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Sample records for established fixation techniques

  1. [External fixator: surgical technique, pinless fixator, change in procedure].

    PubMed

    Oberli, H; Frigg, R; Schenk, R

    1994-12-01

    External Fixation-Technique: The advantages of external over internal fixation are as follows: a) endosteal and periosteal blood supply is undisturbed, b) "low-tech" equipment may be used, c) secondary adjustments are possible and d) easy implant removal. These benefits however are outweighed by the main disadvantages of long term external fixation i.e. pin complications and delayed union of fractures. Better understanding of postoperative management and careful application of screws of improved design will lead to better results. Today's standard applications of external fixation for tibial fractures is a unilateral fixator, using Schanz screws. The pin-bone interface is the most critical site of all external fixation. By avoiding heat necrosis (low temperature drilling) and preventing micro motion at the pin-bone interface (by applying bending- or more recently radial-preload), pin complications such as infection and loosening can be reduced. Two Schanz screws are inserted into each main fragment and are connected with one short tube per fragment. The fracture is then reduced by using these tubes as handles. After reduction a third tube connects the first two by means of two tube-to-tube clamps. This type of fixation will easily allow for three dimensional secondary corrections of alignment. Approximately three weeks following the injury some motion at the fracture site will stimulate callus formation. This can be achieved by destabilisation, dynamisation or "active stimulation" of the fracture site [2]. Pinless fixator: The pinless external fixator holds the fragments firmly with pointed clamps that penetrate about one millimeter into cortical bone without entering and contaminating the medullary canal.(ABSTRACT TRUNCATED AT 250 WORDS)

  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. Arthroscopic Bony Bankart Fixation Using a Modified Sugaya Technique

    PubMed Central

    Gupta, Anil K.; McCormick, Frank M.; Abrams, Geoffrey D.; Harris, Joshua D.; Bach, Bernard R.; Romeo, Anthony A.; Verma, Nikhil N.

    2013-01-01

    Arthroscopic fixation of bony Bankart lesions in the setting of anterior shoulder instability has had successful long-term results. Key factors such as patient positioning, portal placement, visualization, mobilization of bony/soft tissues, and anatomic reduction and fixation are crucial to yield such results. We present a modified Sugaya technique that is reproducible and based on such key principles. This technique facilitates ease of anchor and suture placement to allow for anatomic reduction and fixation. PMID:24265994

  5. A Novel Technique for Attaining Maxillomandibular Fixation in the Edentulous Mandible Fracture

    PubMed Central

    Knotts, Christopher; Workman, Meredith; Sawan, Kamal; El Amm, Christian

    2012-01-01

    Edentulous mandible fractures present a unique and challenging surgical problem, particularly because of lack of occlusive dental surfaces to capitalize upon maxillomandibular fixation (MMF). We present a novel technique to achieve MMF using rigid plates spanning the oral cavity to fixate the maxilla to the mandible. The process is rapid and allows stability using the established principles of rigidity, external fixation, and osteosynthesis. This technique allows for a faster MMF than with a Gunning splint and allows for easier oral hygiene. An illustrative case and pre- and postoperative imaging are provided. PMID:23449752

  6. A novel technique for attaining maxillomandibular fixation in the edentulous mandible fracture.

    PubMed

    Knotts, Christopher; Workman, Meredith; Sawan, Kamal; El Amm, Christian

    2012-03-01

    Edentulous mandible fractures present a unique and challenging surgical problem, particularly because of lack of occlusive dental surfaces to capitalize upon maxillomandibular fixation (MMF). We present a novel technique to achieve MMF using rigid plates spanning the oral cavity to fixate the maxilla to the mandible. The process is rapid and allows stability using the established principles of rigidity, external fixation, and osteosynthesis. This technique allows for a faster MMF than with a Gunning splint and allows for easier oral hygiene. An illustrative case and pre- and postoperative imaging are provided.

  7. Acrylic Resin Molding Based Head Fixation Technique in Rodents.

    PubMed

    Roh, Mootaek; Lee, Kyungmin; Jang, Il-Sung; Suk, Kyoungho; Lee, Maan-Gee

    2016-01-12

    Head fixation is a technique of immobilizing animal's head by attaching a head-post on the skull for rigid clamping. Traditional head fixation requires surgical attachment of metallic frames on the skull. The attached frames are then clamped to a stationary platform resulting in immobilization of the head. However, metallic frames for head fixation have been technically difficult to design and implement in general laboratory environment. In this study, we provide a novel head fixation method. Using a custom-made head fixation bar, head mounter is constructed during implantation surgery. After the application of acrylic resin for affixing implants such as electrodes and cannula on the skull, additional resins applied on top of that to build a mold matching to the port of the fixation bar. The molded head mounter serves as a guide rails, investigators conveniently fixate the animal's head by inserting the head mounter into the port of the fixation bar. This method could be easily applicable if implantation surgery using dental acrylics is necessary and might be useful for laboratories that cannot easily fabricate CNC machined metal head-posts.

  8. Vacuum suction fixation versus staple fixation in TAPP laparoscopic hernia repair: introduction of a new technique for mesh fixation.

    PubMed

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

    2016-01-01

    Proper mesh fixation is critical for successful TAPP laparoscopic hernia repair. Conventional mesh fixation may cause chronic neuralgia, groin paresthesia or other complications. This study aimed at introducing a new vacuum suction technique for mesh fixation and evaluating its efficacy and safety compared with traditional staple fixation way. Clinical data of 242 patients undergoing TAPP from July 2011 to March 2014 were retrospectively analyzed. Patients were divided into vacuum suction fixation group and staple fixation group. The operation time, hospital stay, complications, recurrence, visual analogue scale pain score and cost were evaluated. All surgeries were successful. The operation time of staple group was (42.34 ± 10.15) min for unilateral hernia and (64.08 ± 16.01) min for bilateral hernias. The postoperative hospital stay was (2.76 ± 0.84) days. One recurrence was observed (0.90%). For vacuum group, the operation time was (42.66 ± 7.76) min and (63.92 ± 10.49) min, and hospital stay was (2.60 ± 0.74) days. No recurrence was observed. There was no significant difference in recurrence, operation time, postoperative pain and hospital stay between two groups (P > 0.05). Average cost were (11,714 ± 726) RMB for vacuum group which was lower than staple group (14,837 ± 1568) RMB (P < 0.05). The top three complications of staple group were scrotal emphysema (10.81%), scrotal seroma (6.31%) and temporary nerve paresthesia (4.50%) while for vacuum group, they were scrotal seroma (3.82%), temporary nerve paresthesia (3.05%), scrotal emphysema (1.53%) and uroschesis (1.53%). The incidence of scrotal emphysema was lower in vacuum group (P < 0.05). No significant difference was observed in other complications (P > 0.05). Both techniques for mesh fixation are safe and effective. There is no significant difference in recurrence, operation time, postoperative pain or hospital stay. The vacuum suction fixation technique is more economical with lower incidence of

  9. Fixation of nasal bone grafts with interosseous wire: our technique.

    PubMed

    Sathe, N; Gaikwad, N; Wadkar, G; Thakare, S

    2011-02-01

    The use of interosseous wire to fix bone grafts is well known. Herein, we describe a technique for fixation of an iliac crest bone graft for nasal augmentation, using a stainless steel wire. A hole in the cancellous part of the graft guides the wire exactly into a groove in the cortical part, preventing slippage and ensuring rigid fixation. The wire is then threaded through a hollow spinal needle passed underneath the skin envelope; this avoids a dorsal incision and thus minimises scarring, reduces the risk of graft exposure and improves the aesthetic result. This technique has two distinct advantages: prevention of wire slippage and avoidance of a dorsal nasal incision. The described method uses an interosseous wire for rigid bone graft fixation, without a dorsal incision. This prevents wire slippage; it also achieves a good cosmetic result by improving the nasal contour via a cantilever effect which raises the nasal tip.

  10. Operative Fixation of Rib Fractures Indications, Techniques, and Outcomes.

    PubMed

    Galos, David; Taylor, Benjamin; McLaurin, Toni

    2017-01-01

    Rib fractures are extremely common injuries and vary in there severity from single nondisplaced fractures to multiple segmental fractures resulting in flail chest and respiratory compromise. Historically, rib fractures have been treated conservatively with pain control and respiratory therapy. However this method may not be the best treatment modality in all situations. Operative fixation of select rib fractures has been increasing in popularity especially in patients with flail chest and respiratory compromise. Newer techniques use muscle sparing approaches and precontoured locking plate technology to obtain stable fixation and allow improved respiration. Current reports shows that rib fracture fixation offers the benefits of improved respiratory mechanics and improved pain control in the severe chest wall injury with resultant improvement in patient outcomes by decreasing time on the ventilator, time in the intensive care unit, and overall hospital length of stay.

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

    PubMed Central

    Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

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

  12. Cemented and cementless fixation: results and techniques.

    PubMed

    Silverton, Craig D

    2006-01-01

    There are multiple reports of successful cemented and cementless total knee arthroplasty in the current literature. Although technically more demanding to implant, selected cementless designs, with nearly 20 years of follow-up, demonstrate near-equal success compared with cemented implants, the gold standard. Far more important than the decision to use a cemented or cementless implant is the use of precise technique, adequate balancing of the soft tissues, and proper overall alignment. Failure to achieve these basic principles can lead to early failure in any total knee replacement system.

  13. Simplified technique of mesh fixation during laparoscopic repair of abdominal ventral hernia.

    PubMed

    Piskun, G; Shaftan, G; Fogler, R

    1999-04-01

    The current techniques for intraperitoneal mesh fixation are complex and time-consuming. We present here a simple technique for the fixation of the mesh during laparoscopic intraperitoneal ventral hernia repair.

  14. A new and easy technique for maxillomandibular fixation

    PubMed Central

    Singh, Virendra; Bhagol, Amrish; Kumar, Ish

    2010-01-01

    Maxillomandibular fixation (MMF) is important in the treatment of maxillofacial fractures and is usually applied by wiring together the fixed upper and lower arch bars. Here, we report a new type of MMF technique, Rohtak Dental College (RDC) technique using 26-gauze stainless steel wires. It is a simple, quick, economical and minimally invasive technique. Its mechanical principle provides an advantage in preventing postoperative periodontal problems. Typical indications for its use are minimally displaced fractures, orthognathic surgeries and in tumor resection surgeries. PMID:22442545

  15. Relative strength of tailor's bunion osteotomies and fixation techniques.

    PubMed

    Haddon, Todd B; LaPointe, Stephan J

    2013-01-01

    A paucity of data is available on the mechanical strength of fifth metatarsal osteotomies. The present study was designed to provide that information. Five osteotomies were mechanically tested to failure using a materials testing machine and compared with an intact fifth metatarsal using a hollow saw bone model with a sample size of 10 for each construct. The osteotomies tested were the distal reverse chevron fixated with a Kirschner wire, the long plantar reverse chevron osteotomy fixated with 2 screws, a mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, the mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, and an additional cerclage wire and a transverse closing wedge osteotomy fixated with a box wire technique. Analysis of variance was performed, resulting in a statistically significant difference among the data at p <.0001. The Tukey-Kramer honestly significant difference with least significant differences was performed post hoc to separate out the pairs at a minimum α of 0.05. The chevron was statistically the strongest construct at 130 N, followed by the long plantar osteotomy at 78 N. The chevron compared well with the control at 114 N, and they both fractured at the proximal model to fixture interface. The other osteotomies were statistically and significantly weaker than both the chevron and the long plantar constructs, with no statistically significant difference among them at 36, 39, and 48 N. In conclusion, the chevron osteotomy was superior in strength to the sagittal and transverse plane osteotomies and similar in strength and failure to the intact model.

  16. "The Dendritic Bonding Technique": A Newly-devised Technique for the Fixation of Mesh Skin Graft.

    PubMed

    Sakamoto, Yoshiaki; Kishi, Kazuo

    2012-07-01

    We describe a newly designed technique for the quick, easy, and cost-effective fixation of mesh skin grafts in a range of skin conditions and patients. We fixed the skin graft using octyl-2-cyanoacrylate (Dermabond; Ethicon), which was termed "Dendritic bonding." This technique exhibits several advantages over surgical stapling and suturing with absorbable sutures.

  17. 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

  18. Clinical outcome of modified cervical lateral mass screw fixation technique.

    PubMed

    Kim, Seong-Hwan; Seo, Won-Deog; Kim, Ki-Hong; Yeo, Hyung-Tae; Choi, Gi-Hwan; Kim, Dae-Hyun

    2012-08-01

    The purpose of this study was 1) to analyze clinically-executed cervical lateral mass screw fixation by the Kim's technique as suggested in the previous morphometric and cadaveric study and 2) to examine various complications and bicortical purchase that are important for b-one fusion. A retrospective study was done on the charts, operative records, radiographs, and clinical follow up of thirty-nine patients. One hundred and seventy-eight lateral mass screws were analyzed. The spinal nerve injury, violation of the facet joint, vertebral artery injury, and the bicortical purchases were examined at each lateral mass. All thirty-nine patients received instrumentations with poly axial screws and rod systems, in which one hundred and seventy-eight screws in total. No vertebral artery injury or nerve root injury were observed. Sixteen facet joint violations were observed (9.0%). Bicortical purchases were achieved on one hundred and fifty-six (87.6%). Bone fusion was achieved in all patients. The advantages of the Kim's technique are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known techniques. The Kim's technique can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.

  19. Subaxial cervical and cervicothoracic fixation techniques--indications, techniques, and outcomes.

    PubMed

    Pelton, Miguel A; Schwartz, Joseph; Singh, Kern

    2012-01-01

    The subaxial and cervicothoracic junction is a relatively difficult area for spine surgeons to navigate. Because of different transitional stressors at the junction of the smaller cervical vertebrae and the larger thoracic segments, proximity to neurovascular structures, and complex anatomy, extreme care and precision must be assumed during fixation in these regions. Lateral mass screws, pedicle screws, and translaminar screws are currently the standard of choice in the subaxial cervical and upper thoracic spine. This article addresses the relevant surgical anatomy, pitfalls, and pearls associated with each of these fixation techniques.

  20. Single-radial-complement-fixation: a new immunodiffusion technique

    PubMed Central

    Haaheim, L. R.

    1978-01-01

    A new immunodiffusion technique in agarose gel for the quantification of complement-fixing antibodies is described. The test involves the incorporation of antigen and complement in a primary agarose gel. Heat-inactivated serum samples are allowed to diffuse radially from wells overnight at 4°C. A secondary gel, containing antibody-coated sheep erythrocytes, is layered on top of the first gel and the system is incubated for 45 min at 37°C. Where complement is fixed, i.e., around wells with positive serum samples, zones of unlysed cells appear. There is a straight line relationship between zone areas so produced and log2 serum titres obtained with the conventional complement fixation test. The method appears to be applicable to a variety of antigens. It has been found suitable for bacterial and viral antigens. The test can also be reversed, thus allowing the quantification of diffusible antigens in a gel containing immune serum and complement. This paper describes in detail the use of this method as a diagnostic tool for the assay of complement-fixing antibodies to the type-specific antigens of influenza virus in paired human sera. ImagesFig. 2 PMID:96950

  1. 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.

  2. Tibial Lengthening Using a Fixator-Assisted Lengthening Plate: A New Technique

    PubMed Central

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

    2016-01-01

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

  3. A new "double-pulley" dual-row technique for arthroscopic fixation of bony Bankart lesion.

    PubMed

    Zhang, Jin; Jiang, Chunyan

    2011-09-01

    The double-row technique is a new concept for arthroscopic treatment of bony Bankart lesion in shoulder instability. It presents a new and reproducible technique for arthroscopic fixation of bony Bankart fragments with suture anchors. This technique creates double-mattress sutures which compress the fragment against its bone bed and restores better bony anatomy of the anterior glenoid rim with stable and non-tilting fixation that may improve healing.

  4. A biomechanical comparison of 2 femoral fixation techniques for anterior cruciate ligament reconstruction in skeletally immature patients: over-the-top fixation versus transphyseal technique.

    PubMed

    Lertwanich, Pisit; Kato, Yuki; Martins, Cesar A Q; Maeyama, Akira; Ingham, Sheila J M; Kramer, Scott; Linde-Rosen, Monica; Smolinski, Patrick; Fu, Freddie H

    2011-05-01

    The purpose of this study was to compare knee kinematics and in situ forces of the graft between 2 femoral fixation techniques of anterior cruciate ligament (ACL) reconstruction: the over-the-top (OTT) fixation and transphyseal (TP) techniques. ACL reconstruction in skeletally immature patients is a challenging procedure. Regarding the femoral fixation techniques, 2 methods are commonly used: the OTT fixation and TP techniques. Ten cadaveric knees (mean age, 57 years; range, 48 to 65 years) were tested with the robotic/universal force-moment sensor system by use of (1) an 89-N anterior tibial load at full extension and 15°, 30°, 60°, and 90° of knee flexion and (2) a combined 7-Nm valgus torque and 5-Nm internal tibial rotation torque at 15° and 30° of knee flexion. Both OTT and TP ACL reconstruction techniques closely restored the intact knee kinematics and had a significant reduction in anterior tibial translation under an anterior tibial load and in coupled anterior tibial translation under a combined rotatory load when compared with an ACL-deficient knee. When both ACL reconstruction techniques were compared, the only difference found was that the in situ force of the ACL graft reconstructed with the OTT technique in response to a combined rotatory load at 30° of flexion was significantly lower than the ACL graft reconstructed with the TP technique (5.3 ± 3.3 N and 10.7 ± 6.0 N, respectively; P = .013). This time 0 testing showed that both ACL reconstruction techniques, OTT and TP, can reproduce the kinematics of the intact knee in response to an anterior tibial load and a combined rotatory load. Both femoral fixation techniques exhibited comparable time 0 kinematics when subjected to simulated clinical examination loading conditions. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  5. Fixator-assisted Technique Enables Less Invasive Plate Osteosynthesis in Medial Opening-wedge High Tibial Osteotomy: A Novel Technique.

    PubMed

    Lee, Dong Hoon; Ryu, Keun Jung; Kim, Jae Hwa; Kim, Hae Hwa; Soung, Sahyun; Shin, Soowan

    2015-10-01

    Opening-wedge high tibial osteotomy is a well-established procedure in the management of medial osteoarthritis of the knee and correction of proximal tibia vara. Recently, surgical approaches using less invasive plate osteosynthesis have been used with the goal of minimizing complications from more extensive soft tissue exposures. However, to our knowledge, less invasive fixator-assisted plate osteosynthesis has not been tested in the setting of opening-wedge high tibial osteotomy. The purposes of this study were (1) to assess the complications associated with use of a fixator-assisted less invasive plate osteosynthesis technique to stabilize an opening-wedge high tibial osteotomy in the treatment of proximal tibial vara; and (2) to evaluate the ability of this technique to achieve correction of the proximal tibial deformity and achieve osseous union. From June 2011 to June 2013, a total of 157 limbs in 83 patients who underwent fixator-assisted high tibial osteotomy for (1) idiopathic genu vara; or (2) osteoarthritis of the knee with proximal tibia vara were initially enrolled. Of these, eight limbs (5%) were excluded on the way; thus, 149 limbs in 77 patients were evaluated. During the period in question, no other techniques were used for proximal tibial osteotomy. The surgical procedures included less preparation of soft tissue, proximal tibial osteotomy, application of a temporary external fixator, correction of alignment, and final fixation with the help of an external fixator. Complications were assessed by chart review and the alignment in both coronal and sagittal planes was compared pre- and postoperatively. Radiographic review to confirm osseous union and alignment was performed by two of the authors not involved in clinical care of the patient. Delayed union was described as union occurring later than 4 months. Thirty limbs out of 149 tibiae (20%) showed complications, all of which were resolved without leaving any sequela. Twenty-seven limbs out of 149

  6. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures.

    PubMed

    Zelle, Boris A; Boni, Guilherme

    2015-01-01

    Statically locked, reamed intramedullary nailing remains the standard treatment for displaced tibial shaft fractures. Establishing an appropriate starting point is a crucial part of the surgical procedure. Recently, suprapatellar nailing in the semi-extended position has been suggested as a safe and effective surgical technique. Numerous reduction techiques are available to achieve an anatomic fracture alignment and the treating surgeon should be familiar with these maneuvers. Open reduction techniques should be considered if anatomic fracture alignment cannot be achieved by closed means. Favorable union rates above 90 % can be achieved by both reamed and unreamed intramedullary nailing. Despite favorable union rates, patients continue to have functional long-term impairments. In particular, anterior knee pain remains a common complaint following intramedullary tibial nailing. Malrotation remains a commonly reported complication after tibial nailing. The effect of postoperative tibial malalignment on the clinical and radiographic outcome requires further investigation.

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

    PubMed

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

    2014-02-01

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

  8. 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.

  9. 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.

  10. Open reduction internal fixation for proximal humerus fractures indications, techniques, and pitfalls.

    PubMed

    Shulman, Brandon S; Egol, Kenneth A

    2013-01-01

    Proximal humerus fractures account for approximately 5% of all fractures. It is estimated that due to our aging population, orthopaedic surgeons will see a three-fold increase in proximal humerus fractures over the next 30 years. Internal fixation with locked plating is the current mainstay of treatment for functionally active patients who desire minimal loss of function. A thorough understanding of the indications, techniques, and drawbacks of treatment with internal fixation is essential to achieve the highest quality of patient care.

  11. 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

  12. Biomechanical characterization of double-bundle femoral press-fit fixation techniques.

    PubMed

    Ettinger, M; Haasper, C; Hankemeier, S; Hurschler, C; Breitmeier, D; Krettek, C; Jagodzinski, M

    2011-03-01

    Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. To date, no biomechanical data exist describing an implant-free double-bundle press-fit procedure. The purpose of this study was to characterize the biomechanical properties of three double-bundle press-fit fixations. In a controlled laboratory study, the patellar-, quadriceps- and hamstring tendons of 10 human cadavers (age: 49.2 ± 18.5 years) were used. An inside out press-fit fixation with a knot in the semitendinosus and gracilis tendons (SG) combined with an additional bone block, with two quadriceps tendon bone block grafts (QU) was compared with press-fit fixation of two bone patellar tendon bone block (PT) grafts in 30 porcine femora. Constructs were cyclically stretched and then loaded until failure. Maximum load to failure, stiffness and elongation during failure testing and cyclical loading were investigated. The maximum load to failure was 703 ± 136 N for SG fixation, 632 ± 130 N for QU and 656 ± 127 N for PT fixation. Stiffness of the constructs averaged 138 ± 26 N/mm for SG, 159 ± 74 N/mm for QU, and 154 ± 50 N/mm for PT fixation. Elongation during initial cyclical loading was 1.2 ± 1.4 mm for SG, 2.0 ± 1.4 mm for QU, and 1.0 ± 0.6 mm for PT (significantly larger for PT and QU between the first 5 cycles compared with cycles 15-20th, P < 0.01). All investigated double-bundle fixation techniques were equal in terms of maximum load to failure, stiffness, and elongation. Unlike with single-bundle press-fit fixation techniques that have been published, no difference was observed between pure tendon combined with an additional bone block and tendon bone grafts. All techniques exhibited larger elongation during initial cyclical loading. All three press-fit fixation techniques that were investigated exhibit comparable biomechanical properties. Preconditioning of the constructs

  13. Odontoid plate fixation without C1-C2 arthrodesis: biomechanical testing of a novel surgical technique and comparison to the conventional screw fixation procedure.

    PubMed

    Platzer, Patrick; Eipeldauer, Stefan; Vécsei, Vilmos

    2010-08-01

    Odontoid plate fixation without C1-C2 arthrodesis appears to be a practicable option for the management of odontoid fractures that are not amenable for conventional screw fixation. The purpose of this study was to measure the mechanical stability of odontoid plate fixation using a specially designed plate construct, and to compare the results to those after conventional screw fixation. The second cervical vertebra was removed from twenty fresh human spinal columns. Stiffness and failure load of the intact odontoid were measured, and type II odontoid fractures were created. Afterward, the specimens were randomly assigned to one of the following four groups: Group I: plate-fixation; Group II: 2-AO-screw-fixation; Group III: 1-AO-screw-fixation; Group IV: Herbert-screw-fixation. In a second series, stiffness and failure load of the stabilized odontoid fractures were assessed for comparison and statistical analysis. Group I showed a significantly higher mean failure load than the other groups. The mean failure load of Group I after fixation of the odontoid fracture was 86% of the mean failure load of the intact odontoid. Comparing Groups II, III and IV, there was no significant difference regarding the failure load. In these three groups the mean failure load after odontoid fixation was approximately 50% of the mean failure load of the intact odontoid. Odontoid plate fixation as an alternative procedure in certain fracture patterns provided a significantly higher biomechanical stability than the technique of odontoid screw fixation. Using a specially designed plate construct, 86% of the original stability of the intact odontoid was restored. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  14. Evaluation of Reduction Accuracy of Suture-Button and Screw Fixation Techniques for Syndesmotic Injuries.

    PubMed

    Kocadal, Onur; Yucel, Mehmet; Pepe, Murad; Aksahin, Ertugrul; Aktekin, Cem Nuri

    2016-12-01

    Among the most important predictors of functional results of treatment of syndesmotic injuries is the accurate restoration of the syndesmotic space. The purpose of this study was to investigate the reduction performance of screw fixation and suture-button techniques using images obtained from computed tomography (CT) scans. Patients at or below 65 years who were treated with screw or suture-button fixation for syndesmotic injuries accompanying ankle fractures between January 2012 and March 2015 were retrospectively reviewed in our regional trauma unit. A total of 52 patients were included in the present study. Fixation was performed with syndesmotic screws in 26 patients and suture-button fixation in 26 patients. The patients were divided into 2 groups according to the fixation methods. Postoperative CT scans were used for radiologic evaluation. Four parameters (anteroposterior reduction, rotational reduction, the cross-sectional syndesmotic area, and the distal tibiofibular volumes) were taken into consideration for the radiologic assessment. Functional evaluation of patients was done using the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale at the final follow-up. The mean follow-up period was 16.7 ± 11.0 months, and the mean age was 44.1 ± 13.2. There was a statistically significant decrease in the degree of fibular rotation (P = .03) and an increase in the upper syndesmotic area (P = .006) compared with the contralateral limb in the screw fixation group. In the suture-button fixation group, there was a statistically significant increase in the lower syndesmotic area (P = .02) and distal tibiofibular volumes (P = .04) compared with the contralateral limbs. The mean AOFAS scores were 88.4 ± 9.2 and 86.1 ± 14.0 in the suture-button fixation and screw fixation group, respectively. There was no statistically significant difference in the functional ankle joint scores between the groups. Although the functional outcomes were similar, the

  15. Biomechanical comparison of intramedullary cortical button fixation and interference screw technique for subpectoral biceps tenodesis.

    PubMed

    Buchholz, Arne; Martetschläger, Frank; Siebenlist, Sebastian; Sandmann, Gunther H; Hapfelmeier, Alexander; Lenich, Andreas; Millett, Peter J; Stöckle, Ulrich; Elser, Florian

    2013-05-01

    The purpose of this study was to biomechanically evaluate a new technique of intramedullary cortical button fixation for subpectoral biceps tenodesis and to compare it with the interference screw technique. We compared intramedullary unicortical button fixation (BicepsButton; Arthrex, Naples, FL) with interference screw fixation (Bio-Tenodesis screw; Arthrex) for subpectoral biceps tenodesis using 10 pairs of human cadaveric shoulders and ovine superficial digital flexor tendons. After computed tomography analysis, the specimens were mounted in a testing machine. Cyclic loading was performed (preload, 5 N; 5 to 70 N at 1.5 Hz for 500 cycles), recording the displacement of the tendon. Load to failure and stiffness were subsequently evaluated with a load-to-failure test (1 mm/s). Cyclic loading showed a displacement of 11.3 ± 2.8 mm for intramedullary cortical button fixation and 9 ± 1.7 mm for interference screw fixation (P = .112). All specimens within the cortical button group passed the cyclic loading test, whereas 3 of 10 specimens within the interference screw group failed by tendon slippage at the screw-tendon-bone interface after a mean of 252 cycles (P = .221). Load-to-failure testing showed a mean load to failure of 218.8 ± 40 N and stiffness of 27.2 ± 7.2 N/mm for the intramedullary cortical button technique. For the interference screw, the mean load to failure was 212.1 ± 28.3 N (P = .625) and stiffness was 40.4 ± 13 N/mm (P = .056). We could not find any major differences in load to failure when comparing the tested techniques for subpectoral biceps tenodesis. Intramedullary cortical button fixation showed no failure during cyclic testing. However, we found a 30% failure rate (3 of 10) for the interference screw fixation. Intramedullary cortical button fixation provides an alternative technique for subpectoral biceps tenodesis with comparable and, during cyclic loading, even superior biomechanical properties to interference screw fixation

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

    PubMed

    Song, Mingzhi; Zhang, Zhen; Lu, Ming; Zong, Junwei; Dong, Chao; Ma, Kai; Wang, Shouyu

    2014-08-09

    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. 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. 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 levels were lower than the other

  17. 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

  18. Osteotomy, compression and other modifications of surgical techniques for internal fixation of extracapsular hip fractures.

    PubMed

    Parker, Martyn J; Handoll, Helen H G

    2009-04-15

    Many different surgical techniques have been described for the internal fixation of extracapsular hip fractures. To compare different aspects of surgical technique used in operations for internal fixation of extracapsular hip fractures in adults. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (January 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2008, Issue 1), MEDLINE, EMBASE, CINAHL, Current Controlled Trials, orthopaedic journals, conference proceedings and reference lists of articles. Date of last search was January 2008. No language restriction was applied. All randomised and quasi-randomised trials investigating operative techniques used in operations for the treatment of extracapsular hip fractures in adults. Two review authors independently selected trials, assessed trial quality and extracted data. Wherever appropriate, data were pooled. Predominantly older people with trochanteric fractures were treated in the 11 included trials.One trial (65 participants undergoing fixation with a fixed nail-plate) found no statistically significant differences between osteotomy versus anatomical reduction. Four trials, involving 465 participants undergoing fixation with a sliding hip screw (SHS), compared osteotomy versus anatomical reduction. Osteotomy was associated with an increased operative blood loss and length of surgery. There were no statistically significant differences for mortality, morbidity or measures of anatomical deformity.Two trials (138 participants) compared SHS fixation of a trochanteric hip fracture augmented with cement against a standard fixation. There were no reoperations even for the four cases of fixation failure in the cement group. The cement group had significantly better quality of life scores at six months. One trial (200 participants) comparing compression versus no compression of a trochanteric fracture in conjunction with SHS fixation found no significant

  19. 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.

