a review.

    PubMed

    Robaei, Dana; Carnt, Nicole; Watson, Stephanie

    2016-09-01

    Microbial keratitis is a sight-threatening condition and an ocular emergency, because of the potential for rapid progression. Intensive topical antimicrobials are the mainstay and the gold standard of treatment for microbial keratitis. However, despite appropriate diagnosis and therapy, treatment failure is still common, and can result in significant morbidity due to corneal perforation and/or scarring. For this reason, clinicians continue to seek novel treatment techniques in order to expand the armamentarium of tools available to manage microbial keratitis, and in doing so improve clinical outcomes. In this review, we examine the evidence for some established, as well as a few emerging ancillary techniques used to manage microbial keratitis. These include topical corticosteroids, corneal collagen cross-linking, intrastromal antimicrobials, amniotic membrane transplantation and miscellaneous other techniques. Of these, collagen cross-linking shows some promise for selected cases of infectious keratitis, although more research in the area is required before it is accepted as mainstream treatment for this potentially blinding condition. PMID:26888977

  2. 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

  3. A Comparison of Clinical Outcomes of Dislocated Intraocular Lens Fixation between In Situ Refixation and Conventional Exchange Technique Combined with Vitrectomy

    PubMed Central

    Eum, Sun Jung; Kim, Myung Jun; Kim, Hong Kyun

    2016-01-01

    Purpose. To evaluate surgical efficacy of in situ refixation technique for dislocated posterior chamber intraocular lens (PCIOL). Methods. This was a single-center retrospective case series. 34 patients (34 eyes) who underwent sclera fixation for dislocated IOLs combined with vitrectomy were studied. Of 34 eyes, 17 eyes underwent IOL exchange and the other 17 eyes underwent in situ refixation. Results. Mean follow-up period was 6 months. Mean logMAR best corrected visual acuity (BCVA) was not significantly different between the groups 6 months after surgery (0.10 ± 0.03 in the IOL exchange group and 0.10 ± 0.05 in the refixation group; p = 0.065). Surgically induced astigmatism (SIA) was significantly lower in the refixation group (0.79 ± 0.41) than in the IOL exchange group (1.29 ± 0.46) (p = 0.004) at 3 months, which persisted to 6 months (1.13 ± 0.18 in the IOL exchange group and 0.74 ± 0.11 in the refixation group; p = 0.006). Postoperative complications occurred in 3 eyes in the IOL exchange group (17.6%) and 2 eyes in the refixation group (11.8%). However, all of the patients were well managed without additional surgery. Conclusion. The in situ refixation technique should be preferentially considered if surgery is indicated since it seemed to produce a sustained less SIA compared to IOL exchange. PMID:27119019

  4. A Comparison of Clinical Outcomes of Dislocated Intraocular Lens Fixation between In Situ Refixation and Conventional Exchange Technique Combined with Vitrectomy.

    PubMed

    Eum, Sun Jung; Kim, Myung Jun; Kim, Hong Kyun

    2016-01-01

    Purpose. To evaluate surgical efficacy of in situ refixation technique for dislocated posterior chamber intraocular lens (PCIOL). Methods. This was a single-center retrospective case series. 34 patients (34 eyes) who underwent sclera fixation for dislocated IOLs combined with vitrectomy were studied. Of 34 eyes, 17 eyes underwent IOL exchange and the other 17 eyes underwent in situ refixation. Results. Mean follow-up period was 6 months. Mean logMAR best corrected visual acuity (BCVA) was not significantly different between the groups 6 months after surgery (0.10 ± 0.03 in the IOL exchange group and 0.10 ± 0.05 in the refixation group; p = 0.065). Surgically induced astigmatism (SIA) was significantly lower in the refixation group (0.79 ± 0.41) than in the IOL exchange group (1.29 ± 0.46) (p = 0.004) at 3 months, which persisted to 6 months (1.13 ± 0.18 in the IOL exchange group and 0.74 ± 0.11 in the refixation group; p = 0.006). Postoperative complications occurred in 3 eyes in the IOL exchange group (17.6%) and 2 eyes in the refixation group (11.8%). However, all of the patients were well managed without additional surgery. Conclusion. The in situ refixation technique should be preferentially considered if surgery is indicated since it seemed to produce a sustained less SIA compared to IOL exchange. PMID:27119019

  5. System engineering techniques for establishing balanced design and performance guidelines for the advanced telerobotic testbed

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Matijevic, J. R.

    1987-01-01

    Novel system engineering techniques have been developed and applied to establishing structured design and performance objectives for the Telerobotics Testbed that reduce technical risk while still allowing the testbed to demonstrate an advancement in state-of-the-art robotic technologies. To estblish the appropriate tradeoff structure and balance of technology performance against technical risk, an analytical data base was developed which drew on: (1) automation/robot-technology availability projections, (2) typical or potential application mission task sets, (3) performance simulations, (4) project schedule constraints, and (5) project funding constraints. Design tradeoffs and configuration/performance iterations were conducted by comparing feasible technology/task set configurations against schedule/budget constraints as well as original program target technology objectives. The final system configuration, task set, and technology set reflected a balanced advancement in state-of-the-art robotic technologies, while meeting programmatic objectives and schedule/cost constraints.

  6. Arthroscopic Meniscal Allograft Transplantation With Soft-Tissue Fixation Through Bone Tunnels

    PubMed Central

    Spalding, Tim; Parkinson, Ben; Smith, Nick A.; Verdonk, Peter

    2015-01-01

    Meniscal allograft transplantation improves clinical outcomes for patients with symptomatic meniscus-deficient knees. We describe an established arthroscopic technique for meniscal allograft transplantation without the need for bone fixation of the meniscal horns. After preparation of the meniscal bed, the meniscus is parachuted into the knee through a silicone cannula and the meniscal horns are fixed with sutures through bone tunnels. The body of the meniscus is then fixed with a combination of all-inside and inside-out sutures. This technique is reliable and reproducible and has clinical outcomes comparable with those of bone plug fixation techniques. PMID:26900554

  7. Arthroscopic Meniscal Allograft Transplantation With Soft-Tissue Fixation Through Bone Tunnels.

    PubMed

    Spalding, Tim; Parkinson, Ben; Smith, Nick A; Verdonk, Peter

    2015-10-01

    Meniscal allograft transplantation improves clinical outcomes for patients with symptomatic meniscus-deficient knees. We describe an established arthroscopic technique for meniscal allograft transplantation without the need for bone fixation of the meniscal horns. After preparation of the meniscal bed, the meniscus is parachuted into the knee through a silicone cannula and the meniscal horns are fixed with sutures through bone tunnels. The body of the meniscus is then fixed with a combination of all-inside and inside-out sutures. This technique is reliable and reproducible and has clinical outcomes comparable with those of bone plug fixation techniques. PMID:26900554

  8. IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION

    PubMed Central

    ABRANTES, Tuanne Rotti; MADEIRA, Maria de Fátima; da SILVA, Denise Amaro; PERIÉ, Carolina dos Santos F. S.; V. MENDES, Artur Augusto; MENEZES, Rodrigo Caldas; SILVA, Valmir Laurentino; FIGUEIREDO, Fabiano Borges

    2016-01-01

    After the report of a second case of canine visceral leishmaniasis (CVL) in São Bento da Lagoa, Itaipuaçu, in the municipality of Maricá, Rio de Janeiro State, an epidemiological survey was carried out, through active search, totaling 145 dogs. Indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), and rapid chromatographic immunoassay based on dual-path platform (DPP(r)) were used to perform the serological examinations. The parasitological diagnosis of cutaneous fragments was performed by parasitological culture, histopathology, and immunohistochemistry. In the serological assessment, 21 dogs were seropositive by IFA, 17 by ELISA, and 11 by DPP(r), with sensitivity of 66.7%, 66.7% and 50%, and specificity of 87.2%, 90.2% and 94%, respectively for each technique. The immunohistochemistry of bone marrow using the cell-block technique presented the best results, with six positive dogs found, three of which tested negative by the other parasitological techniques. Leishmania sp. was isolated by parasitological culture in three dogs. The detection of autochthonous Leishmania infantum in Itaipuaçu, and the high prevalence of seropositive dogs confirm the circulation of this parasite in the study area and alert for the risk of expansion in the State of Rio de Janeiro. PMID:26910449

  9. IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION.

    PubMed

    Abrantes, Tuanne Rotti; Madeira, Maria de Fátima; Silva, Denise Amaro da; Perié, Carolina Dos Santos F S; V Mendes Júnior, Artur Augusto; Menezes, Rodrigo Caldas; Silva, Valmir Laurentino; Figueiredo, Fabiano Borges

    2016-01-01

    After the report of a second case of canine visceral leishmaniasis (CVL) in São Bento da Lagoa, Itaipuaçu, in the municipality of Maricá, Rio de Janeiro State, an epidemiological survey was carried out, through active search, totaling 145 dogs. Indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), and rapid chromatographic immunoassay based on dual-path platform (DPP(r)) were used to perform the serological examinations. The parasitological diagnosis of cutaneous fragments was performed by parasitological culture, histopathology, and immunohistochemistry. In the serological assessment, 21 dogs were seropositive by IFA, 17 by ELISA, and 11 by DPP(r), with sensitivity of 66.7%, 66.7% and 50%, and specificity of 87.2%, 90.2% and 94%, respectively for each technique. The immunohistochemistry of bone marrow using the cell-block technique presented the best results, with six positive dogs found, three of which tested negative by the other parasitological techniques. Leishmania sp. was isolated by parasitological culture in three dogs. The detection of autochthonous Leishmania infantum in Itaipuaçu, and the high prevalence of seropositive dogs confirm the circulation of this parasite in the study area and alert for the risk of expansion in the State of Rio de Janeiro. PMID:26910449

  10. 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

  11. FIXATION OF FRACTURES OF THE DISTAL EXTREMITY OF THE RADIUS USING THE MODIFIED KAPANDJI TECHNIQUE: EVALUATION OF THE RADIOLOGICAL RESULTS

    PubMed Central

    Neto, Antonio Piva; Lhamby, Fabio Colla

    2015-01-01

    To demonstrate a simple and efficacious option for treating fractures of the distal extremity of the radius using Kirschner wires. Methods: Between September 2008 and April 2009, 48 patients with fractures of the distal extremity of the radius, classified as A3 according to the AO classification, were treated surgically using a modification of the Kapandji technique. Results: Out of the 48 wrists operated, 42 (87.5%) presented postoperative measurements within the acceptable limits. We used the parameters of McQuenn and Caspers who considered that the radial angulation should be wider than 19° and the volar angulation should be narrower than -12°. All the postoperative volar inclination measurements were narrower than -3°. The mean preoperative radial inclination was 13.14° and the mean postoperative value was 21.18°. The mean preoperative volar inclination was 28.75° and the mean postoperative value was 3.31°. The mean preoperative radial height was 5.25 mm and the mean postoperative value was 9.48 mm. Conclusion: The technique described here had excellent stability for treating fractures of the distal extremity of the radius classified as A3. It was easy to implement and minimally invasive, with minimal surgical complications, and it was inexpensive. PMID:27027023

  12. Fixation of chiral smectic liquid crystal (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate using UV curing techniques

    NASA Astrophysics Data System (ADS)

    Afrizal, Hikam, Muhammad; Soegiyono, Bambang; Riswoko, Asep; Nurdelima, Umeir

    2014-03-01

    Chiral Smectic Liquid Crystal (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate has been synthesized using method of steglich esterification at room temperature. The mesomorphic behavior of chiral smectic at 55°C that showed schlieren texture in POM analysis. Fixation of structure chiral smectic liquid crystal by means of photopolymerization of monomer (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate under UV irradiation which called UV curing techniques. The curing process using UV 3 lamps 100 volt at 60°C for an hour. The product of photopolymerization could be seen by analysis of FTIR spectra both monomer and polymer. FTIR spectra of monomer, two peaks for ester carbonyl and C-C double bond groups appeared at 1729.09 cm-1and 3123.46 cm-1. After UV curing process, peak for the carbonyl group at 1729.09 cm-1 decreased and a new peak at 1160.21 cm-1 appeared due to the carbonyl group attached to a C-C bond group and then peak at 3123.46 cm-1 for C-C double bond group was disappeared.

  13. Fixation of chiral smectic liquid crystal (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate using UV curing techniques

    SciTech Connect

    Afrizal, Nurdelima,; Umeir; Hikam, Muhammad; Soegiyono, Bambang; Riswoko, Asep

    2014-03-24

    Chiral Smectic Liquid Crystal (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate has been synthesized using method of steglich esterification at room temperature. The mesomorphic behavior of chiral smectic at 55°C that showed schlieren texture in POM analysis. Fixation of structure chiral smectic liquid crystal by means of photopolymerization of monomer (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate under UV irradiation which called UV curing techniques. The curing process using UV 3 lamps 100 volt at 60°C for an hour. The product of photopolymerization could be seen by analysis of FTIR spectra both monomer and polymer. FTIR spectra of monomer, two peaks for ester carbonyl and C-C double bond groups appeared at 1729.09 cm-1and 3123.46 cm{sup −1}. After UV curing process, peak for the carbonyl group at 1729.09 cm{sup −1} decreased and a new peak at 1160.21 cm{sup −1} appeared due to the carbonyl group attached to a C-C bond group and then peak at 3123.46 cm{sup −1} for C-C double bond group was disappeared.

  14. Establishment of a primary reference solar cell calibration technique in Korea: methods, results and comparison with WPVS qualified laboratories

    NASA Astrophysics Data System (ADS)

    Ahn, SeungKyu; Ahn, SeJin; Yun, Jae Ho; Lee, Dong-Hoon; Winter, Stefan; Igari, Sanekazu; Yoon, KyungHoon

    2014-06-01

    A primary reference solar cell calibration technique recently established at the Korea Institute of Energy Research in Korea is introduced. This calibration technique is an indoor method that uses a highly collimated continuous-type solar simulator and absolute cavity radiometer traceable to the World Radiometric Reference. The results obtained using this calibration technique are shown with a precise uncertainty analysis, and the system configuration and calibration procedures are introduced. The calibration technique avoids overestimating the short-circuit current of a reference solar cell due to multiple reflections of incident simulator light using a novel method. In addition, the uncertainty analysis indicates that the calibration technique has an expanded uncertainty of approximately 0.7% with a coverage factor of k = 2 for a c-Si reference cell calibration. In addition, the developed primary reference solar cell calibration technique was compared with other techniques established in the World Photovoltaic Scale (WPVS) qualified calibration laboratories to verify its validity and reliability.