  20. A new technique of bone cement augmentation via the disc space for percutaneous pedicle screw fixation.

    PubMed

    Park, Chang Kyu; Park, Choon Keun; Lee, Dong Chan; Lee, Dong Geun

    2016-01-01

    In elderly patients with severe osteoporosis, instrumented lumbar interbody fusion may result in fixation failure or nonunion because of decreased pedicle screw pullout strength or increased interbody graft subsidence risk. Thus, given its many advantages, percutaneous pedicle screw fixation with cement augmentation can be an effective method to use in elderly patients. The authors report on an easy, safe, and economical technique for bone cement augmentation using a bone biopsy needle inserted into the disc space in 2 osteoporotic patients who were treated with posterior interbody fusion and percutaneous pedicle screw fixation. Two elderly patients who complained of back pain and intermittent neurological claudication underwent posterior interbody fusion with percutaneous pedicle screw fixation. After routinely assembling rods on the screws, a bone biopsy needle was inserted into the disc space via the operative field; the needle was then placed around the tips of the screws using fluoroscopic radiography for guidance. Bone cement was injected through the bone biopsy needle, also under fluoroscopic radiography guidance. Both patients' symptoms improved after the operation, and there was no evidence of cage subsidence or screw loosening at the 4-month follow-up. The indirect technique of bone cement augmentation via the disc space for percutaneous screw fixation could be an easy, safe, and economical method.

  1. Pelvic Fixation in Adult and Pediatric Spine Surgery: Historical Perspective, Indications, and Techniques: AAOS Exhibit Selection.

    PubMed

    Jain, Amit; Hassanzadeh, Hamid; Strike, Sophia A; Menga, Emmanuel N; Sponseller, Paul D; Kebaish, Khaled M

    2015-09-16

    Achieving solid osseous fusion across the lumbosacral junction has historically been, and continues to be, a challenge in spine surgery. Robust pelvic fixation plays an integral role in achieving this goal. The goals of this review are to describe the history of and indications for spinopelvic fixation, examine conventional spinopelvic fixation techniques, and review the newer S2-alar-iliac technique and its outcomes in adult and pediatric patients with spinal deformity. Since the introduction of Harrington rods in the 1960s, spinal instrumentation has evolved substantially. Indications for spinopelvic fixation as a means to achieve lumbosacral arthrodesis include a long arthrodesis (five or more vertebral levels) or use of three-column osteotomies in the lower thoracic or lumbar spine, surgical treatment of high-grade spondylolisthesis, and correction of lumbar deformity and pelvic obliquity. A variety of techniques have been described over the years, including Galveston iliac rods, Jackson intrasacral rods, the Kostuik transiliac bar, iliac screws, and S2-alar-iliac screws. Modern iliac screws and S2-alar-iliac screws are associated with relatively low rates of pseudarthrosis. S2-alar-iliac screws have the advantages of less implant prominence and inline placement with proximal spinal anchors. Collectively, these techniques provide powerful methods for obtaining control of the pelvis in facilitating lumbosacral arthrodesis.

  2. The "medio-latero-superior trajectory technique": an alternative cortical trajectory for pedicle fixation.

    PubMed

    Mobbs, Ralph J

    2013-02-01

    An alternative pedicle trajectory for use at the superior end of a construct to limit dissection of the mobile superior facet joint and reduce incision length and muscle dissection, thus minimizing approach-related trauma during pedicle fixation, is reported. The medio-latero-superior trajectory technique involves a starting point on the medial aspect of the pars and angulation of the pedicle screw in a mediolateral and caudocranial direction. This approach takes advantage of a predominantly cortical trajectory to assist with bone fixation. Drawbacks of this new screw trajectory are discussed along with its potential benefits.

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

    PubMed Central

    Kusnezov, Nicholas; Rensing, Nicholas

    2017-01-01

    Fracture of the calcaneal tuberosity with a concomitant Achilles tendon rupture presents a difficult challenge for the treating surgeon. The ultimate goal of treatment is to restore function of both the gastrocnemius-soleus complex and the Achilles tendon. This particular subset of fractures occurs often in diabetics and elderly patients with osteoporosis making fixation of the displaced fragment rather complex. If the Achilles tendon disruption is only discovered later once the fracture is healed, subsequent management is difficult with surgical treatment being more morbid. While this is a rare injury, the consequences of a missed chronic Achilles tendon disruption are severe with significant dysfunction. It is therefore important to have a high index of suspicion for concomitant injury and to be prepared for dual fixation. We present a novel hybrid surgical fixation technique, which may be used in this instance. PMID:28357147

  4. Radiomics: a new application from established techniques.

    PubMed

    Parekh, Vishwa; Jacobs, Michael A

    2016-01-01

    The increasing use of biomarkers in cancer have led to the concept of personalized medicine for patients. Personalized medicine provides better diagnosis and treatment options available to clinicians. Radiological imaging techniques provide an opportunity to deliver unique data on different types of tissue. However, obtaining useful information from all radiological data is challenging in the era of "big data". Recent advances in computational power and the use of genomics have generated a new area of research termed Radiomics. Radiomics is defined as the high throughput extraction of quantitative imaging features or texture (radiomics) from imaging to decode tissue pathology and creating a high dimensional data set for feature extraction. Radiomic features provide information about the gray-scale patterns, inter-pixel relationships. In addition, shape and spectral properties can be extracted within the same regions of interest on radiological images. Moreover, these features can be further used to develop computational models using advanced machine learning algorithms that may serve as a tool for personalized diagnosis and treatment guidance.

  5. Radiomics: a new application from established techniques

    PubMed Central

    Parekh, Vishwa; Jacobs, Michael A.

    2016-01-01

    The increasing use of biomarkers in cancer have led to the concept of personalized medicine for patients. Personalized medicine provides better diagnosis and treatment options available to clinicians. Radiological imaging techniques provide an opportunity to deliver unique data on different types of tissue. However, obtaining useful information from all radiological data is challenging in the era of “big data”. Recent advances in computational power and the use of genomics have generated a new area of research termed Radiomics. Radiomics is defined as the high throughput extraction of quantitative imaging features or texture (radiomics) from imaging to decode tissue pathology and creating a high dimensional data set for feature extraction. Radiomic features provide information about the gray-scale patterns, inter-pixel relationships. In addition, shape and spectral properties can be extracted within the same regions of interest on radiological images. Moreover, these features can be further used to develop computational models using advanced machine learning algorithms that may serve as a tool for personalized diagnosis and treatment guidance. PMID:28042608

  6. The innovative safe fixative for histology, histopathology, and immunohistochemistry techniques: "pilot study using shellac alcoholic solution fixative".

    PubMed

    Ali Jamal, Awatif; Abd El-Aziz, Gamal Said; Hamdy, Raid Mahmoud; Al-Hayani, Abdulmonem; Al-Maghrabi, Jaudah

    2014-05-01

    The concerns over health and workplace hazards of formalin fixative, joined to its cross-linking of molecular groups that results in suboptimal immunohistochemistry, led us to search for an innovative safe fixative. Shellac is a natural material which is used as a preservative in foods and pharmaceutical industries. This study was undertaken to evaluate the fixation adequacy and staining quality of histopathological specimens fixed in the "shellac alcoholic solution" (SAS), and also to determine the validity of immunohistochemical staining of SAS-fixed material in comparison to those fixed in formalin. Fresh samples from 26 cases from various human tissues were collected at the frozen section room of King Abdulaziz University Hospital, and fixed in SAS fixative or in neutral buffered formaldehyde (NBF) for 12, 18, 24, and 48 h, and processed for paraffin sectioning. Deparaffinized sections were stained with hematoxylin and eosin (H&E) and immunostained for different antigens. The tissues fixed in SAS for >18 h showed best staining quality of H&E comparable to NBF-fixed tissues. Comparison of the immunohistochemical staining of different tissues yielded nearly equivalent readings with good positive nuclear staining quality in both fixatives. These findings support the fixation and preservation adequacy of SAS. Furthermore, it was concluded that the good staining quality obtained with SAS-fixed tissues, which was more or less comparable with the quality obtained with the formalin fixed tissues, supports the validity of this new solution as a good innovative fixative.

  7. Multiple Looping Technique for Tibial Fixation in Posterior Cruciate Ligament Reconstruction of the Knee

    PubMed Central

    Noh, Jung Ho; Yoon, Kyoung Ho; Song, Sang Jun; Roh, Young Hak; Lee, Jae Woo

    2015-01-01

    The outcomes of posterior cruciate ligament reconstruction may be negatively affected by insufficient tibial tunnel fixation due to relatively lower bone density of the proximal tibia. We introduce a new technique of tibial fixation for posterior cruciate ligament reconstruction using free tendon Achilles allograft that is less affected by the bone density of the tibial metaphysis. PMID:25973367

  8. An eye movement technique for correlating fixational target eye movements with location on the retinal image.

    PubMed

    Barrett, S F; Zwick, H

    2000-01-01

    Recent investigation demonstrate that ocular motility in eyes with retinal pathology may show a lower propensity to visit such areas of the retina as compared to non-pathological retinal sites. While current ophthalmic instruments with the ability to image both the retina and visual function test target placement on the retina have provided this observation, the ability to quantify in real time these images as an eye movement measurement is presently lacking and the objective of this paper. A Rodenstock confocal scanning ophthalmoscope (CSLO) was used to image the retina during the performance of a visual fixation task. Direct observation of acuity target placement at the retina under continuous viewing conditions was possible with this apparatus. Target fixation eye movement images of the retina were rapidly digitized from video tape records and registered using a specialized rapid retinal image tracking algorithm. Fixational eye movement pattern densities at the retina were derived from these data. Preliminary data obtained demonstrate the utility of this technique in quantifying fixation eye movement patterns observed in three human patients with vocation-related laser retinal injury. In all patients, areas of severe retinal damage was generally avoided. The density of ocular eye movement tends to reflect regions of retinal normality and avoidance of retinal regions with severe pathology. Variation in eye movement density may exist where pathology is less severe.

  9. The use of dual C-arms during fixation of calcaneal fractures: a technique tip.

    PubMed

    Abousayed, Mostafa M; Toussaint, Rull James; Kwon, John Y

    2014-06-01

    We describe a simple technique using dual C-arms (large and mini C-arm together) for open reduction internal fixation of calcaneal fractures in the lateral decubitus position that (1) decreases the difficulty of obtaining proper intraoperative imaging; (2) limits C-arm movement, which decreases risk of contamination and operative time; and (3) minimizes the drawbacks of each imaging fluoroscopic modality. Level V, Technical tip, Expert opinion.

  10. Nucleic acid quantity and quality from paraffin blocks: defining optimal fixation, processing and DNA/RNA extraction techniques.

    PubMed

    Turashvili, Gulisa; Yang, Winnie; McKinney, Steven; Kalloger, Steve; Gale, Nadia; Ng, Ying; Chow, Katie; Bell, Lynda; Lorette, Julie; Carrier, Melinda; Luk, Margaret; Aparicio, Samuel; Huntsman, David; Yip, Stephen

    2012-02-01

    Although the extraction and analysis of nucleic acids from formalin-fixed paraffin-embedded tissues is a routine and growing part of pathology practice, no generally accepted recommendations exist to guide laboratories in their selection of tissue fixation, processing and DNA/RNA extraction techniques. The aim of this study was to determine how fixation method and length, paraffin embedding, processing conditions and nucleic acid extraction methods affect quality and quantity of DNA and RNA, and their performance in downstream applications. Nine tissue samples were subjected to freezing, fixation in formalin for <24 h and 7 days followed by conventional processing, and fixation in molecular fixative for <24 h and 7 days followed by rapid processing. DNA and RNA were isolated using in-house extraction and commercial kits, and assessed by PCR reactions for amplicons with varying sizes ranging from 268 to 1327 bp and one-step RT-PCR for 621 bp and 816 bp amplicons of housekeeping genes. Molecular fixative (MF) appeared to perform well under nearly all circumstances (extraction methods, fixation lengths and longer amplicons), often performing as well as frozen samples. Formalin fixation generally performed well only for shorter length amplicons and short fixation (<24 h). WaxFree kit showed consistently higher success rates for DNA and poorer rates for RNA. RecoverAll kit generally performed suboptimally in combination with prolonged formalin fixation. In conclusion, the Molecular Fixative regardless of fixation length, and the rapid tissue processing system were able to preserve large DNA and RNA fragments in paraffin blocks, making these techniques preferable for use in downstream molecular diagnostic assays. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Speed-Bridge arthroscopic reinsertion of tibial eminence fracture (complementary to the adjustable button fixation technique).

    PubMed

    Hardy, A; Casabianca, L; Grimaud, O; Meyer, A

    2017-02-01

    In comminuted fractures of the intercondyloid eminence of the tibial spine, the quality of the reduction and the arthroscopic fixation, notably adjustable suture button fixation, is sometimes disappointing with reduction defects of the anterior bone block. In the Speed-Bridge technique, the two traction sutures of the adjustable button fixation are replaced with two braided sutures of different colors. After the button is placed above the eminence, reduction is obtained by tightening the loop of the button. The accessory communitive fragments are then packed in the depression around the main fragment. A second row provides bone suturing for these accessory fragments; traction sutures of the button are attached anteromedially and laterally with knotless anchors to obtain a Speed-Bridge-type inverted-V bone suture. The Speed-Bridge arthroscopic reinsertion technique of the tibial eminence effectively completes the adjustable button bone suture technique for communitive fractures to obtain better reduction and good stability. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Femoral fixation strength following soft-tissue posterolateral corner reconstruction using fibular-based technique: Biomechanical analysis of four techniques in normal and low-density synthetic bone.

    PubMed

    Gallo, Robert A; Sathyendra, Vikram; Sharkey, Neil A; Lewis, Gregory S

    2015-12-01

    Optimal femoral fixation of soft-tissue grafts has been described for anterior cruciate ligament reconstruction. Posterolateral corner reconstruction differs from ACL reconstruction in two ways: (a) soft-tissue fixation into the femur requires two tails and (b) the line of force is different. Our purpose was to determine the optimal femoral fixation of soft-tissue grafts during posterolateral corner reconstructions. We hypothesized that interference screw fixation is the strongest technique in normal-density lateral femoral condyle, whereas, cortically-based fixation techniques are stronger methods in low-density lateral femoral condyle. We evaluated elongation during cyclic loading, yield load, peak load-to-failure, and stiffness of four soft-tissue graft femoral fixation methods during posterolateral corner reconstruction. Our model included bovine flexor tendons and contoured synthetic bones. Grafts were secured to the lateral epicondyle in normal- or low-density bone models using spiked washer, button, interference screw, or button and interference screw. Five specimens for each were tested in each bone density. Analysis of variance using Tukey-Kramer adjustment for multiple hypothesis testing was used. Six cadaver bones whose density was analyzed using computerized tomography scan quantitation were tested using interference screw fixation. No method produced significantly stronger yield load or peak load-to-failure in normal-density bone. In low-density bone, cortically-based methods produced significantly higher yield load or peak load-to-failure. Yield load or peak load-to-failure was significantly higher in normal-density bone when using spiked washer or interference screw fixation. No femoral fixation method tested produced superior yield load or peak load-to-failure. Spiked washer and interference screw fixation are inferior fixation methods in low-density bone. For fibular-based posterolateral corner reconstructions, all fixation methods tested are

  13. 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

  14. Posterior approach for subtalar joint distraction arthrodesis by compact external fixation: a technique guide.

    PubMed

    Laporta, Guido; Bock, Felicia; Ghate, Nihar

    2013-01-01

    Subtalar joint arthrodesis is a commonly used surgical procedure for the management of rearfoot pathologic features. We present a technique guide for a posterior incisional approach to subtalar joint arthrodesis for correction of a calcaneal deformity secondary to calcaneal fracture malunion. This technique uses a monolateral external fixation device for controlled distraction and intercallary allograft placement. In contrast to a standard lateral approach, this incision provides better visualization of the joint space, and the use of a distractor enhances access to the joint surfaces for fusion preparation and maintains alignment while internal fixation is applied. A 44-year-old male underwent isolated subtalar joint arthrodesis to repair a malunion of a nonsurgically managed calcaneal fracture sustained 1 year before the surgical intervention. Controlled distraction was applied using a Hoffmann(®) Compact™ MRI external fixation device. This device maintained distraction and tibial-calcaneal alignment until placement of the allograft-bone marrow aspirate. The use of external fixation is a viable option for distraction arthrodesis in subtalar joint fusions. It facilitates frontal plane deformity correction. We have described the surgical technique and presented a case in which the posterior approach with distraction was successfully used in subtalar joint arthrodesis. At 12 weeks postoperatively, serial radiographs displayed incorporation of the graft, with distraction maintained at the subtalar joint arthrodesis site. At the 3-month follow-up visit, the patient had successfully transitioned to weightbearing in a CAM walker without any complications. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Proximal screws placement in intertrochanteric fractures treated with external fixation: comparison of two different techniques

    PubMed Central

    2011-01-01

    Background To compare two different techniques of proximal pin placement for the treatment of intertrochanteric fractures in elderly patients utilizing the Orthofix Pertrochanteric Fixator. Methods Seventy elderly high-risk patients with an average age of 81 years were treated surgically for intertrochanteric fracture, resulting from a low energy trauma. Patients were randomly divided in two groups regarding to the proximal pin placement technique. In Group A the proximal pins were inserted in a convergent way, while in Group B were inserted in parallel. Results All fractures healed uneventfully after a mean time of 98 days. The fixator was well accepted and no patient had significant difficulties while sitting or lying. The mean VAS score was 5.4 in group A and 5.7 in group B. At 12 months after surgery, in group A the average Harris Hip Score and the Palmer and Parker mobility score was 67 and 5.8, respectively. In group B, the average Harris Hip Score and the Palmer and Parker mobility score was 62 and 5.6, respectively. No statistically significant difference was found regarding the functional outcome. The mean radiographic exposure during pin insertion in Group A and Group B was 15 and 6 seconds, respectively. The difference between the two groups, regarding the radiographic exposure, was found to be significant. Conclusion Proximal screw placement in a parallel way is simple, with significant less radiation exposure and shorter intraoperative duration. In addition, fixation stability is equal compared to convergent pin placement. PMID:21939534

  16. Effect of meniscus replacement fixation technique on restoration of knee contact mechanics and stability.

    PubMed

    D'Lima, D D; Chen, P C; Kessler, O; Hoenecke, H R; Colwell, C W

    2011-06-01

    The menisci are important biomechanical components of the knee. We developed and validated a finite element model of meniscal replacement to assess the effect of surgical fixation technique on contact behavior and knee stability. The geometry of femoral and tibial articular cartilage and menisci was segmented from magnetic resonance images of a normal cadaver knee using MIMICS (Materialise, Leuven, Belgium). A finite element mesh was generated using HyperWorks (Altair Inc, Santa Ana, CA). A finite element solver (Abaqus v6.9, Simulia, Providence, RI) was used to compute contact area and stresses under axial loading and to assess stability (reaction force generated during anteroposterior translation of the femur). The natural and surgical attachments of the meniscal horns and peripheral rim were simulated using springs. After total meniscectomy, femoral contact area decreased by 26% with a concomitant increase in average contact stresses (36%) and peak contact stresses (33%). Replacing the meniscus without suturing the horns did little to restore femoral contact area. Suturing the horns increased contact area and reduced peak contact stresses. Increasing suture stiffness correlated with increased meniscal contact stresses as a greater proportion of tibiofemoral load was transferred to the meniscus. A small incremental benefit was seen of simulated bone plug fixation over the suture construct with the highest stiffness (50 N/mm). Suturing the rim did little to change contact conditions. The nominal anteroposterior stiffness reduced by 3.1 N/mm after meniscectomy. In contrast to contact area and stress, stiffness of the horn fixation sutures had a smaller effect on anteroposterior stability. On the other hand suturing the rim of the meniscus affected anteroposterior stability to a much larger degree. This model emphasizes the importance of the meniscus in knee biomechanics. Appropriate meniscal replacement fixation techniques are likely to be critical to the clinical

  17. 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.

  18. Biomechanical Comparison of All-Suture Anchor Fixation and Interference Screw Technique for Subpectoral Biceps Tenodesis.

    PubMed

    Chiang, Florence L; Hong, Chih-Kai; Chang, Chih-Hsun; Lin, Cheng-Li; Jou, I-Ming; Su, Wei-Ren

    2016-07-01

    To compare the biomechanical characteristics of the subpectoral Y-knot all-suture anchor fixation with those of the interference screw technique. Sixteen fresh-frozen human cadaveric shoulders with a mean age of 67.6 ± 5.8 years (range, 52 to 74 years) were studied. The specimens were randomly grouped into 2 experimental biceps tenodesis groups (n = 8): Y-knot all-suture anchor or interference screw. The specimens were cyclically tested to failure by applying tensile forces parallel to the longitudinal axis of the humerus. A preload of 5 N was applied for 2 minutes prior to cyclic loading for 500 cycles from 5 to 70 N at 1 Hz; subsequently, a load-to-failure test at 1 mm/s was performed. The ultimate failure load, stiffness, displacement at cyclic and failure loading, and mode of failure were recorded. The all-suture anchor technique displayed values of ultimate failure load and stiffness comparable to that of the interference screw technique. The displacement at cyclic and failure loading of the all-suture anchor trials were significantly greater than the interference screw (P = .0002). The all-suture anchor specimens experienced anchor pullout and tendon tear equally during the trials, whereas the interference screw group experienced tendon tear in most of the cases and screw pullout in 2 trials. The Y-knot all-suture anchor fixation provides equivalent ultimate failure load and stiffness when compared with the interference screw technique in tenodesis of the proximal biceps tendon from a subpectoral approach. However, the interference screw technique demonstrates significantly less displacement in response to cyclic and failure loading. The all-suture anchor fixation is an alternative technique for subpectoral biceps tenodesis even at greater displacement when compared with the interference screw fixation during cyclic and failure loading. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  19. Multipoint Suture Fixation Technique for Abdominal Wall Reconstruction with Component Separation and Onlay Biological Mesh Placement.

    PubMed

    Denney, Brad; de la Torre, Jorge I

    2017-05-01

    Component separation with mesh reinforcement has become the primary modality for complex abdominal wall reconstruction. However, many fundamental questions remain unanswered, such as whether underlay versus overlay mesh placement is superior, and what is the best means of suture fixation technique for mesh placement? This study presents the senior author's technique for onlay biologic mesh placement with multipoint suture fixation in combination with component separation and its subsequent low recurrence rates. This is a retrospective review of the senior author's cases of component separation with onlay biologic mesh placement during his tenure at the home institution of the University of Alabama at Birmingham. A total of 75 patients were included, all of whom underwent complex abdominal wall reconstruction from September 2002 to April 2012. Patients were excluded from the dataset if their surgery occurred less than two years before date of data collection to give a minimum 2-year follow-up. Patients were identified by Current Procedural Terminology codes for component separation and their charts reviewed by the home institution's electronic medical record. Data point entries included patient demographics and comorbidities, concomitant procedures such as bowel resection or panniculectomy, and characteristics of the reconstruction such as type of mesh used. Primary data endpoints were complications following surgery, particularly recurrence and laxity. A total of 75 patients were included in the study from September 2002 to April 2012 with a minimum 2-year follow-up period. The recurrence rate was 13 per cent and the rate of laxity 2.7 per cent. There was one death (1.35%). The most frequent complication was seromas at a rate of 17 per cent. Multipoint fixation suture technique for abdominal wall reconstruction with component separation and onlay biologic mesh is a reproducible technique with reliably low recurrence rates.

  20. 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.

  1. Revisiting fixation and embedding techniques for optimal detection of dendritic cell subsets in tissues.

    PubMed

    Accart, Nathalie; Sergi, Florinda; Rooke, Ronald

    2014-09-01

    Organ-specific cell types are maintained by tissue homeostasis and may vary in nature and/or frequency in pathological situations. Moreover, within a cell lineage, some sub-populations, defined by combinations of cell-surface markers, may have specific functions. Dendritic cells are the epitome of such a population as they may be subdivided into discrete sub-groups with defined functions in specific compartments of various organs. Technically, to study the distribution of DC sub-populations, it involves performing multiparametric immunofluorescence on well-conserved organ structures. However, immunodetection may be impacted by protein cross-linking and antigenic epitope masking by the use of 10% neutral-buffered formalin. To circumvent this and to preserve a good morphological tissue structure, we evaluated alternative fixatives such as Periodate Lysine Paraformaldehyde or Tris Zinc fixatives in combination with other embedding techniques. The cryosection protocols were adapted for optimal antigen detection but offered a poor morphological preservation. We therefore developed a new methodology based on Tris Zinc fixative, gelatin-sucrose embedding and freezing. Using multiple DC markers, we demonstrate that this treatment is an optimal protocol for cell-surface marker detection on high-quality tissue sections. © The Author(s) 2014.

  2. Stabilization of subaxial cervical spines by lateral mass screw fixation with modified Magerl's technique.

    PubMed

    Wu, Jau-Ching; Huang, Wen-Cheng; Chen, Yu-Chun; Shih, Yang-Hsin; Cheng, Henrich

    2008-12-01

    There are various techniques in lateral mass screw placement in the cervical spine currently available, including the Roy-Camille, Magerl, Anderson, and An techniques. Each has different entrance points and trajectories for screw insertion, and some even have different methods for different level of the subaxial cervical spine. The potential risk of vascular and neurologic injury varies with different techniques and different levels of the cervical spine. We proposed a modified technique with a universal method of screw placement suitable for stabilization of every level of the subaxial cervical spines, from C3 to C7. We have applied this modified technique on a large series of patients and obtained satisfactory results. A retrospective study was conducted of the charts, records, and clinical follow-up of 115 patients who received internal fixation with lateral mass screws and rods in the Department of Neurosurgery of Taipei Veterans General Hospital (Taipei, Taiwan) from 2004 to 2006. All patients received lateral mass screw placement in various levels of the subaxial cervical spines. The clinical and radiologic follow-up were carefully evaluated and analyzed. All 115 patients with different pathological situations requiring stabilization received instrumentations with polyaxial screws and rod systems, in which 673 screws in total were used in various levels of the cervical spine between C3 and C7: 129 screws in C3, 115 in C4, 193 in C5, 101 in C6, and 135 in C7. The most often used screw length was 16 mm (385/673, 57%). Good bony fusion was observed in all patients except 1 (99.1%). The mean follow-up period was 14 months (4-35 months). No neurologic or vascular injury was noted clinically. Follow-up radiologic examinations found that the screw placements were well positioned. Based on our experience, lateral mass fixation of subaxial cervical spines with our modified technique is safe and effective. This technique of lateral mass screw placement yielded good

  3. Vertical shear fractures of the medial malleolus: a biomechanical study of five internal fixation techniques.

    PubMed

    Toolan, B C; Koval, K J; Kummer, F J; Sanders, R; Zuckerman, J D

    1994-09-01

    Fifty embalmed human tibias were osteotomized to create a simulated vertical shear (supination-adduction) fracture of the medial malleolus and were stabilized using one of five internal fixation techniques. In offset axial testing, which simulated supination-adduction loading, the fixation strength of tibias stabilized with either cortical or cancellous lag screws placed perpendicular to the osteotomy was over five times greater than the strength of those treated with an antiglide plate and nearly two and a half times greater than those treated with cancellous lag screws placed oblique to the osteotomy. The tibias stabilized with cancellous lag screws placed perpendicular to the osteotomy exhibited twice the fixation strength of the tibias stabilized with an antiglide plate and distal lag screw. The tibias stabilized with an antiglide plate and distal lag screw and perpendicularly placed cortical or cancellous lag screws demonstrated three times greater resistance to displacement to the applied supination-adduction load than those stabilized with an antiglide plate alone. In offset transverse testing, to simulate loading in external rotation, the mean failure load of the tibias stabilized with cancellous lag screws placed perpendicular to the osteotomy was over two and a half times greater than those stabilized with an antiglide plate and distal lag screw. No significant differences were observed in the resistance to displacement for these tests. These results support the use of lag screws placed perpendicular to the fracture surface for stabilization of vertical shear fractures of the medial malleolus and indicate that the use of an antiglide plate, with or without a distal lag screw, does not offer any advantage over lag screw fixation.

  4. In Vitro Evaluation of Inflow Cannula Fixation Techniques in Left Ventricular Assist Device Surgery.

    PubMed

    Hanke, Jasmin S; Krabatsch, Thomas; Rojas, Sebastian V; Deniz, Ezin; Ismail, Issam; Martens, Andreas; Shrestha, Malakh; Haverich, Axel; Netuka, Ivan; Schmitto, Jan D

    2017-03-01

    The therapy of terminal heart failure with left ventricular assist devices has become a standard in cardiac surgery. Yet the surgical implantation technique is not standardized and differs from center to center. Complications associated with left ventricular assist device (LVAD) inflow cannula placement are thrombosis, suction events, and flow disturbances. Within this in vitro study we aimed to investigate if the fixation technique of the sewing ring has an impact on the position of the inflow cannula. For this in vitro study the HeartMate III LVAD (Thoratec Corporation, Pleasanton, CA, USA) was used. In five sessions, two approaches were considered for coring of the ventricle for LVAD inflow cannula insertion: "sew-then-core" and "core-then-sew." In the "sew-then-core" technique, the sewing cuff is first affixed to the heart, usually with 8-16 interrupted pledgeted mattress sutures. Subsequently, a cylindrical knife is used to resect a cylindrical core of myocardium to permit cannula insertion. In the "core-then-sew" technique, the sequence is reversed such that the knife is used before the suture ring is affixed. When the "sew-then-core" technique is used, the mattress sutures may be placed with full-thickness bites that penetrate the endocardium (i.e., transmural stitching) or partial-thickness bites that do not penetrate the endocardium (i.e., epicardial stitching). When the "core-then-sew" technique is used, the suture is passed fully into the ventricular lumen and fed back through the cored hole, at which point the needle may be reinserted into the freshly cored myocardium such that it exits the epicardium (i.e., transmural stitching with back stitch) or not (i.e., transmural stitching without back stitch). These four different sewing ring fixation suturing techniques were tested by experienced surgeons to affix the sewing ring: transmural stitching, epicardial stitching, transmural stitching with back stitch, and transmural stitching without back stitch

  5. Hybrid Decompression and Fixation Technique for the Treatment of Multisegmental Cervical Spondylotic Myelopathy

    PubMed Central

    Araos-Silva, Walter; Reyes-Sánchez, Alejandro; Rosales-Olivarez, Luis Miguel; Alpizar-Aguirre, Armando; Melendez, Francisco Lopez

    2016-01-01

    Background Cervical spondilotic myelopathy (CSM) is defined as the compromise of the spinal cord due to degenerative changes of the cervical spine. It is the most common cause of spinal cord dysfunction in patients over 55 years. An early surgical management it is paramount to achieve better neurological outcome. There is still controversy regarding the appropriate surgical treatment for multisegmental CSM involving three or more levels. The hybrid decompression and fixation technique combines one or two level corpectomy and a single level discectomy in order to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy Methods A prospective case-control study was made between 2011 and 2013. A total of 15 patients with diagnosis of CSM received surgical treatment with an anterior hybrid decompression and fixation technique procedure. Inclusion criteria were myelopathy confirmed by radiographic studies, magnetic resonance image (MRI) and electromyography. Results During the 2010-2013 period 15 patients were managed by hybrid decompression and fixation technique. Average age 64.8 years SD9.4. The follow up period was 29.6 SD ± 9.8 months. The JOA score improved significantly to 13.8 +/- 1.9 points at follow-up (paired t test, P = 0.001), Nurick Scale preoperative was 3.3 and improved to 2.4 mean, was significantly (Wilcoxon signed rank test p=0.006) The mean C2-C7 lordosis angle was 10.8° +/- 8.9 before surgery, and 14.3° +/- 8.8 at follow-up, there was no significant loss of lordosis angle between the preoperative and follow-up measurements (Wilcoxon signed rank test, P =0.149); At follow-up, graft non fusion was seen in 1 patient (7%, k=1); Conclusions In this small number, single surgeon, prospective series the use of a single level corpectomy and an adjacent discectomy was shown to provide similar outcomes and complication rates as alternative surgical techniques. The authors thus consider this a viable surgical alternative with

  6. Comparison of histopathologic criteria and skeletal muscle fixation techniques for the diagnosis of polysaccharide storage myopathy in horses.

    PubMed

    Firshman, A M; Valberg, S J; Bender, J B; Annandale, E J; Hayden, D W

    2006-05-01

    The purpose of the study reported here was to determine the effect of three methods of fixation of skeletal muscle biopsy specimens on the histopathologic appearance of muscle sections and to determine criteria that were most consistently associated with a diagnosis of polysaccharide storage myopathy (PSSM) in horses. Surgically excised semimembranosus muscle biopsy specimens were obtained from nine horses previously diagnosed with PSSM and from 15 control horses. Portions of each specimen were fixed in formalin, frozen immediately, and chilled for 24 hours prior to freezing. Sections stained with hematoxylin and eosin (HE), periodic acid-Schiff (PAS), and amylase-PAS were scored for histopathologic criteria by three investigators blinded to the sample origin. The presence of amylase-resistant, abnormal polysaccharide was found to be the most sensitive and specific diagnostic indicator for PSSM, and was readily detected regardless of the fixation technique or investigator. Other less-specific features associated with PSSM included atrophy and cytoplasmic and subsarcolemmal vacuoles; however, their histologic scores varied among fixation technique and investigators. Scores for subsarcolemmal and cytoplasmic amylase-sensitive glycogen in horses with PSSM were similar to those for control horses and varied among fixation techniques. In conclusion, PSSM is most accurately diagnosed in muscle biopsy specimens on the basis of appearance of amylase-resistant, abnormal polysaccharide, not amylase-sensitive glycogen, regardless of fixation technique. In general, frozen sections appeared to be better suited for studying myopathies because many histopathologic features of skeletal muscle were obscured by formalin fixation.

  7. A New and Easy Technique of Maxillomandibular Fixation in Treatment of Mandibular Fractures

    PubMed Central

    Singh, Virendra; Bhagol, Amrish

    2011-01-01

    The present work evaluated the success of maxillomandibular fixation (MMF) by a new and simplified technique in management of minimally displaced mandibular fractures. A total of 20 patients who sustained various types of mandibular fractures were treated at the Government Dental College, Rohtak, India by a new MMF technique. The patients were evaluated by preoperative and postoperative radiography, and clinical testing was performed to assess the degree of tooth mobility adjacent to the site of MMF. The time required for MMF was also noted. Patient recovery was uneventful in all 20 cases, and the period of MMF ranged from 2 to 4 weeks (mean 21 days). The outcome was good. The mean time for performing MMF was 12 minutes (range, 10 to 15 minutes). It is a simple, quick, economical, and minimally invasive technique. Its mechanical principle provides an advantage in preventing postoperative periodontal problems. PMID:22942948

  8. Block bone graft fixation (onlay): a modification of the surgical technique.

    PubMed

    Gealh, Walter Cristiano; dos Santos, Pâmela Letícia; Pereira, Cassiano Costa Silva; Okamoto, Tetuo; Antoniali, Cristina; Okamoto, Roberta

    2014-03-01

    Several reconstructive methods of the alveolar ridge have been reported to make possible future rehabilitations with implants. Many of these methods come from studies done in animals, mainly rats. With this clinical practice based on scientific evidence, any experimental procedure that can be undertaken in real life is fundamental. Thus, any research that emulates as closely as possible those techniques used in humans are important. This study describes the modification of the technique for block bone graft fixation (onlay) in rats using the "lag screw"-type technique, normally used in clinical procedures for grafts in humans. The conclusion was that the execution of the described procedures minimizes interference of blood flow in the area because of the maintenance of the muscle insertion in the buckle aspect of the most anterior region of the mandible, providing better stability to the graft and better contact interface of the graft and receptor bed.

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

    PubMed Central

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

    2016-01-01

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

  10. 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

  11. Assessment of the RIVET fixation system for cranioplasty using the pull-out technique.

    PubMed

    Sakamoto, Yoshiaki; Minabe, Toshiharu; Kato, Tatsuya; Kishi, Kazuo

    2015-03-01

    Cranioplasty using custom-made hydroxyapatite (HAP) ceramic implants is a common procedure to repair skull defects. However, commercially available titanium screws are only minimally stabilized due to characteristic brittleness. We developed the RIVET technique which involves fixing a bioabsorbable plate atop a HAP block using bioabsorbable screws extending beyond both layers, and evaluated fixation strength using the pull-out test and microtomography. Three experimental conditions were compared: a non-RIVET group, RIVET group, and dry skull control group. Pull-out strength significantly differed across groups (non-RIVET group, 1.33 ± 1.21 kgf; RIVET group, 4.46 ± 0.84 kgf; and control group, 6.99 ± 1.14 kgf, P < 0.01). Microtomography of the dry skull control group revealed thread grooves fitted to the screws. The non-RIVET and RIVET groups presented fewer thread grooves than the control group, and the screws did not fit perfectly to the HAP block. However, fixation in the RIVET group was more stable, as the rivet was firmly lodged into the implant. In conclusion, by melting and creating the rivet, pull-out strength can be increased and rigid stabilization of HAP can be obtained. This technique uses commercially available absorbable plate and screws, and thus can be used widely in clinical applications involving HAP blocks with different porosities and thicknesses. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  12. A New Technique for Solving Tightrope Cutout during Acromioclavicular Joint Fixation: A Case Report

    PubMed Central

    Abdullah, AF; Nadarajah, S

    2017-01-01

    Acromioclavicular joint (ACJ) dissociation is one of the common injuries affecting adults. The stability of ACJ largely depends on the integrity of acromioclavicular ligament, coracoclavicular ligament, capsule, trapezius muscle and deltoid muscle. The injury has been classified by Rockwood into six types and treatment options can be guided by the classification. TightRope fixation is one of the many surgical procedures available to address acromioclavicular joint separation. It consists of tensioning of a no. 5 Fibrewire suture secured at both ends to low-profile metallic buttons. Despite various advantages of using this technique, complications such as suture cut-out, clavicle fracture and suture failure have been documented. The author presents a case of a type III acromioclavicular joint dissociation treated with TightRope which suture cutout was noted intra-operatively. Decision to amend the fixation using a cut one-third tubular plate as an additional anchor for the metallic button on the clavicle was made. Patient’s progress was evaluated using the University of California at Los Angeles Shoulder Score (UCLA Shoulder Score) and significant improvement was noted six months post operatively. We propose this technique as a solution to the encountered problem. PMID:28435576

  13. Proposed technique for inguinal hernia repair with self-gripping mesh: avoiding fixation to undesired structures.

    PubMed

    Porrero, J L; Cano-Valderrama, O; Castillo, M J; Alonso, M T

    2015-10-01

    Self-gripping meshes have been developed to avoid fixing sutures during inguinal hernia repair. Operative time is shorter when using a self-gripping mesh than with conventional Lichtenstein repair. However, these meshes can be difficult to handle because they fix to undesired structures. The aim of this report is to describe a new technique to avoid this problem. Inguinal hernia dissection is made as usual. Once dissection is finished, a Parietex ProGrip(®) (Covidien, Dublin, Ireland) flat sheet mesh is cut depending on the size needed. A small split is made between the lower and medium third of the mesh to mark where the split for the spermatic cord will be. Using this mark, the upper third of the mesh is folded over the medium third, hiding the microgrips that make this a self-gripping mesh. In this way, only the lower third of the mesh has the microgrips exposed and the mesh can be fixed to the pubic bone and inguinal ligament without fixation to undesired structures. Once the lower third of the mesh is fixed, the split for the spermatic cord is completed and the upper part of the mesh is passed below the spermatic cord. Then, the mesh is unfolded to expose the microgrips again and the medium and upper third of the mesh are descended to its final position. This proposed technique for inguinal hernia repair with self-gripping mesh makes the surgery easier, avoiding mesh fixation to undesired structures.

  14. 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

  15. 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

  16. Using biomechanics to improve the surgical technique for internal fixation of intracapsular femoral neck fractures.

    PubMed

    Wu, Chi-Chuan

    2010-01-01

    Despite advances in science and technology, the success rate for the treatment of displaced intracapsular femoral neck fractures in high-energy injuries remains disappointing. The blood supply system in the femoral head of humans does not favor recovery from these fractures. Once these fractures occur, osteonecrosis and nonunion rates may be as high as 30%, even if the newest technique is used. There are some surgical techniques used to supplement internal fixation to reestablish the blood supply in the femoral head, but none have been evidently successful. After analysis of related studies, the author concludes that immediate surgical treatment using improved techniques incorporating the principles of biomechanics can improve the success rate of treatment of these fractures. Using these principles, the fracture site can achieve sufficient stability. Consequently, the blood supply in the femoral head and neck can be reestablished earlier and loss of reduction of fragments during treatment can be minimized. Thus, the chance of full recovery from these complicated fractures can be maximized. In this study, the biomechanical characteristics of these fractures and the principles associated with the surgical techniques used for treating them are reviewed and clarified. Finally, a surgical technique which is ideal from the author's viewpoint is presented. The author believes that the recommended surgical technique may become the best method for treating these complicated fractures.

  17. A new surgical technique using steel suture for trans-scleral fixation of posterior chamber intraocular lenses

    PubMed Central

    Ram, Jagat; Gupta, Nishant; Chaudhary, Manish; Verma, Neelam

    2013-01-01

    Background: A new emerging complication of trans-scleral fixation of posterior chamber (PC) intraocular lens (IOL) with polypropylene suture is high rates of spontaneous dislocation of the IOL due to disintegration or breakage of suture. Materials: We report a new surgical technique of trans-scleral fixation of posterior chamber intraocular lens (SF PCIOL) with steel suture to eliminate the complication of dislocation of IOL fixed with polypropylene suture in one adult and a child. Results: We successfully achieved stable fixation and good centration of IOL after SF PCIOL with steel suture in these patient having inadequate posterior capsular support. Both eyes achieved best corrected visual acuity 20/40 at 18 months follow-up. Conclusions: Steel suture is a viable option for trans-scleral fixation of posterior chamber intraocular lens. PMID:23619504

  18. Cerclage wire-plate composite for fixation of quadrilateral plate fractures of the acetabulum: a checkrein and pulley technique.

    PubMed

    Farid, Yasser R

    2010-05-01

    Acetabular fractures with complete or incomplete quadrilateral plate separation frequently present with central displacement of the femoral head. Failure of stable fixation of medial wall fractures leaves residual subluxation despite reduction of other fracture components. Several fixation techniques may be either technically demanding or insufficient for stable fixation in conditions of comminution, osteoporosis, or neglected injuries. The proposed wire-plate composite uses a reconstruction spring plate over the pelvic brim for medial wall buttressing. One hole on its true pelvic limb provides a pulley to deviate a cerclage wire or cable passed through the greater sciatic notch into the true pelvis. This enhances buttressing against medial protrusion. Application through anterior approaches is simple and fixation is reliable in difficult fractures without the risk of joint penetration because all quadrilateral plate buttressing implants remain extraosseous.

  19. Decontamination Techniques and Fixative Coatings Evaluated in the Building 235-F Legacy Source Term Removal Study

    SciTech Connect

    WAYNE, FARRELL

    2005-04-21

    Savannah River Site Building 235-F was being considered for future plutonium storage and stabilization missions but the Defense Nuclear Facilities Safety Board (DNFSB) noted that large quantities of Plutonium-238 left in cells and gloveboxes from previous operations posed a potential hazard to both the existing and future workforce. This material resulted from the manufacture of Pu-238 heat sources used by the NASA space program to generate electricity for deep space exploration satellites. A multi-disciplinary team was assembled to propose a cost- effective solution to mitigate this legacy source term which would facilitate future DOE plutonium storage activities in 235-F. One aspect of this study involved an evaluation of commercially available radiological decontamination techniques to remove the legacy Pu-238 and fixative coatings that could stabilize any residual Pu-238 following decontamination activities. Four chemical methods were identified as most likely to meet decontamination objectives for this project and are discussed in detail. Short and long term fixatives will be reviewed with particular attention to the potential radiation damage caused by Pu-238, which has a high specific activity and would be expected to cause significant radiation damage to any coating applied. Encapsulants that were considered to mitigate the legacy Pu-238 will also be reviewed.

  20. What is the best fixation technique for the treatment of supracondylar humerus fractures in children?

    PubMed

    Patriota, Gyoguevara Sol Queiroz Andrade; Assunção Filho, Carlos Alberto; Assunção, Carlos Alberto

    2017-01-01

    To define the best technique for the surgical treatment of supracondylar fracture of the humerus (SFH) in children, evaluating percutaneous pinning with side wires vs. cross-pinning. Randomized controlled trials using the Medline, CAPES, and BIREME. The criteria for inclusion of articles criteria were: (1) randomized controlled trials (RCTs) comparing percutaneous wire fixation techniques, (2) SFH Gartland II B, III, and IV, and (3) children aged 1-14 years. The following were used as main variables: incidence of iatrogenic injury to the ulnar nerve and loss reduction. Eight studies were selected (521 patients) comparing surgical treatment with pinning in supracondylar fracture of the humerus in children Gartland II type B, III or IV. Iatrogenic injury to the ulnar nerve was greater with the cross-pinning technique, with RR 0.28 and p = 0.03, while the mini-open technique presented RR 0.14 and p = 0.2. A statistically significant greater loss of reduction in the lateral pinning was observed in FSU Gartland III and IV(p = 0.04). Based upon this meta-analysis of prospective randomized clinical trials, the following is recommended: (1) percutaneous pinning with lateral wires in supracondylar fractures of the humerus in children classified as Gartland II type B; (2) use of crossed wires for Gartland type III or IV, using the mini-open technique for the medial wire.

  1. Biomechanical in vitro validation of intramedullary cortical button fixation for distal biceps tendon repair: a new technique.

    PubMed

    Siebenlist, Sebastian; Lenich, Andreas; Buchholz, Arne; Martetschläger, Frank; Eichhorn, Stefan; Heinrich, Petra; Fingerle, Alexander; Doebele, Stefan; Sandmann, Gunther H; Millett, Peter J; Stöckle, Ulrich; Elser, Florian

    2011-08-01

    Extramedullary cortical button-based fixation for distal biceps tendon ruptures exhibits maximum load to failure in vitro but cannot restore the anatomic footprint and has the potential risk for injury to the posterior interosseous nerve. Double intramedullary cortical button fixation repair provides superior fixation strength to the bone when compared with single extramedullary cortical button-based repair. Controlled laboratory study. The technique of intramedullary cortical button fixation with 1 or 2 buttons was compared with single extramedullary cortical button-based repair using 12 paired human cadaveric elbows. All specimens underwent computed tomography analysis to determine intramedullary dimensions of the radial tuberosity as well as the thickness of the anterior and posterior cortices before biomechanical testing. Maximum load to failure and failure modes were recorded. For baseline measurements, the native tendon was tested for maximum load to failure. The intramedullary area of the radial tuberosity provides sufficient space for single or double intramedullary cortical button implantation. The mean thickness of the anterior cortex was 1.13 ± 0.15 mm, and for the posterior cortex it was 1.97 ± 0.48 mm (P < .001). We found the highest loads to failure for double intramedullary cortical button fixation with a mean load to failure of 455 ± 103 N, versus 275 ± 44 N for single intramedullary cortical button fixation (P < .001) and 305 ± 27 N for single extramedullary cortical button-based technique (P = .003). There were no statistically significant differences between single intramedullary and single extramedullary button fixation repair (P = .081). The mean load to failure for the native tendon was 379 ± 87 N. Double intramedullary cortical button fixation provides the highest load to failure in the specimens tested. Double intramedullary cortical button fixation provides reliable fixation strength to the bone for distal biceps tendon repair and

  2. Cement technique for reducing post-operative bursitis after trochanteric fixation.

    PubMed

    Derman, Peter B; Horneff, John G; Kamath, Atul F; Garino, Jonathan

    2013-02-01

    Post-operative trochanteric bursitis is a known complication secondary to the surgical approach in total hip arthroplasty. This phenomenon may be partially attributable to repetitive microtrauma generated when soft tissues rub against implanted hardware. Significant rates of post-operative trochanteric bursitis have been observed following procedures in which a trochanteric fixation device, such as a bolt-washer mechanism or a cable-grip/claw system, is used to secure the trochanteric fragment after trochanteric osteotomy. We present a simple technique for use with a bolt-washer system or grip plate in which trochanteric components are covered in bone wax followed by a layer of cement to decrease friction and to diminish the risk of post-operative bursitis.

  3. A modified fixation technique for a decompressional shortening osteotomy: a retrospective analysis.

    PubMed

    Herzog, Jessica L; Goforth, W David; Stone, Paul A; Paden, Matthew H

    2014-01-01

    A long metatarsal and/or metatarsophalangeal joint dislocation associated with a digital contracture is a surgical challenge. Without appropriate surgical correction, the patient will be predisposed to numerous complications, including persistent subluxation or dislocation, recurrent metatarsalgia, dorsiflexory contracture of the digit, transfer lesions, and inadequate pain relief. The results of the present surgical treatment options have varied, with the most common complication being a floating toe. The purpose of our study was to introduce a decompression, shortening, lesser metatarsal osteotomy with a modified fixation technique using a T-plate and to report our results. Additionally, we have discussed trigonometric analysis of metatarsal declination and shortening. We retrospectively reviewed the outcomes of 30 consecutive patients with 33 osteotomies who had been treated surgically for pathologic features associated with a long metatarsal and varying biomechanical abnormalities. Before surgery, all the patients had been treated conservatively for a minimum of 3 months. The surgical procedure included a dorsal to plantar V-shaped shortening osteotomy of a lesser metatarsal that was fixated with a T plate. The patients were assessed radiographically and using the American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal-Interphalangeal Scale and visual analog scale. The mean age at surgery was 53 (range 37 to 75) years, with a mean follow-up period of 9.1 (range 6 to 15.4) months. The average shortening of the metatarsal was 2.7 mm. One patient (3%) had had asymptomatic delayed union and 2 patients (6%) hypertrophic nonunion. No incidence of malunion or avascular necrosis was identified. Five cases (15.2%) of hardware failure occurred. The mean American Orthopaedic Foot and Ankle Society score was 76.7 postoperatively. The visual analog scale score had improved from 6.7 to 1.7. Of the 30 patients, 72% rated the overall surgical experience as

  4. Suture anchor fixation of displaced olecranon fractures in the elderly: a case series and surgical technique.

    PubMed

    Bateman, Dexter K; Barlow, Jonathan D; VanBeek, Corinne; Abboud, Joseph A

    2015-07-01

    Olecranon fractures are common in elderly patients, causing significant morbidity and functional impairment. Traditional surgical treatments are often complicated by hardware failure and prominence, frequently requiring reoperation. To address these concerns, a suture anchor fixation technique was developed and clinically evaluated. A consecutive series of elderly patients treated with this technique from 2006 to 2013 at a single institution were studied. All cases were surgically repaired with nonmetallic fully threaded suture anchors in a double-row fashion. Clinical outcome measures including the shortened Disabilities of the Arm, Shoulder, and Hand score, the Oxford Elbow Score, and the 12-Item Short Form Health Survey score were obtained. Eight female patients with Mayo IIA or IIB fractures were identified. The mean age of the patients at time of operation was 73.5 ± 10.7 years (range, 59.3-88.8 years). The average time from injury to operation was 5.7 ± 3.7 days. The average follow-up was 5.1 ± 2.5 years (range, 0.8-7.4 years). Six patients were available for long-term follow-up; 1 patient had died, and 1 patient was unable to be contacted despite multiple attempts. There were no intraoperative complications or reoperations. All 8 patients healed uneventfully in an acceptable position without displacement. Postoperatively, the average Oxford Elbow Score was 47.17 ± 2.04; the average shortened Disabilities of the Arm, Shoulder, and Hand score was 6.43 ± 9.47; and the average 12-Item Short Form Health Survey scores were 49.02 ± 16.59 and 55.38 ± 4.05 for the physical and mental component scales, respectively. Suture anchor fixation of olecranon fractures in the elderly population provides excellent long-term radiographic and clinical outcomes without hardware complications associated with traditional fixation methods. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  5. Inferior fixation with a new pin design for external fixation: a randomized study in 50 patients operated on by the hemicallotasis technique.

    PubMed

    Toksvig-Larsen, Sören; W-Dahl, Annette

    2008-02-01

    Tibial osteotomy by the hemicallotasis technique (HCO) requires strong pin fixation. We compared pin fixation in HCO using a new self-drilling XCaliber pin (Orthofix) with optimized thread and tip design, with the commonly used standard pin (Orthofix). 50 patients, mean age 51 (35-66) years, to be treated by HCO were randomized to standard pins or XCaliber pins. In the metaphyseal bone, hydroxyapatite-coated (HA-coated) pins were used in both types of pins. In the diaphyseal bone, non-coated pins were used. The torque forces for insertion and extraction (in Nm) were measured. The insertion torque was higher for both the proximal and distal standard pins (2.1 Nm (SD 0.9) and 7.0 Nm (1.3), respectively) than for the XCaliber pins (1.3 Nm (0.8) and 3.6 Nm (1.4)). The extraction torque force was higher for the proximal standard pins (4.3 Nm (3.1)) than for the proximal XCaliber pins (1.5 Nm (1.7)) (p < 0.001). The extraction torque for the distal standard pins was 1.9 Nm (2.0) and for the distal XCaliber pins it was 1.4 Nm (1.1). The commonly used standard pin gives stronger fixation during the treatment of HCO.

  6. 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

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

    PubMed

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

    2015-01-01

    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. 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. 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. 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). 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.

  8. 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

  9. 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

  10. 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.

  11. Anterior cruciate ligament reconstruction using the Bio-TransFix femoral fixation device and anteromedial portal technique.

    PubMed

    Hantes, Michael E; Dailiana, Zoe; Zachos, Vasilios C; Varitimidis, Sokratis E

    2006-05-01

    The cross-pin femoral fixation technique for soft tissue grafts is a popular option in anterior cruciate ligament (ACL) reconstruction. One of these devices is the Bio-TransFix (Arthrex Inc., Naples, FL, USA) which provides high fixation strength. According to the manufacturer, the femoral tunnel is created by placing the femoral aiming device through the tibial tunnel (transtibial technique). However, using this technique it is very difficult or even impossible to place the graft at the anatomical ACL attachment site at the "10 o'clock" position. In this report, we describe the use of the Bio-TransFix device with an anteromedial portal technique. Using this technique, the surgeon has more freedom to place the graft in an anatomical position, while combining the advantages of the excellent biomechanical properties of this device.

  12. Suprapectoral biceps tenodesis: a biomechanical comparison of a new "soft anchor" tenodesis technique versus interference screw biceps tendon fixation.

    PubMed

    Baleani, Massimiliano; Francesconi, Dunia; Zani, Lorenzo; Giannini, Sandro; Snyder, Stephen J

    2015-02-01

    The interference screw technique is commonly used in tenodesis of the long head of the biceps for its well-documented robust fixation strength. Some complications may occur after tenodesis with interference screw such as persistent pain, bone fracture and cyst formation. A new technique using a small "soft anchor" has been proposed to avoid the risk of occurrence of the above-mentioned complications associated with the use of the interference screw. However, the proposed technique must provide adequate fixation strength. This study investigated the mechanical performance of the new technique and compared it with interference screw fixation. Fourteen human humeri and proximal biceps were tested after tenodesis using the two techniques. The fixation constructs were cycled 500 times between 20N and 100N at 1Hz to simulate some level of post-operative physical activity. Then, a tensile test to failure was performed to determine the strength of the two tenodesis constructs. The ultimate strength was 238N (SD 96N) and 172N (SD 58N) for the "soft anchor" and the interference screw, respectively (P=0.14). In two out of seven repetitions in both groups, failure occurred at low load level due to inaccuracies in performing tenodesis. Considering these cases as outliers, the strength values increased up to 290N (SD 40N) and 202N (SD 32N) for the "soft anchor" and the interference screw, respectively (P=0.02). The "soft anchor" technique provides a fixation strength comparable with the interference screw, but without using a screw. It could be considered as an alternative for suprapectoral biceps tenodesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. “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

  14. NON-UNIONS AFTER FIXATION OF HUMERAL FRACTURES USING HACKETHAL'S BUNDLE NAILING TECHNIQUE

    PubMed Central

    OBRUBA, PETR; RAMMELT, STEFAN; KOPP, LUBOMIR; EDELMANN, KAREL; AVENARIUS, JAKUB

    2016-01-01

    ABSTRACT Objective: The aim of the study was to identify factors contributing to the development of non-union after fixation of diaphyseal humeral fractures using Hackethal's intramedullary nailing technique. Methods: In the time period from 2001 to 2010 156 patients with diaphyseal humeral fractures were treated surgically using Hackethal's technique. Six of them (3.8%) developed non-union. This group included three women and two men aged 63-69 years and one woman aged 37 years. The following parameters of the patients were recorded: age, gender, comorbidities, substance abuse, mechanism of injury, fracture type and location according to the AO/ASIF classification, and the operative technique. Results: A non-union developed in six patients treated with Hackethal´s method (3.8%). Five of six non-unions (83%) were observed in patients in their sixties. In the subgroup of sexagenarians, non-union developed in 20.8% of surgically treated patients, as compared to 3.8 % in entire group. In the union group, fractures have been caused by high energy trauma in 52% of patients. In patients who developed non-union, high energy trauma caused 67% of fractures. With correct surgical technique the development of a non-union was observed in 0.7% of patients, with incorrect technique in 35.7% (p<0.001). Conclusion: Treatment of diaphyseal humeral fractures with Hackethal's intramedullary elastic bundle nailing resulted in an overall high union rate. Factors contributing to the development of non-union were extension of this method to AO type B3 and C fractures and technical imperfection during implantation. Level of Evidence III, Prospective, Case-Control Study. PMID:28149195

  15. 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

  16. Transtrapezial Approach for Fixation of Acute Scaphoid Fractures: Rationale, Surgical Techniques, and Results: AAOS Exhibit Selection.

    PubMed

    Verstreken, Frederik; Meermans, Geert

    2015-05-20

    The ideal position for a screw used for scaphoid fixation is central. The purpose of this study was to compare the current volar percutaneous approaches used for scaphoid fracture fixation, explore different options to improve central screw placement, and describe our experience with the transtrapezial approach.

  17. Wiring Techniques for the Fixation of Trochanteric Fragments during Bipolar Hemiarthroplasty for Femoral Intertrochanteric Fracture: Clinical Study and Technical Note

    PubMed Central

    Cho, Yongsuk; Kim, Junhyun; Kim, Dong-Won

    2017-01-01

    Purpose Femoral intertrochanteric fractures are common in the elderly. Appropriate surgical fixation of trochanteric fracture fragments can restore normal anatomical structure and ambulation, and can aid in the recovery of biomechanical function of the hip. We evaluated clinical outcomes of bipolar hemiarthroplasty using a wiring technique for trochanteric fracture fragment fixation. Materials and Methods From September 2006 to February 2015, a total of 260 cases underwent simultaneous bipolar hemiarthroplasty and wire fixation. A total of 65 patients (69 hips) with an average age of 78 years and more than one year of follow-up was included in the study. Using pre-, postoperative and follow-up radiograms, we evaluated wire fixation failure and also assessed changes in walking ability. Results Loosening or osteolysis around the stem was not observed; however, we did observe bone growth around the stem (54 cases), cortical hypertrophy (6 cases), a wide range of sclerotic lines but no stem subsidence (1 case), wire breakage (9 cases), and fracture fragment migration with no significant functional deficiency (2 cases). Conclusion Our study showed that additional wiring for trochanteric fracture fragment fixation following bipolar hemiarthroplasty can help restore normal anatomy. The added stability results in faster rehabilitation, and good clinical and radiographic outcomes. We recommend this procedure in this type of fracture. PMID:28316962

  18. [Establishment and primary analysis of the three-dimensional finite element model of mandibular bilateral sagittal split ramus osteotomy with rigid internal fixation].