  15. 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

  16. CAD CAM trans-tibial temporary prosthesis: analysis and comparison with an established technique.

    PubMed

    Ruder, G K

    1992-12-01

    The purpose of this study was to evaluate the application of CAD CAM in the production of temporary trans-tibial prostheses. The CAD CAM system was assessed based on the number of socket attempts, number of prosthetic appointments, and temporary prosthesis rehabilitation time. These parameters were considered to be related to the quality of socket fit and were influenced by the entire interdisciplinary team including the patient. A concurrent prospective comparison between the CAD CAM system and an established fiberglass/pelite liner technique was also performed. Patients (n = 30), were fitted with either a conventional or a CAD CAM socket. Records were kept before and after discharge until the interdisciplinary team considered the patient ready for definitive prosthesis casting. After approximately 90 postoperative days, patients were deemed fit to proceed from their initial plaster cast prostheses to their temporary prostheses. The group fitted with conventional sockets had an in-patient rehabilitation phase of 10.5 +/- 15.0 days and required 2.9 +/- 1.1 prosthetic appointments. In-patients fitted with CAD CAM sockets required 5.1 +/- 1.8 appointments and were hospitalised for 23.6 +/- 15.0 days. The significantly increased rehabilitation duration and number of appointments (p = 0.01), were generally due to incorrect socket volume and/or inadequately modified relief/loading areas. In this study 67% of the patients fitted with CAD CAM sockets required at least one additional attempt. The clinical evaluation and modification of the temporary prostheses, including the decision to remake a particular socket, were carried out by the same prosthetist who cast the patients.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1491953

  17. Estimating steatosis and fibrosis: Comparison of acoustic structure quantification with established techniques

    PubMed Central

    Karlas, Thomas; Berger, Joachim; Garnov, Nikita; Lindner, Franziska; Busse, Harald; Linder, Nicolas; Schaudinn, Alexander; Relke, Bettina; Chakaroun, Rima; Tröltzsch, Michael; Wiegand, Johannes; Keim, Volker

    2015-01-01

    AIM: To compare ultrasound-based acoustic structure quantification (ASQ) with established non-invasive techniques for grading and staging fatty liver disease. METHODS: Type 2 diabetic patients at risk of non-alcoholic fatty liver disease (n = 50) and healthy volunteers (n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography (TE), controlled attenuation parameter (CAP), proton magnetic resonance spectroscopy (1H-MRS; only available for the diabetic cohort), and ASQ. ASQ parameters mode, average and focal disturbance (FD) ratio were compared with: (1) the extent of liver fibrosis estimated from TE and non-alcoholic fatty liver disease (NAFLD) fibrosis scores; and (2) the amount of steatosis, which was classified according to CAP values. RESULTS: Forty-seven diabetic patients (age 67.0 ± 8.6 years; body mass index 29.4 ± 4.5 kg/m²) with reliable CAP measurements and all controls (age 26.5 ± 3.2 years; body mass index 22.0 ± 2.7 kg/m²) were included in the analysis. All ASQ parameters showed differences between healthy controls and diabetic patients (P < 0.001, respectively). The ASQ FD ratio (logarithmic) correlated with the CAP (r = -0.81, P < 0.001) and 1H-MRS (r = -0.43, P = 0.004) results. The FD ratio [CAP < 250 dB/m: 107 (102-109), CAP between 250 and 300 dB/m: 106 (102-114); CAP between 300 and 350 dB/m: 105 (100-112), CAP ≥ 350 dB/m: 102 (99-108)] as well as mode and average parameters, were reduced in cases with advanced steatosis (ANOVA P < 0.05). However, none of the ASQ parameters showed a significant difference in patients with advanced fibrosis, as determined by TE and the NAFLD fibrosis score (P > 0.08, respectively). CONCLUSION: ASQ parameters correlate with steatosis, but not with fibrosis in fatty liver disease. Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies. PMID:25945002

  18. Whole Animal Perfusion Fixation for Rodents

    PubMed Central

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

    2012-01-01

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

  19. Suspensory Anterior Tibial Fixation in the Anatomic Transtibial Posterior Cruciate Ligament Reconstruction

    PubMed Central

    Elazab, Ashraf; Lee, Yong Seuk; Kang, Seo Goo

    2016-01-01

    The transtibial technique is the most relevant among many surgical techniques for posterior cruciate ligament reconstruction, and many types of fixation devices are used for tibial fixation according to the technique and the length of the graft. However, bone density in the fixation areas should be taken into consideration when choosing the fixation device to achieve rigid and stable fixation. However, density is not a substantial issue for anteromedial cortical fixation using a cortical suspension device. We describe tibial fixation with a TightRope RT (Arthrex, Naples, FL), which is a cortical suspension device, in anatomic transtibial posterior cruciate ligament reconstruction. PMID:27073781

  20. Distal Humerus Fractures: Open Reduction Internal Fixation.

    PubMed

    Mighell, Mark A; Stephens, Brent; Stone, Geoffrey P; Cottrell, Benjamin J

    2015-11-01

    Distal humerus fractures are challenging injuries for the upper extremity surgeon. However, recent techniques in open reduction internal fixation have been powerful tools in getting positive outcomes. To get such results, the surgeon must be aware of how to properly use these techniques in their respective practices. The method of fixation depends on the fracture, taking the degree of comminution and the restoration of the columns and articular surface into account. This article helps surgeons understand the concepts behind open reduction internal fixation of the distal humerus and makes them aware of pitfalls that may lead to negative results. PMID:26498548

  1. Tips and Tricks in Mallet Fracture Fixation.

    PubMed

    Chin, Yuin Cheng; Foo, Tun-Lin

    2016-10-01

    We describe three steps to aid fracture assessment and fixation in the extensor block pin technique for mallet fractures. The first step is the use of fluoroscopy in the initial assessment to determine indication for fixation. Next is the use of supplementary extension block pin to control larger dorsal fragments. The third technique described details the steps of open reduction of nascently malunited fractures. PMID:27595969

  2. Established and Emerging Atmospheric Pressure Surface Sampling/Ionization Techniques for Mass Spectrometry

    SciTech Connect

    Van Berkel, Gary J; Pasilis, Sofie P; Ovchinnikova, Olga S

    2008-01-01

    The number and type of atmospheric pressure techniques suitable for sampling analytes from surfaces, forming ions from those analytes, and subsequently transporting those ions into vacuum for interrogation by mass spectrometry has rapidly expanded over the last several years. Moreover, the literature in this area is complicated by an explosion in acronyms for these techniques, many of which provide no information relating to the chemical or physical processes involved. In this review, we sort this vast array of techniques into a relatively few categories on the basis of the approaches used for surface sampling and ionization. For each technique, we explain, as best known, many of the underlying principles of operation, describe representative applications, and in some cases, discuss needed research or advancements and attempt to forecast their future analytical utility.

  3. Novel application of an established technique for removing a knotted ureteric stent.

    PubMed

    Tempest, Heidi; Turney, Ben; Kumar, Sunil

    2011-01-01

    This report describes a case whereby a ureteric stent became knotted during removal and lodged within the upper ureter. The authors describe a novel minimally invasive technique to remove the knotted ureteric stent using the holmium laser. PMID:22701009

  4. Establishing the skill of climate field reconstruction techniques for precipitation with pseudoproxy experiments in Europe

    NASA Astrophysics Data System (ADS)

    Wagner, S.; Gomez-Navarro, J. J.; Zorita, E.; Werner, J.; Luterbacher, J.

    2014-12-01

    In recent years important efforts were focused in the development of Climate Field Reconstructions (CFR). These techniques allow merging a limited number of local reconstructions to produce a regular grid which accommodates climatic information from different proxy sources. Pseudo Proxy Experiments (PPE) are idealized experiments performed with synthetic data, typically generated with comprehensive climate models. The PPEs aim at assessing the accuracy that can be expected by (statistical) state-of-the-art reconstruction techniques, but also at identifying potential shortcomings and improvements.In this study a number of PPEs are investigated in order to assess the ability of three different CFR techniques to reconstruct precipitation over Europe. The methods comprise of a linear fit (Canonical Correlation Analysis, CCA), a simple non-linear approach (the Analog Method, AM) and a Bayesian model (Bayesian Hierarchical Method, BHM). Given the inherent complexity of this variable, hardly reproduced by state-of-the-art global circulation models, some downscaling technique is necessary to design meaningful PPEs. In this study the synthetic data consist of a high-resolution climate simulation performed with a Regional Climate Model over Europe for the last two Millennia. Results indicate that unlike BHM, CCA systematically underestimates the variance. TheAM can be adjusted to overcome this shortcoming, presenting an intermediate behavior between the two aforementioned techniques. However, a trade-off between reconstruction target correlations and reconstructed variance is the drawback common to all CFR techniques. CCA (BHM) represent the largest (lowest) skill in preserving the temporal evolution, whereas the AM can be tuned to reproduce better correlation at the expense of a loss in variance. While BHM, in the form employed here, has been shown to perform well for temperatures, it does heavily rely on prescribed spatial correlation lengths. For temperature this

  5. Pleural effusion of malignant aetiology: cell block technique to establish the diagnosis.

    PubMed

    García Carretero, Rafael; Manotas-Hidalgo, Manuela; Romero Brugera, Marta; El Bouayadi Mohamed, Liliam

    2016-01-01

    We describe cases of two previously healthy women presenting with progressively worsening breathlessness for 1-2 months. In both cases, physical examination was suggestive of a left-sided pleural effusion, confirmed by chest X-ray. Analysis of aspirated fluid showed a lymphocytic exudate, but cytological analysis was negative for malignancy in both patients. CT scan revealed malignancies as the underlying cause of the effusions. Both patients were managed with intercostal drainage in order to collect a sufficient amount of pleural fluid to perform a new technique in our hospital: cell block. This proved to be extremely useful in assessing the definitive diagnosis and management of both women. We briefly discuss the approach to a malignant pleural effusion and the aid of this not-so-new technique. PMID:26994057

  6. The Role of Neuroimaging Techniques in Establishing Diagnosis, Prognosis and Therapy in Disorders of Consciousness

    PubMed Central

    Gosseries, Olivia; Pistoia, Francesca; Charland-Verville, Vanessa; Carolei, Antonio; Sacco, Simona; Laureys, Steven

    2016-01-01

    Non-communicative brain damaged patients raise important clinical and scientific issues. Here, we review three major pathological disorders of consciousness: coma, the unresponsive wakefulness syndrome and the minimally conscious state. A number of clinical studies highlight the difficulty in making a correct diagnosis in patients with disorders of consciousness based only on behavioral examinations. The increasing use of neuroimaging techniques allows improving clinical characterization of these patients. Recent neuroimaging studies using positron emission tomography, functional magnetic resonance imaging, electroencephalography and transcranial magnetic stimulation can help assess diagnosis, prognosis, and therapeutic treatment. These techniques, using resting state, passive and active paradigms, also highlight possible dissociations between consciousness and responsiveness, and are facilitating a more accurate understanding of brain function in this challenging population. PMID:27347265

  7. The Role of Neuroimaging Techniques in Establishing Diagnosis, Prognosis and Therapy in Disorders of Consciousness.

    PubMed

    Gosseries, Olivia; Pistoia, Francesca; Charland-Verville, Vanessa; Carolei, Antonio; Sacco, Simona; Laureys, Steven

    2016-01-01

    Non-communicative brain damaged patients raise important clinical and scientific issues. Here, we review three major pathological disorders of consciousness: coma, the unresponsive wakefulness syndrome and the minimally conscious state. A number of clinical studies highlight the difficulty in making a correct diagnosis in patients with disorders of consciousness based only on behavioral examinations. The increasing use of neuroimaging techniques allows improving clinical characterization of these patients. Recent neuroimaging studies using positron emission tomography, functional magnetic resonance imaging, electroencephalography and transcranial magnetic stimulation can help assess diagnosis, prognosis, and therapeutic treatment. These techniques, using resting state, passive and active paradigms, also highlight possible dissociations between consciousness and responsiveness, and are facilitating a more accurate understanding of brain function in this challenging population. PMID:27347265

  8. Weakly Supervised Human Fixations Prediction.

    PubMed

    Zhang, Luming; Li, Xuelong; Nie, Liqiang; Yang, Yi; Xia, Yingjie

    2016-01-01

    Automatically predicting human eye fixations is a useful technique that can facilitate many multimedia applications, e.g., image retrieval, action recognition, and photo retargeting. Conventional approaches are frustrated by two drawbacks. First, psychophysical experiments show that an object-level interpretation of scenes influences eye movements significantly. Most of the existing saliency models rely on object detectors, and therefore, only a few prespecified categories can be discovered. Second, the relative displacement of objects influences their saliency remarkably, but current models cannot describe them explicitly. To solve these problems, this paper proposes weakly supervised fixations prediction, which leverages image labels to improve accuracy of human fixations prediction. The proposed model hierarchically discovers objects as well as their spatial configurations. Starting from the raw image pixels, we sample superpixels in an image, thereby seamless object descriptors termed object-level graphlets (oGLs) are generated by random walking on the superpixel mosaic. Then, a manifold embedding algorithm is proposed to encode image labels into oGLs, and the response map of each prespecified object is computed accordingly. On the basis of the object-level response map, we propose spatial-level graphlets (sGLs) to model the relative positions among objects. Afterward, eye tracking data is employed to integrate these sGLs for predicting human eye fixations. Thorough experiment results demonstrate the advantage of the proposed method over the state-of-the-art. PMID:26168451

  9. Arthroscopic fixation of type III acromioclavicular dislocations.

    PubMed

    Somers, Jan F A; Van der Linden, Dietert

    2007-10-01

    Type III Acromio-Clavicular Joint dislocations can be treated successfully by surgical stabilisation in situ, with or without reconstruction of the coracoclavicular ligaments. The authors describe a simple and reliable mode of fixation, performed arthroscopically. The technique can be used for in situ fixation, or as part of an arthroscopically assisted Weaver and Dunn procedure. Using a metallic anchor loaded with a braided polyfilament suture, a strong and reliable fixation of the clavicle to the coracoid process is obtained. No hardware removal is necessary. Concomitant glenohumeral pathology can be treated simultaneously. PMID:18019910

  10. Establishing the skill of climate field reconstruction techniques for precipitation with pseudoproxy experiments

    NASA Astrophysics Data System (ADS)

    Gómez-Navarro, Juan José; Werner, Johannes; Wagner, Sebastian; Luterbacher, Jürg; Zorita, Eduardo

    2015-09-01

    This study aims at assessing the skill of several climate field reconstruction techniques (CFR) to reconstruct past precipitation over continental Europe and the Mediterranean at seasonal time scales over the last two millennia from proxy records. A number of pseudoproxy experiments are performed within the virtual reality of a regional paleoclimate simulation at 45 km resolution to analyse different aspects of reconstruction skill. Canonical Correlation Analysis (CCA), two versions of an Analog Method (AM) and Bayesian hierarchical modeling (BHM) are applied to reconstruct precipitation from a synthetic network of pseudoproxies that are contaminated with various types of noise. The skill of the derived reconstructions is assessed through comparison with precipitation simulated by the regional climate model. Unlike BHM, CCA systematically underestimates the variance. The AM can be adjusted to overcome this shortcoming, presenting an intermediate behaviour between the two aforementioned techniques. However, a trade-off between reconstruction-target correlations and reconstructed variance is the drawback of all CFR techniques. CCA (BHM) presents the largest (lowest) skill in preserving the temporal evolution, whereas the AM can be tuned to reproduce better correlation at the expense of losing variance. While BHM has been shown to perform well for temperatures, it relies heavily on prescribed spatial correlation lengths. While this assumption is valid for temperature, it is hardly warranted for precipitation. In general, none of the methods outperforms the other. All experiments agree that a dense and regularly distributed proxy network is required to reconstruct precipitation accurately, reflecting its high spatial and temporal variability. This is especially true in summer, when a specifically short de-correlation distance from the proxy location is caused by localised summertime convective precipitation events.