    PubMed

    Xu, Chong-Tao; Sun, Geng-Lin; Zhou, Jian; Wang, Peng-Lin

    2007-05-01

    Establish the three-dimensional finite element models of mandibular bilateral sagittal split ramus osteotomy (BSSRO) with rigid internal fixation (RIF), for further study of BSSRO. CT scanned technology and the finite element software (ANSYS) were used to establish the original three-dimensional model of mandible, modify the model to animate the BSSRO, then establish the model of RIF, last mesh the model to establish the finite element model of BSSRO with RIF. Apply 100 N occlusion force at the central incisor; calculate the stress distribution of the mandible and the RIF. Three-dimensional finite element models of BSSRO with RIF were established, such as miniplate model, bicortical fixation screw model. When biting with the incisor and fixed with upper plate, the stress of the medial screw position of the distal and medial segment of mandible is high. When fixed with bicortical fixation screw, the highest stress position located at the internal surface of the medial screw' s position of the distal segment of mandible. The mentioned methods proved feasible in establishing the finite element models of BSSRO with RIF . The models can be applied to the study of BSSRO with RIF.

  19. 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

  20. Cervical pedicle screw fixation in traumatic cervical subluxation after laminectomy using the pedicle axis view technique under fluoroscopy.

    PubMed

    Machino, Masaaki; Yukawa, Yasutsugu; Ito, Keigo; Nakashima, Hiroaki; Kanbara, Shunsuke; Morita, Daigo; Kato, Fumihiko

    2012-10-10

    Cervical pedicle screw (CPS) fixation has recently been performed in patients in need of cervical reconstruction. We report the case of a 50-year-old man who was operated for traumatic cervical vertebra subluxation using CPS fixation, in whom laminectomy had been performed in the past. We performed CPS fixation using the pedicle axis view technique under fluoroscopy. The four pedicle screws were accurately inserted within the pedicles without perforating the bone cortex of the pedicles. A navigation system is useful for cervical spine surgery because it enables a surgeon to perform relatively safe and accurate surgery during transpedicular screw fixation. However, attachment of the stereotactic reference arc to the spinous process is impossible, and the application of a navigation system is limited in cases in which laminectomy has been performed in the past. We have been using the pedicle axis view technique under fluoroscopy and have found that if we take care of the entry point accurately, we can safely insert the pedicle screw in cases with fewer landmarks.

  1. Review of techniques for monitoring the healing fracture of bones for implementation in an internally fixated pelvis.

    PubMed

    Wong, Lydia Chwang Yuh; Chiu, Wing Kong; Russ, Matthias; Liew, Susan

    2012-03-01

    Sacral fractures from high-impact trauma often cause instability in the pelvic ring structure. Treatment is by internal fixation which clamps the fractured edges together to promote healing. Healing could take up to 12 weeks whereby patients are bedridden to avoid hindrances to the fracture from movement or weight bearing activities. Immobility can lead to muscle degradation and longer periods of rehabilitation. The ability to determine the time at which the fracture is stable enough to allow partial weight-bearing is important to reduce hospitalisation time. This review looks into different techniques used for monitoring the fracture healing of bones which could lead to possible methods for in situ and non-invasive assessment of healing fracture in a fixated pelvis. Traditional techniques being used include radiology and CT scans but were found to be unreliable at times and very subjective in addition to being non in situ. Strain gauges have proven to be very effective for accurate assessment of fracture healing as well as stability for long bones with external fixators but may not be suitable for an internally fixated pelvis. Ultrasound provides in situ monitoring of stiffness recovery but only assesses local fracture sites close to the skin surface and has only been tested on long bones. Vibration analysis can detect non-uniform healing due to its assessment of the overall structure but may suffer from low signal-to-noise ratio due to damping. Impedance techniques have been used to assess properties of non-long bones but recent studies have only been conducted on non-biological materials and more research needs to be done before it can be applicable for monitoring healing in the fixated pelvis.

  2. Reduction and fixation of sacroiliac joint dislocation by the combined use of S1 pedicle screws and the galveston technique.

    PubMed

    Abumi, K; Saita, M; Iida, T; Kaneda, K

    2000-08-01

    This retrospective study was designed to analyze the results of the treatment with S1 pedicle screws and the Galveston technique of seven patients with sacroiliac dislocation. To evaluate the effectiveness of the combined use of S1 pedicle screws and the Galveston technique for the treatment of sacroiliac dislocation. Although several procedures for internal fixation of sacroiliac dislocation have been reported, there have been no reports discussing surgical treatment of sacroiliac dislocation by the combined use of S1 pedicle screws and the Galveston technique. Seven patients with sacroiliac dislocation were treated with pedicle screws of S1 and iliac rod according to the Galveston technique. In the seven patients, the dislocation was associated with vertical displacement of the sacroiliac joint and rotational deformity of the pelvic ring. They were classified into Type-C pelvic disruption according to the Tile's classification. Three patients with disruption of the symphysis pubis underwent additional fixation of the symphysis using a dynamic compression plate. The remaining four patients were treated by the posterior procedure alone. The vertical displacement was completely reduced in five patients, and the rotational deformity was completely corrected in four patients. The reduction was maintained at the time of the final follow-up evaluation. There were no perioperative complications with the exception of late infection in one patient. The combined use of S1 pedicle screws and the Galveston technique provided immediate stability and sufficient reduction for sacroiliac dislocation in seven patients in this study. This hybrid internal fixation procedure is useful for reduction and fixation of sacroiliac dislocation associated with the vertical and rotational instability of the pelvic ring.

  3. Clinical and radiological outcome after mini-open Latarjet technique with fixation of coracoid with Arthrex wedge mini-plate.

    PubMed

    Chaudhary, Deepak; Goyal, Ankit; Joshi, Deepak; Jain, Vineet; Mohindra, Mukul; Mehta, Nitin

    2016-01-01

    Technical faults leading to coracoid fractures during screw insertion and coracoid graft osteolysis are concerns with standard screw fixation techniques in Latarjet procedure. The purpose of this study is to share our experience using Arthrex wedge profile plate with mini-open technique for graft fixation, that ensures better load distribution between coracoid graft and glenoid. We did retrospective analysis of 24 patients with recurrent anterior shoulder instability after failed arthroscopic Bankart's repair. Arthroscopic examination of affected shoulder was done in lateral position before making patient supine for open Latarjet. A low profile wedge plate (Arthrex) with two screws was used for the procedure. CT analysis was performed post-operatively at 6 months to see graft union and results were evaluated using the Rowe and Walch Duplay score. Mean follow-up time was 26 months. Postoperatively, mean forward elevation was 170.6 + 4.6° (loss of average 5.9°) and mean external rotation was 42.5 + 5.3° (loss of average 3.1°). All patients returned to their previous occupation. None reported to be having any recurrent subluxation. Functional assessment done using Rowe score and Walch Duplay score showed statistically significant improvement (p value 0.034). There were no implant-related complications and no case of coracoid graft osteolysis. Mini-open Latarjet with graft fixation with Arthrex mini-plate provides satisfactory outcome in patients who require reoperation due to dramatic bone loss and failed soft tissue reconstruction. The modified incision improves exposure enabling plate fixation and the secure fixation accelerates rehabilitation.

  4. Clinical and radiological outcome after mini-open Latarjet technique with fixation of coracoid with Arthrex wedge mini-plate

    PubMed Central

    Chaudhary, Deepak; Goyal, Ankit; Joshi, Deepak; Jain, Vineet; Mohindra, Mukul; Mehta, Nitin

    2016-01-01

    Background Technical faults leading to coracoid fractures during screw insertion and coracoid graft osteolysis are concerns with standard screw fixation techniques in Latarjet procedure. The purpose of this study is to share our experience using Arthrex wedge profile plate with mini-open technique for graft fixation, that ensures better load distribution between coracoid graft and glenoid. Methods We did retrospective analysis of 24 patients with recurrent anterior shoulder instability after failed arthroscopic Bankart's repair. Arthroscopic examination of affected shoulder was done in lateral position before making patient supine for open Latarjet. A low profile wedge plate (Arthrex) with two screws was used for the procedure. CT analysis was performed post-operatively at 6 months to see graft union and results were evaluated using the Rowe and Walch Duplay score. Results Mean follow-up time was 26 months. Postoperatively, mean forward elevation was 170.6 + 4.6° (loss of average 5.9°) and mean external rotation was 42.5 + 5.3° (loss of average 3.1°). All patients returned to their previous occupation. None reported to be having any recurrent subluxation. Functional assessment done using Rowe score and Walch Duplay score showed statistically significant improvement (p value 0.034). There were no implant-related complications and no case of coracoid graft osteolysis. Conclusions Mini-open Latarjet with graft fixation with Arthrex mini-plate provides satisfactory outcome in patients who require reoperation due to dramatic bone loss and failed soft tissue reconstruction. The modified incision improves exposure enabling plate fixation and the secure fixation accelerates rehabilitation. PMID:26908972

  5. Comparison of pelvic fixation techniques in neuromuscular spinal deformity correction: Galveston rod versus iliac and lumbosacral screws.

    PubMed

    Peelle, Michael W; Lenke, Lawrence G; Bridwell, Keith H; Sides, Brenda

    2006-09-15

    Retrospective radiographic and clinical review. To evaluate the safety and efficacy of iliac screws as a method of pelvic fixation in neuromuscular spinal deformity correction using the Galveston rod technique as a comparison group. Sacropelvic fixation in patients with neuromuscular spinal deformity has traditionally used Galveston rods placed into the iliac wing. Difficulties with radiographic halos around the rods (loosening), rod contouring, and attaching to lumbar spine anchors have prompted their replacement with iliac screws. A minimum 2-year radiographic and clinical follow-up compared 20 patients with the Galveston technique to 20 patients with an iliac screw undergoing posterior spinal fusion (T2/T3-pelvis) for neuromuscular spinal deformity. All patients with the Galveston technique had sublaminar wires for their lumbar anchors, while the majority of patients with an iliac screw technique had at least 2 lumbar and/or sacral screws placed in addition to the iliac screws. There were no significant differences between the 2 groups in preoperative, postoperative, and latest follow-up (mean 3.1 years) measurements for coronal Cobb measures, coronal and sagittal C7 plumblines, and T1 offset. Pelvic obliquity was similar in both groups preoperatively (22 degrees) but at latest follow-up was statistically improved in the patients with an iliac screw (4.4 degrees) versus those with the Galveston technique (7.3 degrees) (P = 0.04). There were 13 patients with the Galveston technique versus 6 with an iliac screw who had radiolucent halos more than 2 mm around the pelvic anchor devices at latest follow-up (P < 0.05). The Galveston technique group had 4 broken rods and 2 reoperations, while the iliac screw group had 1 broken screw and no reoperations. Using iliac screws for pelvic fixation in neuromuscular spinal deformity affords equivalent maintenance of pelvic obliquity and scoliosis correction compared to the Galveston technique. Furthermore, the iliac screw

  6. 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.

  7. The "bony Bankart bridge" procedure: a new arthroscopic technique for reduction and internal fixation of a bony Bankart lesion.

    PubMed

    Millett, Peter J; Braun, Sepp

    2009-01-01

    Arthroscopic treatment of bony Bankart lesions can be challenging. We present a new easy and reproducible technique for arthroscopic reduction and suture anchor fixation of bony Bankart fragments. A suture anchor is placed medially to the fracture on the glenoid neck, and its sutures are passed around the bony fragment through the soft tissue including the inferior glenohumeral ligament complex. The sutures of this anchor are loaded in a second anchor that is placed on the glenoid face. This creates a nontilting 2-point fixation that compresses the fragment into its bed. By use of the standard technique, additional suture anchors are used superiorly and inferiorly to the bony Bankart piece to repair the labrum and shift the joint capsule. We call this the "bony Bankart bridge" procedure.

  8. Excision Versus Fixation of the Radial Head: A Comparative Study of the Functional Outcomes of the Two Techniques

    PubMed Central

    Shetty, Sanath Kumar; Shetty, Ashwin; Balan, Bijith; Rai, H.Ravindranath; Hegde, Anoop

    2017-01-01

    Introduction The management of displaced and comminuted radial head fractures has been a matter of debate amongst surgeons for many years. Radial head excision formed the mainstay of surgical management of these injuries. Over the years, there have been improvements in the surgical techniques and availability of better implants and instrumentation techniques, hence, open reduction and internal fixation of these fractures is gaining popularity. Aim To compare the outcome of elbow function between radial head excision and open reduction and internal fixation of the radial head with mini screws of Mason Type II and Type III radial head fractures and to assess the complications that occur in both techniques. Materials and Methods A prospective study was conducted in the Department of Orthopaedic Surgery of Justice K.S.Hegde Charitable hospital. A total of 40 patients between the age group of 30-50 years with Mason Type II and Type III fresh closed radial head fractures were included in the study. Group I consisted of 20 patients who underwent radial head excision and Group II consisted of 20 patients who underwent open reduction and internal fixation with mini screws. Patients were reviewed at postoperative week 3, 6 and 24. Radiographs were taken and functional outcome assessment of the elbow was done during all the follow ups. Elbow physiotherapy was started on postoperative week three. Scoring of elbow function was done as per the Disabilities of the Arm, Shoulder and Hand (DASH) scoring system. Results were tabulated, compared and analysed statistically using the ‘chi-square test’. Results At the end of six months, the patients of the open reduction and internal fixation group had lower DASH scores (4.82±2.73 points) than the radial head excision group (14.23±5.60 points). This inferred that patients who underwent open reduction and internal fixation had better functional outcomes than the excision group. Complications of proximal radial migration was noted

  9. Biomechanical characterization of unicortical button fixation: a novel technique for proximal subpectoral biceps tenodesis.

    PubMed

    DeAngelis, Joseph P; Chen, Alvin; Wexler, Michael; Hertz, Benjamin; Grimaldi Bournissaint, Leandro; Nazarian, Ara; Ramappa, Arun J

    2015-05-01

    Proximal biceps tenodesis is one method for treating biceps-related pain. Tenodesis protects the length-tension relationship of the biceps muscle, maintains strength, and provides a better cosmetic appearance than tenotomy. The purpose of this investigation was to compare the mechanical properties of a unicortical metal button and an interference screw in proximal biceps tenodesis. Six pairs of fresh-frozen shoulders were dissected, leaving the proximal biceps tendon as a free graft. On each pair of shoulders, a biceps tenodesis was performed using an interference screw or a unicortical metal button. The specimens were mounted and a cyclic load (10-60 N) was applied at 1 Hz for 200 cycles, followed by an axial load to failure. The displacement, ultimate load to failure, and mode of failure were recorded. Displacement in response to cyclic loading was 3.7 ± 2.2 mm for the interference screw and 1.9 ± 1.0 mm for the cortical button (P = 0.03). Load at failure for the interference screw was 191 ± 64 N (stiffness: 24 ± 11 N/mm) and 183 ± 61 N (stiffness: 24 ± 7. N/mm) for the unicortical button (P = n.s. for both cases). As a novel technique for subpectoral biceps tenodesis, a unicortical button demonstrated significantly less displacement in response to cyclic loading than the interference screw. The ultimate load to failure and stiffness for the two methods were not different. In this way, a unicortical button may provide a reliable alternative method of fixation with a potentially lower risk of post-operative humeral fracture and a construct that permits early mobilization following biceps tenodesis.

  10. Techniques for establishing local breeding populations of wood ducks

    USGS Publications Warehouse

    Doty, H.A.; Kruse, A.D.

    1972-01-01

    A study was conducted on the Arrowwood National Wildlife Refuge in east-central North Dakota to further evaluate a technique for establishing nesting wood ducks (Aix sponsa) by releasing propagated birds and installing nest houses. No wood duck nesting had been recorded previously in the area. During May-July 1968, 253 ducklings, hand-reared at the Northern Prairie Wildlife Research Center near Jamestown, North Dakota, were released when 9 to 16 days old into a 0.5-acre enclosure on the refuge, where they grew to flight stage and departed. Seventy-eight nest houses were installed in August on the refuge. About 76 percent of the ducks survived until late September, when southward migration began. The first-year band recovery rate by hunters of 4.7 percent was comparable to that of wild immature wood ducks. Most recoveries occurred between North Dakota and Minnesota in the north and Texas and Louisiana in the south. There were 16 nesting attempts, which produced 175 ducklings, by homing female wood ducks in the boxes in 1969. The number of nesting attempts increased to 34 in 1970, with a production of 311 ducklings.

  11. 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

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

    PubMed

    White, Brian J; Herzog, Mackenzie M

    2016-02-01

    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.

  13. Pediatric occipitocervical fixation: radiographic criteria, surgical technique, and clinical outcomes based on experience of a single surgeon.

    PubMed

    Martinez-Del-Campo, Eduardo; Turner, Jay D; Rangel-Castilla, Leonardo; Soriano-Baron, Hector; Kalb, Samuel; Theodore, Nicholas

    2016-10-01

    OBJECTIVE If left untreated, occipitocervical (OC) instability may lead to serious neurological injury or death. Open internal fixation is often necessary to protect the neurovascular elements. This study reviews the etiologies for pediatric OC instability, analyzes the radiographic criteria for surgical intervention, discusses surgical fixation techniques, and evaluates long-term postoperative outcomes based on a single surgeon's experience. METHODS The charts of all patients < 18 years old who underwent internal OC fixation conducted by the senior author were retrospectively reviewed. Forty consecutive patients were identified for analysis. Patient demographic data, OC junction pathology, radiological diagnostic tools, surgical indications, and outcomes are reported. RESULTS The study population consisted of 20 boys and 20 girls, with a mean age of 7.3 years. Trauma (45% [n = 18]) was the most common cause of instability, followed by congenital etiologies (37.5% [n = 15]). The condyle-C1 interval had a diagnostic sensitivity of 100% for atlantooccipital dislocation. The median number of fixated segments was 5 (occiput-C4). Structural bone grafts were used in all patients. Postsurgical neurological improvement was seen in 88.2% (15/17) of patients with chronic myelopathy and in 25% (1/4) of patients with acute myelopathy. Preoperatively, 42.5% (17/40) of patients were neurologically intact and remained unchanged at last follow-up, 42.5% (17/40) had neurological improvement, 12.5% (5/40) remained unchanged, and 2.5% (1/40) deteriorated. All patients had successful fusion at 1-year follow-up. The complication rate was 7.5% (3/40), including 1 case of vertebral artery injury. CONCLUSIONS Occipitocervical fixation is safe in children and provides immediate immobilization, with excellent survival and arthrodesis rates. Of the radiographic tools evaluated, the condyle-C1 interval was the most predictive of atlantooccipital dislocation.

  14. Clinical Results of Technique for Double Bundle Anterior Cruciate Ligament Reconstruction Using Hybrid Femoral Fixation and Retroscrew

    PubMed Central

    Kim, Doo-Sup; Yi, Chang-Ho; Chung, Hoi-Jung

    2011-01-01

    Background Anatomic anterior cruciate ligament (ACL) reconstruction has been presented as a means to more accurately restore the native anatomy of this ligament. This article describes a new method that uses a double bundle to perform ACL reconstruction and to evaluate the clinical outcome. Methods Grafts are tibialis anterior tendon allograft for anteromedial bundle (AMB) and hamstring tendon autograft without detachment of the tibial insertion for posterolateral bundle (PLB). This technique creates 2 tunnels in both the femur and tibia. Femoral fixation was done by hybrid fixation using Endobutton and Rigidfix for AMB and by biointerference screw for PLB. Tibial fixations are done by Retroscrew for AMB and by native insertion of hamstring tendon for PLB. Both bundles are independently and differently tensioned. We performed ACL reconstruction in 63 patients using our new technique. Among them, 47 participated in this study. The patients were followed up with clinical examination, Lysholm scales and International Knee Documentation Committee (IKDC) scoring system and radiological examination with a minimum 12 month follow-up duration. Results Significant improvement was seen on Lachman test and pivot-shift test between preoperative and last follow-up. Only one of participants had flexion contracture about 5 degrees at last follow-up. In anterior drawer test by KT-1000, authors found improvement from average 8.3 mm (range, 4 to 18 mm) preoperatively to average 1.4 mm (range, 0 to 6 mm) at last follow-up. Average Lysholm score of all patients was 72.7 ± 8.8 (range, 54 to 79) preoperatively and significant improvement was seen, score was 92.2 ± 5.3 (range, 74 to 97; p < 0.05) at last follow-up. Also IKDC score was normal in 35 cases, near normal in 11 cases, abnormal in 1 case at last follow-up. Conclusions Our new double bundle ACL reconstruction technique used hybrid fixation and Retroscrew had favorable outcomes. PMID:22162791

  15. Radiographic changes in the operative treatment of acute acromioclavicular joint dislocation – tight rope technique vs. K-wire fixation

    PubMed Central

    Horst, Klemens; Dienstknecht, Thomas; Andruszkow, Hagen; Gradl, Gertraud; Kobbe, Philipp; Pape, Hans-Christoph

    2013-01-01

    Summary Background Operative treatment of higher degree acromioclavicular joint luxation is common. A new option is made available by the tight rope technique. It claims to provide adequate outcome with the use of a minimally invasive technique. First clinical studies justified its medical use, but the equivalence to established surgical methods remains unclear. We therefore analyzed radiographic data from patients that were treated with the tight rope system (TR) and compared them to those treated with K-wires (KW) fixation. Material/Methods Retrospective study with inclusion criteria: surgery for acromioclavicular joint luxation between 2004 and 2011, classified as Rockwood type III, no concomitant injury, first event injury. We compared pre- and post-operative X-rays with those taken at the end of treatment. Clinical data from follow-ups and radiographic data were evaluated. The main outcome variable was the remaining distance between the acromion and clavicle (ACD), as well as the coracoid process and clavicle (CCD). Results 27 patients (TR: n=16; KW: n=11) with comparable demographics and injury severity were included. Surgery reduced ACD (TR: p=0.002; KW: p<0.001) and CCD (TR: p=0.001; KW: p=0.003). Heterotopic ossification or postoperative osteolysis was not significantly associated with either one of the procedures. Three patients (18.75%) in the TR group showed impaired wound healing, migrating K-wires were recorded in 2 patients (18.2%) and impingement syndrome occurred in 1 patient (9.1%) with K-wires. Posttraumatic arthritis was not seen. There was a loss of reduction in 2 cases within the TR-group (12.51%) and 1 in the KW-group (9.1%). At last follow up, ACD and CCD were wider in both groups compared to the healthy side. Conclusions This study shows that the Tight rope system is an effective alternative in the treatment of higher degree acromioclavicular luxation and comparable to the established methods. PMID:24505220

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

    PubMed

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

    2013-01-01

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

  18. Pressing fixation of mallet finger fractures with the end of a K-wire (a new fixation technique for mallet fractures).

    PubMed

    Zhang, Wenlong; Zhang, Xu; Zhao, Gang; Gao, Shunhong; Yu, Zhiliang

    2016-02-01

    The aim of this study was to describe and evaluate a surgical technique for the treatment of mallet finger fractures using a K-wire stabilization of the distal interphalangeal (DIP) joint and another K-wire pressing the bone fragment. Between June 2007 and March 2014, 41 patients (28 men, 13 women) with isolated closed mallet finger fracture were treated using two K-wires. In the cohort, the mean joint surface involvement was 44.3% (range: 28-62%). With a mean period of 23.6 months, patient follow-up lasted 13-34 months. The fingers were evaluated for loss of extension and flexion of the (DIP) joints. The results were graded using Crawford's criteria. Union of all fractures took place at an average of 5.5 weeks after the surgical procedure. Average extension lag was 4°, and active flexion 71°. According to the Crawford rating scale, 35 fingers were excellent, four were good, one was fair, and one was poor. Pressing fixation of the bone fragment with the end of a K-wire was a useful technique in the treatment of mallet finger fractures. Therapeutic IV. Copyright © 2015. Published by Elsevier Ltd.

  19. Neck of femur fracture fixation in a bilateral amputee: an uncommon condition requiring an improvised fracture table positioning technique.

    PubMed

    Berg, Andrew James; Bhatia, Chandra

    2014-02-21

    While neck of femur fractures are common it is rare to see this injury in a bilateral leg amputee. Special consideration needs to be given to the management of these patients. We report the case of a 58-year-old man with bilateral leg amputation who presented to the emergency department with left hip pain following a fall. A fracture of the left neck of femur with extension into the femoral shaft was diagnosed. Internal fixation was planned with a dynamic hip screw. Standard fracture table setup, which allows for traction of the fractured limb and positioning of the contralateral limb such that anteroposterior and lateral X-rays can be obtained, was not possible in this case due to the amputations. We highlight considerations that need to be made in positioning a bilateral amputee for neck of femur fracture fixation and also highlight an improvised technique that can be utilised by other surgeons.

  20. V-shaped double-row distal triceps tendon repair: a novel technique using unicortical button fixation.

    PubMed

    Scheiderer, Bastian; Lacheta, Lucca; Imhoff, Andreas B; Siebenlist, Sebastian

    2017-03-14

    This report was designed to present a novel technique combining suture anchor and unicortical button fixation for distal triceps tendon repair. For anatomical reinsertion of an acute distal triceps tendon rupture, two suture anchors and one unicortical button forming a V-shaped configuration were used. The operative approach is described in detail. Excellent clinical and functional results were achieved in the early postoperative phase. The patient reached full elbow range of motion and extension muscle strength (5/5) compared to the uninjured arm 12 weeks after surgery. Complications did not occur. This is the first report using unicortical button fixation in distal triceps tendon repair with promising preliminary results. Technical description, case report, Level V.

  1. Ptosis repair using preserved fascia lata with the modified direct tarsal fixation technique.

    PubMed

    Suh, Ji Young; Ahn, Hee Bae

    2013-10-01

    To evaluate the clinical outcome of frontalis sling operation using preserved fascia lata with modified direct tarsal fixation in congenital ptosis patients. Forty-seven congenital ptosis patients (60 eyes) who underwent a frontalis sling operation using preserved fascia lata with modified direct tarsal fixation method between March 2001 and December 2008 with a mean follow-up time of 52 months (range, 26 to 122 months) were included in this study. The medical records were reviewed retrospectively. A retrospective chart review was conducted in patients who were diagnosed with congenital ptosis and underwent frontalis suspension surgery using preserved fascia lata with modified direct tarsal fixation from 2001 through 2008 at Dong-A University Hospital. The patients were 34 males and 14 females. The age of the patients ranged from 1 to 18 years with an average age of 4.51 years. At a mean follow-up of 60 months, good final results were achieved in 46 eyes (76.6%), fair in 8 eyes (13.3%), and poor in 6 eyes (10%). The poor results consisted of undercorrection of 1 eye and recurrence in 5 eyes. The accumulative survival rate was 87.2%, with all recurrences occurring within 12 months postoperatively. Frontalis sling operation by preserved fascia lata with modified direct tarsal fixation appears to be an effective treatment for severe congenital ptosis, showing good long term results.

  2. 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

  3. The Kapandji technique for fixation of distal radius fractures--a biomechanical comparison of primary stability.

    PubMed

    Mittelmeier, W; Braun, C; Schäfer, R

    2001-01-01

    The goal of this study was to compare Kapandji-K-wiring and established K-wiring techniques of the distal radius fracture for primary stability in a biomechanical model: dorsal K-wiring according to Kapandji using different angles of the K-wire, parallel and diagonal alignment of the K-wires. A new testing system which uses a synthetic material enabled us to carry out the cantilever bending test. By application of a lower load, the Kapandji procedure shows a higher reactive torque and stiffness. A higher reaction force of the other techniques, especially of the parallel wiring, are only observable under high-grade bending stress. Application of the Kapandji procedure with K-wires at a smaller angle to the axis of the radius results in the highest primary stability of the procedures investigated in the essential range of initial deformation.

  4. Evaluation of a minimally invasive surgical fixation technique for young children with the Concerto Pin cochlear implant system.

    PubMed

    Schnabl, Johannes; Wolf-Magele, Astrid; Pok, Stefan Marcel; Url, Christoph; Zorowka, Patrick; Sprinzl, Georg

    2015-08-01

    In 2011, Med-El (Innsbruck, Austria) introduced a new cochlear implant system, designed to require a minimally invasive surgical technique and allow greater positional flexibility for its fixation on the skull. The Concerto Pin implant system is a good option for patients with thinner bone, such as children and elderly. The aim of this study was to investigate the implant’s stability in children using our minimally invasive surgical technique. This was a prospective, longitudinal study with a single-subject, repeated-examination design. Six children, implanted with a Concerto Pin using our minimally invasive surgical technique between October 2011 and September 2012, were assessed 1, 3 and 6 months after surgery. In each case, the implant remained in a stable position and no adverse events or problems with healing were observed at any time during the investigation. The minimally invasive technique and the method of implant fixation that bypass drilling a deep implant bed constitute a good option for patients with thinner bone, such as children. This clinical study shows the safety and stability of the Concerto Pin implant system using a minimally invasive surgical technique.

  5. [Radial external fixator for closed treatment of type III and IV supracondylar humerus fractures in children. A new surgical technique].

    PubMed

    Slongo, T

    2014-02-01

    Closed, anatomical reduction and reliable fixation of type III and IV supracondylar fractures that are either difficult or impossible to treat with conventional methods. According the Pediatric Comprehensive AO Classification for long bones this technique is preferred for type III and IV supracondylar fractures that cannot be reduced using closed standard manipulative techniques, where stable fixation using standard percutaneous wire configurations cannot be achieved, when severe swelling, open fracture, primary neurological or vascular problems ("pulseless pink hand") or multiple injuries indicate that optimal management of the injured limb should be free from cast. In patients with comorbidities (e.g., seizures or spasticity) requiring more stable fixation. In principle there are no contraindications. Prior to reduction of the fracture, fluoroscopically controlled insertion of a single Schanz screw into the lateral (radial) aspect of the distal fragment, which is defined by bulls eyeing the capitellum in the perfect lateral radiographic projection of the epiphysis, parallel to the physis. For very distal fractures this screw may be intra-epiphyseal, although usual placement is in the metaphysis just distal to the fracture line. After obtaining perfect lateral radiographic projection of the distal humeral metaphyseal-diaphyseal junction, a second Schanz screw is inserted independently into the proximal fracture fragment at the proximal end of the lateral supracondylar ridge in the sagittal plane perpendicular to the long axis of the humeral diaphysis. By bringing the screws parallel to each other in the coronal and transverse planes direct manipulations of the fragments and anatomical reduction using the so-called joystick technique is achieved. Fracture reduction can then be adjusted anatomically under fluoroscopic control and through clinical assessment. Once reduction is achieved the fragments have to be secured with a so-called "anti-rotation" K-wire. This

  6. Comparison between the fixation of peritoneal dialysis catheters to the peritoneal wall and the conventional placement technique: clinical experience and follow-up of a new implant technique for peritoneal dialysis catheters.

    PubMed

    Io, Hiroaki; Maeda, Kunimi; Sekiguchi, Yoshimi; Shimaoka, Tetsutaro; Aruga, Seiki; Nakata, Junichiro; Nakamoto, Hirotaka; Hotta, Yoko; Koyanagi, Ichiro; Inaba, Masanori; Kanda, Reo; Nakano, Takanori; Wakabayashi, Keiichi; Sasaki, Yuu; Inuma, Jiro; Kaneko, Kayo; Hamada, Chieko; Fukui, Mitsumine; Tomino, Yasuhiko

    2014-01-01

    Peritoneal dialysis (PD) catheters often become severely dislocated, which may lead to malfunction. With the aim of preventing this complication, we have developed a simple method of fixing the catheter downwards in the peritoneal cavity (fixation technique), a technique that does not require a laparoscope. Sixteen patients were implanted using the conventional placement technique and 25 patients were implanted using the fixation technique. The location of the catheter tip was classified from grade 1 (downward, normal) to 5 (dislocated). The frequency of dislocation (defined as the extended time and/or decrease in volume when draining the PD solution) was measured for both the fixation technique and conventional placement technique. There was a significant difference in grade between the fixation technique (2.72 ± 1.01) and conventional technique (3.92 ± 1.31). The time until first dislocation was significantly different between the fixation technique (59.3 ± 48.1 days) and conventional technique (8.8 ± 14.6 days). The time until any dislocation was significantly different between the fixation technique (69.2 ± 41.9 days) and conventional technique (12.9 ± 13.7 days). Complications were not significantly different between the fixation technique and conventional technique. The fixation technique appears to be simple, safe, and useful for preventing severe dislocation and for lengthening the time until dislocation in PD patients.

  7. Plate fixation of odontoid fractures without C1-C2 arthrodesis: practice of a novel surgical technique for stabilization of odontoid fractures, including the opportunity to extend the fixation to C3.

    PubMed

    Platzer, Patrick; Thalhammer, Gerhild; Krumboeck, Anna; Schuster, Rupert; Kutscha-Lissberg, Florian; Zehetgruber, Isabella; Braunsteiner, Thomas; Vécsei, Vilmos

    2009-04-01

    Surgical treatment of odontoid fractures that do not allow interfragmentary fracture compression involves either posterior atlantoaxial arthrodesis or additional anterior stabilization using a plate construct. The purpose of this study was to determine the clinical and radiographic outcome after anterior plate fixation of odontoid fractures that were not suitable for anterior screw fixation. We reviewed the clinical and radiographic records of 9 patients with an average age of 54 years at the time of surgery who had undergone anterior plate fixation of an odontoid fracture. Indications for using a plate construct were odontoid fractures with anterior oblique fracture lines, fractures with comminution or major displacement, and pathological fractures. Eight patients returned to their preinjury activity level and were satisfied with their treatment. One patient reported chronic pain symptoms and a notable decrease in cervical spine motion. Using the Smiley-Webster Scale to quantify their clinical outcome, we achieved an overall outcome score of 1.6. Bony fusion was achieved in all patients. Reduction or fixation failed in 2 patients. Reoperation for technical failures was not necessary in any of the patients. We had promising results using anterior plate fixation for surgical treatment of odontoid fractures that did not allow interfragmentary fracture compression. Because this method avoids the rigid fixation of the atlantoaxial joint in contrast to techniques of posterior cervical arthrodesis, it seems to be a practical option for the management of fracture types that require additional stabilization of the odontoid.

  8. Rapid and simple fixation-staining technique of fresh frozen cryostat sections for SIMS microscopy.

    PubMed

    Li, H; Okabe, M; Yoshida, T; Takaya, K

    2001-12-01

    Before observing freeze-dried cryosections by ion microscopy, it is necessary to perform localization of the analysis site by light microscopy. The present study reports a rapid fixation-staining method for preparing freeze-dried or air-dried cryosections, wherein cryosections are observed after immersion in Carnoy-Lebrun fixative for 30 s and staining in undiluted Giemsa solution for 30 s. Cryostat sections of goldfish intestine and kidney tissue on the silicon wafer substratum were subsequently examined by SIMS. Positive cesium ion images showed a general histology of the intestinal villi with goblet cells. Their granules contained large amounts of sodium, magnesium, potassium and calcium on ion images. By contrast, iron, copper and CsFe ion images showed diffuse distribution throughout the sections.

  9. "NIMS technique" for minimally invasive spinal fixation using non-fenestrated pedicle screws: A technical note.

    PubMed

    Rajesh, Alugolu; Pelluru, Pavan Kumar; Kumar, Ashish

    2015-01-01

    Case series. To reduce the cost of minimally invasive spinal fixation. Minimally invasive spine (MIS) surgery is an upcoming modality of managing a multitude of spinal pathologies. However, in a resource-limited situations, using fenestrated screws (FSs) may prove very costly for patients with poor affordability. We here in describe the Nizam's Institute of Medical Sciences (NIMS) experience of using routine non-FSs (NFSs) for transpedicular fixation by the minimally invasive way to bridge the economic gap. A total of 7 patients underwent NFS-minimally invasive spine (MIS) surgery. Male to female distribution was 6:1. The average blood loss was 50 ml and the mean operating time was 2 and 1/2 h. All patients were mobilized the very next day after confirming the position of implants on X-ray/computed tomography. All 7 patients are doing well in follow-up with no complaints of a backache or fresh neurological deficits. There was no case with pedicle breach or screw pullout. The average cost of a single level fixation by FS and NFS was ₹1, 30,000/patient and ₹32,000/patient respectively ('2166 and '530, respectively). At the end of 1-year follow-up, we had two cases of screw cap loosening and with a displacement of the rod cranio-caudally in one case which was revised through the same incisions. Transpedicular fixation by using NFS for thoracolumbar spinal pathologies is a cost-effective extension of MIS surgery. This may extend the benefits to a lower socioeconomic group who cannot afford the cost of fenestrated screw (FS).

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

    PubMed Central

    Lyu, J; Zhao, P-q

    2016-01-01

    Purpose We 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 methods The 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. Results The 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. Conclusion The simplified ab externo scleral fixation technique offers an effective and minimally invasive surgical alternative to salvage dislocated previously scleral-sutured PMMA IOLs. PMID:26795420

  11. Talking Techne: Techniques to Establish an Active Online Discussion Forum

    ERIC Educational Resources Information Center

    Palenque, Stephanie Maher; DeCosta, Meredith

    2015-01-01

    Discussion forums are critically important to the online classroom, as they virtually take the place of a classroom discussion and become a stage on which active learning takes place. Active learning occurs when instructors practice certain techniques in the discussion that are carefully and thoughtfully crafted and guided. The authors propose the…

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

    PubMed Central

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

    2013-01-01

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

  13. Outcomes of lumbopelvic fixation in the treatment of complex sacral fractures using minimally invasive surgical techniques.

    PubMed

    Jazini, Ehsan; Weir, Tristan; Nwodim, Emeka; Tannous, Oliver; Saifi, Comron; Caffes, Nicholas; Costales, Timothy; Koh, Eugene; Banagan, Kelley; Gelb, Daniel; Ludwig, Steven C

    2017-09-01

    Complex sacral fractures with vertical and anterior pelvic ring instability treated with traditional fixation methods are associated with high rates of failure and poor clinical outcomes. Supplemental lumbopelvic fixation (LPF) has been applied for additional stability to help with fracture union. The study aimed to determine whether minimally invasive LPF provides reliable fracture stability and acceptable complication rates in cases of complex sacral fractures. This is a retrospective cohort study at a single level I trauma center. The sample includes 24 patients who underwent minimally invasive LPF for complex sacral fracture with or without associated pelvic ring injury. Reoperation for all causes, loss of fixation, surgical time, transfusion requirements, length of hospital stay, postoperative day at mobilization, and mortality were evaluated. Patient charts from 2008 to 2014 were reviewed. Of the 32 patients who underwent minimally invasive LPF for complex sacral fractures, 24 (12 male, 12 female) met all inclusion and exclusion criteria. Outcome measures were assessed with a retrospective chart review and radiographic review. The authors did not receive external funding for this study. Acute reoperation was 12%, and elective reoperation was 29%. Two (8%) patients returned to the operating room for infection, one (4.2%) required revision for instrumentation malposition, and seven (29%) underwent elective removal of instrumentation. No patient experienced failure of instrumentation or loss of correction. Average surgical time was 3.6 hours, blood loss was 180 mL, transfusion requirement was 2.1 units of packed red blood cells, and postoperative mobilization was on postoperative day 5. No mortalities occurred as a result of the minimally invasive LPF procedure. Compared with historic reports of open LPF, our results demonstrate reliable maintenance of reduction and acceptable complication rates with minimally invasive LPF for complexsacral fractures. The

  14. Wiring technique for lesser trochanter fixation in proximal IM nailing of unstable intertrochanteric fractures: A modified candy-package wiring technique.

    PubMed

    Kim, Gyeong Min; Nam, Kwang Woo; Seo, Kyu-Bum; Lim, Chaemoon; Kim, Jiyun; Park, Yong-Geun

    2017-02-01

    The purpose of this study was to introduce a new surgical technique, that involves modified Candy-package wiring followed by IM nailing fixation and to determine the clinical and radiological results obtained in patients with unstable intertrochanteric fractures with a lesser trochanter fragment. This study included 22 patients who were undergone proximal IM nailing with lesser trochanter wiring between January 2014 to June 2015. All patients were treated with minimally invasive technique of candy-package wiring for lesser trochanter fragments. The mean age was 75.8 years (range, 53-88) and average follow-up period was 15.1 months (range, 12-24). Each patient was followed up for a minimum of 12 months and their clinical and radiological results were analyzed. The mean period required for fracture union was 16.6 weeks. (range, 8-25) and union was successfully completed in all cases. The WOMAC scores at the last F/U visit (average; 45.4, range; 21-75) were not significantly different to pre-trauma status (average; 36.5, range; 19-59) (p=0.087). In comparison of ambulatory capacity prior to trauma, ambulatory aggravation was noted in four cases (18.2%), and eighteen cases (81.8%) was sustained walking ability of prior of trauma. Wiring breakage was found in two cases and heterotrophic ossification in one case. There were no functional deficeit related to the radiologic finding in these patients. With regard to postoperative complications, were no cut-outs, breakage, or pullout of screws. When surgically repairing unstable intertrochanteric fractures with lesser trochanter comminution using proximal IM nailing method, the modified Candy-packaging wiring technique increases the fixation force at the fracture site. Thus, through this technique, both firm fixation of the lesser trochanter and more stable bony union were obtained. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Comparison of five different fixation techniques of sagittal split ramus osteotomy using three-dimensional finite elements analysis.

    PubMed

    Sato, F R L; Asprino, L; Noritomi, P Y; da Silva, J V L; de Moraes, M

    2012-08-01

    The aim of this study was to compare the mechanical stress over hemimandible substrate and hardware after sagittal split ramus osteotomy (SSRO) fixed with five different techniques using three-dimensional (3D) finite element analysis. A 3D finite element model of a hemimandible was created and a 5mm advancement SSRO was simulated on a computer model. The model was fixed with five different techniques: 3 linear 60° screw arrangement; 3 linear 90° screw arrangement; 3 inverted L screw arrangement; 1 conventional miniplate; and 1 locking miniplate with four monocortical screws. Load was applied until 3mm displacement was reached and the results were compared with previous mechanical and photoelastic tests, thus analysing the mechanical stresses developed in the proximity of miniplates and screws and within the fixation system itself. The maximum principal stress values demonstrate a lower mechanical stress rate in bone and in the fixation system with the inverted L arrangement, followed by the linear 90° and linear 60° arrangements. The locking miniplate/screw system presented lower maximum principal stress and better stress distribution compared with the conventional system. Under the conditions tested, the reversed L arrangement provided the most favourable stress dissipation behaviour. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  16. Results of deformity correction in children with X-linked hereditary hypophosphatemic rickets by external fixation or combined technique.

    PubMed

    Popkov, Arnold; Aranovich, Anna; Popkov, Dmitry

    2015-12-01

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

  17. New Technique for Mandibular Symphyseal Distraction by a Double-Level Anchorage and Fixation System: Advantages and Results.

    PubMed

    Carlino, Franco; Pantaleo, Giuseppe; Ciuffolo, Fabio; Claudio, Pier Paolo; Cortese, Antonio

    2016-09-01

    A surgical technique to widen the mandible is the mandibular midline distraction: the most common indications for mandibular midline distraction are severe mandibular anterior crowding, severe mandibular transverse deficiency, uni- or bilateral crossbite, impacted anterior teeth with inadequate space, and tipped teeth. Commonly used distraction devices can be divided into 2 systems: bone-borne distraction system appliance, dental-borne distraction systems. Each system has peculiar advantages, disadvantages, and different indications. To combine advantages of both systems we developed a new technique adopting an immediate basal bone widening with fixation after osteotomy and a dental borne rigid lingual system for distraction. The aim of this work is to show a new technique for symphysis mandibular distraction based on a double-level anchorage and fixation system on clinical patients showing final results and advantages. Two patients affected by dento-alveolar and basal bone maxillary and mandibular transversal collapse even in association with other skeletal malocclusion were selected. Patients were clinically and radiographically studied and analyzed at different times before and after surgery. Dental and basal bone measurements were performed clinically and radiographically. The results were optimal with perfect dental arches alignment followed by closing of the open bites with multiple-segmented surgery in a second surgical time. No misalignment of the 2 mandibular halves was noticed during the distraction procedure. Dental-bone discrepancies correction is mandatory before orthodontic treatment alignment. Transversal jaw expansion can be achieved safely and stably by distraction of both maxillae for the combination of osteogenesis and histogenesis with augmentation of both bone and soft tissue. Bone-borne distraction will result in more stable results; dental-borne devices will result in more simple and aesthetically rewarding procedures. Hybrid techniques

  18. 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

  19. The Effect of Insertion Technique on Temperatures for Standard and Self-Drilling External Fixation Pins.

    PubMed

    Manoogian, Sarah; Lee, Adam K; Widmaier, James C

    2017-08-01

    No studies have assessed the effects of parameters associated with insertion temperature in modern self-drilling external fixation pins. The current study assessed how varying the presence of irrigation, insertion speed, and force impacted the insertion temperatures of 2 types of standard and self-drilling external fixation half pins. Seventy tests were conducted with 10 trials for 4 conditions on self-drilling pins, and 3 conditions for standard pins. Each test used a thermocouple inside the pin to measure temperature rise during insertion. Adding irrigation to the standard pin insertion significantly lowered the maximum temperature (P <0.001). Lowering the applied force for the standard pin did not have a significant change in temperature rise. Applying irrigation during the self-drilling pin tests dropped average rise in temperature from 151.3 ± 21.6°C to 124.1 ± 15.3°C (P = 0.005). When the self-drilling pin insertion was decreased considerably from 360 to 60 rpm, the temperature decreased significantly from 151.3 ± 21.6°C to 109.6 ± 14.0°C (P <0.001). When the force applied increased significantly, the corresponding self-drilling pin temperature increase was not significant. The standard pin had lower peak temperatures than the self-drilling pin for all conditions. Moreover, slowing down the insertion speed and adding irrigation helped mitigate the temperature increase of both pin types during insertion.

  20. Biomechanical testing of distal femur osteotomy plate fixation techniques: the role of simulated physiological loading.

    PubMed

    Brinkman, Justus-Martijn; Hurschler, Christof; Agneskirchner, Jens; Lobenhoffer, Philip; Castelein, René M; van Heerwaarden, Ronald J

    2014-12-01

    Implants for fracture and/or osteotomy fixation are often tested according to basic mechanical test models such as open gap tests or 4-point-bending tests. These may be suitable to test and compare different implants for safety and clinical approval, but are not always representative of the post-operative situation, which is decisive when it comes to bone healing. In the current study the Knee Expert Group of the Association for the Study of Internal Fixation has compared the available open gap test results of the latest version of the TomoFix Medial Distal Femoral Plate and the antecedent plate design, with the test results of a more physiological and life-like test model. In the open gap test model the antecedent plate design was found to have superior stiffness and fatigue strength. In the current study simulated postoperative conditions for medial closing wedge supracondylar osteotomies were used. The constructs were subjected to cyclical axial and torsional loading and were subsequently tested to failure. The more life-like tests in this study showed that the latest version was either more or equally stable and stiff than the antecedent version of the plate, in all of the tests. It is argued that the difference in results between the two loading models is due to differences in test design. These test results stress the importance of not only using standard open gap and 4-point-bending tests, but also to use as life-like as possible test conditions for any form of biomechanical testing of new implants.

  1. Evaluation of different screw fixation techniques and screw diameters in sagittal split ramus osteotomy: finite element analysis method.

    PubMed

    Sindel, A; Demiralp, S; Colok, G

    2014-09-01

    Sagittal split ramus osteotomy (SSRO) is used for correction of numerous congenital or acquired deformities in facial region. Several techniques have been developed and used to maintain fixation and stabilisation following SSRO application. In this study, the effects of the insertion formations of the bicortical different sized screws to the stresses generated by forces were studied. Three-dimensional finite elements analysis (FEA) and static linear analysis methods were used to investigate difference which would occur in terms of forces effecting onto the screws and transmitted to bone between different application areas. No significant difference was found between 1·5- and 2-mm screws used in SSRO fixation. Besides, it was found that 'inverted L' application was more successful compared to the others and that was followed by 'L' and 'linear' formations which showed close rates to each other. Few studies have investigated the effect of thickness and application areas of bicortical screws. This study was performed on both advanced and regressed jaws positions.

  2. Improvements in the technique of vascular perfusion-fixation employing a fluorocarbon-containing perfusate and a peristaltic pump controlled by pressure feedback.

    PubMed

    Rostgaard, J; Qvortrup, K; Poulsen, S S

    1993-11-01

    A new improved technique for whole-body perfusion-fixation of rats and other small animals is described. The driving force is a peristaltic pump which is feedback regulated by a pressure transducer that monitors the blood-perfusion pressure in the left ventricle of the heart. The primary perfusate-fixative is composed of a blood substitute--13.3% oxygenated fluorocarbon FC-75--in 0.05 M cacodylate buffer (pH 7.4) with a 2% glutaraldehyde. The secondary perfusate-fixative is composed of 2% glutaraldehyde in 0.05 M cacodylate buffer (pH 7.4) with 20 mM CaCl2. A double-barrelled, self-holding cannula is used to cannulate the heart; the outer and inner barrels of the cannula are connected to the peristaltic pump and to the pressure transducer, respectively. The tissue oxygen tension in the rat is monitored by a subcutaneous oxygen electrode. Measurements showed that tissue hypoxia/anoxia did not develop before or during the perfusion-fixation. Thus, the technique permits study of specimens which do not exhibit fixation gradients and do not contain cells fixed in a state of asphyxia. This is substantiated by electron micrographs of cells from different organs, revealing new fine structural elements. By adding oxygenated fluorocarbon to glutaraldehyde perfusate-fixatives, enough oxygen is made accessible for cellular respiration as well as for the oxygen-consuming chemical reactions of glutaraldehyde with the tissue. Data on anaesthesia, operative manoeuvres, mechanical components of the system, preparation of fixatives and flow of the perfusate-fixatives are furnished and discussed.

  3. Translaminar screws of the axis--an alternative technique for rigid screw fixation in upper cervical spine instability.

    PubMed

    Meyer, D; Meyer, F; Kretschmer, Th; Börm, W

    2012-04-01

    C2 pedicle screws or transarticular atlantoaxial screws are technically demanding and carry an increased risk of vertebral artery injury. In up to 20% of cases, pedicle and transarticular screw placement is not possible due to a high-riding vertebral artery or very small C2 pedicles in addition to other anatomical variations. Translaminar screws have been reported to rigidly capture posterior elements of C2 and therefore appear to be a suitable alternative. We present our first experiences and clinical results with this new method in two neurosurgical spine centers. Twenty-seven adult patients were treated between 2007 and 2010 in two neurosurgical spine departments with C2 translaminar screw fixation for upper cervical spine instability of various origins (e.g., trauma, tumor, dens pseudarthrosis). Eight patients were men and 19 were women. Mean age was 68.9 years. In most cases, translaminar screws were used because of contraindications for pedicle or transarticular screws as a salvage technique. All patients were clinically assessed and had CT scans postoperatively to verify correct screw placement. Follow-up was performed with reexamination on an ambulatory basis. Mean follow-up was 7.6 months for all patients. In 27 patients, 52 translaminar screws were placed. There were no intraoperative complications. Postoperatively, we identified four screw malpositions using a new accuracy grading scale. One screw had to be revised because of violation of the spinal canal >4 mm. None of the patients had additional neurological deficits postoperatively, and all showed stable cervical conditions at follow-up. Two patients died due to causes not associated with the stabilization technique. The fusion rate for patients with C1/C2 fixation is 92.9%. Translaminar screws can be used at least as an additional technique for cases of upper cervical spine instability when pedicle screw placement is contraindicated or not possible. The current data suggest comparable

  4. Fixation of posterior process fractures of the olecranon using a modified suture bridge technique: report of 2 cases.

    PubMed

    Cha, Soo Min; Shin, Hyun Dae; Kim, Kyung Cheon; Noh, Chang Kyun

    2014-12-01

    We encountered 2 patients with posterior process fractures of the olecranon and fixed the fragment using a modified suture bridge method without a metallic implant. The suture anchor was inserted distally through the fracture plane, and the small tip of proximal olecranon was reduced to the ulna. Computed tomography revealed bony union 4 and 5 months later. At the 1-year postoperative follow-up examination, the clinical outcomes were satisfactory in both patients. This suture bridge technique was reliable for small fragment fixation in posterior process fracture of the olecranon based on the tension band theory with no problems induced by metallic hardware. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  5. Comparison of immunodiffusion techniques with standard complement fixation assay for quantitation of coccidioidal antibodies.

    PubMed Central

    Wieden, M A; Galgiani, J N; Pappagianis, D

    1983-01-01

    Quantitative immunodiffusion (QID) and complement fixation (CF) methods were compared for their agreement in detecting coccidioidal antibodies. For these studies, we assayed 719 sera from 181 patients with coccidioidomycosis. Over 60% of the specimens had CF results of 1:2 to 1:256. A total of 43 patients had five or more specimens obtained over periods of between 1 and 8 years. The QID method, as originally performed, agreed within a twofold dilution of the CF titer in 191 of 267 sera (71.5%). Modification of QID by repeated filling of the antigen and serum wells improved agreement to 84.7% (383 of 452 sera). The degree of CF titer change in patients over time periods was more closely matched by the modified than by the original QID method. Discrepancies between the CF and QID methods appeared not to be due to a subpopulation of patients. QID measurement of coccidioidal antibodies may be a useful substitute for the CF assay in certain clinical laboratories. Images PMID:6415091

  6. Fixation techniques and stem dimensions in hinged total knee arthroplasty: a finite element study.

    PubMed

    El-Zayat, Bilal Farouk; Heyse, Thomas J; Fanciullacci, Nelson; Labey, Luc; Fuchs-Winkelmann, Susanne; Innocenti, Bernardo

    2016-12-01

    No evidence-based guidelines are available to determine the appropriate stem length, and whether or not to cement stems in revision total knee arthroplasty (TKA). Therefore, the objective of this study was to compare stresses and relative movement of cemented and uncemented stems of different lengths using a finite element analysis. A finite element model was created for a synthetic tibia. Two stem lengths (95 and 160 mm) and two types of fixation (cemented or press fit) of a hinged TKA were examined. The average compressive stress distribution in different regions of interest, as well as implant micromotions, was determined and compared during lunge and squat motor tasks. Both long and short stems in revision TKA lead to high stresses, primarily in the region around the stem tip. The presence of cement reduces the stresses in the bone in every region along the stem. Short stem configurations are less affected by the presence of cement than the long stem configuration. Press-fit stems showed higher micromotions compared to cemented stems. Lowest stresses and micromotion were found for long cemented stems. Cementless stems showed more micromotion and increased stress levels especially at the level of the stem tip, which may explain the clinical phenomenon of stem-end pain following revision knee arthroplasty. These findings will help the surgeon with optimal individual implant choice.

  7. Single-Row or Double-Row Fixation Technique for Full-Thickness Rotator Cuff Tears: A Meta-Analysis

    PubMed Central

    Zhou, Jiaojiao; Yuan, Chaoqun; Chen, Kai; Cheng, Biao

    2013-01-01

    Background The single-row and double-row fixation techniques have been widely used for rotator cuff tears. However, whether the double-row technique produces superior clinical or anatomic outcomes is still considered controversial. This study aims to use meta-analysis to compare the clinical and anatomical outcomes between the two techniques. Methods The Pubmed, Embase, and Cochrane library databases were searched for relevant studies published before November 1, 2012. Studies clearly reporting a comparison of the single-row and double-row techniques were selected. The Constant, ASES, and UCLA scale systems and the rotator cuff integrity rate were evaluated. The weighted mean differences and relative risks were calculated using a fixed-effects or random-effects model. Results Eight studies were included in this meta-analysis. The weighted mean differences of the ASES (−0.84; P = 0.04; I2 = 0%) and UCLA (−0.75; P = 0.007; I2 = 0%) scales were significantly low in the single-row group for full-thickness rotator cuff tears. For tear sizes smaller than 3 cm, no significant difference was found between the groups no matter in Constant (P = 0.95; I2 = 0%), ASES (P = 0.77; I2 = 0%), or UCLA (P = 0.24; I2 = 13%) scales. For tear sizes larger than 3 cm, the ASES (−1.95; P = 0.001; I2 = 49%) and UCLA (−1.17; P = 0.006; I2 = 0%) scales were markedly lower in the single-row group. The integrity of the rotator cuff (0.81; P = 0.0004; I2 = 10%) was greater and the partial thickness retear rate (1.93; P = 0.007; I2 = 10%) was less in the double-row group. Full-thickness retears showed no difference between the groups (P = 0.15; I2 = 0%). Conclusion The meta-analysis suggests that the double-row fixation technique increases post-operative rotator cuff integrity and improves the clinical outcomes, especially for full-thickness rotator cuff tears larger than 3 cm. For tear sizes smaller than 3 cm

  8. Utilization of a Technique of Percutaneous S2 Alar-Iliac Fixation in Immunocompromised Patients with Spondylodiscitis.

    PubMed

    Funao, Haruki; Kebaish, Khaled M; Isogai, Norihiro; Koyanagi, Takahiro; Matsumoto, Morio; Ishii, Ken

    2017-01-01

    Spondylodiscitis still remains a serious problem, especially in immunocompromised patients. Surgery is necessary when nonsurgical treatment is unsuccessful. Although minimally invasive spine stabilization (MISt) with percutaneous pedicle screws is less invasive, percutaneous sacropelvic fixation techniques are not common practice. Here, we describe 2 cases in which spondylodiscitis in the lumbosacral spine was treated with percutaneous stabilization using an S2 alar-iliac (S2AI) screw technique. Case 1 is a 77-year-old man who presented with low back pain and high fever. He was diagnosed with spondylodiscitis at L4-5. He had a history of lung cancer, which was complicated by the recurrence. Because nonsurgical treatment failed, MISt with percutaneous S2AI screws was performed. The patient's low back pain subsided markedly 1 week after surgery, and there was no screw/rod breakage or recurrence of infection during the follow-up period. Case 2 is a 71-year-old man who presented with hemiparesis because of a stroke. He also developed high fever and was diagnosed with spondylodiscitis at L5-S1. Because nonsurgical treatment failed, the patient was treated by MISt with percutaneous S2AI screws while being maintained on anticoagulants for stroke. Although his clinical symptoms had markedly improved, a postoperative lumbar computed tomography scan demonstrated a bone defect at L5-S1. An anterior spinal fusion with an iliac bone graft at L5-S1 was performed when a temporary cessation of anticoagulants was permitted. Both patients tolerated the procedures well and had no major perioperative complications. MISt with percutaneous S2AI screws was less invasive and efficacious for lumbosacral spondylodiscitis in providing rigid percutaneous sacropelvic fixation. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Establishment of microbial eukaryotic enrichment cultures from a chemically stratified antarctic lake and assessment of carbon fixation potential.

    PubMed

    Dolhi, Jenna M; Ketchum, Nicholas; Morgan-Kiss, Rachael M

    2012-04-20

    phototrophic and mixotrophic protists from Lake Bonney. Sampling depths in the water column were chosen based on the location of primary production maxima and protist phylogenetic diversity (4, 11), as well as variability in major abiotic factors affecting protist trophic modes: shallow sampling depths are limited for major nutrients, while deeper sampling depths are limited by light availability. In addition, lake water samples were supplemented with multiple types of growth media to promote the growth of a variety of phototrophic organisms. RubisCO catalyzes the rate limiting step in the Calvin Benson Bassham (CBB) cycle, the major pathway by which autotrophic organisms fix inorganic carbon and provide organic carbon for higher trophic levels in aquatic and terrestrial food webs (12). In this study, we applied a radioisotope assay modified for filtered samples (13) to monitor maximum carboxylase activity as a proxy for carbon fixation potential and metabolic versatility in the Lake Bonney enrichment cultures.

  10. New entry point for C2 screw, in posterior C1-C2 fixation (Goel-Harm's technique) significantly reducing the possibility of vertebral artery injury.

    PubMed

    Patkar, Sushil Vasant

    2016-02-01

    To reduce the chance of vertebral artery injury in posterior C1 lateral mass and C2 pedicle/pars screw-rod fixation (Goel-Harms technique ). 49 patients, 30 males and 19 females, 12years - 82 years, underwent posterior C1-C2 fixation from February 2007 till June2013. A new entry point for the posterior C2 screw, 3mm below the midpoint of the C1-C2 joint which is directed medially and downwards into the C2 body , probably avoids the vertebral artery. As the screw now bypasses the pedicle/ pars , the chance of injuring the vertebral artery is probably reduced. No case of intra-operative vertebral artery injury. The new technique of C2 screw fixation allows rigid immobilization of the C1-C2 joint without significant risk of vertebral artery injury.