  11. Perioperative Intravascular Fluid Assessment and Monitoring: A Narrative Review of Established and Emerging Techniques

    PubMed Central

    Singh, Sumit; Kuschner, Ware G.; Lighthall, Geoffrey

    2011-01-01

    Accurate assessments of intravascular fluid status are an essential part of perioperative care and necessary in the management of the hemodynamically unstable patient. Goal-directed fluid management can facilitate resuscitation of the hypovolemic patient, reduce the risk of fluid overload, reduce the risk of the injudicious use of vasopressors and inotropes, and improve clinical outcomes. In this paper, we discuss the strengths and limitations of a spectrum of noninvasive and invasive techniques for assessing and monitoring intravascular volume status and fluid responsiveness in the perioperative and critically ill patient. PMID:21785588

  12. Tamponade following sternoclavicular dislocation surgical fixation.

    PubMed

    Bensafi, H; Laffosse, J-M; Taam, S A; Molinier, F; Chaminade, B; Puget, J

    2010-05-01

    The authors report a case of posterior sternoclavicular dislocation surgically reduced and stabilized with tenodesis, according to the Burrows technique completed by temporary wire fixation. The patient presented postoperative pericardiac tamponade appearing progressively from brachiocephalic blood vessels bleeding. Emergency drainage was surgically placed associated with removal of the material, thus curing the patient. This complication, although exceptional, formally contraindicates the use of wire fixation in surgery of the sternoclavicular joint. PMID:20488152

  13. Experience of Delphi technique in the process of establishing consensus on core competencies

    PubMed Central

    Raghav, Pankaja Ravi; Kumar, Dewesh; Bhardwaj, Pankaj

    2016-01-01

    Introduction: The Department of Community Medicine and Family Medicine (CMFM) has been started as a new model for imparting the components of family medicine and delivering health-care services at primary and secondary levels in all six newly established All India Institute of Medical Sciences (AIIMS), but there is no competency-based curriculum for it. The paper aims to share the experience of Delphi method in the process of developing consensus on core competencies of the new model of CMFM in AIIMS for undergraduate medical students in India. Methods: The study adopted different approaches and methods, but Delphi was the most critical method used in this research. In Delphi, the experts were contacted by e-mail and their feedback on the same was analyzed. Results: Two rounds of Delphi were conducted in which 150 participants were contacted in Delphi-I but only 46 responded. In Delphi-II, 26 participants responded whose responses were finally considered for analysis. Three of the core competencies namely clinician, primary-care physician, and professionalism were agreed by all the participants, and the least agreement was observed in the competencies of epidemiologist and medical teacher. The experts having more experience were less consistent as responses were changed from agree to disagree in more than 15% of participants and 6% changed from disagree to agree. Conclusion: Within the given constraints, the final list of competencies and skills for the discipline of CMFM compiled after the Delphi process will provide a useful insight into the development of competency-based curriculum of the subject. PMID:27563586

  14. Scaling Analysis Techniques to Establish Experimental Infrastructure for Component, Subsystem, and Integrated System Testing

    SciTech Connect

    Sabharwall, Piyush; O'Brien, James E.; McKellar, Michael G.; Housley, Gregory K.; Bragg-Sitton, Shannon M.

    2015-03-01

    Hybrid energy system research has the potential to expand the application for nuclear reactor technology beyond electricity. The purpose of this research is to reduce both technical and economic risks associated with energy systems of the future. Nuclear hybrid energy systems (NHES) mitigate the variability of renewable energy sources, provide opportunities to produce revenue from different product streams, and avoid capital inefficiencies by matching electrical output to demand by using excess generation capacity for other purposes when it is available. An essential step in the commercialization and deployment of this advanced technology is scaled testing to demonstrate integrated dynamic performance of advanced systems and components when risks cannot be mitigated adequately by analysis or simulation. Further testing in a prototypical environment is needed for validation and higher confidence. This research supports the development of advanced nuclear reactor technology and NHES, and their adaptation to commercial industrial applications that will potentially advance U.S. energy security, economy, and reliability and further reduce carbon emissions. Experimental infrastructure development for testing and feasibility studies of coupled systems can similarly support other projects having similar developmental needs and can generate data required for validation of models in thermal energy storage and transport, energy, and conversion process development. Experiments performed in the Systems Integration Laboratory will acquire performance data, identify scalability issues, and quantify technology gaps and needs for various hybrid or other energy systems. This report discusses detailed scaling (component and integrated system) and heat transfer figures of merit that will establish the experimental infrastructure for component, subsystem, and integrated system testing to advance the technology readiness of components and systems to the level required for commercial

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

    PubMed

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

    2015-12-01

    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

  16. Assessment of visual fixation in vegetative and minimally conscious states

    PubMed Central

    2014-01-01

    Background Visual fixation plays a key role in the differentiation between vegetative state/unresponsive wakefulness (VS/UWS) syndrome and minimally conscious state (MCS). However, the use of different stimuli changes the frequency of visual fixation occured in patients, thereby possibly affecting the accuracy of the diagnosis. In order to establish a standardized assessment of visual fixation in patients in disorders of consciousness (DOC), we compared the frequency of visual fixation elicited by mirror,a ball and a light. Method Visual fixation was assessed in eighty-one post-comatose patients diagnosed with a MCS or VS/UWS. Occurrence of fixation to different stimuli was analysis used Chi-square testing. Result 40 (49%) out of the 81 patients showed fixation to visual stimuli. Among those, significantly more patients (39, 48%) had visual fixation elicited by mirror compared to a ball (23, 28%) and mirror compared to a light (20, 25%). Conclusion The use of a mirror during the assessment of visual fixation showed higher positive response rate, compared to other stimuli in eliciting a visual fixating response. Therefore, fixation elicited by a mirror can be a very sensitive and accurate test to differentiate the two disorders of consciousness. PMID:25027769

  17. Fixation: A Bibliography.

    ERIC Educational Resources Information Center

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

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

  18. 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

  19. Maxwellian eye fixation during natural scene perception.

    PubMed

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

    2012-01-01

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

  20. Maxwellian Eye Fixation during Natural Scene Perception

    PubMed Central

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

    2012-01-01

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

  1. Doubling of marine dinitrogen-fixation rates based on direct measurements.

    PubMed

    Großkopf, Tobias; Mohr, Wiebke; Baustian, Tina; Schunck, Harald; Gill, Diana; Kuypers, Marcel M M; Lavik, Gaute; Schmitz, Ruth A; Wallace, Douglas W R; LaRoche, Julie

    2012-08-16

    Biological dinitrogen fixation provides the largest input of nitrogen to the oceans, therefore exerting important control on the ocean's nitrogen inventory and primary productivity. Nitrogen-isotope data from ocean sediments suggest that the marine-nitrogen inventory has been balanced for the past 3,000 years (ref. 4). Producing a balanced marine-nitrogen budget based on direct measurements has proved difficult, however, with nitrogen loss exceeding the gain from dinitrogen fixation by approximately 200 Tg N yr−1 (refs 5, 6). Here we present data from the Atlantic Ocean and show that the most widely used method of measuring oceanic N2-fixation rates underestimates the contribution of N2-fixing microorganisms (diazotrophs) relative to a newly developed method. Using molecular techniques to quantify the abundance of specific clades of diazotrophs in parallel with rates of 15N2 incorporation into particulate organic matter, we suggest that the difference between N2-fixation rates measured with the established method and those measured with the new method can be related to the composition of the diazotrophic community. Our data show that in areas dominated by Trichodesmium, the established method underestimates N2-fixation rates by an average of 62%. We also find that the newly developed method yields N2-fixation rates more than six times higher than those from the established method when unicellular, symbiotic cyanobacteria and γ-proteobacteria dominate the diazotrophic community. On the basis of average areal rates measured over the Atlantic Ocean, we calculated basin-wide N2-fixation rates of 14 ± 1 Tg N yr−1 and 24 ±1 Tg N yr−1 for the established and new methods, respectively. If our findings can be extrapolated to other ocean basins, this suggests that the global marine N2-fixation rate derived from direct measurements may increase from 103 ± 8 Tg N yr−1 to 177 ± 8 Tg N yr−1, and that the contribution

  2. Single-Specimen Technique to Establish the J-Resistance of Linear Viscoelastic Solids with Constant Poisson's Ratio

    NASA Technical Reports Server (NTRS)

    Gutierrez-Lemini, Danton; McCool, Alex (Technical Monitor)

    2001-01-01

    A method is developed to establish the J-resistance function for an isotropic linear viscoelastic solid of constant Poisson's ratio using the single-specimen technique with constant-rate test data. The method is based on the fact that, for a test specimen of fixed crack size under constant rate, the initiation J-integral may be established from the crack size itself, the actual external load and load-point displacement at growth initiation, and the relaxation modulus of the viscoelastic solid, without knowledge of the complete test record. Since crack size alone, of the required data, would be unknown at each point of the load-vs-load-point displacement curve of a single-specimen test, an expression is derived to estimate it. With it, the physical J-integral at each point of the test record may be established. Because of its basis on single-specimen testing, not only does the method not require the use of multiple specimens with differing initial crack sizes, but avoids the need for tracking crack growth as well.

  3. Overcoming Organizational Fixation: Creating and Sustaining an Innovation Culture

    ERIC Educational Resources Information Center

    Stempfle, Joachim

    2011-01-01

    Fixation on established paradigms and practices can severely limit the capability of organizations to change, thereby jeopardizing the ability of organizations to keep up with changes in their environment and new technological developments. Overcoming organizational fixation is therefore a requirement for any organization that strives to achieve…

  4. 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.

  5. A simple technique for reconstruction of medial patellofemoral ligament with bone-fascia tunnel fixation at the medial margin of the patella: a 6-year-minimum follow-up study

    PubMed Central

    2014-01-01

    Background Medial patellofemoral ligament (MPFL) reconstruction has become an accepted technique to treat patellofemoral instability, and numerous surgical techniques have been described to reconstruct the MPFL. We describe a MPFL reconstruction procedure where bone-fascia tunnel fixation occurs at the medial margin of the patella for recurrent patellar dislocation. Objective MPFL reconstruction is the preferred operative treatment for recurrent patellar dislocation. The purpose of this study was to report a simple technique for reconstruction of medial patellofemoral ligament with bone-fascia tunnel fixation at the medial margin of the patella for recurrent patellar dislocation and to evaluate the results at 6-year-minimum follow-up. Methods The study included 65 patients (28 males, 37 females; mean age, 29.4 ± 5.6 years) who underwent MPFL reconstruction using the bone-fascia tunnel fixation at the medial margin of the patella technique and who were followed for a mean duration of 78.5 ± 3.8 months. Objective assessment, Kujala scale, Lysholm score, and Tegner activity score were obtained preoperatively and at the time of final follow-up. Results There were no patellar complications, including redislocation, in the present study. The congruence angle had significant improvement from 19.2° ± 6.3° before surgery to −6.03° ± 0.50° at the last follow-up. The lateral patellar angle had significant improvement from −6.9° ± 3.5° before surgery to 5.1° ± 2.4° at the last follow-up. The patellar tilt angle had significant improvement from 24.5° ± 5.2° before surgery to 12.30° ± 1.90° at the last follow-up. The Kujala score was significantly increased from 52.9 ± 3.2 points preoperatively to 90.1 ± 5.8 points postoperatively (P < 0.05). The mean Lysholm score was significantly increased from 47.2 ± 5.2 to 92.5 ± 6.2 points postoperatively (P < 0.05). The Tegner activity score improved

  6. Application of plant growth regulators, a simple technique for improving the establishment success of plant cuttings in coastal dune restoration

    NASA Astrophysics Data System (ADS)

    Balestri, Elena; Vallerini, Flavia; Castelli, Alberto; Lardicci, Claudio

    2012-03-01

    Exogenous application of plant growth regulators (PGRs) may be an effective technique for increasing the rooting ability and the growth of vegetative fragments (cuttings) of plants used in dune restoration programs. Various concentrations (0, 50 and 100 mg l-1) of two auxins, alpha-naphtaleneacetic acid (NAA) and indole-3-butyric acid (IBA), and two cytokinins, 6-furfurylaminopurine (Kinetin) and 6-benzylaminopurine (BAP), were applied separately to cuttings of two widely used species for restoration, Ammophila arenaria and Sporobuls virginicus. Root development and production of new buds in cuttings were examined under laboratory conditions one month after application. Cuttings were also examined one year after transplanting into a sandy substratum under natural conditions, to test for possible long term effects of PGRs on plant establishment success and growth. The response of the two study species to PGRs differed substantially. In A. arenaria the auxin NAA at 100 mg l-1 reduced the time for root initiation and increased the rooting capacity of cuttings, while the cytokinin Kinetin at 50 mg l-1 facilitated root growth. No auxin had effect on rooting or growth of S. virginicus cuttings, but treatment with 100 mg l-1 Kinetin resulted in higher rooting success than the control. One year after planting, the cuttings of A. arenaria treated with 100 mg l-1 NAA showed a higher establishment success (90% vs. 55%) and produced more culms and longer roots than the control; those treated with cytokinins did not differ in the establishment success from the control, but had longer roots, more culms and rhizomes. On the other hand, the cuttings of S. virginicus treated with 100 mg l-1 Kinetin showed a higher establishment success (75% vs. 35%) and had more culms than the control. Therefore, in restoration activities that involved A. arenaria, a pre-treatment of cuttings with NAA would be beneficial, as it allows the production of a higher number of well-developed plants with

  7. Fixation of distal radius fractures in adults: a review.

    PubMed

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

    2013-04-01

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

  8. A Framework for Establishment of a Risk Assessment Model for Soil Erosion by Integrating the AHP Approach and Modeling Techniques

    NASA Astrophysics Data System (ADS)

    Wang, M.; Wu, Q.

    2006-12-01

    A new approach for establishment of an analytical risk assessment model to evaluate the risk index for soil erosion is proposed in which the analytical hierarchy process (AHP) approach and the model calibration and validation processes are integrated. A flowchart presenting a general procedure for implementation of the proposed approach is included. A case study is presented to demonstrate applications of this proposed framework through investigation of soil erosion by water in a joining area that partially covers the Shanxi province, Shaanxi province, and Inner Mongolia Autonomous Region of China. Based on field survey and information analyses, pertinent factors for soil erosion by water in this region are assessed and nine dominating factors are identified. The dominating factors considered include the soil type, rainstorm intensity, landform accounting for physiognomy type, ravine density, and land slope, vegetation coverage, mining area, level of water and soil conservation, and type of land uses. The GIS thematic layers of degrees of risk on soil erosion for those dominating factors are constructed. The weight of each thematic layer is determined through the AHP approach and modeling techniques. This model is then applied in predicting development of soil erosion at a typical scenario for this study area. A brief discussion on construction and application of this model is presented. It is demonstrated that the presented methodology is practicable for establishing a risk assessment mode for soil erosion by water for an area of interest where pertinent information such as remote sensing data is available. Furthermore, a predictive soil erosion model established by the proposed approach may be implemented for investigations of other pertinent environmental issues such as relative and quantitative risk assessments of migration of absorbed contaminants in soil, resulted from agricultural non-point source pollution, into a river or lake through soil erosion.

  9. Introduction to Lumbosacral and Sacropelvic Fixation Strategies.

    PubMed

    Hsieh, Patrick C; Mummaneni, Praveen V

    2016-07-01

    We are pleased to present this Neurosurgical Focus video supplement on lumbosacral and sacropelvic fixation strategies. Despite advancement in surgical techniques and technologies in spine, achieving consistent solid fusion across the lumbosacral junction remains a major challenge. The anatomy of the lumbosacral junction allows for a higher range of motion compared to other areas of the thoracolumbar spine. The L5-S1 interspace is exposed to significant shear forces. As a result, complications such as pseudoarthrosis, screw pull-out, implant fracture, or sacral fractures can occur. Complications are particularly seen in long fusion constructs ending across the lumbosacral junction. To reduce these complications, various lumbosacral and sacropelvic fixation techniques have been developed and utilized. The current supplement is intended to provide instructional videos that illustrate several current techniques for lumbosacral and sacropelvic fixation. The collection includes techniques for anterior L5-S1 interbody fusion, minimally invasive L5-S1 interbody fusions, lumbosacral pedicle screw placement, sacroiliac fusion, and sacro-alar-iliac screw placement. The authors of the videos in the supplement have provided detailed narration and video illustration to describe the nuances of the various open and minimally invasive techniques for lumbosacral and sacral-pelvic fixation. We are pleased to have such a collection of quality video illustration from experts in the field. It's been our privilege to serve as guest editors for this supplement and we believe that you will enjoy the contents of this supplement. PMID:27364425

  10. Establishment of a trimodality analytical platform for tracing, imaging and quantification of gold nanoparticles in animals by radiotracer techniques.

    PubMed

    Chen, Chien-Hung; Lin, Fong-Sian; Liao, Wei-Neng; Liang, Sanching L; Chen, Min-Hua; Chen, Yo-Wen; Lin, Wan-Yu; Hsu, Ming-Hua; Wang, Mei-Ya; Peir, Jinn-Jer; Chou, Fong-In; Chen, Ching-Ya; Chen, Sih-Yu; Huang, Su-Chin; Yang, Mo-Hsiung; Hueng, Dueng-Yuan; Hwu, Yeukuang; Yang, Chung-Shi; Chen, Jen-Kun

    2015-01-01

    This study aims to establish a (198)Au-radiotracer technique for in vivo tracing, rapid quantification, and ex vivo visualization of PEGylated gold nanoparticles (GNPs) in animals, organs and tissue dissections. The advantages of GNPs lie in its superior optical property, biocompatibility and versatile conjugation chemistry, which are promising to develop diagnostic probes and drug delivery systems. (198)Au is used as a radiotracer because it simultaneously emits beta and gamma radiations with proper energy and half-life; therefore, (198)Au can be used for bioanalytical purposes. The (198)Au-tagged radioactive gold nanoparticles ((198)Au-GNPs) were prepared simply by irradiating the GNPs in a nuclear reactor through the (197)Au(n,γ)(198)Au reaction and subsequently the (198)Au-GNPs were subjected to surface modification with polyethylene glycol to form PEGylated (198)Au-GNPs. The (198)Au-GNPs retained physicochemical properties that were the same as those of GNP before neutron irradiation. Pharmacokinetic and biodisposition studies were performed by intravenously injecting three types of (198)Au-GNPs with or without PEGylation into mice; the γ radiation in blood specimens and dissected organs was then measured. The (198)Au-radiotracer technique enables rapid quantification freed from tedious sample preparation and shows more than 95% recovery of injected GNPs. Clinical gamma scintigraphy was proved feasible to explore spatial- and temporal-resolved biodisposition of (198)Au-GNPs in living animals. Moreover, autoradiography, which recorded beta particles from (198)Au, enabled visualizing the heterogeneous biodisposition of (198)Au-GNPs in different microenvironments and tissues. In this study, the (198)Au-radiotracer technique facilitated creating a trimodality analytical platform for tracing, quantifying and imaging GNPs in animals. PMID:25424326

  11. Establishment of optimal scan delay for multi-phase computed tomography using bolus-tracking technique in canine pancreas.

    PubMed

    Choi, Soo-Young; Choi, Ho-Jung; Lee, Ki-Ja; Lee, Young-Won

    2015-09-01

    To establish a protocol for a multi-phase computed tomography (CT) of the canine pancreas using the bolus-tracking technique, dynamic scan and multi-phase CT were performed in six normal beagle dogs. The dynamic scan was performed for 60 sec at 1-sec intervals after the injection (4 ml/sec) of a contrast medium, and intervals from aortic enhancement appearance to aortic, pancreatic parenchymal and portal vein peaks were measured. The multi-phase CT with 3 phases was performed three times using a bolus-tracking technique. Scan delays were 0, 15 and 30 in first multi-phase scan; 5, 20 and 35 in second multi-phase scan; and 10, 25 and 40 sec in third multi-phase scan, respectively. Attenuation values and contrast enhancement pattern were analyzed from the aorta, pancreas and portal vein. The intervals from aortic enhancement appearance to aortic, pancreatic parenchymal and portal vein peaks were 3.8 ± 0.7, 8.7 ± 0.9 and 13.3 ± 1.5 sec, respectively. The maximum attenuation values of the aorta, pancreatic parenchyma and portal vein were present at scan sections with no scan delay, a 5-sec delay and a 10-sec delay, respectively. When a multi-phase CT of the canine pancreas is triggered at aortic enhancement appearance using a bolus-tracking technique, the recommended optimal delay times of the arterial and pancreatic parenchymal phases are no scan delay and 5 sec, respectively. PMID:25843155

  12. Improving Carbon Fixation Pathways

    PubMed Central

    Ducat, Daniel C.

    2012-01-01

    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 alternative pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials. PMID:22647231

  13. 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.

  14. Anatomic Locking Plate Fixation for Scaphoid Nonunion

    PubMed Central

    Yeung, Just; Sapienza, Anthony

    2016-01-01

    Nonunion can occur relatively frequently after scaphoid fracture and appears to be associated with severity of injury. There have been a number of techniques described for bone grafting with or without screw fixation to facilitate fracture healing. However, even with operative fixation of scaphoid fractures with bone grafting nonunion or malunion rates of 5 to 10 percent are still reported. This is the first report of an anatomic locking plate for scaphoid fracture repair in a 25-year-old right hand dominant healthy male. PMID:27366338

  15. Established and emerging cardiovascular magnetic resonance techniques for the assessment of stable coronary heart disease and acute coronary syndromes

    PubMed Central

    Ripley, David P.; Motwani, Manish; Plein, Sven

    2014-01-01

    Coronary heart disease (CHD) is a leading cause of death and disability worldwide. International guidelines recommend cardiovascular magnetic resonance (CMR) as an investigative option in those presenting with chest pain to inform diagnosis, risk stratify and determine the need for revascularization. CMR offers a unique method to assess global and regional cardiac function, myocardial perfusion, myocardial viability, tissue characterisation and proximal coronary anatomy all within a single study. This results in high diagnostic accuracy for the detection of significant coronary stenoses and an established role in the management of both stable CHD and acute coronary syndromes (ACS). The growing evidence base for the prognostic value of CMR, emerging advances in acquisition techniques, improvements in hardware and the completion of current major multi-centre clinical CMR trials will further raise its prominence in international guidelines and routine cardiological practice. This article will focus on the rapidly evolving role of the multi-parametric CMR examination in the assessment of patients with stable and unstable CHD. PMID:25392820

  16. Update: Biological Nitrogen Fixation.

    ERIC Educational Resources Information Center

    Wiseman, Alan; And Others

    1985-01-01

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

  17. The Fixation of Nitrogen.

    ERIC Educational Resources Information Center

    Andrew, S. P. S.

    1978-01-01

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

  18. Feasibility of purely endoscopic intramedullary fixation of mandibular condyle fractures.

    PubMed

    Frake, Paul C; Goodman, Joseph F; Joshi, Arjun S

    2015-01-01

    The investigators of this study hypothesized that fractures of the mandibular condyle can be repaired using short-segment intramedullary implants and purely endoscopic surgical technique, using a basic science, human cadaver model in an academic center. Endoscopic instrumentation was used through a transoral mucosal incision to place intramedullary implants of 2 cm in length into osteotomized mandibular condyles. The surgical maneuvers that required to insert these implants, including condyle positioning, reaming, implant insertion, and seating of the mandibular ramus, are described herein. Primary outcome was considered as successful completion of the procedure. Ten cadaveric mandibular condyles were successfully repaired with rigid intramedullary internal fixation without the use of external incisions. Both insertion of a peg-type implant and screwing a threaded implant into the condylar head were possible. The inferior portion of the implant remained exposed, and the ramus of the mandible was manipulated into position on the implant using retraction at the sigmoid notch. The results of this study suggest that purely endoscopic repair of fractures of the mandibular condyle is possible by using short-segment intramedullary titanium implants and a transoral endoscopic approach without the need for facial incisions or punctures. The biomechanical advantages of these intramedullary implants, including improved strength and resistance to mechanical failure compared with miniplates, have been recently established. The combination of improved implant design and purely endoscopic technique may allow for improved fixation and reduced surgical- and implant-related morbidity in the treatment of condylar fractures. PMID:25534058

  19. PRE-OPERATIVE PLANNING AND SURGICAL TECHNIQUE OF THE OPEN WEDGE SUPRACONDYLAR OSTEOTOMY FOR CORRECTION OF VALGUS KNEE AND FIXATION WITH A FIXED-ANGLE IMPLANT

    PubMed Central

    Paccola, Cleber Antonio Jansen

    2015-01-01

    The step-by-step preoperative planning for supracondylar opening wedge osteotomy of the femur for precise correction of the load axis of the lower limb using a fixed-angle implant (95° AO blade plate) is presented. The surgical technique and the use of a bone graft from the same site for filling in the defect are also presented. PMID:27026976

  20. Biomechanical characteristics of C1-2 cable fixations.

    PubMed

    Dickman, C A; Crawford, N R; Paramore, C G

    1996-08-01

    The biomechanical characteristics of four different methods of C1-2 cable fixation were studied to assess the effectiveness of each technique in restoring atlantoaxial stability. Biomechanical testing was performed on the upper cervical spines of four human cadaveric specimens. Physiological range loading was applied to the atlantoaxial specimens and three-dimensional motion was analyzed with stereophotogrammetry. The load-deformation relationships and kinematics were measured, including the stiffness, the angular ranges of motion, the linear ranges of motion, and the axes of rotation. Specimens were nondestructively tested in the intact state, after surgical destabilization, and after each of four different methods of cable fixation. Cable fixation techniques included the interspinous technique, the Brooks technique, and two variants of the Gallie technique. All specimens were tested immediately after fixation and again after the specimen was fatigued with 6000 cycles of physiological range torsional loading. All four cable fixation methods were moderately flexible immediately; the different cable fixations allowed between 5 degrees and 40 degrees of rotational motion and between 0.6 and 7 mm of translational motion to occur at C1-2. The Brooks and interspinous methods controlled C1-2 motion significantly better than both of the Gallie techniques. The motion allowed by one of the Gallie techniques did not differ significantly from the motion of the unfixed destabilized specimens. All cable fixation techniques loosened after cyclic loading and demonstrated significant increases in C1-2 rotational and translational motions. The bone grafts shifted during cyclic loading, which reduced the effectiveness of the fixation. The locations of the axes of rotation, which were unconstrained and mobile in the destabilized specimens, became altered with cable fixation. The C1-2 cables constrained motion by shifting the axes of rotation so that C-1 rotated around the fixed cable

  1. Arthroscopic-Assisted Fixation of Ideberg Type III Glenoid Fractures

    PubMed Central

    Tao, Matthew A.; Garrigues, Grant E.

    2015-01-01

    Operative treatment of scapular fractures with extension into the glenoid can be a challenging clinical scenario. Though traditionally addressed in an open fashion, the morbidity of this approach, complemented by advancements in arthroscopic technique and instrumentation, has led to increasing use of arthroscopic-assisted fixation. We describe our technique, including pearls and pitfalls, for minimally invasive fixation of Ideberg type III glenoid fractures. This approach minimizes morbidity, allows optimal visualization and reduction, and provides good functional results. PMID:26052487

  2. Calcaneal Tuberosity Fixation Using a Locking Compression Hook Plate.

    PubMed

    Agni, Nickil; Fearon, Paul

    2016-01-01

    Calcaneal tuberosity fractures account for 1% to 3% of all calcaneal fractures. Surgical fixation is particularly challenging owing to osteoporosis and numerous comorbidities and risk factors in this patient population. Numerous techniques have been proposed; however, we describe the use of a locking compression hook plate in the treatment of type 2 fracture patterns. This has the advantage of providing stable fixation in osteoporotic bone, avoiding the disadvantages of soft tissue and metalwork irritation that have been described with other techniques. PMID:27067200

  3. Open reduction internal fixation of distal clavicle fracture with supplementary button coracoclavicular fixation.

    PubMed

    Hanflik, Andrew; Hanypsiak, Bryan T; Greenspoon, Joshua; Friedman, Darren J

    2014-10-01

    Distal clavicle fractures are common, and no standard treatment exists. Many different surgical modalities exist. This report describes an open reduction internal fixation technique that achieves both plate and coracoclavicular stabilization using a button device. A precontoured superior-lateral plate is secured to the clavicle. A 3.2-mm spade-tipped drill bit is drilled across the clavicle and coracoid, passing through 4 cortices. The button is loaded onto an insertion device, passed across the 4 cortices, and captured on the undersurface of the coracoid under fluoroscopic guidance. This construct is linked to the distal clavicle plate by heavy sutures using a second button that sits in the plate. The lateral locking holes are then filled to finalize fixation. This technique provides for a simplified way to achieve coracoclavicular stabilization when using a plate for fixation of distal clavicle fractures. PMID:25473604

  4. Open Reduction Internal Fixation of Distal Clavicle Fracture With Supplementary Button Coracoclavicular Fixation

    PubMed Central

    Hanflik, Andrew; Hanypsiak, Bryan T.; Greenspoon, Joshua; Friedman, Darren J.

    2014-01-01

    Distal clavicle fractures are common, and no standard treatment exists. Many different surgical modalities exist. This report describes an open reduction internal fixation technique that achieves both plate and coracoclavicular stabilization using a button device. A precontoured superior-lateral plate is secured to the clavicle. A 3.2-mm spade-tipped drill bit is drilled across the clavicle and coracoid, passing through 4 cortices. The button is loaded onto an insertion device, passed across the 4 cortices, and captured on the undersurface of the coracoid under fluoroscopic guidance. This construct is linked to the distal clavicle plate by heavy sutures using a second button that sits in the plate. The lateral locking holes are then filled to finalize fixation. This technique provides for a simplified way to achieve coracoclavicular stabilization when using a plate for fixation of distal clavicle fractures. PMID:25473604

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

    PubMed

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

    2015-01-01

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

  6. 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.

  7. Finite-Element Analysis of a New Designed Miniplate which is Used via Intraoral Approach to the Mandible Angle Fracture: Comparison of the Different Fixation Techniques.