  11. Lateral mass screw fixation of the atlas: surgical technique and anatomy.

    PubMed

    Joaquim, Andrei F; Ghizoni, Enrico; Rubino, Pablo A; Anderle, Diogo V; Tedeschi, Helder; Rhoton, Albert L; de Oliveira, Evandro

    2010-01-01

    The use of lateral mass atlas screws is an important technique to achieve fusion and stability at the craniocervical region affected by different pathologies (degenerative, traumatic, inflammatory, neoplastic, or congenital). This paper describes the anatomy and techniques necessary for proper insertion of posterior C1 lateral mass screws, using anatomic dissection and intraoperative pictures. Knowledge of the anatomy and the surgical technique of insertion of C1 lateral mass screws are of paramount importance to have good surgical results. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Hybrid Decompression and Fixation Technique Versus Plated 3-Vertebra Corpectomy for 4-Segment Cervical Myelopathy: Analysis of 81 Cases With a Minimum 2-Year Follow-Up.

    PubMed

    Odate, Seiichi; Shikata, Jitsuhiko; Kimura, Hiroaki; Soeda, Tsunemitsu

    2016-07-01

    A retrospective comparative study. The purpose of this study was to compare the stability and outcomes of a hybrid technique with those of a 3-vertebra corpectomy in the management of 4-segment cervical myelopathy. Patients with primarily ventral disease and loss of cervical lordosis are considered good candidates for anterior surgery. Cervical corpectomy is commonly performed in patients with multilevel cervical myelopathy. Corpectomies including >3 vertebraes entail an extremely high risk of reconstruction failure. To avoid the need to perform a 3-vertebra corpectomy, we use a hybrid decompression and fixation technique. This hybrid technique is a technique to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy. A total of 81 patients with multilevel cervical myelopathy who underwent 4-segment cervical fixation with a minimum 2-year follow-up were included. The hybrid technique involved combining a plated 2-vertebra corpectomy and single-level discectomy with stand-alone cage fixation. This technique was performed in 39 patients, and the plated 3-vertebra corpectomy was performed in 42 patients. Nine patients (21%) who underwent the plated 3-vertebra corpectomy were treated with halo immobilization, but no patient in the hybrid group required this treatment (P=0.002). There were fewer instances of reconstruction failure in the hybrid group than in the 3-vertebra corpectomy group (0% vs. 10%, respectively; P=0.048) and fewer instances of C5 palsy (3% vs. 17%, respectively; P <0.0001). The incidence of postoperative C5 palsy was 25% for C3-C5 corpectomy, 19% for C4-C6 corpectomy, and 11% for C4-C5 corpectomy+C6-C7 discectomy. The hybrid technique has the following advantages over 3-vertebra corpectomy for 4-segment cervical fixation: a shorter graft bone and plate are required; the fixed segment has greater initial stability; postoperative external immobilization is simplified; and the risk of reconstruction failure and

  13. Comparison of a reverse-transverse cross pin technique with a same side cross pin type II external skeletal fixator in 89 dogs.

    PubMed

    Tsai, Kun-Yang; Pead, Matthew

    2015-01-01

    The objective of this study was to determine whether a novel reverse-transverse cross pin insertion technique could increase the stability of type II external skeletal fixators (ESF) in dogs compared with an alternate, same side cross pin ESF. Reverse-transverse cross pin technique and type II ESFs same side cross pin technique were applied and compared among subjects. Two of 42 ESFs (4.8%) applied with the reverse-transverse cross pin technique and 39 of 47 ESFs (83%) applied with the same side cross pin technique were subjectively unstable at the time of fixator removal (P < 0.001). The same side cross pin ESFs had significantly more pin tract new bone formation than the reverse-transverse ESFs (P = 0.038). In summary, this approach may provide a method of treating a variety of musculoskeletal conditions and soft tissue cases, which reverse-transverse cross pin ESFs are tolerated in dogs for a variety of conditions.

  14. Patch-augmented rotator cuff repair: influence of the patch fixation technique on primary biomechanical stability.

    PubMed

    Jung, Christian; Spreiter, Gregor; Audigé, Laurent; Ferguson, Stephen J; Flury, Matthias

    2016-05-01

    There is an ongoing debate about the potential of patch augmentation to improve biomechanical stability and healing associated with rotator cuff repair. The biomechanical properties of three different patch-augmented rotator cuff repair techniques were assessed in vitro and compared with a standard repair. Dermal collagen patch augmentation may increase the primary stability and strength of the repaired tendon in vitro, depending on the technique used for patch application. Forty cadaveric sheep shoulders with dissected infraspinatus tendons were randomized into four groups (n = 10/group) for tendon repair using a knotless double-row suture anchor technique. A xenologous dermal extracellular matrix patch was used for augmentation in the three test groups using an "integrated", "cover", or "hybrid" technique. Tendons were preconditioned, cyclically loaded from 10 to 30 N at 1 Hz, and then loaded monotonically to failure. Biomechanical properties and the mode of failure were evaluated. Patch augmentation significantly increased the maximum load at failure by 61 % in the "cover" technique test group (225.8 N) and 51 % in the "hybrid" technique test group (211.4 N) compared with the non-augmented control group (140.2 N) (P ≤ 0.015). For the test group with "integrated" patch augmentation, the load at failure was 28 % lower (101.6 N) compared with the control group (P = 0.043). There was no significant difference in initial and linear stiffness among the four experimental groups. The most common mode of failure was tendon pullout. No anchor dislocation, patch disruption or knot breakage was observed. Additional patch augmentation with a collagen patch influences the biomechanical properties of a rotator cuff repair in a cadaveric sheep model. Primary repair stability can be significantly improved depending on the augmentation technique.

  15. Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques: A CONSORT-Compliant Article: Erratum.

    PubMed

    2015-02-01

    [In the article "Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques: A CONSORT-compliant" article, which appeared in Volume 94, Issue 1 of Medicine, a line denoting dual authorship was omitted. K. Kojima and B. Gueorguiev contributed equally to the article.].

  16. Internal fixation of fractured ribs in neonatal foals with nylon cable tie using a modified technique.

    PubMed

    Williams, T Boullhesen; Williams, Jarred M; Rodgerson, Dwayne H

    2017-06-01

    Nylon cable tie has been shown to be an effective and economical method for fixing fractured ribs in the neonatal foal. This article describes a modification of the previously described technique. Under general anesthesia, the fractured ribs were exposed and a hole was drilled in the dorsal and ventral fragments. The fracture was not reduced, leaving the fragments overriding each other. The nylon cable tie was passed through the hole in the dorsal fragment from the external surface of the rib. The free end of the cable tie was then passed through the hole in the ventral fragment from the external surface of the rib and the tie was tightened. This technique was used in 4 neonatal foals with no complications. The modification of the original technique represents a method to minimize soft tissue trauma, implant failure, and complications.

  17. A biomechanical comparison of the Rogers interspinous and the Lovely-Carl tension band wiring techniques for fixation of the cervical spine.

    PubMed

    Brasil, A V; Coehlo, D G; Filho, T E; Braga, F M

    2000-07-01

    The authors conducted a biomechanical study in which they compared the uses of the Rogers interspinous and the Lovely-Carl tension band wiring techniques for internal fixation of the cervical spine. An extensive biomechanical evaluation (stiffness in positive and negative rotations around the x, y, and z axes; range of motion in flexion-extension, bilateral axial rotation, and bilateral bending; and neutral zone in flexion-extension, bilateral axial rotation, and lateral bending to the right and to the left) was performed in two groups of intact calf cervical spines. After these initial tests, all specimens were subjected to a distractive flexion Stage 3 ligamentous lesion. Group 1 specimens then underwent surgical fixation by the Rogers technique, and Group 2 specimens underwent surgery by using the Lovely-Carl technique. After fixation, specimens were again submitted to the same biomechanical evaluation. The percentage increase or decrease between the pre- and postoperative parameters was calculated. These values were considered quantitative indicators of the efficacy of the techniques, and the efficacy of the two techniques was compared. Analysis of the findings demonstrated that in the spines treated with the Lovely-Carl technique less restriction of movement was produced without affecting stiffness, compared with those treated with the Rogers technique, thus making the Lovely-Carl technique clinically less useful.

  18. Comparison of two tension-band fixation materials and techniques in transverse patella fractures: a biomechanical study.

    PubMed

    Rabalais, R David; Burger, Evalina; Lu, Yun; Mansour, Alfred; Baratta, Richard V

    2008-02-01

    This study compared the biomechanical properties of 2 tension-band techniques with stainless steel wire and ultra high molecular weight polyethylene (UHMWPE) cable in a patella fracture model. Transverse patella fractures were simulated in 8 cadaver knees and fixated with figure-of-8 and parallel wire configurations in combination with Kirschner wires. Identical configurations were tested with UHMWPE cable. Specimens were mounted to a testing apparatus and the quadriceps was used to extend the knees from 90 degrees to 0 degrees; 4 knees were tested under monotonic loading, and 4 knees were tested under cyclic loading. Under monotonic loading, average fracture gap was 0.50 and 0.57 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.16 and 0.04 mm, respectively, in the parallel wire construct. Under cyclic loading, average fracture gap was 1.45 and 1.66 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.45 and 0.60 mm, respectively, in the parallel wire construct. A statistically significant effect of technique was found, with the parallel wire construct performing better than the figure-of-8 construct in both loading models. There was no effect of material or interaction. In this biomechanical model, parallel wires performed better than the figure-of-8 configuration in both loading regimens, and UHMWPE cable performed similarly to 18-gauge steel wire.

  19. 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

  20. In vitro biomechanical evaluation of internal fixation techniques on the canine lumbosacral junction

    PubMed Central

    Dillard, Stacy; Roe, Simon

    2015-01-01

    Few biomechanical studies have evaluated the effect of internal stabilization techniques after decompressive surgery on the stability of the canine lumbosacral junction. The purpose of this canine cadaver study is to evaluate the stability of the canine lumbosacral (LS) spine in flexion and extension following laminectomy and discectomy and then stabilization with each of the three techniques: pins and polymethylmethacrylate (P/PMMA), two dorsal locking plates (SOP) or bilateral transarticular facet screws (FACET).Using a cantilever biomechanical system, bending moments were applied to the LS and range of motion (ROM) was recorded via a rotational potentiometer. With 3 Nm, the ROM (n = 4 in each group) for P/PMMA, SOP and FACET were 1.92 ± 0.96°, 2.56 ± 0.55°and 3.18 ± 1.14°, respectively. With moments up to 35 Nm, the P/PMMA specimens appeared stable. Sacroiliac motion in the SOP and FACET groups invalidated further comparisons. Each of the stabilization techniques (P/PMMA, SOP, and FACET) significantly decreased the range of motion in flexion and extension for low bending moments. PMID:26312169

  1. In vitro biomechanical evaluation of internal fixation techniques on the canine lumbosacral junction.

    PubMed

    Early, Peter; Mente, Peter; Dillard, Stacy; Roe, Simon

    2015-01-01

    Few biomechanical studies have evaluated the effect of internal stabilization techniques after decompressive surgery on the stability of the canine lumbosacral junction. The purpose of this canine cadaver study is to evaluate the stability of the canine lumbosacral (LS) spine in flexion and extension following laminectomy and discectomy and then stabilization with each of the three techniques: pins and polymethylmethacrylate (P/PMMA), two dorsal locking plates (SOP) or bilateral transarticular facet screws (FACET).Using a cantilever biomechanical system, bending moments were applied to the LS and range of motion (ROM) was recorded via a rotational potentiometer. With 3 Nm, the ROM (n = 4 in each group) for P/PMMA, SOP and FACET were 1.92 ± 0.96°, 2.56 ± 0.55°and 3.18 ± 1.14°, respectively. With moments up to 35 Nm, the P/PMMA specimens appeared stable. Sacroiliac motion in the SOP and FACET groups invalidated further comparisons. Each of the stabilization techniques (P/PMMA, SOP, and FACET) significantly decreased the range of motion in flexion and extension for low bending moments.

  2. Combined S-1 and S-2 sacral alar-iliac screws as a salvage technique for pelvic fixation after pseudarthrosis and lumbosacropelvic instability: combined S-1 and S-2 sacral alar-iliac screws as a salvage technique for pelvic fixation after pseudarthrosis and lumbosacropelvic instability: technical note.

    PubMed

    Mattei, Tobias A; Fassett, Daniel R

    2013-09-01

    Lumbosacropelvic pseudarthrosis after long spinal fusions for treatment of adult degenerative scoliosis remains a challenging condition. Moreover, although pelvic fixation with iliac screws is widely used in deformity surgery to provide a biomechanically strong distal anchor for long thoracolumbar constructs, there are very few options available after failed pelvic fixation with iliac screws. The authors conducted a retrospective review of the surgical charts and imaging findings of patients subjected to revision surgery for lumbosacropelvic pseudarthrosis from August 2011 to August 2012. This review identified 5 patients in whom a salvage technique combining both S-1 and S-2 sacral alar-iliac (SAI) screws had been performed. In this technical note, the authors present a detailed anatomical discussion and an appraisal of the sequential intraoperative steps of this new technique involving a combination of S-1 and S-2 SAI screws. The discussion is illustrated with a surgical case in which this technique was used to treat a patient with pseudarthrosis that had developed after fixation with classic iliac screws. In conclusion, although S-2 SAI screws have previously been reported as an interesting alternative to classic iliac wing screws, this report is the first on the use of combined S-1 and S-2 SAI screws for pelvic fixation as a salvage technique for lumbosacropelvic instability. According to the reported experience, this technique provides a biomechanically robust construct for definitive pelvic fixation during revision surgeries in the challenging scenarios of pseudarthrosis and instability of the lumbosacropelvic region.

  3. 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

  4. Rapid microwave fixation of rat mast cells. I. Localization of granule chymase with an ultrastructural postembedding immunogold technique.

    PubMed

    Login, G R; Galli, S J; Morgan, E; Arizono, N; Schwartz, L B; Dvorak, A M

    1987-11-01

    We defined the ultrastructural localization of chymase in rat peritoneal mast cells using standard aldehyde fixation and a newly described microwave fixation method (Login GR, Dvorak AM: Microwave energy fixation for electron microscopy. Am J Pathol 120: 230, 1985; Login GR, Stavinoha WB, Dvorak AM: Ultrafast microwave energy fixation for electron microscopy. J Histochem Cytochem 34:381, 1986) and postembedding immunogold labeling. Thin sections were exposed first to goat IgG anti-rat chymase and second to gold-conjugated rabbit Ig directed against goat IgG. By transmission electron microscopy, gold particles were localized to the matrix of cytoplasmic granules. Control sections treated with nonimmune sera did not exhibit labeling of mast cells. Thin sections treated simultaneously with purified rat mast cell chymase and anti-chymase antibody in competition studies, showed a marked reduction in granule staining. These findings demonstrate that a microwave fixation method can be used to rapidly fix cell suspensions for postembedding immunocytochemical studies.

  5. Miniarthrotomy assisted percutaneous screw fixation for displaced medial malleolus fractures – A novel technique

    PubMed Central

    Saini, Pramod; Aggrawal, Abhinav; Meena, Sanjay; Trikha, Vivek; Mittal, Samarth

    2014-01-01

    Aim To describe here a technique of miniarthrotomy assisted percutaneous screw insertion for displaced Herscovici type B and C medial malleolar fractures. Method Incision was made centred over the superomedial angle of the ankle mortise, about half a cm medial to tibialis anterior. Arthrotomy was done and reduction obtained. Percuntaneously, two 4 mm cancellous cannulated screws were inserted through medial malleolus. Results and conclusion This approach allows direct visualization of reduction, removal of entrapped soft tissue and preservation of saphenous vein and nerve. PMID:25983507

  6. Subpectoral biceps tenodesis: a new technique using an all-suture anchor fixation.

    PubMed

    Su, Wei-Ren; Ling, Florence Y; Hong, Chih-Kai; Chang, Chih-Hsun; Lin, Cheng-Li; Jou, I-Ming

    2015-02-01

    There are several options for LHB tenodesis; yet, there is no standard of care. This technical note describes an extramedullary all-suture anchor technique for LHB tenodesis that is similar to the extramedullary cortical button technique. The LHB tenodesis is performed by using the Y-Knot (1.3-mm; ConMed Linvatec, Largo, FL).The biceps tenotomy is completed arthroscopically, and a standard subpectoral approach is used for the tenodesis. A reamer is first used to drill through the anterior cortex of the humerus; subsequently, a 1.3-mm drill bit is used to drill through the posterior cortex. The Y-Knot anchor is passed through the bone tunnel and secured on the posterior cortical bone. A modified rolling hitch suture is placed 10 mm distal to the end of the LHB tendon by using one suture limb of the Y-Knot anchor. The other suture limb is pulled to shuttle the LHB tendon into the humerus, and the construct is fixed by tying down one limb to the other. This technical note describes an alternative method for subpectoral biceps tenodesis and uses a small drill hole, conserves bone, and minimizes trauma to the tendon. V.

  7. A new laparoscopic technique for uterine prolapse: one-sided uterine fixation through the round ligament.

    PubMed

    Hsieh, Ching-Hung

    2011-02-01

    In this study, we provide a description of laparoscopic uterine suspension technique through round ligament. From 1997 to 2010, 55 patients with uterine prolapse were treated by laparoscopic uterine suspension. It is performed by suturing and tying a 1-0 Ethibond on the left round ligament at its insertion into the uterus. Then curved forceps pass the lateral puncture wound into the extraperitoneal space along the round ligament and penetrates the anterior leaf of the broad ligament into the peritoneal cavity and grasps the free ends of the Ethibond. They are withdrawn extraperitoneally along the round ligament then tightly tied at the fasciae on either side of the lateral puncture wound. Forty-two out of 55 patients (76.4%) experienced a reduction of prolapse to stage 0, regardless of what stage they started from. Twelve out of 55 (21.8%) experienced a reduction of prolapse varying from one to two stages. One out of 55 (1.8%) experienced no reduction in prolapse. This technique reconstructs a new, inelastic round ligament.

  8. Biomechanical comparison of two techniques for arthroscopic suprapectoral biceps tenodesis: interference screw versus implant-free intraosseous tendon fixation.

    PubMed

    Sampatacos, Nels; Getelman, Mark H; Henninger, Heath B

    2014-11-01

    A novel arthroscopic technique allows for intraosseous tendon placement in biceps tenodesis using bone tunnels and suture while avoiding the expense of an implant. No biomechanical characterization exists for this construct. Tensile tests were used to compare a suture-only biceps tenodesis technique (arthroscopic biceps intraosseous tenodesis [ABIT]) with interference screws in 7 pairs of cadaveric shoulders. The ABIT used a modified finger-trap suture method to secure the tendon to itself through an intraosseous bone tunnel. Interference screw placement followed the manufacturer's protocol for implantation. An open technique was used to provide consistency during laboratory preparation. During cyclic loading, the screws were significantly stiffer (P = .040) but dissipated more energy (P = .002). During failure loading, suture-only specimens showed significantly greater failure loads (P < .001) and deformation (P = .046). The failure mechanism for the ABIT method was tendon elongation with progressive tensioning and slippage of the tendon through the suture mass. No complete tendon failure occurred for the ABIT. Gross tendon failure occurred in all interference screw tests at the bone-tendon-screw interface. No screw or suture failed in any biceps tendon test. The ABIT construct showed significantly higher failure loads and deformation compared with interference screws. The comparable stiffness after cycling of both constructs suggests that micromotion at the bone-tendon interface is similar, which-in addition to the intraosseous fixation-may be important in promoting healing. The ABIT construct was found to absorb and restore more energy (hysteresis), suggesting potential for greater tendon preservation, which may translate into improved construct longevity. The suture-only method can eliminate the expense of an implant. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  9. Meniscal Allograft Transplantation With Soft Tissue in Bone Socket Fixation: Arthroscopic Technique With Technical Pearls.

    PubMed

    Roberson, Troy A; Wyland, Douglas J

    2017-04-01

    Meniscal allograft transplantation may slow the progression of degenerative changes in the meniscus-deficient knee. The current literature suggests patients can experience good early to mid-term satisfaction and patient-reported outcomes with reasonable expectations of return to work. More ambitious applications in athletes have also shown good results although long-term data are lacking. Traditionally, meniscal allograft transplantation has been considered an open procedure with incorporation of bone blocks from the allograft source. However, as arthroscopic techniques have advanced, it has become possible to perform this procedure through a predominantly arthroscopic approach while securing the soft tissue graft in bone tunnels. The current demonstration provides this background and technical pearls for success in arthroscopic meniscal allograft transplantation.

  10. A Simple Technique of Studying Water Deficit Effects on Nitrogen Fixation in Nodules without Influencing the Whole Plant

    PubMed Central

    Khanna-Chopra, Renu; Koundal, Kirpa R.; Sinha, Suresh K.

    1984-01-01

    Cowpea (Vigna unguiculata L. Walp cv C-152) plants were grown in a system in which watering was withheld from the soil zone containing nodules, while the plants were able to maintain normal water status. The system was developed in a pot by making two soil zones, an upper and a lower separated by a gravel column between these two zones. Plants extended their roots into the lower layer of soil and were able to absorb water. The dry matter accumulation, photosynthesis rate, and leaf area development of the plant were not affected when the upper soil zone was dried, but the water potential of the nodules was lower than in the nodules in fully irrigated pots. Nitrogenase activity in the nodules obtained from plants stressed in the upper zone only was lower than in nodules obtained from fully irrigated plants. The present technique is helpful in distinguishing the direct water stress effects on nitrogen fixation compared to those mediated via photosynthate availability. PMID:16663809

  11. Safety screw fixation technique in a case of coracoid base fracture with acromioclavicular dislocation and coracoid base cross-sectional size data from a computed axial tomography study.

    PubMed

    Kawasaki, Yoshiteru; Hirano, Tetsuya; Miyatake, Katsutoshi; Fujii, Koji; Takeda, Yoshitsugu

    2014-07-01

    Coracoid base fracture accompanied by acromioclavicular joint dislocation with intact coracoclavicular ligaments is a rare injury. Generally, an open reduction with screw fixation is the first treatment choice, as it protects the important structures around the coracoid process. This report presents a new technique of screw fixation for coracoid base fracture and provides anatomic information on cross-sectional size of the coracoid base obtained by computed tomography (CT). An axial image of the coracoid base was visualized over the neck of the scapula, and a guidewire was inserted into this circle under fluoroscopic guidance. The wire was inserted easily into the neck of scapula across the coracoid base fracture with imaging in only 1 plane. In addition, 25 measurements of the coracoid base were made in 25 subjects on axial CT images. Average length of the long and short axes at the thinnest part of the coracoid base was 13.9 ± 2.0 mm (range 10.6-17.0) and 10.5 ± 2.2 mm (6.6-15.1), respectively. This new screw fixation technique and measurement data on the coracoid base may be beneficial for safety screw fixation of coracoid base fracture.

  12. Pars plana suture fixation for intraocular lenses dislocated into the vitreous cavity using a closed-eye cow-hitch technique.

    PubMed

    Nakashizuka, Hiroyuki; Shimada, Hiroyuki; Iwasaki, Yutaka; Matsumoto, Yoko; Sato, Yukihiro

    2004-02-01

    We describe a modified intraocular cow-hitch technique for pars plana suture fixation of intraocular lenses (IOLs) that dislocated into the vitreous cavity in 3 patients who had a 3-port vitrectomy and IOL implantation because of retinal disease. To reposition the dislocated IOL after the residual vitreous was removed, 2 additional sclerotomies for suture fixation were made 3.0 mm posterior to the limbus. A loop (cow-hitch knot) was made with 10-0 polypropylene for suture fixation. After the neck of the cow-hitch loop was grasped with an intraocular forceps, the loop was used to lasso a haptic of the dislocated IOL, which was then pulled forward to the sclerotomy. The same procedure was used for the other haptic, and both sutures were secured to the sclera under scleral flaps. In all patients, the dislocated IOLs were repositioned without the need for extraction. The procedures were uneventful. Pars plana suture fixation with the intraocular cow-hitch technique can be used to reposition an IOL that has dislocated into the vitreous cavity.

  13. 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

  14. Catheter fixation and ligation: a simple technique for ventriculostomy management following endovascular stenting.

    PubMed

    Sweeney, Justin M; Vasan, Rohit; van Loveren, Harry R; Youssef, A Samy; Agazzi, Siviero

    2013-05-01

    The object of this study was to describe a unique method of managing ventriculostomy catheters in patients on antithrombotic therapy following endovascular treatment of ruptured intracranial aneurysms. The authors retrospectively reviewed 3 cases in which a unique method of ventriculostomy management was used to successfully avoid catheter-related hemorrhage while the patient was on dual antiplatelet therapy. In this setting, ventriculostomy catheters are left in place and fixed to the calvarium with titanium straps effectively ligating them. The catheter is divided and the distal end is removed. The proximal end can be directly connected to a distal shunt system during this stage or at a later date if necessary. The method described in this report provided a variety of management options for patients requiring external ventricular drainage for subarachnoid hemorrhage. No patient suffered catheter-related hemorrhage. This preliminary report demonstrates a safe and effective method for discontinuing external ventricular drainage and/or placing a ventriculoperitoneal shunt in the setting of active coagulopathy or antithrombotic therapy. The technique avoids both the risk of hemorrhage related to catheter removal and reinsertion and the thromboembolic risks associated with the reversal of antithrombotic therapy. Some aneurysm centers have avoided the use of stent-assisted coiling in cases of ruptured aneurysms to circumvent ventriculostomy-related complications; however, the method described herein should allow continued use of this important treatment option in ruptured aneurysm cases. Further investigation in a larger cohort with long-term follow-up is necessary to define the associated risks of infection using this method.

  15. 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. Georg Thieme

  16. Biomechanical evaluation of supplemental percutaneous lumbo-sacro-iliac screws for spinopelvic fixation following total sacrectomy.

    PubMed

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

    2015-05-01

    This is a cadaveric biomechanical study evaluating the biomechanical properties of a novel spinopelvic fixation technique with percutaneous lumbo-sacro-iliac (LSI) screws in an unstable total sacrectomy model. To compare standard posterior dual rod spinopelvic fixation alone with dual rod fixation supplemented with LSI screw fixation. Primary or metastatic tumors of the sacrum requiring a total sacrectomy can result in spinopelvic 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. Ten fresh-frozen cadaveric spinopelvic 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). After 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 Student t test was used for statistical analysis with significance set at P<0.05. 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 2 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. 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 warranted that take into account forward bending and sagittal stability.

  17. 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

  18. Burnei's "double X" internal fixation technique for supracondylar humerus fractures in children: indications, technique, advantages and alternative interventions : Study and Research Group in Pediatric Orthopaedics-2012.

    PubMed

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

    2013-06-15

    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. 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 patients with supracondylar

  19. A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryziaslatipes) eggs and eleutheroembryos as lipid rich models.

    PubMed

    Mondon, J A; Howitt, J; Tosiano, M; Kwok, K W H; Hinton, D E

    2011-01-01

    Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.

  20. Soft tissue repair for tibialis anterior tendon ruptures using plate and screw fixation technique in combination with anterolateral thigh flaps transplantation.

    PubMed

    Mao, Haijun; Xu, Guanyue

    2015-09-17

    Traumatic ruptures of the tibialis anterior tendon are rare but can cause substantial functional deficiencies. This study aimed to evaluate the feasibility of a surgery for soft tissue repair of traumatic rupture of the tibialis anterior tendon by using a plate and screw fixation repair in combination with the free anterolateral thigh flaps transplantation. Eight consecutive patients with anterior tibialis tendon ruptures who visited orthopedics departments from February 2008 to February 2012 were included in our study. The ruptured tendon was reconstructed with plate and screw fixation technique, and the tissue defects were repaired with anterolateral thigh free flaps. The complications and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores were evaluated. Postoperative manual strength test was performed using a 0 to 5 scale. All flaps survived without any complications. The average preoperative and postoperative AOFAS ankle-hindfoot scores of the patients were 51 and 95, respectively. Good ankle dorsiflexion strength against strong resistance was observed in eight ankles postoperatively (manual strength of one patient was 4/5, the others were 5/5), and a substantial improvement in strength was noted compared with the preoperative examination. Soft tissue repair for tibialis anterior tendon rupture using plate and screw fixation technique in combination with anterolateral thigh flaps transplantation is a feasible technique and yield satisfactory results.

  1. [Underlying mechanisms and related techniques of stand establishment of cotton on coastal saline-alkali soil].

    PubMed

    Dong, He-Zhong

    2012-02-01

    Stand establishment is the most difficult step for cotton planting on coastal saline-alkali soil. To establish and improve the techniques for stand establishment is the key in the production of high-yielding cotton on saline-alkali soil. Based on the previous studies and our own research progress in this field, this paper reviewed the effects and the underlying mechanisms of making unequal salt distribution in root zone, increasing soil moisture and temperature, establishing under-mulching greenhouse, and introducing seed coating agent in promoting stand establishment of cotton on saline-alkali soil. It was suggested that under the conditions of the average salt content in topsoil being not able to reduce, improving at least partial root zone environment through the induction of unequal salt distribution in the root zone and increasing soil moisture and temperature could significantly reduce salt injury and improve stand establishment. Flat seeding under plastic mulching on low-salinity soil, furrow seeding with mulching on moderate- or high-salinity soil, early mulching before sowing on rain-fed saline soil, and late sowing of short-season cotton in heat-limited area were the efficient techniques for improving the stand establishment of cotton on coastal saline-alkali soil. This review could provide full guarantee for the cotton stand establishment on coastal saline-alkali soil.

  2. Surgical Treatment of Occipitocervical Dislocation with Atlas Assimilation and Klippel-Feil Syndrome Using Occipitalized C1 Lateral Mass and C2 Fixation and Reduction Technique.