    PubMed

    Coskunses, Fatih Mehmet; Kocyigit, Ismail Doruk; Atil, Fethi; Tekin, Umut; Suer, Berkay Tolga; Tuz, Hakan Hifzi; Ozgul, Ozkan; Yagiz, Ayberk

    2015-07-01

    The mandible is the largest facial bone as well as the most commonly fractured bone in the maxillofacial region. Despite numerous studies conducted to identify optimal treatment modalities and plates configurations for intraoral and transoral approaches, no definitive conclusion has been reached. This study used finite element analysis (FEA) to assess 4 scenarios for treatment of an angle fracture (6-hole noncompression miniplate; 6-hole single plate/Champy's technique, 3D strut plate; 2 parallel 4-hole noncompression miniplates). Analysis included segmental displacement and Von Mises Stress evaluations of a 3D reconstruction of a human mandible. Von Mises Stress values for plates did not vary significantly among treatment groups. Moreover, no significant differences were observed in cumulative displacement of segments subjected to vertical and horizontal loads, with all treatment configurations demonstrating clinical acceptability. PMID:26091053

  8. Clinical Results of Internal Fixation of Subcapital Femoral Neck Fractures

    PubMed Central

    Moon, Kyoung Ho; Shin, Joong Sup; Shin, Eun Ho; Ahn, Chi Hoon; Choi, Geon Hong

    2016-01-01

    Background Subcapital femoral neck is known to cause many complications, such as avascular necrosis (AVN) of the femoral head or nonunion, compared with other femoral neck fractures. The purpose of this study was to analyze the incidence of AVN and fixation failures in patients treated with internal fixation using cannulated screws for the subcapital femoral neck fractures. Methods This study targeted a total of 84 cases of subcapital femoral neck fractures that underwent internal fixation using cannulated screws. The average follow-up time after surgery was 36.8 months (range, 24 to 148 months). Results Nine hips (10.7%) showing AVN of the femoral head and 6 hips (7.1%) showing fixation failures were observed. The factors affecting the incidence of AVN of the femoral head after sustaining fractures correlated well with fracture types in the Garden classification (p = 0.030). The factors affecting fixation failure were the degree of reduction (p = 0.001) measured by the Garden alignment index and firm fixation (p = 0.009) assessed using the technique of 3-point fixation through the inferomedial cortical bone of the femoral neck. Conclusions The complication rates for subcapital femoral neck fractures were lower than those previously reported; hence, internal fixation could be a primary treatment option for these fractures. PMID:27247738

  9. Sludge fixation and stabilization

    SciTech Connect

    Smith, R.H.

    1982-08-03

    The physical and chemical fixation and stabilization of waste products from a sulfur-fuel burning unit through controlled crystallization of dissolved calcium sulfite. A low ph calcium sulfite solution is added to the waste containing aqueous sludge produced by a gas desulfurization unit thereby raising the ph of the calcium sulfite to crystalize the calcium sulfite and bind and encapsulate the waste products into a solid mass.

  10. 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.

  11. Methods to shorten the duration of an external fixator in the management of tibial infections

    PubMed Central

    Emara, Khaled M; Ghafar, Khaled Abd Al; Al Kersh, Mohamed Ahmed

    2011-01-01

    Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening condition. The only option available in such a clinical situation is segment transport using the Ilizarov technique of distraction osteogenesis; yet the most common problem in cases of bone transport with the Ilizarov technique in massive bone loss, is the long duration of the fixator. In addition to autologous bone grafting, several mechanical, biologic, and external physical treatment modalities may be employed to promote bone formation and maturation during segment transport in osteomyelitis patients. Mechanical approaches include compressive loading of the distraction regenerate, increased frequency of small increments of distraction, and compression-distraction. Intramedullary nailing and hemicorticotomy can reduce the time in external fixation; however, these techniques are associated with technical difficulties and complications. Exogenous application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external fixation. Other promising modalities include diphosphonates, physician-directed use (off-label use) of bone morphogenetic proteins, and local injection of bone marrow aspirate and platelet gel at the osteotomy site. Well-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis after segment transfer. PMID:22474640

  12. Arthroscopic fixation of an avulsion fracture of the tibia involving the posterior cruciate ligament: a modified technique in a series of 22 cases.

    PubMed

    Chen, L B; Wang, H; Tie, K; Mohammed, A; Qi, Y J

    2015-09-01

    A total of 22 patients with a tibial avulsion fracture involving the insertion of the posterior cruciate ligament (PCL) with grade II or III posterior laxity were reduced and fixed arthroscopically using routine anterior and double posteromedial portals. A double-strand Ethibond suture was inserted into the joint and wrapped around the PCL from anterior to posterior to secure the ligament above the avulsed bony fragment. Two tibial bone tunnels were created using the PCL reconstruction guide, aiming at the medial and lateral borders of the tibial bed. The ends of the suture were pulled out through the bone tunnels and tied over the tibial cortex between the openings of the tunnels to reduce and secure the bony fragment. Satisfactory reduction of the fracture was checked arthroscopically and radiographically. The patients were followed-up for a mean of 24.5 months (19 to 28). Bone union occurred six weeks post-operatively. At final follow-up, all patients had a negative posterior drawer test and a full range of movement. KT-1000 arthrometer examination showed that the mean post-operative side-to-side difference improved from 10.9 mm (standard deviation (sd) 0.7) pre-operatively to 1.5 mm (sd 0.6) (p = 0.001). The mean Tegner and the International Knee Documentation Committee scores improved significantly (p = 0.001). The mean Lysholm score at final follow-up was 92.0 (85 to 96). We conclude that this technique is convenient, reliable and minimally invasive and successfully restores the stability and function of the knee. PMID:26330588

  13. Comparison of the mechanical performance of trochanteric fixation devices.

    PubMed

    Hersh, C K; Williams, R P; Trick, L W; Lanctot, D; Athanasiou, K

    1996-08-01

    The transtrochanteric surgical approach to the hip is commonly used, especially for revision hip surgery. Failure of the trochanter to heal can lead to hardware failure, persistent pain, and limp. Rigid internal fixation is needed in this approach to achieve an adequate rate of healing. Newer cable and cable grip systems have been designed to improve trochanteric fixation, but have not been compared to the older Charnley wire fixation techniques. In this study, an in vitro mechanical method previously used to test wire fixation methods was used to compare wire, cable, and cable grip fixation methods. A quasistatic mechanical distraction device was used to compare structural stiffness, load to clinical failure, energy to clinical failure, and maximum load resisted by the fixation devices. The cable grip system was found to be stiffer, to resist a larger load to mechanical failure at 1-cm displacement, and to absorb a greater amount of energy to clinical failure when compared with the other systems. These data suggest that use of the cable grip fixation method should result in improved clinical success compared with the Charnley wire technique. PMID:8769467

  14. Hexapod External Fixation of Tibia Fractures in Children.

    PubMed

    Iobst, Christopher A

    2016-06-01

    Most tibia fractures in children can be treated nonoperatively. For fractures that do require surgery, however, the most common methods of management include plating or flexible nail insertion. Some fracture patterns, such as periphyseal fractures, fractures with bone and/or soft tissue loss, or fractures with delayed presentation, are not easily amenable to these techniques. Hexapod external fixators are especially helpful in these difficult cases. The purpose of this review is to discuss the principles of performing hexapod circular external fixation applied to pediatric tibia fractures. Some of the additional capabilities of the hexapod external fixator will also be highlighted. PMID:27078228

  15. Translational Vision Rehabilitation: From Eccentric Fixation to Reading Rehabilitation.

    PubMed

    Mishra, Anuradha; Jackson, Mary Lou

    2016-01-01

    Eccentric fixation is a commonly used adaptive strategy in patients with central vision loss. A common complaint in patients with central vision loss is reading difficulty. The mechanisms as to how and why eccentric fixation develops comprise an exciting area of research. As we better understand this phenomenon, we may apply these findings to the clinical setting and in particular to reading rehabilitation. Biofeedback is a new technique that can be applied to eccentric fixation and may have a role in reading rehabilitation. PMID:26959144

  16. Anterior subcutaneous internal fixation for treatment of unstable pelvic fractures

    PubMed Central

    2014-01-01

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

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

    PubMed Central

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

    2007-01-01

    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. PMID:18780085

  18. Anatomic Study of Anterior Transdiscal Axial Screw Fixation for Subaxial Cervical Spine Injuries.

    PubMed

    Ji, Wei; Zheng, Minghui; Qu, Dongbin; Zou, Lin; Chen, Yongquan; Chen, Jianting; Zhu, Qingan

    2016-08-01

    Anterior transdiscal axial screw (ATAS) fixation is an alternative or supplement to the plate and screw constructs for the upper cervical spine injury. However, no existing literatures clarified the anatomic feasibility of this technique for subaxial cervical spine. Therefore, the objective of this study was to evaluate the anatomical feasibility and to establish guidelines for the use of the ATAS fixation for the subaxial cervical spine injury.Fifty normal cervical spines had radiographs to determine the proposed screw trajectory (the screw length and insertion angle) and the interbody graft-related parameters (the disc height and depth, and the distance between anterior vertebral margin and the screw) for all levels of the subaxial cervical spine. Following screw insertion in 8 preserved human cadaver specimens, surgical simulation and dissection verified the feasibility and safety of the ATAS fixation.Radiographic measurements showed the mean axial screw length and cephalic incline angle of all levels were 41.2 mm and 25.2°, respectively. The suitable depth of the interbody graft was >11.7 mm (the distance between anterior vertebral margin and the screw), but <17.1 mm (disc depth). Except the axial screw length, increase in all the measurements was seen with level up to C5-C6 segment. Simulated procedure in the preserved specimens demonstrated that ATAS fixation could be successfully performed at C2-C3, C3-C4, C4-C5, and C5-C6 levels, but impossible at C6-C7 due to the obstacle of the sternum. All screws were placed accurately. None of the screws penetrated into the spinal canal and caused fractures determined by dissecting the specimens.The anterior transdiscal axial screw fixation, as an alternative or supplementary instrumentation for subaxial cervical spine injuries, is feasible and safe with meticulous surgical planning. PMID:27495016

  19. Anatomic Study of Anterior Transdiscal Axial Screw Fixation for Subaxial Cervical Spine Injuries

    PubMed Central

    Ji, Wei; Zheng, Minghui; Qu, Dongbin; Zou, Lin; Chen, Yongquan; Chen, Jianting; Zhu, Qingan

    2016-01-01

    Abstract Anterior transdiscal axial screw (ATAS) fixation is an alternative or supplement to the plate and screw constructs for the upper cervical spine injury. However, no existing literatures clarified the anatomic feasibility of this technique for subaxial cervical spine. Therefore, the objective of this study was to evaluate the anatomical feasibility and to establish guidelines for the use of the ATAS fixation for the subaxial cervical spine injury. Fifty normal cervical spines had radiographs to determine the proposed screw trajectory (the screw length and insertion angle) and the interbody graft-related parameters (the disc height and depth, and the distance between anterior vertebral margin and the screw) for all levels of the subaxial cervical spine. Following screw insertion in 8 preserved human cadaver specimens, surgical simulation and dissection verified the feasibility and safety of the ATAS fixation. Radiographic measurements showed the mean axial screw length and cephalic incline angle of all levels were 41.2 mm and 25.2°, respectively. The suitable depth of the interbody graft was >11.7 mm (the distance between anterior vertebral margin and the screw), but <17.1 mm (disc depth). Except the axial screw length, increase in all the measurements was seen with level up to C5–C6 segment. Simulated procedure in the preserved specimens demonstrated that ATAS fixation could be successfully performed at C2–C3, C3–C4, C4–C5, and C5–C6 levels, but impossible at C6–C7 due to the obstacle of the sternum. All screws were placed accurately. None of the screws penetrated into the spinal canal and caused fractures determined by dissecting the specimens. The anterior transdiscal axial screw fixation, as an alternative or supplementary instrumentation for subaxial cervical spine injuries, is feasible and safe with meticulous surgical planning. PMID:27495016

  20. 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.

  1. Lateral Mass Fixation in the Subaxial Cervical Spine.

    PubMed

    Kurd, Mark F; Millhouse, Paul W; Schroeder, Gregory D; Kepler, Christopher K; Vaccaro, Alexander R

    2015-08-01

    The use of lateral mass screws and rods in the subaxial spine has become the standard method of fixation for posterior cervical spine fusions. Multiple techniques have been described for the placement of lateral mass screws, including the Magerl, the Anderson, and the An techniques. While these techniques are all slightly different, the overall goal is to obtain solid bony fixation while avoiding the neurovascular structures. The use of lateral mass screws has been shown to be a safe and effective technique for achieving a posterior cervical fusion. PMID:26049972

  2. Biological Nitrogen Fixation In Tropical Dry Forests Of Costa Rica

    NASA Astrophysics Data System (ADS)

    Gei, M. G.; Powers, J. S.

    2012-12-01

    Evidence suggests that tropical dry forests (TDF) are not nitrogen (N) deficient. This evidence includes: high losses of gaseous nitrogen during the rainy season, high ecosystem soil N stocks and high N concentrations in leaves and litterfall. Its been commonly hypothesized that biological nitrogen fixation is responsible for the high availability of N in tropical soils. However, the magnitude of this flux has rarely if ever been measured in tropical dry forests. Because of the high cost of fixing N and the ubiquity of N fixing legume trees in the TDF, at the individual tree level symbiotic fixation should be a strategy down-regulated by the plant. Our main goal was to determine the rates of and controls over symbiotic N fixation. We hypothesized that legume tree species employ a facultative strategy of nitrogen fixation and that this process responds to changes in light availability, soil moisture and nutrient supply. We tested this hypothesis both on naturally established trees in a forest and under controlled conditions in a shade house by estimating the quantities of N fixed annually using the 15N natural abundance method, counting nodules, and quantifying (field) or manipulating (shade house) the variation in important environmental variables (soil nutrients, soil moisture, and light). We found that in both in our shade house experiment and in the forest, nodulation varied among different legume species. For both settings, the 15N natural abundance approach successfully detected differences in nitrogen fixation among species. The legume species that we studied were able to regulate fixation depending on the environmental conditions. They showed to have different strategies of nitrogen fixation that follow a gradient of facultative to obligate fixation. Our data suggest that there exists a continuum of nitrogen fixation strategies among species. Any efforts to define tropical legume trees as a functional group need to incorporate this variation.

  3. Deformation measurement of the bone fixed with external fixator using holographic interferometry

    NASA Astrophysics Data System (ADS)

    Kojima, Arata; Ogawa, Ryokei; Izuchi, N.; Yamamoto, Manabu; Nishimoto, T.; Matsumoto, Toshiro

    1991-08-01

    Mechanical properties of tibia fixed with an external fixative device (external fixator) were investigated under some simulated loading conditions. Deformation measurements were performed using double exposure holographic interferometry and real-time holographic interferometry. According to the results of the holographic interferometry, strains on the fixation pins and rods were also measured using strain gauges. The results showed that, with most types of external fixator, dislocations of both fractured ends were mainly caused by decrease in strength of the fixation pins. With increase in strength of fixation pins, angular deformation of the rod was more obvious. Increase in the strength of the rod was not always effective in decreasing dislocation of both fractured ends. Changes in bracing technique with marked change in rigidity of external fixator were useful to decrease dislocation of both fractured ends.