    PubMed

    Yin, Yi-Heng; Qiao, Guang-Yu; Yu, Xin-Guang

    2016-11-01

    To introduce and assess a surgical treatment of occipitocervical (OC) dislocation with atlas assimilation and Klippel-Feil syndrome (KFS) using occipitalized C1 lateral mass and C2 fixation and reduction technique. From January 2007 to August 2013, 58 symptomatic patients with OC dislocation and KFS of C2-3 congenital fusion and atlas assimilation were surgically treated in our institution via this technique. After opening the C1-2 facet joints via a posterior approach, OC reduction was conducted by intraoperative manipulation and C1 lateral mass and C2 pedicle screw and rod fixation. The instrument position, fusion status, and clinical outcome were analyzed. The average follow-up was 36 months (range, 18-52 months). Radiologically, effective reduction was achieved in 56 patients (96.6%) and <50% reduction in 2 (3.4%) who had additional transoral decompression. Neurologic improvement and solid bone fusion were achieved in all patients. The clinical symptoms improved for all patients, with the averaged Japanese Orthopedic Association myelopathy scores increasing from 11.5 to 15.6 (P < 0.01). In patients with OC dislocation and KFS of C2-3 fusion and atlas assimilation, posterior manipulative reduction combined with occipitalized C1 lateral mass and C2 fixation provides a reliable and effective treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Percutaneous reduction and fixation of an intra-articular calcaneal fracture using an inflatable bone tamp: description of a novel and safe technique

    PubMed Central

    2012-01-01

    Calcaneal fractures are common injuries involving the hind foot and often a source of significant long-term morbidity. Treatment options have changed throughout the ages from periods of preferred nonoperative management to closed reduction with a mallet, and more recently, open reduction and anatomic internal fixation. The current treatment of choice; however, is often debated, as open management of these fractures carries many risks to include wound breakdown and infection. A less invasive form of surgical management through small incisions, while maintaining the ability to obtain joint congruency, anatomic alignment, and restore calcaneal height and width would be ideal. We propose a novel form of fracture reduction using an inflatable bone tamp and percutaneous fracture fixation. Preoperative planning and experienced fluoroscopy is crucial to successful management using this method. Although we achieved successful radiographic outcome in this case, long-term functional outcome of this technique are yet to be published. PMID:22420710

  4. Posterior C1-C2 Fixation Using Absorbable Suture for Type II Odontoid Fracture in 2-Year-Old Child: Description of a New Technique and Literature Review.

    PubMed

    Labbe, Jean L; Peres, Olivier; Leclair, Olivier; Goulon, Renaud; Scemama, Patrice; Jourdel, François; Bertrou, Véronique; Murgier, Jerome

    2016-12-01

    Odontoid synchondrosis fractures are rare in children, even though they are the more common cervical fracture in children less than 7 years old. Nonoperative treatment with external orthosis immobilization is the treatment of choice for stable undisplaced or minimally displaced injuries. In unstable fractures, when reduction cannot be achieved or maintained, surgical fixation is recommended. We report a 2-year-old boy with an unstable fracture of the odontoid treated surgically using an absorbable monofilament suture for C1-C2 interlaminar fixation without bone grafting. This suture was strong enough to provide the stability necessary to allow healing of the synchondrosis and the delayed resorption of the suture was followed by complete restoration of the mobility between C1 and C2. This case illustrates that surgical stabilization using an absorbable suture in young children with an unstable odontoid fracture is a safe and effective alternative to other surgical techniques.

  5. Surgical technique: establishing a pre-clinical large animal model to test aortic valve leaflet substitute

    PubMed Central

    Knirsch, Walter; Cesarovic, Niko; Krüger, Bernard; Schmiady, Martin; Frauenfelder, Thomas; Frese, Laura; Dave, Hitendu; Hoerstrup, Simon Philipp; Hübler, Michael

    2016-01-01

    To overcome current limitations of valve substitutes and tissue substitutes the technology of tissue engineering (TE) continues to offer new perspectives in congenital cardiac surgery. We report our experiences and results implanting a decellularized TE patch in nine sheep in orthotropic position as aortic valve leaflet substitute. Establishing the animal model, feasibility, cardiopulmonary bypass issues and operative technique are highlighted. PMID:28149571

  6. 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. © 2014 American Association of Anatomists.

  7. Contact angle hysteresis on polymer substrates established with various experimental techniques, its interpretation, and quantitative characterization.

    PubMed

    Bormashenko, Edward; Bormashenko, Yelena; Whyman, Gene; Pogreb, Roman; Musin, Albina; Jager, Rachel; Barkay, Zahava

    2008-04-15

    The effect of contact angle hysteresis (CAH) was studied on various polymer substrates with traditional and new experimental techniques. The new experimental technique presented in the article is based on the slow deformation of the droplet, thus CAH is studied under the constant volume of the drop in contrast to existing techniques when the volume of the drop is changed under the measurement. The energy of hysteresis was calculated in the framework of the improved Extrand approach. The advancing contact angle established with a new technique is in a good agreement with that measured with the needle-syringe method. The receding angles measured with three experimental techniques demonstrated a very significant discrepancy. The force pinning the triple line responsible for hysteresis was calculated.

  8. Evaluation of a technique of circumoval precipitin test using blood taken on filter paper and a microtiter technique of complement fixation test of Schistosoma japonicum.

    PubMed

    Tanaka, H; Matsuda, H; Blas, B L; Noseñas, J S

    1975-04-01

    For the circumoval precipitin test (COPT) blood was taken on quantitative blood sampling filter paper by finger prick from outpatients at the Schistosomiasis Control Pilot Project, Palo, Leyte, Philippines. The volume of serum available per strip of filter paper was 0.04 ml and this was extracted at 1:3, 1:5 and 1:8 dilutions. Lyophilized eggs of Schistosoma japonicum were mixed with the diluted serum on a microscope glass slide and incubated at 37 degrees C for 2 days. The reaction was read following the criterion made by Yokogawa et al. [11]. The serum at 1:8 was too dilute to make correct diagnosis; serum at 1:3 dilution contained too much hemoglobin which made microscopic observation difficult and the extract at 1:5 was found to be appropriate. There was no remarkable difference in antigenicity among 3 preparations of lyophilized eggs from Kofu strain, Japan, and those of new and old preparations from Philippine strain. Under the best condition, false negative results appeared in 15.3% of 152 outpatients in Leyte and false positives in 2% of 50 human sera collected in Tokyo. This method of COPT is not satisfactory for the diagnosis of individual cases but is useful in the epidemiological assessment of Schistosoma infections because of the simplicity of blood sampling from dwellers of infested areas and also because it shows nearly the same sensitivity as that of a single fecal examination by the MIFC method. A microtiter technique of complement fixation test (CFT) was also studied. This method, however, was less sensitive than the COPT or a single fecal examination as to give 23.7% false negatives. Frequency distributions of CF and COP titers were analysed among egg positive, egg negative and treated groups. The results showed that treatment with stibophen had little influence in lowering the serum response, especially in COPT.

  9. 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

  10. Management of Gustilo Anderson III B open tibial fractures by primary fascio-septo-cutaneous local flap and primary fixation: The ‘fix and shift’ technique

    PubMed Central

    Ramasamy, P R

    2017-01-01

    Background: Open fractures of tibia have posed great difficulty in managing both the soft tissue and the skeletal components of the injured limb. Gustilo Anderson III B open tibial fractures are more difficult to manage than I, II, and III A fractures. Stable skeletal fixation with immediate soft tissue cover has been the key to the successful outcome in treating open tibial fractures, in particular, Gustilo Anderson III B types. If the length of the open wound is larger and if the exposed surface of tibial fracture and tibial shaft is greater, then the management becomes still more difficult. Materials and Methods: Thirty six Gustilo Anderson III B open tibial fractures managed between June 2002 and December 2013 with “fix and shift” technique were retrospectively reviewed. All the 36 patients managed by this technique had open wounds measuring >5 cm (post debridement). Under fix and shift technique, stable fixation involved primary external fixator application or primary intramedullary nailing of the tibial fracture and immediate soft tissue cover involved septocutaneous shift, i.e., shifting of fasciocutaneous segments based on septocutaneous perforators. Results: Primary fracture union rate was 50% and reoperation rate (bone stimulating procedures) was 50%. Overall fracture union rate was 100%. The rate of malunion was 14% and deep infection was 16%. Failure of septocutaneous shift was 2.7%. There was no incidence of amputation. Conclusion: Management of Gustilo Anderson III B open tibial fractures with “fix and shift” technique has resulted in better outcome in terms of skeletal factors (primary fracture union, overall union, and time for union and malunion) and soft tissue factors (wound healing, flap failure, access to secondary procedures, and esthetic appearance) when compared to standard methods adopted earlier. Hence, “fix and shift” could be recommended as one of the treatment modalities for open III B tibial fractures. PMID:28216752

  11. New bone formation in nongrafted sinus lifting with space-maintaining management: a novel technique using a titanium bone fixation device.

    PubMed

    Kaneko, Takahiro; Masuda, Issei; Horie, Norio; Shimoyama, Tetsuo

    2012-03-01

    Sinus lifting without graft materials allows new bone formation in the sinus, but the amount of bone formation varies. This study aimed to investigate whether nongrafted sinus lifting using a titanium bone fixation device can promote bone formation in the sinus. Patients with atrophic posterior maxillae jeopardizing implant stability were included. After nongrafted sinus lifting in combination with implant placement, repositioning of the bone window and additional space-maintaining management were performed by use of the bone fixation device. The primary variables recorded retrospectively included implant survival and preoperative and postoperative alveolar crest height with and without Schneiderian membrane perforation. Independent variables included patient demographics, position and dimension of the implants, complications, and follow-up period. The t test was used for comparing differences in bone levels. The implant survival rate was estimated by uses of Kaplan-Meier statistics. The study included 11 patients (4 men and 7 women) and a total of 21 implants. Radiographically, new bone formation around the implant was generally observed in accordance with the implant apex. Postoperative alveolar crest height (mean, 10.9 ± 2.2 mm) was significantly higher compared with residual alveolar crest height (mean, 4.7 ± 1.4 mm), and no significant difference in bone formation was seen according to membrane perforation. The cumulative survival rate was 95.2%. This nongrafted sinus-lifting procedure using a bone fixation device could attain predictable bone formation. Additional space-maintaining management using a bone fixation device in a nongrafted sinus lift offers a useful technique for promoting bone formation in the sinus. Copyright © 2012. Published by Elsevier Inc.

  12. Percutaneous Facet Screw Fixation in the Treatment of Symptomatic Recurrent Lumbar Facet Joint Cyst: A New Technique

    SciTech Connect

    Amoretti, Nicolas Gallo, Giacomo Bertrand, Anne-Sophie; Bard, Robert L.; Kelekis, Alexis

    2016-01-15

    We present a case of percutaneous treatment of symptomatic recurrent lumbar facet joint cyst resistant to all medical treatments including facet joint steroid injection. Percutaneous transfacet fixation was then performed at L4–L5 level with a cannulated screw using CT and fluoroscopy guidance. The procedure time was 30 min. Using the visual analog scale (VAS), pain decreased from 9.5, preoperatively, to 0 after the procedure. At 6-month follow-up, an asymptomatic cystic recurrence was observed, which further reduced at the 1-year follow-up. Pain remained stable (VAS at 0) during all follow-ups. CT- and fluoroscopy-guided percutaneous cyst rupture associated with facet screw fixation could be an alternative to surgery in patients suffering from a symptomatic recurrent lumbar facet joint cyst.

  13. Distraction osteogenesis technique using an intramedullary nail and a monolateral external fixator in the reconstruction of massive postosteomyelitis skeletal defects of the femur

    PubMed Central

    Li, Zhihong; Zhang, Xiangsheng; Duan, Liqun; Chen, Xiaoming

    2009-01-01

    Background Large skeletal defects due to postosteomyelitis are uncommon, and they present a challenging reconstructive problem. The aim of our study was to summarize our experience performing a distraction osteogenesis technique using an intramedullary nail and a monolateral external fixator in the reconstruction of massive postosteomyelitis skeletal defects of the femur. Methods Between January 1998 and October 2004, 17 patients with massive postosteomyelitis skeletal defects of the femur (11 men and 6 women), underwent the reconstruction procedure. After osteotomy of diaphysis of the femur, we inserted an intramedullary nail into the femur, and we placed a monolateral external fixator with half-pins lateral to the nail. Lengthening was started on the seventh postoperative day at a rate of 1 mm/d. Once we achieved solid bone union, we removed the monolateral external fixator; the intramedullary nail remained for bone consolidation until reconsruction was complete. We assessed the outcomes clinically and radiographically at a mean of 70.3 months postoperatively. Results At follow-up (mean 70.3, range 14.0–96.0 mo), all the skeletal defects were filled, bone union at docking sites was achieved without bone graft and leg length discrepancies were less than 2.5 cm in all patients. The mean gain in length was 12.9 (range 10.2–18.4) cm. According to Paley and Maar's evaluation criteria, we graded the bone results as excellent for 10 patients, good for 5, fair for 1 and poor for 1. We graded the functional results as excellent for 12 patients, good for 4 and fair for 1. The mean external fixator index was 18.1 d/cm; the consolidation index was 35.7 d/cm. Ten patients experienced pin infection, and 1 patient experienced a recurrence of deep infection. There were no neurologic or vascular injuries. Conclusion Our study demonstrates that a distraction osteogenesis technique using an intramedullary nail and a monolateral external fixator is a reliable method for the

  14. Less invasive lumbopelvic fixation technique using a percutaneous pedicle screw system for unstable pelvic ring fracture in a patient with severe multiple traumas.

    PubMed

    Yano, Sei; Aoki, Yasuchika; Watanabe, Atsuya; Nakajima, Takayuki; Takazawa, Makoto; Hirasawa, Hiroyuki; Takahashi, Kazuhisa; Nakagawa, Koichi; Nakajima, Arata; Takahashi, Hiroshi; Orita, Sumihisa; Eguchi, Yawara; Suzuki, Takane; Ohtori, Seiji

    2017-02-01

    Pelvic ring fractures are defined as life-threatening injuries that can be treated surgically with external or internal fixation. The authors report on an 81-year-old woman with an unstable pelvic fracture accompanying multiple traumas that was successfully treated with a less invasive procedure. The patient was injured in a traffic accident and sustained a total of 20 fractures, including pelvic ring, bilateral rib, and lumbar transverse processes fractures, and multiple fractures of both upper and lower extremities. The pelvic ring fracture was unstable with fractures of the bilateral sacrum with right sacroiliac disruption, right superior and inferior pubic rami, left superior pubic ramus, and ischium. During emergency surgery, bilateral external fixation was applied to the iliac crest to stabilize the pelvic ring. Second and third surgeries were performed 11 and 18 days after the first emergency surgery, respectively, to treat the multiple fractures. At the third surgery, the pelvic ring fracture was stabilized surgically using a less invasive posterior fixation technique. In this technique, 2 iliac screws were inserted on each side following an 8-cm midline posterior incision from the S-1 to S-3 spinous process, with the subcutaneous tissue detached from the fascia of the paraspinal muscles. The S-2 spinous process was removed and 2 rods were connected to bilateral iliac screws to stabilize the bilateral ilium in a switchback fashion. A crosslink device was applied to connect the 2 rods at the base of the S-2 spinous process. Following pelvic fixation, percutaneous pedicle screws were inserted into L-4 and L-5 vertebral bodies on both sides, and connected to the cranial rod connecting the bilateral iliac screws, thus completing the lumbopelvic fixation. The postoperative course was favorable with no postoperative complications. At the 10-month follow-up, bone union had been achieved at the superior ramus of the pubis, the patient did not complain of pain, and

  15. A Challenging Case of Limb Salvage Requiring a Combination of Composite Fixation and Masquelet Technique to Address Significant Segmental Bone Loss

    PubMed Central

    Blair, C.; Simela, A. T.; Cross, B. J.

    2015-01-01

    Cases of limb salvage following skeletal trauma involving significant bone loss pose a particular challenge to the reconstructive surgeon. Certain techniques for addressing this complex issue have been advanced in recent years and have met with considerable success. The Masquelet technique involves a staged procedure in which a temporary skeletal stabilization is paired with implantation of an antibiotic spacer and left in place for 6–8 weeks, during which time a “pseudomembrane” forms around the cement spacer. During the second stage of the procedure, the pseudomembrane is incised, the antibiotic spacer removed, and bone graft is placed. We present a case of significant segmental femur loss in a 19-year-old male opting for limb salvage in which a 17-centimeter segmental loss of bone was essentially regrown using a combination of the Masquelet technique with supplemental endosteal fixation. PMID:25789190

  16. Pullout strength of a novel hybrid fixation technique (Tape Locking Screw™) in soft-tissue ACL reconstruction: A biomechanical study in human and porcine bone.

    PubMed

    Ayzenberg, M; Arango, D; Gershkovich, G E; Samuel, P S; Saing, M

    2017-06-01

    A novel hybrid anterior cruciate ligament (ACL) reconstruction technique known as Tape Locking Screw™ (TLS) is gaining popularity. Utilizing a suspension-type construct in conjunction with an interference screw, this technique has demonstrated successful initial clinical results with the use of quadruple hamstring graft. However, there is currently limited data available on the biomechanical strength of this fixation. This study investigates the pullout strength of the construct in human distal femora as well as in a porcine model. The construct is tested in isolation, without the use of any graft. We hypothesized that the pullout strength of this construct would be similar to or better than current fixation systems available. The Tape Locking Screw hybrid fixation system was implanted into twenty-two fresh frozen human distal femora (50-89 years old) randomized to 10×20mm titanium or polyether ether ketone (PEEK) screws by a single sports fellowship trained orthopedic surgeon. Given that the graft is secured to polyethylene terephthalate tape within the construct, the construct was implanted without any graft in order to isolate the device for biomechanical testing. After implantation, a tensile force was applied directly to the loop of tape at a loading rate of 5mm/min using an electromechanical testing system. The failure load was calculated from the resultant load-displacement curve. Specimens were then visually examined for mode of failure. Similar biomechanical tests were performed on sixteen porcine femora. In the human model, the mean pullout strength was 523±269N with the PEEK screw and 578±245N with the titanium screw. In the porcine femur model, mean strength was 616±177N with PEEK, 584±245N with titanium. There was no statistically significant difference in failure loads between these four groups. Tape slippage at the screw bone interface was the primary mode of failure in all the groups tested. Our results demonstrate that the hybrid technique

  17. Anatomical evaluation of the groove for the vertebral artery in the axis vertebrae for atlanto-axial transarticular screw fixation technique.

    PubMed

    Kazan, S; Yildirim, F; Sindel, M; Tuncer, R

    2000-01-01

    Anatomical measurements were studied on 40 dry axis vertebrae to determine the suitability of the groove for the vertebral artery for atlanto-axial transarticular screw fixation technique. We measured 13 parameters including three angular and 10 linear dimensions related to the groove of the vertebral artery, pedicle, and pars interarticularis and evaluated 80 measurements for each parameter. All measurements were done after placing a Kischner guide wire through the pedicle. We found that differences between measurements on the left and right sides of each vertebra were nonsignificant. In spite of the variability in measurements such as height, width, and median angle of the pedicle, the decline angle for instrumentation, the depth of the groove for the vertebral artery, and the internal height of the pars interarticularis, all of these had good symmetry. However, there were statistically significant differences between the sides in measurements for both the width (P=0.05) and the angle (P<0.02) of the pedicle allowing instrumentation and they did not show good symmetry. The risk of vertebral artery injury was found to be 22.5% per specimen, or 16.25% per screw inserted because the internal height of the pars interarticularis at point of fixation was technique would be extremely dangerous in 7.5% of specimens. In conclusion, the internal height of the pars interarticularis and the width of the pedicle for instrumentation should be evaluated together in thin CT sections preoperatively, because of the risk of vertebral artery injury in patients upon which atlanto-axial transarticular screw fixation is to be performed.

  18. Using a freeze substitution fixation technique and histological crimp analysis for characterizing regions of strain in ligaments loaded in situ.

    PubMed

    Boorman, Richard S; Norman, Tony; Matsen, Frederick A; Clark, John M

    2006-04-01

    Type I collagen fibrils in tendons and ligaments assume a sinusoidal wave shape, or crimp, which straightens only with tensile load. The load response of crimp has been studied primarily in isolated subunits and not in complex, intact structures. The purpose of our study was to determine if freeze substitution fixation of an entire ligament could preserve changes in crimp morphology induced by functionally relevant loading conditions. We hypothesized that, in ligaments prepared by freeze-substitution fixation under load, crimp would progressively extinguish with increasing loads, and nonuniform strain following partial section could be detected from crimp morphology. Tensile loads ranging from 0 to 220 N were applied to patellar ligaments of 16 fresh rabbit stifle joints using simulated isometric quadriceps pull through the patella. The loaded joints were flash frozen with isopentane cooled in liquid nitrogen, then fixed using freeze substitution. Another six ligaments were loaded to 150 N following incision of the anterior third and evaluated under polarized light microscopy for crimp distribution. Ligaments with no or low loads could be identified by the presence of crimp on mid-sagittal sections. Strain distribution was inhomogeneous, in that the ligament displayed a consistent pattern of collagen fiber recruitment among three morphologically distinct bands seen on coronal sections. At very low loads (about 18 N), the fibers in a central band were uncrimped; anterior and deep bands uncrimped at higher loads. The crimp in the entire specimen was extinguished at about 67 N, which correlates closely with the previously reported toe-region of the stress-strain curve of the rabbit patellar ligament. When the anterior third was transected, fibers within that segment retained a crimp in ligaments prepared under loads that ordinarily would ablate all crimp. These findings suggest that freeze fixation could be used to map the functional microstructure of ligaments or

  19. Fixation of diaphyseal fractures with a segmental defect: a biomechanical comparison of locked and conventional plating techniques.

    PubMed

    Fulkerson, Eric; Egol, Kenneth A; Kubiak, Erik N; Liporace, Frank; Kummer, Frederick J; Koval, Kenneth J

    2006-04-01

    Locking plates are an alternative to conventional compression plate fixation for diaphyseal fractures. The objective of this study was to compare the stability of various plating with locked screw constructs to conventional nonlocked screws for fixation of a comminuted diaphyseal fracture model using a uniform, synthetic ulna. Locked screw construct variables were the use of unicortical or bicortical screws, and increasing bone to plate distance. This biomechanical study compared various construct groups after cyclic axial loading and three-point bending. Results were analyzed via one-way analysis of variance. Displacements after cyclical axial loading and number of cycles to failure in cyclic bending were used to assess construct stability. The constructs fixed by plates with bicortical locked screws withstood significantly more cycles to failure than the other constructs (p < 0.001). Significantly less displacement occurred after axial loading with bicortical locked screws than with bicortical nonlocked screws. Increased distance of the plate from the bone surface, and use of unicortical locked screws led to early failure with cyclic loading for constructs with locked screws. These results support the use of plating with bicortical locked screws as an alternative to conventional plating for comminuted diaphyseal fractures in osteoporotic bone. Bicortical locked screws with minimal displacement from the bone surface provide the most stable construct in the tested synthetic comminuted diaphyseal fracture model. The results of this study suggest use of plates with unicortical screws for the described fracture is not recommended.

  20. 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

  1. Influence of Different Tibial Fixation Techniques on Initial Stability in Single-Stage Anterior Cruciate Ligament Revision With Confluent Tibial Tunnels: A Biomechanical Laboratory Study.

    PubMed

    Schliemann, Benedikt; Treder, Maximilian; Schulze, Martin; Müller, Viktoria; Vasta, Sebastiano; Zampogna, Biaggio; Herbort, Mirco; Kösters, Clemens; Raschke, Michael J; Lenschow, Simon

    2016-01-01

    To kinematically and biomechanically compare 4 different types of tibial tunnel management in single-stage anterior cruciate ligament (ACL) revision reconstruction with the control: primary ACL reconstruction using a robotic-based knee testing setup. Porcine knees and flexor tendons were used. One hundred specimens were randomly assigned to 5 testing groups: (1) open tibial tunnel, (2) bone plug technique, (3) biodegradable interference screw, (4) dilatation technique, and (5) primary ACL reconstruction. A robotic/universal force-moment sensor testing system was used to simulate the KT-1000 (MEDmetric, San Diego, CA) and pivot-shift tests. Cyclic loading and load-to-failure testing were performed. Anterior tibial translation increased significantly with all of the techniques compared with the intact ACL (P < .05). In the simulated KT-1000 test, groups 2 and 3 achieved results equal to those of primary ACL reconstruction (P > .05). The open tunnel and dilated tunnel techniques showed significantly greater anterior tibial translation (P < .05). The results of the simulated pivot-shift test were in accordance with those of the KT-1000 test. No significant differences could be observed regarding stiffness or maximum load to failure. However, elongation was significantly lower in the primary ACL reconstruction group compared with groups 1 and 3 (P = .02 and P = .03, respectively). Filling an incomplete and incorrect tibial tunnel with a press-fit bone plug or a biodegradable interference screw in a standardized laboratory situation provided initial biomechanical properties and knee stability comparable with those of primary ACL reconstruction. In contrast, the dilatation technique or leaving the malplaced tunnel open did not restore knee kinematics adequately in this model. Backup extracortical fixation should be considered because the load to failure depends on the extracortical fixation when an undersized interference screw is used for aperture fixation. Our

  2. Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

    PubMed Central

    2017-01-01

    Herein, the benefits which extrusion can provide for the automated continuous synthesis of organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this. This review highlights these transformations and discusses how this previous research can be applied to the future of organic compound manufacture. PMID:28179950

  3. Extrusion - back to the future: Using an established technique to reform automated chemical synthesis.

    PubMed

    Crawford, Deborah E

    2017-01-01

    Herein, the benefits which extrusion can provide for the automated continuous synthesis of organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this. This review highlights these transformations and discusses how this previous research can be applied to the future of organic compound manufacture.

  4. 15 CFR 923.42 - State establishment of criteria and standards for local implementation-Technique A.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... standards for local implementation-Technique A. 923.42 Section 923.42 Commerce and Foreign Trade Regulations...—Technique A. (a) The management program must provide for any one or a combination of general techniques... zone. The first such control technique, at subsection 306(d)(11)(A) of the Act, is state establishment...

  5. Is Arthroscopic Technique Superior to Open Reduction Internal Fixation in the Treatment of Isolated Displaced Greater Tuberosity Fractures?

    PubMed

    Liao, Weixiong; Zhang, Hao; Li, Zhongli; Li, Ji

    2016-05-01

    Arthroscopic double-row suture-anchor fixation and open reduction and internal fixation (ORIF) are used to treat displaced greater tuberosity fractures, but there are few data that can help guide the surgeon in choosing between these approaches. We therefore asked: (1) Is there a difference in surgical time between arthroscopic double-row suture anchor fixation and ORIF for isolated displaced greater tuberosity fractures? (2) Are there differences in the postoperative ROM and functional scores between arthroscopic double-row suture anchor fixation and ORIF for isolated displaced greater tuberosity fractures? (3) Are there differences in complications resulting in additional operations between the two approaches? Between 2006 and 2012, we treated 79 patients surgically for displaced greater tuberosity fractures. Of those, 32 (41%) were considered eligible for our study based on inclusion criteria for isolated displaced greater tuberosity fractures with a displacement of at least 5 mm but less than 2 cm. During that time, we generally treated patients with displaced greater tuberosity fractures with a displacement greater than 1 cm or with a fragment size greater than 3×3 cm with open treatment, and patients with displaced greater tuberosity fractures with a displacement less than 1 cm or with a fragment size less than 3×3 cm with arthroscopic treatment. Fifty-three underwent open treatment based on those indications, and 26 underwent arthroscopic treatment, of whom 17 (32%) and 15 (58%) were available for followup at a mean of 34 months (range, 24-28 months). All patients with such fractures identified from our institutional database were treated by these two approaches and no other methods were used. Surgical time was defined as the time from initiation of the incision to the time when suture of the incision was finished, and was determined by an observer with a stopwatch. Patients were followed up in the outpatient department at 6, 12, and 24 weeks, and every 6

  6. Management of severe open ankle-foot trauma by a simple external fixation technique: an alternative during war and in resource-poor and low-technology environments.

    PubMed

    Pedrini, Gianpaolo; Cardi, Maurizio; Landini, Alberto; Strada, Gino

    2011-03-01

    Severe open foot and ankle injuries are still a challenge for the orthopaedic surgeon. Their treatment is even more difficult in third world countries and in war settings where high-energy trauma with severe soft tissue damage is more frequent. Lack of equipment, poor resources and hygiene, and different cultural systems make most of the standard proposed treatments difficult to apply. The authors describe an inexpensive, rapid, minimally invasive, and easy-to-apply external fixation technique for the treatment of severe open ankle-foot fractures. With the main goal of soft tissue management rather than definitive treatment of any bony injuries, this technique was developed over time during many consecutive missions in Sierra Leone and Afghanistan as an alternative to more appropriate treatments with surprisingly satisfactory short- and long-term results.

  7. The Effect of Fixation Technique on Continuous Interscalene Nerve Block Catheter Success: A Randomized, Double-Blind Trial.

    PubMed

    Auyong, David B; Cantor, David Asher; Green, Cynthia; Hanson, Neil A

    2017-03-01

    Continuous peripheral nerve blocks offer advantages over single-injection blocks, including extended analgesia and reduction in opioid consumption. These benefits require that the perineural catheter remain intact for the duration of the planned local anesthetic infusion. Mechanical displacement of catheters, leaking, and consequent failure are known complications. The aim of this study was to evaluate continuous perineural catheter tip-to-nerve apposition in vivo over 48 hours comparing 2 different simple fixation strategies. Subjects presenting for a continuous interscalene nerve block were randomized to perineural catheter fixation with 1 of 2 types of adhesive: Dermabond (2-octylcyanoacrylate) or Mastisol (alcohol 23A, gum mastic, storax, and methyl salicylate), covered with a simple transparent dressing. The primary outcome was the evaluation of catheter-to-nerve apposition maintenance over 48 hours via both a blinded ultrasound evaluation of local anesthetic distribution and a blinded clinical assessment. Secondary outcomes included leakage at the catheter site, pain scores, opioid consumption, catheter-to-skin migration at the insertion site, and patient satisfaction. Sixty-six subjects were recruited and randomized to compare adhesive group catheter tip-to-nerve apposition on postoperative day 2 (POD 2). Within the intention-to-treat cohort, a statistically significant decrease of perineural catheter tip-to-nerve apposition in the Mastisol group (64.7%) compared with the Dermabond group (90.6%) on POD 2 (odds ratios [OR] 0.19; 95% confidence interval [CI] 0.05-0.75; P = .012) was observed. Similar results were observed on POD 1 (OR 0.19; 95% CI 0.03-1.38; P = NS) and POD 2 (OR 0.14; 95% CI 0.02-0.97; P = .008) within the as-treated cohort. Catheter leakage (OR 67; 95% CI 7.3-589) and median catheter migration difference at the skin insertion site (2.0 cm; 95% CI 0.5-2.5) were also significantly greater in the Mastisol group than in the Dermabond group from

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

    PubMed Central

    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/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

  9. Single-screw Fixation of Adolescent Salter-II Proximal Humeral Fractures: Biomechanical Analysis of the "One Pass Door Lock" Technique.