  4. Time Savings and Surgery Task Load Reduction in Open Intraperitoneal Onlay Mesh Fixation Procedure

    PubMed Central

    Roy, Sanjoy; Hammond, Jeffrey; Panish, Jessica; Shnoda, Pullen; Savidge, Sandy; Wilson, Mark

    2015-01-01

    Background. This study assessed the reduction in surgeon stress associated with savings in procedure time for mechanical fixation of an intraperitoneal onlay mesh (IPOM) compared to a traditional suture fixation in open ventral hernia repair. Study Design. Nine general surgeons performed 36 open IPOM fixation procedures in porcine model. Each surgeon conducted two mechanical (using ETHICON SECURESTRAPTM Open) and two suture fixation procedures. Fixation time was measured using a stopwatch, and related surgeon stress was assessed using the validated SURG-TLX questionnaire. T-tests were used to compare between-group differences, and a two-sided 95% confidence interval for the difference in stress levels was established using nonparametric methodology. Results. The mechanical fixation group demonstrated an 89.1% mean reduction in fixation time, as compared to the suture group (p < 0.00001). Surgeon stress scores measured using SURG-TLX were 55.5% lower in the mechanical compared to the suture fixation group (p < 0.001). Scores in five of the six sources of stress were significantly lower for mechanical fixation. Conclusions. Mechanical fixation with ETHICON SECURESTRAPTM Open demonstrated a significant reduction in fixation time and surgeon stress, which may translate into improved operating efficiency, improved performance, improved surgeon quality of life, and reduced overall costs of the procedure. PMID:26240834

  5. 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

  6. 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.

  7. Design and Optimization of Resorbable Silk Internal Fixation Devices

    NASA Astrophysics Data System (ADS)

    Haas, Dylan S.

    Limitations of current material options for internal fracture fixation devices have resulted in a large gap between user needs and hardware function. Metal systems offer robust mechanical strength and ease of implantation but require secondary surgery for removal and/or result in long-term complications (infection, palpability, sensitivity, etc.). Current resorbable devices eliminate the need for second surgery and long-term complications but are still associated with negative host response as well as limited functionality and more difficult implantation. There is a definitive need for orthopedic hardware that is mechanically capable of immediate fracture stabilization and fracture fixation during healing, can safely biodegrade while allowing complete bone remodeling, can be resterilized for reuse, and is easily implantable (self-tapping). Previous work investigated the use of silk protein to produce resorbable orthopedic hardware for non- load bearing fracture fixation. In this study, silk orthopedic hardware was further investigated and optimized in order to better understand the ability of silk as a fracture fixation system and more closely meet the unfulfilled market needs. Solvent-based and aqueous-based silk processing formulations were cross-linked with methanol to induce beta sheet structure, dried, autoclaved and then machined to the desired device/geometry. Silk hardware was evaluated for dry, hydrated and fatigued (cyclic) mechanical properties, in vitro degradation, resterilization, functionalization with osteoinductive molecules and implantation technique for fracture fixation. Mechanical strength showed minor improvements from previous results, but remains comparable to current resorbable fixation systems with the advantages of self-tapping ability for ease of implantation, full degradation in 10 months, ability to be resterilized and reused, and ability to release molecules for osteoinudction. In vivo assessment confirmed biocompatibility, showed

  8. External fixation of distal radius fractures.

    PubMed

    Slutsky, David J

    2007-12-01

    External fixation has been used for the treatment of distal radius fractures for more than 50 years. Although the fixator configurations have undergone considerable modification over time, the type of fixator itself is not as important as the underlying principles that provide the foundation for external fixation. Although volar plate fixation is currently in vogue, the indications for external fixation remain largely unchanged. Newer fixator designs have also expanded the traditional usage to include nonbridging applications that allow early wrist motion. The following discussion focuses on the myriad uses for external fixation as well as the shortcomings and potential pitfalls. PMID:18070654

  9. Fixation by active accommodation

    NASA Astrophysics Data System (ADS)

    Pahlavan, Kourosh; Uhlin, Tomas; Eklundh, Jan-Olof

    1992-11-01

    The field of computer vision has long been interested in disparity as the cue for the correspondence between stereo images. The other cue to correspondence, blur, and the fact that vergence is a combination of the two processes, accommodative vergence and disparity vergence, have not been equally appreciated. Following the methodology of active vision that allows the observer to control all his visual parameters, it is quite natural to take advantage of the powerful combination of these two processes. In this article, we try to elucidate such an integration and briefly analyze the cooperation and competition between accommodative vergence and disparity vergence on one hand and disparity and blur stimuli on the other hand. The human fixation mechanism is used as a guide-line and some virtues of this mechanism are used to implement a model for vergence in isolation. Finally, some experimental results are reported.

  10. Interference Screw vs. Suture Anchor Fixation for Open Subpectoral Biceps Tenodesis: Does it Matter?

    PubMed Central

    Millett, Peter J; Sanders, Brett; Gobezie, Reuben; Braun, Sepp; Warner, Jon JP

    2008-01-01

    Background Bioabsorbable interference screw fixation has superior biomechanical properties compared to suture anchor fixation for biceps tenodesis. However, it is unknown whether fixation technique influences clinical results. Hypothesis We hypothesize that subpectoral interference screw fixation offers relevant clinical advantages over suture anchor fixation for biceps tenodesis. Study Design Case Series. Methods We performed a retrospective review of a consecutive series of 88 patients receiving open subpectoral biceps tenodesis with either interference screw fixation (34 patients) or suture anchor fixation (54 patients). Average follow up was 13 months. Outcomes included Visual Analogue Pain Scale (0–10), ASES score, modified Constant score, pain at the tenodesis site, failure of fixation, cosmesis, deformity (popeye) and complications. Results There were no failures of fixation in this study. All patients showed significant improvement between their preoperative and postoperative status with regard to pain, ASES score, and abbreviated modified Constant scores. When comparing IF screw versus anchor outcomes, there was no statistical significance difference for VAS (p = 0.4), ASES score (p = 0.2), and modified Constant score (P = 0.09). One patient (3%) treated with IF screw complained of persistent bicipital groove tenderness, versus four patients (7%) in the SA group (nonsignificant). Conclusion Subpectoral biceps tenodesis reliably relieves pain and improves function. There was no statistically significant difference in the outcomes studied between the two fixation techniques. Residual pain at the site of tenodesis may be an issue when suture anchors are used in the subpectoral location. PMID:18793424

  11. Intrafocal pin plate fixation of distal ulna fractures associated with distal radius fractures.

    PubMed

    Foster, Brian J; Bindra, Randy R

    2012-02-01

    Subcapital ulnar fractures in association with distal radius fractures in elderly patients increase instability and pose a treatment challenge. Fixation of the ulnar fracture with traditional implants is difficult due to the subcutaneous location, comminution, and osteoporosis. We describe an intrafocal pin plate that provides fixation by a locking plate on the distal ulna and intramedullary fixation within the shaft. The low profile and percutaneous technique make this device a useful alternative for treatment of subcapital ulna fractures in the elderly. PMID:22192166

  12. Salivary bacterial fingerprints of established oral disease revealed by the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS) technique

    PubMed Central

    Belstrøm, Daniel; Paster, Bruce J.; Fiehn, Nils-Erik; Bardow, Allan; Holmstrup, Palle

    2016-01-01

    Background and objective The composition of the salivary microbiota, as determined using various molecular methods, has been reported to differentiate oral health from diseases. Thus, the purpose of this study was to utilize the newly developed molecular technique HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing) for comparison of the salivary microbiota in patients with periodontitis, patients with dental caries, and orally healthy individuals. The hypothesis was that this method could add on to the existing knowledge on salivary bacterial profiles in oral health and disease. Design Stimulated saliva samples (n=30) were collected from 10 patients with untreated periodontitis, 10 patients with untreated dental caries, and 10 orally healthy individuals. Salivary microbiota was analyzed using HOMINGS and statistical analysis was performed using Kruskal–Wallis test with Benjamini–Hochberg's correction. Results From a total of 30 saliva samples, a mean number of probe targets of 205 (range 120–353) were identified, and a statistically significant higher mean number of targets was registered in samples from patients with periodontitis (mean 220, range 143–306) and dental caries (mean 221, range 165–353) as compared to orally healthy individuals (mean 174, range 120–260) (p=0.04 and p=0.04). Nine probe targets were identified with a different relative abundance between groups (p<0.05). Conclusions Cross-sectional comparison of salivary bacterial profiles by means of HOMINGS analysis showed that different salivary bacterial profiles were associated with oral health and disease. Future large-scale prospective studies are needed to evaluate if saliva-based screening for disease-associated oral bacterial profiles may be used for identification of patients at risk of acquiring periodontitis and dental caries. PMID:26782357

  13. 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)

  14. Characteristics of Fixational Eye Movements in People With Macular Disease

    PubMed Central

    Kumar, Girish; Chung, Susana T. L.

    2014-01-01

    Purpose. Fixation stability is known to be poor for people with macular disease and has been suggested as a contributing factor for the poor visual performance of these individuals. In this study, we examined the characteristics of the different components of fixational eye movements and determined the component that plays a major role in limiting fixation stability in people with macular disease. Methods. Sixteen observers with macular disease and 14 older adults with normal vision (control observers) monocularly fixated a small cross presented using a Rodenstock scanning laser ophthalmoscope, for trials of 30 seconds. The retinal image and the position of the cross on the retina were recorded digitally. Eye movements were extracted from the recorded videos at a sampling rate of 540 Hz using a cross-correlation technique. A velocity criterion of 8°/s was used to differentiate between slow drifts and microsaccades. Results. Observers with macular disease demonstrated higher fixation instability, larger amplitudes of slow drifts and microsaccades, and lower drift velocities, when compared with older adults with normal vision. The velocity and the rate of microsaccades were comparable between the two groups of observers. Multiple linear regression analysis showed that the amplitude of microsaccades, and to a smaller extent, the amplitude of slow drifts, play a major role in limiting fixation stability. Conclusions. Fixation stability in people with macular disease is primarily limited by the amplitude of microsaccades, implying that rehabilitative strategies targeted at reducing the amplitude of microsaccades should improve fixation stability, and may lead to improved visual functions. PMID:25074769

  15. Primary Water Stress Corrosion Cracks in Nickel Alloy Dissimilar Metal Welds: Detection and Sizing Using Established and Emerging Nondestructive Examination Techniques

    SciTech Connect

    Braatz, Brett G.; Cumblidge, Stephen E.; Doctor, Steven R.; Prokofiev, Iouri

    2012-12-31

    The U.S. Nuclear Regulatory Commission has established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) as a follow-on to the international cooperative Program for the Inspection of Nickel Alloy Components (PINC). The goal of PINC was to evaluate the capabilities of various nondestructive evaluation (NDE) techniques to detect and characterize surface-breaking primary water stress corrosion cracks in dissimilar-metal welds (DMW) in bottom-mounted instrumentation (BMI) penetrations and small-bore (≈400-mm diameter) piping components. A series of international blind round-robin tests were conducted by commercial and university inspection teams. Results from these tests showed that a combination of conventional and phased-array ultrasound techniques provided the highest performance for flaw detection and depth sizing in dissimilar metal piping welds. The effective detection of flaws in BMIs by eddy current and ultrasound shows that it may be possible to reliably inspect these components in the field. The goal of PARENT is to continue the work begun in PINC and apply the lessons learned to a series of open and blind international round-robin tests that will be conducted on a new set of piping components including large-bore (≈900-mm diameter) DMWs, small-bore DMWs, and BMIs. Open round-robin testing will engage universities and industry worldwide to investigate the reliability of emerging NDE techniques to detect and accurately size flaws having a wide range of lengths, depths, orientations, and locations. Blind round-robin testing will invite testing organizations worldwide, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from easy to very difficult to detect and size. This paper presents highlights of PINC and reports on the plans and progress for

  16. Open Reduction and Internal Fixation of Mandibular Fracture without Rigid Maxillomandibular Fixation.

    PubMed

    El-Anwar, Mohammad Waheed; Sayed El-Ahl, Magdy Abdalla; Amer, Hazem Saed

    2015-10-01

    Introduction The ability to treat fracture with open reduction and internal fixation (OR/IF) has dramatically revolutionized the approach to mandible fracture. With OR/IF, the postoperative role of rigid maxillomandibular fixation (MMF) has declined, but it is used to maintain proper occlusion until internal fixation of the fracture is achieved. Objective To assess intraoperative manual MMF during OR/IF of selected cases of mandibular fractures. Methods This prospective study was conducted on 80 patients with isolated mandibular fractures managed by OR/IF using two titanium miniplates. The patients were classified into two groups: a control group (40 patients) treated by OR/IF after intraoperative rigid MMF followed by immediate MMF removal, and a study group (40 patients) treated by rigid MMF, which was replaced by temporary intraoperative manual MMF (3MF) until plate fixation. Results There were no significant differences of the postoperative complication and dental occlusion, although a highly significant reduction of operative time was achieved in the 3MF group. Patient who received the 3MF technique had statistically significantly better average intrinsic vertical mouth opening in the early postoperative period (1 week after surgery), and normal mouth opening could be achieved in all cases in both groups 8 weeks after surgery. Conclusions Intraoperative rigid MMF is not mandatory and can be replaced in selected cases of fracture mandible by manual maintenance of proper dental occlusion until hardware fixation, gaining the advantages of shorter operative time and less risk of blood-transmitted diseases to the surgical team and the patient in addition to the benefits of immediate postoperative mandible mobilization. PMID:26491477

  17. Open Reduction and Internal Fixation of Mandibular Fracture without Rigid Maxillomandibular Fixation

    PubMed Central

    El-Anwar, Mohammad Waheed; Sayed El-Ahl, Magdy Abdalla; Amer, Hazem Saed

    2015-01-01

    Introduction The ability to treat fracture with open reduction and internal fixation (OR/IF) has dramatically revolutionized the approach to mandible fracture. With OR/IF, the postoperative role of rigid maxillomandibular fixation (MMF) has declined, but it is used to maintain proper occlusion until internal fixation of the fracture is achieved. Objective To assess intraoperative manual MMF during OR/IF of selected cases of mandibular fractures. Methods This prospective study was conducted on 80 patients with isolated mandibular fractures managed by OR/IF using two titanium miniplates. The patients were classified into two groups: a control group (40 patients) treated by OR/IF after intraoperative rigid MMF followed by immediate MMF removal, and a study group (40 patients) treated by rigid MMF, which was replaced by temporary intraoperative manual MMF (3MF) until plate fixation. Results There were no significant differences of the postoperative complication and dental occlusion, although a highly significant reduction of operative time was achieved in the 3MF group. Patient who received the 3MF technique had statistically significantly better average intrinsic vertical mouth opening in the early postoperative period (1 week after surgery), and normal mouth opening could be achieved in all cases in both groups 8 weeks after surgery. Conclusions Intraoperative rigid MMF is not mandatory and can be replaced in selected cases of fracture mandible by manual maintenance of proper dental occlusion until hardware fixation, gaining the advantages of shorter operative time and less risk of blood-transmitted diseases to the surgical team and the patient in addition to the benefits of immediate postoperative mandible mobilization. PMID:26491477

  18. Percutaneous Lumbopelvic Fixation for Reduction and Stabilization of Sacral Fractures With Spinopelvic Dissociation Patterns

    PubMed Central

    Quinnan, Stephen M.

    2016-01-01

    Summary: Sacral fractures that result in spinopelvic dissociation are unstable injuries that are often treated surgically, with iliosacral screw fixation and/or lumbopelvic fixation from L4 to the pelvis. Open lumbopelvic fixation allows for direct fracture reduction and immediate postoperative weight bearing, but is associated with a relatively high wound complication rate. Open surgery often takes several hours and can be associated with significant blood loss, and therefore may not be well tolerated physiologically in these patients who often have multiple injuries. We developed a percutaneous lumbopelvic reduction and fixation technique to address these issues. PMID:26894767

  19. Dorsal multiple plating without routine transarticular screws for fixation of Lisfranc injury.

    PubMed

    Stern, Richard E; Assal, Mathieu

    2014-12-01

    Following a Lisfranc joint injury, stable fixation of the tarsometatarsal joints is crucial to avoid deformity and posttraumatic osteoarthritis, but the ideal method of fixation remains controversial. Kirschner wire (K-wire) fixation of all involved joints with cast immobilization resulted in loss of position, and was replaced by open reduction with improved fixation using transarticular screws. However, it seems intuitive that transarticular screws will result in further damage to already traumatized joints, and this has led to plate-spanning techniques. The objective of this study was to describe the method of dorsal multiple plating without the routine use of transarticular screws, and to report on the ability of plate fixation to maintain alignment comparable to that of transarticular screw fixation in 15 patients. PMID:25437072

  20. Impact of Infection on Fracture Fixation.

    PubMed

    Willey, Michael; Karam, Matthew

    2016-04-01

    Surgical site infection can be a devastating complication that results in significant morbidity in patients who undergo operative fixation of fractures. Reducing the rate of infection and wound complications in high-risk trauma patients by giving early effective antibiotics, improving soft tissue management, and using antiseptic techniques is a common topic of discussion. Despite heightened awareness, there has not been a significant reduction in surgical site infection over the past 40 years. Patients should be treated aggressively to eliminate or suppress the infection, heal the fracture if there is a nonunion, and maintain the function of the patient. PMID:26772944

  1. BENCH SCALE FIXATION OF SOILS FROM THE TACOMA TAR PITS SUPRFUND SITE

    EPA Science Inventory

    This report documents the results of bench-scale soil fixation study conducted with materials from the Tacoma Tar Pits SuperfundSite. Chemical fixation (also called stabilization/solidification)is a relatively new technique for remediating contaminated soils. It entails both immo...

  2. Minimally invasive dynamic hip screw for fixation of hip fractures

    PubMed Central

    Ho, Michael; Garau, Giorgio; Walley, Gayle; Oliva, Francesco; Panni, Alfredo Schiavone; Longo, Umile Giuseppe

    2008-01-01

    We compared a minimally invasive surgical technique to the conventional (open approach) surgical technique used in fixation of hip fractures with the dynamic hip screw (DHS) device. Using a case-control design (44 cases and 44 controls), we tested the null hypothesis that there is no difference between the two techniques in the following outcome measures: duration of surgery, time to mobilisation and weight bearing postoperatively, length of hospital stay, mean difference of pre- and postoperative haemoglobin levels, position of the lag screw of the DHS device in the femoral head, and the tip–apex distance. The minimally invasive DHS technique had significantly shorter duration of surgery and length of hospital stay. There was also less blood loss in the minimally invasive DHS technique. The minimally invasive DHS technique produces better outcome measures in the operating time, length of hospital stay, and blood loss compared to the conventional approach while maintaining equal fixation stability. PMID:18478227

  3. Adult tibial eminence fracture fixation: arthroscopic procedure using K-wire folded fixation.

    PubMed

    Bonin, Nicolas; Jeunet, Laurent; Obert, Laurent; Dejour, David

    2007-07-01

    The purpose of this article is to describe a new and simple technique for arthroscopic fixation of tibial intercondylar eminence avulsion fractures using folded surgical pin. This technique allows reduction and fixation of the bone fragment without using special equipment. After standard arthroscopic procedure to explore the knee and to remove fracture debris and blood clot, the bone block is reduced and advanced with the spike of the anterior cruciate ligament tibial drill guide. A 1.8-mm K-wire is drilled through the guide from the proximal tibia into the reduced fragment. It is bent on its end into the joint with a strong needle case. The K-wire is then pulled back until good fragment compression to the tibia appears with the wire starting unbending. Next, the other side is bent on the anterior tibial cortex and cut. This arthroscopic fixation allows elastic compression fragment stabilization that authorizes early weight bearing and rehabilitation programs. The material is extracted by traction after 6 months. PMID:17235617

  4. S-1 and S-2-alar-iliac screw fixation via intraoperative navigation.

    PubMed

    Pham, Martin H; Jakoi, Andre M; Hsieh, Patrick C

    2016-07-01

    Adult deformity patients often require fixation to the sacrum and pelvis for construct stability and improved fusion rates. Although certain sacropelvic fixation techniques can be challenging, the availability of intraoperative navigation has made many of these techniques more feasible. In this video case presentation, the authors demonstrate the techniques of S-1 bicortical screw and S-2-alar-iliac screw fixation under intraoperative navigation in a 67-year-old female. This instrumentation placement was part of an overall T-10-pelvis construct for the correction of adult spinal deformity. The video can be found here: https://youtu.be/3HZo-80jQr8 . PMID:27364427

  5. Rapid Microwave Fixation of Cell Monolayers Preserves Microtubule-associated Cell Structures

    PubMed Central

    Reipert, Siegfried; Kotisch, Harald; Wysoudil, Bhuma; Wiche, Gerhard

    2008-01-01

    Microwave (MW) fixation has been suggested as a method to rapidly immobilize cellular dynamics for fine structural studies in the electron microscope. To show its suitability for studies on cell monolayers, one has to apply MW fixation systematically in correlation with samples on the light microscopy level. Examples for MW fixation of cell monolayers, however, are still rare. MW-accelerated fixation for relatively long periods of time (1–2 min) has been reported without showing its suitability at the fine structural level. Here, we provide a rapid MW fixation protocol for cell monolayers on a subminute time scale. The impact of the MW-accelerated glutaraldehyde fixation on temperature-sensitive cytoskeletal components such as microtubules was evaluated. For testing the effectiveness of MW-assisted primary fixation, saponin treatment of the monolayers was included. Simultaneous MW-accelerated fixation and extraction by saponin was necessary to achieve a gradual improvement in visualization of cytoskeletal aspects in association with cell junctions, mitochondria, and centrioles. To establish a valuable routine program for fine structural studies of resin-embedded cell models on substrata, a protocol combining MW fixation with automatic processing in a tissue processor is provided. (J Histochem Cytochem 56:697–709, 2008) PMID:18413652

  6. 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

  7. Nitrogen fixation control under drought stress. Localized or systemic?

    PubMed

    Marino, Daniel; Frendo, Pierre; Ladrera, Ruben; Zabalza, Ana; Puppo, Alain; Arrese-Igor, Cesar; González, Esther M

    2007-04-01

    Legume-Rhizobium nitrogen fixation is dramatically affected under drought and other environmental constraints. However, it has yet to be established as to whether such regulation of nitrogen fixation is only exerted at the whole-plant level (e.g. by a systemic nitrogen feedback mechanism) or can also occur at a local nodule level. To address this question, nodulated pea (Pisum sativum) plants were grown in a split-root system, which allowed for half of the root system to be irrigated at field capacity, while the other half was water deprived, thus provoking changes in the nodule water potential. Nitrogen fixation only declined in the water-deprived, half-root system and this result was correlated with modifications in the activities of key nodule's enzymes such as sucrose synthase and isocitrate dehydrogenase and in nodular malate content. Furthermore, the decline in nodule water potential resulted in a cell redox imbalance. The results also indicate that systemic nitrogen feedback signaling was not operating in these water-stressed plants, since nitrogen fixation activity was maintained at control values in the watered half of the split-root plants. Thus, the use of a partially droughted split-root system provides evidence that nitrogen fixation activity under drought stress is mainly controlled at the local level rather than by a systemic nitrogen signal. PMID:17416644

  8. Hiatus Hernia Repair with Bilateral Oesophageal Fixation

    PubMed Central

    Martin, David

    2015-01-01

    Background. Despite advances in surgical repair of hiatus hernias, there remains a high radiological recurrence rate. We performed a novel technique incorporating bilateral oesophageal fixation and evaluated outcomes, principally symptom improvement and hernia recurrence. Methods. A retrospective study was performed on a prospective database of patients undergoing hiatus hernia repair with bilateral oesophageal fixation. Retrospective and prospective quality of life (QOL), PPI usage, and patient satisfaction data were obtained. Hernia recurrence was assessed by either barium swallow or gastroscopy. Results. 87 patients were identified in the database with a minimum of 3 months followup. There were significant improvements in QOL scores including GERD HRQL (29.13 to 4.38, P < 0.01), Visick (3 to 1), and RSI (17.45 to 5, P < 0.01). PPI usage decreased from a median of daily to none, and there was high patient satisfaction (94%). 57 patients were assessed for recurrence with either gastroscopy or barium swallow, and one patient had evidence of recurrence on barium swallow at 45 months postoperatively. There was an 8% complication rate and no mortality or oesophageal perforation. Conclusions. This study demonstrates that our technique is both safe and effective in symptom control, and our recurrence investigations demonstrate at least short term durability. PMID:26065030

  9. Comparison of surgical outcomes between fixation with hook plate and loop suspensory fixation for acute unstable acromioclavicular joint dislocation: a systematic review and meta-analysis.

    PubMed

    Arirachakaran, Alisara; Boonard, Manusak; Piyapittayanun, Peerapong; Phiphobmongkol, Vajarin; Chaijenkij, Kornkit; Kongtharvonskul, Jatupon

    2016-08-01

    Treatment of acute (≤4 weeks) high-grade acromioclavicular (AC) joint separation (types III-VI) is still controversial. Currently, the two modern techniques that are widely used include hook plate fixation and coracoclavicular (CC) ligament fixation using a suspensory loop device (tightrope, synthetic ligament or absorbable polydioxansulfate sling). These techniques are both reported to have superior clinical outcomes. This systematic review and meta-analysis aimed to assess and compare clinical outcomes of hook plate fixation versus fixation of the CC ligament using a loop suspensory fixation (LSF) device for the treatment of AC joint injury. These clinical outcomes consist of the Constant-Murley score (CMS), pain visual analog score (VAS) and postoperative complications. Relevant comparative studies were identified from MEDLINE and Scopus from inception to October 5, 2015. Five of 571 studies were eligible; 5, 3, 3, and 5 studies were included in the pooling of CMS, pain VAS, surgical time and postoperative complications, respectively. The unstandardized mean difference (UMD) of the CMS for LSF was 4.43 [95 % confidence interval (CI) 0.73, 8.14], which was statistically significantly higher than the CMS in hook plate fixation. For VAS, the UMD was 0.02 points (95 % CI -3.54, 3.73) higher than LSF but without statistical significance. The surgical time of LSF was 16.21 min (95 % CI 6.27, 26.15) statistically significantly higher than hook plate fixation. LSF had a lower chance of postoperative complications by 0.62 units (95 % CI 0.30, 1.32) when compared to hook plate fixation, but this also was not statistically significant. In acute high-grade AC joint injuries, loop suspensory fixation had higher postoperative functional CMS and mean surgical time when compared to hook plate fixation. However, for postoperative VAS and complication rates, there were no statistically significant differences between groups. PMID:27334621

  10. Effects of tissue fixation on coherent anti-Stokes Raman scattering images of brain

    NASA Astrophysics Data System (ADS)

    Galli, Roberta; Uckermann, Ortrud; Koch, Edmund; Schackert, Gabriele; Kirsch, Matthias; Steiner, Gerald

    2014-07-01

    Coherent anti-Stokes Raman scattering (CARS) microscopy is an emerging multiphoton technique for the label-free histopathology of the central nervous system, by imaging the lipid content within the tissue. In order to apply the technique on standard histology sections, it is important to know the effects of tissue fixation on the CARS image. Here, we report the effects of two common fixation methods, namely with formalin and methanol-acetone, on mouse brain and human glioblastoma tissue. The variations induced by fixation on the CARS contrast and intensity were compared and interpreted using Raman microspectroscopy. The results show that, whenever unfixed cryosections cannot be used, fixation with formalin constitutes an alternative which does not deteriorate substantially the contrast generated by the different brain structures in the CARS image. Fixation with methanol-acetone strongly modifies the tissue lipid content and is therefore incompatible with the CARS imaging.

  11. The Role of Resorbable Mesh as a Fixation Device in Craniosynostosis.

    PubMed

    Konofaos, Petros; Goubran, Sameh; Wallace, Robert D

    2016-01-01

    The purpose of the study was to present our experience with endocranial fixation using the Resorb-X mesh (KLS Martin, Jacksonville, FL) in frontoorbital reconstruction. A retrospective review of all patients underwent frontoorbital advancement at our institution from 2003 to 2012 was performed. Inclusion criterion included: pediatric patients who underwent frontoorbital advancement for craniosynostosis; patients underwent treatment of the craniosynostosis only at our center; resorbable fixation devises were applied only endocranially; and follow-up was ≥ 2 years. Patients' evaluation included demographic information, postoperative complications, surgical outcomes, and postoperative computed tomographic imaging if accessible. Thirty-nine patients met the inclusion criteria. Resorbable plates were used in 16 patients and Resorb-X mesh in 23 patients. Observed complications were unrelated to the fixation system used. Resorption of fixation devices was evident in all patients after 20 months following reconstruction. There were no incidents of local reaction to the fixation system. Frontoorbital area contour was deemed good in 24 patients and excellent in 15 patients by both families and attending surgeon. There was a statistical significant difference (P = 0.030) between patients ≤ 12 months and >12 months regarding the complications rate. Endocranial fixation using the Resorb-X mesh is easily applicable, avoids material palpability, and provides stable and secure fixation. This technique is superior to the conventional endocranial osseous fixation with absorbable plates, as it avoids some of its possible complications while providing all the benefits of resorbable fixation. PMID:26674902

  12. Nitrogen fixation in the mucus of Red Sea corals.

    PubMed

    Grover, Renaud; Ferrier-Pagès, Christine; Maguer, Jean-François; Ezzat, Leila; Fine, Maoz

    2014-11-15

    Scleractinian corals are essential constituents of tropical reef ecological diversity. They live in close association with diazotrophs [dinitrogen (N2)-fixing microbes], which can fix high rates of N2. Whether corals benefit from this extrinsic nitrogen source is still under debate. Until now, N2 fixation rates have been indirectly estimated using the acetylene reduction assay, which does not permit assessment of the amount of nitrogen incorporated into the different compartments of the coral holobiont. In the present study, the (15)N2 technique was applied for the first time on three Red Sea coral species. Significant (15)N enrichment was measured in particles released by corals to the surrounding seawater. N2 fixation rates were species specific and as high as 1.6-2 ng N day(-1) l(-1). However, no significant enrichment was measured in the symbiotic dinoflagellates or the coral host tissues, suggesting that corals do not benefit from diazotrophic N2 fixation. PMID:25278474

  13. Arthroscopy Assisted Percutaneous Fixation of Ideberg Type Iii Glenoid Fractures

    PubMed Central

    Acharya, Prashant; Arora, Bakul; Pinto, Nelson

    2015-01-01

    Introduction: Intra-articular glenoid fractures are extremely rare and may be associated with other injuries. Traditionally open reduction and internal fixation has been recommended in displaced intra-articular glenoid fractures. However open reduction is difficult and it may not be possible to address the associated intra-articular soft tissue injuries. A few reports of arthroscopic assisted fixation of these fractures have been recently published. We are reporting a case of Ideberg type 3 glenoid fracture and its treatment. Case Report: We are presenting our case where a 52 year old man presented with Type 3 intra-articular glenoid fracture. The fracture was fixed percutaneously under simultaneous arthroscopic and fluoroscopic guidance. Conclusion: Intra-articular glenoid fractures are uncommon and difficult to treat. Arthroscopy assisted percutaneous fixation technique can be a valuable adjunct for the surgeon in dealing with not only the fracture but also the associated soft-tissue injuries. PMID:27299041

  14. Hemispheric titanium porous coated acetabular component without screw fixation.

    PubMed

    Dorr, L D; Wan, Z; Cohen, J

    1998-06-01

    One hundred fifteen hips in 108 patients with primary total hip arthroplasty using the anatomic porous replacement hemispheric acetabular component implanted without adjunctive screw fixation had a mean postoperative followup time of 6 years (range, 5-7.4 years). Clinical evaluation was performed using the Harris hip score and patient self assessment using a modified Short Form-36 questionnaire. Radiographs were measured for radiolucent lines, polyethylene wear, osteolysis, migration, and fractures. No acetabular metal shell had been revised for loosening or was radiographically loose with or without migration (more than 3 mm) at final followup. Reoperation was done in nine (8%) hips because of polyethylene insert wear or disassembly. No fracture of the acetabular bone occurred at the time of surgery or was observed on radiograph. Fixation of the metal shell was stable, with progressive radiolucent lines observed at final followup in 2% of the hips. Osteolysis was recorded in one patient with two acetabular components. The fixation of noncemented hemispheric porous coated acetabular components is more related to the technique of acetabular bone preparation and press fit implantation than to whether additional screws or peg fixation are used. Fixation of this acetabular component without screws at an average of 6 years after surgery is reproducible and predictable in primary hip arthroplasty. The design of modular polyethylene inserts has been improved and should reduce the wear rate of reoperations of the polyethylene insert. PMID:9646758

  15. Hydroponic Growth and the Nondestructive Assay for Dinitrogen Fixation 1

    PubMed Central

    Imsande, John; Ralston, Edward J.

    1981-01-01

    Hydroponic growth medium must be well buffered if it is to support sustained plant growth. Although 1.0 millimolar phosphate is commonly used as a buffer for hydroponic growth media, at that concentration it is generally toxic to a soybean plant that derives its nitrogen solely from dinitrogen fixation. On the other hand, we show that 1.0 to 2.0 millimolar 2-(N-morpholino)ethanesulfonic acid, pKa 6.1, has excellent buffering capacity, and it neither interferes with nor contributes nutritionally to soybean plant growth. Furthermore, it neither impedes nodulation nor the assay of dinitrogen fixation. Hence, soybean plants grown hydroponically on a medium supplemented with 1.0 to 2.0 millimolar 2-(N-morpholino)ethanesulfonic acid and 0.1 millimolar phosphate achieve an excellent rate of growth and, in the absence of added fixed nitrogen, attain a very high rate of dinitrogen fixation. Combining the concept of hydroponic growth and the sensitive acetylene reduction technique, we have devised a simple, rapid, reproducible assay procedure whereby the rate of dinitrogen fixation by individual plants can be measured throughout the lifetime of those plants. The rate of dinitrogen fixation as measured by the nondestructive acetylene reduction procedure is shown to be approximately equal to the rate of total plant nitrogen accumulation as measured by Kjeldahl analysis. Because of the simplicity of the procedure, one investigator can readily assay 50 plants individually per day. PMID:16662112

  16. 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. PMID:21669346

  17. 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.

  18. Complement fixation test to C. burnetii

    MedlinePlus

    ... ency/article/003520.htm Complement fixation test to C burnetii To use the sharing features on this ... JavaScript. The complement fixation test to Coxiella burnetii ( C burnetti ) is a blood test that checks for ...

  19. Phase-contrast Hounsfield units of fixated and non-fixated soft-tissue samples

    DOE PAGESBeta

    Willner, Marian; Fior, Gabriel; Marschner, Mathias; Birnbacher, Lorenz; Schock, Jonathan; Braun, Christian; Fingerle, Alexander A.; Noël, Peter B.; Rummeny, Ernst J.; Pfeiffer, Franz; et al

    2015-08-31

    X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissuemore » specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. In addition, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results.« less

  20. Phase-contrast Hounsfield units of fixated and non-fixated soft-tissue samples

    SciTech Connect

    Willner, Marian; Fior, Gabriel; Marschner, Mathias; Birnbacher, Lorenz; Schock, Jonathan; Braun, Christian; Fingerle, Alexander A.; Noël, Peter B.; Rummeny, Ernst J.; Pfeiffer, Franz; Herzen, Julia; Rozhkova, Elena A.

    2015-08-31

    X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissue specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. In addition, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results.

  1. Phase-Contrast Hounsfield Units of Fixated and Non-Fixated Soft-Tissue Samples

    PubMed Central

    Willner, Marian; Fior, Gabriel; Marschner, Mathias; Birnbacher, Lorenz; Schock, Jonathan; Braun, Christian; Fingerle, Alexander A.; Noël, Peter B.; Rummeny, Ernst J.; Pfeiffer, Franz; Herzen, Julia

    2015-01-01

    X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissue specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. Furthermore, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results. PMID:26322638

  2. Serum albumin and fixation failure with cannulated hip screws in undisplaced intracapsular femoral neck fracture.

    PubMed

    Riaz, O; Arshad, R; Nisar, S; Vanker, R

    2016-07-01

    Introduction Internal fixation of undisplaced intracapsular femoral neck fractures with cannulated hip screws is a widely accepted surgical technique, despite reported failure rates of 12%-19%. This study determined whether preoperative serum albumin levels are linked to fixation failure. Methods We retrospectively reviewed 251 consecutive undisplaced intracapsular femoral neck fracture patients treated with cannulated hip screws in a district general hospital. Preoperative albumin levels were measured, and the fixation technique, classification and posterior tilt on radiography assessed. Fixation failure was defined as a screw cut, avascular necrosis (AVN) or non-union. Results Of the patients, 185 were female and 66 male. The mean age was 77 years (range 60-101 years). Thirty seven (15%) patients had fixation failure: 10 (4%) due to AVN; 12 (5%) due to non-union; and 15 (6%) due to fixation collapse. Low serum albumin levels were significantly associated with failure (p=0.01), whereas gender (p=0.56), operated side (p=0.62), age (p=0.34) and screw configuration (p=0.42) were not. A posterior tilt angle greater than 20° on lateral radiography significantly predicted failure (p=0.002). Conclusions Preoperative serum albumin is an independent predictor of cannulated hip screw fixation failure in undisplaced femoral neck fractures. Nutritional status should therefore be considered when deciding between surgical fixation and arthroplasty to avoid the possibility of revision surgery, along with an increased risk of morbidity and mortality. PMID:27055409

  3. 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

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

    PubMed

    Howat, William J; Wilson, Beverley A

    2014-11-01

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

  5. Shift of visual fixation dependent on background illumination.

    PubMed

    Barash, S; Melikyan, A; Sivakov, A; Tauber, M

    1998-05-01

    Visual fixation, the act of maintaining the eyes directed toward a location of interest, is a highly skilled behavior necessary for high-level vision in primates. In spite of its significance, visual fixation is not well understood; it is not even clear what attributes of the visual input are used to control fixation. Here we show, in four Macaca fascicularis monkeys, that the position the eyes assume during fixation depends on the luminance of the background. Dark background yields fixation positions that are shifted upward with respect to the fixation positions obtained with a dimly illuminated, featureless background. This phenomenon was observed previously in a nutshell by Snodderly; here first we rigorously establish its existence by testing proper controls. We then study the properties of this upshift of the fixation position. We show that, although the size of the upshift varies between monkeys, for all monkeys the upshift is larger than the radius of the fovea. Hence, if the background is dim, the eyes are positioned during fixation so that the target does not fall on the fovea. The size of the upshift remains almost unchanged while the eyes fixate at different orbital positions; thus the upshift is not caused by orbital mechanics. The upshift clearly is present even at the first days of training, but with additional training in fixation with dark background, the upshift increases in size. The upshift rotates with the head. The upshift increases gradually with decreasing levels of background luminosity. Luminosity, not visual contrast, is indeed the primary variable determining the size of the upshift. The contribution of a unit area of the retina to the upshift decreases as inverse square root of distance from the target; therefore, it is the perifoveal region of the retina that mostly contributes to the upshift, while the far periphery has little influence. The upshift can be induced or be canceled in the midst of a fixation by changing the background

  6. The Harris-Galante porous acetabular component press-fit without screw fixation. Five-year radiographic analysis of primary cases.

    PubMed

    Schmalzried, T P; Wessinger, S J; Hill, G E; Harris, W H

    1994-06-01

    One hundred twenty-two primary total hip arthroplasties were followed for an average of 56 months (range, 48-66 months) in which the Harris-Galante (Zimmer, Warsaw, IN) porous ingrowth acetabular component had been press-fit into the innominate bone without screw fixation. There were no acetabular fractures. No socket was revised for loosening and none were radiographically loose. There was no evidence of disruption of the titanium porous mesh. There was no acetabular osteolysis. Compared to the authors' series of primary hip reconstructions using this same prosthesis inserted with line-to-line reaming and screw fixation, the data indicate that the tight peripheral fit associated with the press-fit technique is effective in reducing both the incidence and extent of bone-implant radiolucencies. However, the increased incidence of radiolucencies near the apex of the acetabulum also suggest that initial contact of the porous surface with live acetabular bone at this location is desirable in order to obtain and maintain an optimal bone-implant interface. Additional studies are necessary to further establish the relationship between the initial fit and long-term fixation of cementless acetabular components. Based on the data and other considerations for eliminating both vascular risk and the potential for fretting wear between the screws and shell, the authors recommend press-fitting without screw fixation for this acetabular component in primary cases when anatomy and bone stock permit. Full seating of the component is recommended in order to obtain dome contact. PMID:8077971

  7. The Surgical Management of Traumatic Lower Cervical Spondylolisthesis with Posterior Percutaneous Pedicle Screw Fixation

    PubMed Central

    Luo, Peng; Ni, Wen-Fei; Wu, Yao-Sen; Wu, Ai-Min; Wang, Xiang-Yang; Xu, Hua-Zi

    2015-01-01

    We reported a technical report of traumatic lower cervical spondylolisthesisca used by bilateral pedicle fracture, without neurological compression. The patient was treated with the minimally invasive technique of percutaneous pedicle screw fixation. Fracture healing and normal cervical motion were confirmed by plain films and physical examinations on the 18-monthpostoperatively. The technique of percutaneous pedicle screw fixation might be an alternative strategy for the treatment of traumatic lower cervical spondylolisthesis with pedicle fracture. PMID:25901240

  8. Probability of fixation of an advantageous mutant in a viral quasispecies.

    PubMed Central

    Wilke, Claus O

    2003-01-01

    The probability that an advantageous mutant rises to fixation in a viral quasispecies is investigated in the framework of multitype branching processes. Whether fixation is possible depends on the overall growth rate of the quasispecies that will form if invasion is successful rather than on the individual fitness of the invading mutant. The exact fixation probability can be calculated only if the fitnesses of all potential members of the invading quasispecies are known. Quasispecies fixation has two important characteristics: First, a sequence with negative selection coefficient has a positive fixation probability as long as it has the potential to grow into a quasispecies with an overall growth rate that exceeds that of the established quasispecies. Second, the fixation probabilities of sequences with identical fitnesses can nevertheless vary over many orders of magnitudes. Two approximations for the probability of fixation are introduced. Both approximations require only partial knowledge about the potential members of the invading quasispecies. The performance of these two approximations is compared to the exact fixation probability on a network of RNA sequences with identical secondary structure. PMID:12618386

  9. Significantly lower femoral neck growth in screw fixation of the asymptomatic contralateral hip in unilateral slipped capital femoral epiphysis.

    PubMed

    Wölfle-Roos, Julia V; Urlaub, Stefanie; Reichel, Heiko; Taurman, Rita

    2016-05-01

    There is an ongoing debate on which fixation technique should be preferred for the prophylactic fixation of the asymptomatic contralateral hip in slipped capital femoral epiphysis (SCFE). In the case of Kirschner-wire (K-wire) fixation, there is a possibility of secondary loss of fixation because of longitudinal growth of the physis, whereas in screw fixation, physeal growth of the femoral neck might be impaired. The aim of this matched-pair study was to compare the longitudinal growth of the femoral neck in screw fixation versus K-wire fixation of the asymptomatic contralateral hip in SCFE. All 18 patients (female : male=3 : 15), who had undergone screw fixation of the asymptomatic contralateral hip between 9/2001 and 9/2011, were matched according to age, bone age, sex, and time to follow-up to another 18 patients with K-wire fixation. The length of the femoral neck of the contralateral hip was measured in parallel to either screw or K-wire from the apex of the femoral head to the opposite cortical bone. The ratio of the femoral neck length measured directly after surgery and on follow-up was defined as femoral neck growth. There was no significant difference between groups with respect to age, modified Oxford Bone age score, and time to follow-up. We found a significant difference in femoral neck growth between patients with screw fixation (5.5±4.3%) compared with K-wire fixation (8.9±5.7%, P=0.048 matched Wilcoxon test). The difference in femoral neck growth of patients with K-wire or screw fixation of the contralateral asymptomatic hip in SCFE was small, but statistically significant. Thus, despite high rates of secondary loss of fixation, K-wire fixation should still be considered, especially in very young patients. PMID:26919622

  10. Computer-assisted percutaneous scaphoid fixation: concepts and evolution.

    PubMed

    Smith, Erin J; Ellis, Randy E; Pichora, David R

    2013-11-01

    Background The treatment for undisplaced scaphoid waist fractures has evolved from conventional cast immobilization to percutaneous screw insertion. Percutaneous fixation reduces some of the risks of open surgery, but can be technically demanding and carries the risk of radiation exposure. Recently, computer-assisted percutaneous scaphoid fixation (CAPSF) has been gaining interest. Materials and Methods Conventional percutaneous scaphoid fixation is performed under fluoroscopic guidance and involves insertion of a guide wire along the length of the scaphoid to facilitate placement of a cannulated screw. Adapting computer-assisted techniques for scaphoid fixation poses several unique challenges including patient tracking and registration. Results To date, five groups have successfully implemented systems for CAPSF. These systems have implemented wrist immobilization strategies to resolve the issue of patient tracking and have developed unique guidance techniques incorporating 2D fluoroscope, cone-beam CT, and ultrasound, to circumvent patient-based registration. Conclusions Computer-aided percutaneous pinning of scaphoid waist fractures can significantly reduce radiation exposure and has the potential to improve the accuracy of this procedure. This article reviews the rationale for, and the evolution of, CAPSF and describes the key principles of computer-assisted technology. PMID:24436833