    PubMed

    Miller, Mark Carl; Redman, Christopher N; Mistovich, R Justin; Muriuki, Muturi; Sangimino, Mark J

    2017-09-01

    Pin fixation of Salter-II proximal humeral fractures in adolescents approaching skeletal maturity has potential complications that can be avoided with single-screw fixation. However, the strength of screw fixation relative to parallel and diverging pin fixation is unknown. To compare the biomechanical fixation strength between these fixation modalities, we used synthetic composite humeri, and then compared these results in composite bone with cadaveric humeri specimens. Parallel pinning, divergent pinning, and single-screw fixation repairs were performed on synthetic composite humeri with simulated fractures. Six specimens of each type were tested in axial loading and other 6 were tested in torsion. Five pair of cadaveric humeri were tested with diverging pins and single screws for comparison. Single-screw fixation was statistically stronger than pin fixation in axial and torsional loading in both composite and actual bone. There was no statistical difference between composite and cadaveric bone specimens. Single-screw fixation can offer greater stability to adolescent Salter-II fractures than traditional pinning. Single-screw fixation should be considered as a viable alternative to percutaneous pin fixation in transitional patients with little expected remaining growth.

  10. Closed reduction using the percutaneous leverage technique and internal fixation with K-wires to treat angulated radial neck fractures in children-case report.

    PubMed

    Jiang, Hai; Wu, Yongtao; Dang, Youting; Qiu, Yusheng

    2017-01-01

    Pediatric radial neck fractures are uncommon. Severely displaced and angulated fractures usually require treatment. Our goals for treatment are to avoid incision, reduce the fracture adequately with no reduction loss, and achieve good postoperative function. We aimed to observe the clinical outcomes of closed reduction with the percutaneous leverage technique and internal fixation with Kirschner-wires (K-wires) to treat angulated radial neck fractures in children.From January 2011 to April 2013, we treated 16 cases of angulated radial neck fracture in 12 boys and 4 girls. Five fractures were type II and 11 fractures were type III using the O'Brien classification. One K-wire was percutaneously introduced into the fracture site using the leverage technique to attain good reduction. Two K-wires were introduced from the proximal to the distal areas of the fracture site. The elbow was immobilized by cast in 90° of flexion and the forearm in supination for 3 to 4 weeks. The K-wires were removed at 3 to 4 weeks postoperatively. All cases were followed up for a mean duration of 3 years 6 months.According to the Metaizeau reduction classification, 12 cases were excellent, and 4 cases were good. According to the Metaizeau clinical classification, 14 cases were excellent, and 2 cases were good. There was no necrosis of the radial head. There was no infection, radioulnar synostosis, and damage of the radial nerve deep branch. There was no limitation in the pronation and supination functions of the forearm.Closed reduction using the percutaneous leverage technique and internal fixation using K-wires is easy to perform. It is encouraged to use this approach as the clinical outcome is good. level IV-retrospective case, treatment study.

  11. Closed reduction using the percutaneous leverage technique and internal fixation with K-wires to treat angulated radial neck fractures in children-case report

    PubMed Central

    Jiang, Hai; Wu, Yongtao; Dang, Youting; Qiu, Yusheng

    2017-01-01

    Abstract Pediatric radial neck fractures are uncommon. Severely displaced and angulated fractures usually require treatment. Our goals for treatment are to avoid incision, reduce the fracture adequately with no reduction loss, and achieve good postoperative function. We aimed to observe the clinical outcomes of closed reduction with the percutaneous leverage technique and internal fixation with Kirschner-wires (K-wires) to treat angulated radial neck fractures in children. From January 2011 to April 2013, we treated 16 cases of angulated radial neck fracture in 12 boys and 4 girls. Five fractures were type II and 11 fractures were type III using the O’Brien classification. One K-wire was percutaneously introduced into the fracture site using the leverage technique to attain good reduction. Two K-wires were introduced from the proximal to the distal areas of the fracture site. The elbow was immobilized by cast in 90° of flexion and the forearm in supination for 3 to 4 weeks. The K-wires were removed at 3 to 4 weeks postoperatively. All cases were followed up for a mean duration of 3 years 6 months. According to the Metaizeau reduction classification, 12 cases were excellent, and 4 cases were good. According to the Metaizeau clinical classification, 14 cases were excellent, and 2 cases were good. There was no necrosis of the radial head. There was no infection, radioulnar synostosis, and damage of the radial nerve deep branch. There was no limitation in the pronation and supination functions of the forearm. Closed reduction using the percutaneous leverage technique and internal fixation using K-wires is easy to perform. It is encouraged to use this approach as the clinical outcome is good. Level of evidence: level IV-retrospective case, treatment study. PMID:28072734

  12. 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

  13. A biomechanical comparison of short segment long bone fracture fixation techniques: single large fragment plate versus 2 small fragment plates.

    PubMed

    Watts, Adriel; Weinhold, Paul; Kesler, William; Dahners, Laurence

    2012-09-01

    To determine whether using 2 small fragment plates (3.5 mm screw size) side by side is biomechanically superior to the use of 1 large fragment plate (4.5 mm screw size), in the fixation of "short segments" in long bone fractures. Fiber-filled epoxy bone surrogates were plated across 1-cm gaps with 3 different constructs. Six surrogates were fixed using 2 side-by-side 3.5-mm waisted compression plates and six 3.5-mm screws, 6 surrogates were fixed using one 4.5-mm waisted compression plate and two 4.5-mm screws, and 6 surrogates were fixed using one 3.5-mm waisted compression plate and three 3.5-mm screws. These constructs then underwent cyclic axial compression in 100-N increments until 500 N was reached. Then, they underwent cyclic cantilever bending at 2 Hz and at a 23.6 N·m moment until fatigue failure occurred. Also, a single load to failure test was performed in cantilever bending to evaluate plate strength. The cumulative gap length change after 500 cycles of loading up to 500 N was 3.4% ± 0.4% for the 3.5 mm double plate construct, 9.5% ± 1.4% for the 4.5 mm single plate construct, and 14.4% ± 0.9% for the 3.5 mm single plate construct. In cantilever bending, the 3.5 mm double plate construct failed after 15,345 ± 2493 cycles, the 4.5 mm single plate construct failed after 2713 ± 1811 cycles, and the 3.5 mm single plate construct failed in its first cycle. In single load to failure testing, the load at offset yield was higher in the 3.5 mm double plate construct than the 4.5 mm single plate construct. This study suggests that in situations where anatomy or other limitations limit the length of bone segments available for fixation, it may be preferable to use 2 small plates with more screws rather than 1 large plate with few screws.

  14. 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.

  15. Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

    PubMed

    Deorio, J K; Ware, A W

    2001-10-01

    The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

  16. Conversion from temporary external fixation to definitive fixation: shaft fractures.

    PubMed

    Dougherty, Paul J; Silverton, Craig; Yeni, Yener; Tashman, Scott; Weir, Robb

    2006-01-01

    Temporary external fixation is the most common method of initial stabilization of diaphyseal fractures in forward surgical hospitals. Once the patient arrives at a stable environment, usually the United States, the fracture is managed with intramedullary nailing, small-pin external fixation, or a modified external fixator. Future research should be directed toward improving methods of care. It is not precisely known when is the best time to convert to definitive fixation without increasing the risk of infection. The risk factors leading to infection and nonunion are not well-established, making that determination even more difficult. Clinical studies of a suitable size should provide insight into these problems. Although temporary external fixation is commonly used, an optimal construct has not been determined. Data from studies of in vivo fracture-site motion after application of the temporary external fixator should be compared with biomechanical testing of similar constructs. These data could be used to recommend optimal temporary external fixation constructs of tibia, femur, and humerus fractures using currently available devices as well as to provide groundwork for the next generation of fixators.

  17. Biomechanical comparison of 2 anterior cruciate ligament graft preparation techniques for tibial fixation: adjustable-length loop cortical button or interference screw.

    PubMed

    Mayr, Raul; Heinrichs, Christian Heinz; Eichinger, Martin; Coppola, Christian; Schmoelz, Werner; Attal, René

    2015-06-01

    Cortical button fixation at the femoral side and interference screws within the tibial bone tunnel are widely used for anterior cruciate ligament graft fixation. Using a bone socket instead of a full tunnel allows cortical button fixation on the tibial side as well. If adjustable-length loop cortical button devices are used for femoral and tibial fixation, the tendon graft has to be secured with sutures in a closed tendon loop. The increased distance of fixation points and potential slippage of the tendon strands at the securing sutures might lead to greater risk of postoperative graft elongation when compared with conventional graft preparation with tibial interference screw fixation. Compared with an anterior cruciate ligament graft with tibial adjustable-length loop cortical button fixation, a graft with tibial interference screw fixation will show less graft elongation during cyclic loading and lower ultimate failure loads. Controlled laboratory study. Grafts with tibial adjustable-length loop cortical button fixation and grafts with tibial interference screw fixation were biomechanically tested in calf tibiae (n = 10 per group). Femoral fixation was equivalent for both groups, using an adjustable-length loop cortical button. Specimens underwent cyclic loading followed by a load-to-failure test. Grafts with screw fixation showed significantly less initial elongation (cycles 1-5: 1.46 ± 0.26 mm), secondary elongation (cycles 6-1000: 1.87 ± 0.67 mm), and total elongation (cycles 1-1000: 3.33 ± 0.83 mm) in comparison with grafts with button fixation (2.47 ± 0.26, 3.56 ± 0.39, and 6.03 ± 0.61 mm, respectively) (P < .001). While pull-out stiffness was significantly higher for grafts with screw fixation (309.5 ± 33.2 vs 185.6 ± 16.4 N/mm) (P < .001), grafts with button fixation were able to withstand significantly higher ultimate failure loads (908 ± 74 vs 693 ± 119 N) (P < .001). Grafts with tibial adjustable-length loop cortical button fixation resulted

  18. Biomechanical comparison of odontoid plate fixation versus odontoid screw fixation.

    PubMed

    Platzer, Patrick; Eipeldauer, Stefan; Leitgeb, Johannes; Aldrian, Silke; Vécsei, Vilmos

    2011-05-01

    Randomized controlled trial with statistically significant difference or statistically no significant difference (Level I). The purpose of this study was to measure the mechanical stability of odontoid plate fixation, using a specially designed plate construct and to compare the results with those after odontoid single-screw and double-screw fixation. Plate fixation of the odontoid process without C1-C2 is a possible option for the management of odontoid fractures that are not suitable for conventional screw fixation. Although earlier biomechanical works have evaluated the effectiveness of different odontoid screw fixation techniques, no study has quantified the mechanical stability of odontoid fixation by a plate device. The second cervical vertebra was removed from 15 fresh human spinal columns. The specimens were fixed to the experimental apparatus with the load cell at the articular surface of the odontoid process. In the first test series, stiffness and failure load of the intact odontoid were measured. Type II odontoid fractures were created by a 45 degree oblique extension loading at the articular surface of the odontoid process. Afterward, the specimens were randomly assigned to 1 of the following 3 groups: in group I (n=5), the fractures were stabilized, using a specially designed plate construct, in group II, the fractures were fixed, using two 3.5 mm cortical screws, and in group III, we used 1 regular 4.5 mm cortical screw. In the second test series, stiffness and failure load of the stabilized odontoid fractures were assessed for comparison and statistical analysis. Group I (plate device) showed a significantly higher mean failure load than group II and group III. The mean failure load of group I, after fixation of the odontoid fracture, was 84% of the mean failure load that was necessary to create a type II odontoid fracture initially. Comparing group II (double screw technique) and group III (single screw technique), there was no significant

  19. Influence of the screw augmentation technique and a diameter increase on pedicle screw fixation in the osteoporotic spine: pullout versus fatigue testing.

    PubMed

    Kueny, Rebecca A; Kolb, Jan P; Lehmann, Wolfgang; Püschel, Klaus; Morlock, Michael M; Huber, Gerd

    2014-10-01

    For posterior spinal stabilization, loosening of pedicle screws at the bone-screw interface is a clinical complication, especially in the osteoporotic population. Axial pullout testing is the standard pre-clinical testing method for new screw designs although it has questioned clinical relevance. The aim of this study was to determine the fixation strength of three current osteoporotic fixation techniques and to investigate whether or not pullout testing results can directly relate to those of the more physiologic fatigue testing. Thirty-nine osteoporotic, human lumbar vertebrae were instrumented with pedicle screws according to four treatment groups: (1) screw only (control), (2) prefilled augmentation, (3) screw injected augmentation, and (4) unaugmented screws with an increased diameter. Toggle testing was first performed on one pedicle, using a cranial-caudal sinusoidal, cyclic (1.0 Hz) fatigue loading applied at the screw head. The initial compressive forces ranged from 25 to 75 N. Peak force increased stepwise by 25 N every 250 cycles until a 5.4-mm screw head displacement. The contralateral screw then underwent pure axial pullout (5 mm/min). When compared to the control group, screw injected augmentation increased fatigue force (27 %, p = 0.045) while prefilled augmentation reduced fatigue force (-7 %, p = 0.73). Both augmentation techniques increased pullout force compared to the control (ps < 0.04). Increasing the screw diameter by 1 mm increased pullout force (24 %, p = 0.19), fatigue force (5 %, p = 0.73), and induced the least stiffness loss (-29 %) from control. For the osteoporotic spine, screw injected augmentation showed the best biomechanical stability. Although pullout testing was more sensitive, the differences observed were not reflected in the more physiological fatigue testing, thus casting further doubt on the clinical relevance of pullout testing.

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

    PubMed

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

    2015-01-01

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

  1. Mini external fixation in the hand.

    PubMed

    Ugwonali, Obinwanne Fidelis C; Jupiter, Jesse B

    2006-09-01

    External fixation is an effective means of addressing several pathologies of the hand. The advantages of its use include the ability to achieve stable fixation, minimize soft tissue trauma at the site of injury, and allow wound care and mobilization of adjacent joints. External fixators can be constructed from material readily available in the operating room or obtained from a commercial source. Sufficient rigidity can be achieved by any of these means. Improper placement, although achieving rigid fixation, may compromise motion and overall function if basic principles of external fixation are not followed or if the anatomy of the hand is not taken into consideration. The objective of this article is to describe the technique of application of mini external fixation, emphasizing the basic principles of external fixation as they relate to the specific anatomy of the hand. In addition to fracture fixation, various other uses are described including distraction lengthening, arthrodesis, treatment of nonunion, and infection.

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

    PubMed

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

    2012-12-01

    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.

  3. 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

  4. Standard Establishment Through Scenarios (SETS): A new technique for occupational fitness standards.

    PubMed

    Blacklock, R E; Reilly, T J; Spivock, M; Newton, P S; Olinek, S M

    2015-01-01

    An objective and scientific task analysis provides the basis for establishing legally defensible Physical Employment Standards (PES), based on common and essential occupational tasks. Infrequent performance of these tasks creates challenges when developing PES based on criterion, or content validity. Develop a systematic approach using Subject Matter Experts (SME) to provide tasks with 1) an occupationally relevant scenario considered common to all personnel; 2) a minimum performance standard defined by time, distance, load or work. Examples provided here relate to the development of a new PES for the Canadian Armed Forces (CAF). SME of various experience are selected based on their eligibility criteria. SME are required to define a reasonable scenario for each task from personal experience, provide occupational performance requirements of the scenario in sub-groups, and discuss and agree by consensus vote on the final standard based on the definition of essential. A common and essential task for the CAF is detailed as a case example of process application. Techniques to avoid common SME rating errors are discussed and advantages to the method described. The SETS method was developed as a systematic approach to setting occupational performance standards and qualifying information from SME.

  5. Effect of induced aniseikonia on fixation performance.

    PubMed

    Remole, A

    1988-01-01

    The purpose of the study was to determine to what extent induced aniseikonia affects fixation performance. Aniseikonia was induced in the vertical meridian only, whereas fixation alignment was monitored in the horizontal meridian. A previously developed technique based on the dependency of border enhancement bandwidth on fixation eccentricity was used to monitor deviations from central fixation during fusion. Stress on the fusion mechanism was supplied by controlled increments of forced horizontal vergence. It was found that deviation from central fixation in the horizontal meridian generally increases with increasing amounts of vertical aniseikonia. The effect is particularly pronounced for small amounts of aniseikonia.

  6. The simple wire interosseous fixation technique (SWIFT) for reattachment of FDP avulsions with a large bony fragment.

    PubMed

    Markeson, Daniel B; Mughal, Maleeha; Subramanian, Padmanabhan; Iyer, Srinivasan

    2012-12-01

    Avulsion injuries of the flexor digitorum profundus tendon can be with or without a bony fragment. Types 3, 4, and 5 injuries often have a sizeable bony fragment. In the past, they have been repaired with either a screw, plate, or pull-out wire with a dorsal button, often in combination with a K wire to immobilize the distal interphalangeal joint. We illustrate with 2 cases a simple technique for secure repair of the flexor digitorum profundus avulsions with a bony fragment. In contrast to previously described techniques, our technique involves minimal dissection, has a significantly reduced risk of fracture to the bony fragment, is completely internalized thereby reducing the risk of postoperative infection and allows immediate mobilization.

  7. Comparing Different Surgical Techniques for Addressing the Posterior Malleolus in Supination External Rotation Ankle Fractures and the Need for Syndesmotic Screw Fixation.

    PubMed

    Li, Mengnai; Collier, Rachel C; Hill, Brian W; Slinkard, Nathaniel; Ly, Thuan V

    Trimalleolar ankle fractures are unstable injuries with possible syndesmotic disruption. Recent data have described inherent morbidity associated with screw fixation of the syndesmosis, including the potential for malreduction, hardware irritation, and post-traumatic arthritis. The posterior malleolus is an important soft tissue attachment for the posterior inferior syndesmosis ligament. We hypothesized that fixation of a sizable posterior malleolar (PM) fracture in supination external rotation type IV (SER IV) ankle fractures would act to stabilize the syndesmosis and minimize or eliminate the need for trans-syndesmotic fixation. A retrospective review of trimalleolar ankle fractures surgically treated from October 2006 to April of 2011 was performed. A total of 143 trimalleolar ankle fractures were identified, and 97 were classified as SER IV. Of the 97 patients, 74 (76.3%) had a sizable PM fragment. Syndesmotic fixation was required in 7 of 34 (20%) and 27 of 40 (68%), respectively, when the PM was fixed versus not fixed (p = .0002). When the PM was indirectly reduced using an anterior to posterior screw, 7 of 15 patients (46.7%) required syndesmotic fixation compared with none of 19 patients when the PM fragment was fixated with direct posterior lateral plate fixation (p = .0012). Fixation of the PM fracture in SER IV ankle fractures can restore syndesmotic stability and, thus, lower the rate of syndesmotic fixation. We found that fixation of a sizable PM fragment in SER IV or equivalent injuries through posterolateral plating can eliminate the need for syndesmotic screw fixation. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  8. A simplified fixation of the new thin cochlear implant receiver-stimulators in children: long term results with the "back-pocket" technique.

    PubMed

    Cuda, Domenico

    2013-07-01

    To describe a simple technique for pediatric cochlear implant receiver-stimulators (R/S) fixation and long term results with it. Clinical sample include thirty-two children with severe-to-profound or profound hearing loss candidate for cochlear implantation. Low-profile devices were used (Med El Concerto and Nucleus CI512). The R/S was housed into a tight subperiosteal pocket carefully dissected behind the mastoidectomy. The pocket was closed with a single periosteal to bone suture around the posterior edge of mastoidectomy. No skull drilling was required for housing the device. No intraoperative complications have been observed. 20% of operating time was saved. No migration of R/S over time was apparent at follow up. The back-pocket technique seems effective in retaining the CI package and in optimizing surgical time and safety in pediatric cochlear implantation. It seems particularly suitable with new generation low profile CI devices. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. 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.

  10. Ethanol-glycerin fixation with thymol conservation: a potential alternative to formaldehyde and phenol embalming.

    PubMed

    Hammer, Niels; Löffler, Sabine; Feja, Christine; Sandrock, Mara; Schmidt, Wolfgang; Bechmann, Ingo; Steinke, Hanno

    2012-01-01

    Anatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For this reason, an adequate substitute was developed. Ethanol-glycerin fixation and thymol conservation are described and compared with formaldehyde and phenol in this technical report. The setup, tissue qualities, financial aspects, and health concerns of this method are discussed. Ethanol-glycerin fixation and thymol conservation provide outstanding haptic and optic tissue qualities. Typical formaldehyde and phenol effects, such as skin, airway, and eye irritation, as well as carcinogenic effects, can be circumvented by using ethanol-glycerin and thymol instead. Ethanol-glycerin fixation is more expensive than formaldehyde and requires an explosion-proof facility. However, the absence of health effects and its convincing tissue qualities balance these higher costs. Therefore, ethanol-glycerin fixation and thymol conservation provide a potential alternative and complement established fixation techniques. The use of carcinogenic formaldehyde and toxic phenol can be effectively restricted through the use of the described method. Copyright © 2012 American Association of Anatomists.

  11. 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

  12. 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

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

    PubMed

    Neto, Antonio Piva; Lhamby, Fabio Colla

    2011-01-01

    To demonstrate a simple and efficacious option for treating fractures of the distal extremity of the radius using Kirschner wires. 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. 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. 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.

  14. Microwave fixation versus formalin fixation of surgical and autopsy tissue.

    PubMed

    Login, G R

    1978-05-01

    Microwave irradiation of surgical and autopsy tissue penetrates, fixes, and hardens the tissue almost immediately (the fluid media used in the microwave consisted of saline, ten percent phosphate buffered formalin, and distilled water). Tissue sections from a representative sample of organs were tested. Comparable sections were simultaneously fixed in a phosphate buffered ten percent formalin bath in a vaccum oven as a control. Hematoxylin and eosin were used to stain the sections. Results equal to and superior to the control method were obtained. Saline microwave fixation was superior to formalin microwave fixation. Tissues placed in Zenker's solution and fixed in standard microwave oven (for approximately one minute) yielded results at least equal to conventional Zenker fixation (approximately two hours). No tissue hardening resulted from Zenker microwave fixation. A unique time versus temperature graph (microwave heating curve) reduces individual variation with this technique.

  15. Techniques for establishing vegetation for long-term erosion control on disturbed slopes in Alabama

    Treesearch

    M. Dougherty; A. Baharanyi; B. Guertal; J. Grace

    2010-01-01

    One year results from 21 outdoor erosion and sediment control plots constructed in 2008 on a 4:1 slope are presented. The study objectives were to evaluate; 1) the effects of incorporating lime and fertilizer on establishment of bermudagrass on steep slopes, 2) the differences in bermudagrass establishment as a function of temporary covers including wheat straw,...

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Percutaneous fixation of scaphoid fractures.

    PubMed

    Slade, J F; Jaskwhich, D

    2001-11-01

    The scaphoid proximal pole and waist fractures presented here were treated by a novel dorsal percutaneous technique with arthroscopic assistance. All fractures healed, with good final functional results and no complications. The advantages of the dorsal percutaneous approach to scaphoid fixation are: (1) the proximal-to-distal placement of the guide pin and screw allow for more precise placement along the central axis of the scaphoid, which decreases healing time and reduces risk of screw thread exposure. (2) The dorsal approach avoids injuring the vulnerable volar ligament anatomy. And (3) the insertion of the screw from the proximal to distal direction allows the more rigid fixation of proximal scaphoid fractures. Arthroscopy allows confirmation of fracture reduction and screw implantation as well as evaluation of concurrent ligament injuries not detected with standard imaging. Percutaneous K-wires act as joysticks to reduce and compress fracture fragments prior to fixation. The presented technique allows for early, rigid internal fixation with minimal associated morbidity. Patients successfully treated with this technique include those with stable and unstable acute fractures of the scaphoid at all locations, including the proximal pole. Nondisplaced fractures that present with delayed or fibrous union without evidence of avascular necrosis, cyst formation, or bony sclerosis may also be treated with this technique. This technique allows for faster rehabilitation and an earlier return to work or avocation without restriction once CT scan confirms a solid union. Some articles document extraordinary rapid healing by standard radiographs; however, we caution that scaphoid bone healing cannot accurately be determined without CT scan. Percutaneous, arthroscopically assisted internal fixation by a dorsal approach may be considered in all acute scaphoid fractures selected for surgical fixation. The dorsal guidewire permits dorsal and volar implantation of a cannulated

  1. Techniques of Play Activity at Physical Education Classes at Specialized Secondary Educational Establishments

    ERIC Educational Resources Information Center

    Martynova, Victoria A.; Kapustin, Aleksandr G.

    2016-01-01

    The issue is urgent today because at present the organization and content of Physical Education (PE) classes at specialized secondary educational establishments (SSEEs) do not completely meet contemporary requirements. The following negative trends prove that, namely: the physical and psychological health decline in school leavers and students,…

  2. One unit's experiences when establishing buttonhole technique, analysis of reasons for failure of procedure: a report.

    PubMed

    Galante, Nelson Zocoler; Rabelo, Lúcia Lima; Yamamoto, Atsuko; Bonato, Rozana Aparecida; Azevedo, Luiz Sergio

    2010-06-01

    The buttonhole technique of access of needle insertion into a single selected site in the arteriovenous fistula has proved to be a reliable alternative to older methods due to its overall low complication rates. Although the use of blunt needles improves the technique, the success rate of cannulation with these needles is difficult to predict. We analysed the short-term outcome of 16 patients receiving in-centre haemodialysis and compared clinical relevant parameters between patients with and without buttonhole technique failure. Our dialysis unit treats about 180 patients and is located in a tertiary hospital in Sao Paulo, Brazil. The variables as discussed in the paper were the same for both groups. The incidence of technique failure was 43.7%. Patients enrolled later in the study had a better buttonhole failure-free survival rates than patients enrolled at the beginning (p < 0.05). Patients' clinical characteristics did not predict the success rate of buttonhole tunnel tracks cannulation with blunt needles. This paper also reports on our successes and failures in buttonhole technique and gives some reasons and reflections for both.

  3. Re-establishing esthetics of fluorosis-stained teeth using enamel microabrasion and dental bleaching techniques.

    PubMed

    Pontes, Danielson Guedes; Correa, Ketlen Michele; Cohen-Carneiro, Flávia

    2012-01-01

    Dental fluorosis manifests itself as white stains on the enamel of teeth exposed to excessive doses of fluoride during their formation. Fluorosis usually occurs as a result of the ingestion of dentifrices, gels and fluoridated solutions. It may be diagnosed as mild, moderate or severe, and in some cases, it may cause the loss of the surface structure of dental enamel. The aim of this study was to report the clinical case of a female patient of 18 years with moderate fluorosis, whose smile was reestablished by the use of an enamel microabrasion technique, followed by in-office bleaching. A microabrasion technique with 6% hydrochloric acid associated with silica carbide showed to be a safe and efficient method for removing white fluorosis stains, while dental bleaching was useful for obtaining a uniform tooth shade. The association of these techniques presented excellent results and the patient was satisfied. Both techniques are painless, fast and easy to perform, in addition to preserving the dental structure. Treatment showed immediate and permanent results; this technique must be divulged among professionals and their patients.

  4. Shape memory alloy fixator system for suturing tissue in minimal access surgery.

    PubMed

    Xu, W; Frank, T G; Stockham, G; Cuschieri, A

    1999-01-01

    A new technique for suturing human tissue is described in which tissue closure is achieved by means of small fixators made from shape memory alloy. The aim of the development is to provide an alternative to thread suturing in minimal access surgery, which is quicker and requires less skill to achieve the required suturing quality. The design of the fixators is described in terms of the thermal shape recovery of shape memory alloy and a novel form of finite element analysis, which uses a nonlinear elastic element for the material property. Thermal analysis of the fixators and surrounding tissue is used to predict the temperature distribution during and after the application of electric current heating. This was checked in an in vitro experiment, which confirmed that deployment caused no detectable collateral damage to surrounding tissue. In vivo animal studies on the use of the shape memory alloy fixator for suturing tissue are ongoing to establish safety and healing effects.

  5. Free Hand Insertion Technique of S2 Sacral Alar-Iliac Screws for Spino-Pelvic Fixation: Technical Note, Acadaveric Study

    PubMed Central

    Park, Jong-Hwa; Kim, Ki-Jeong; Jahng, Tae-Ahn

    2015-01-01

    A rigid spino-pelvic fixation to anchor long constructs is crucial to maintain the stability of long fusion in spinal deformity surgery. Besides obtaining immediate stability and proper biomechanical strength of constructs, the S2 alar-iliac (S2AI) screws have some more advantages. Four Korean fresh-frozen human cadavers were procured. Free hand S2AI screw placement is performed using anatomic landmarks. The starting point of the S2AI screw is located at the midpoint between the S1 and S2 foramen and 2 mm medial to the lateral sacral crest. Gearshift was advanced from the desired starting point toward the sacro-iliac joint directing approximately 20° angulation caudally in sagittal plane and 30° angulation horizontally in the coronal plane connecting the posterior superior iliac spine (PSIS). We made a S2AI screw trajectory through the cancellous channel using the gearshift. We measured caudal angle in the sagittal plane and horizontal angle in the coronal plane. A total of eight S2AI screws were inserted in four cadavers. All screws inserted into the iliac crest were evaluated by C-arm and naked eye examination by two spine surgeons. Among 8 S2AI screws, all screws were accurately placed (100%). The average caudal angle in the sagittal plane was 17.3±5.4°. The average horizontal angle in the coronal plane connecting the PSIS was 32.0±1.8°. The placement of S2AI screws using the free hand technique without any radiographic guidance appears to an acceptable method of insertion without more radiation or time consuming. PMID:26819698

  6. Determination of protein loss during aqueous and phase partition fixation using formalin and glutaraldehyde

    SciTech Connect

    Mays, E.T.; Feldhoff, R.C.; Nettleton, G.S.

    1984-10-01

    In phase partition fixation tissue is immersed in an organic solvent at equilibrium with an aqueous phase containing a fixing agent. By using radioisotope labeling techniques the effects of phase partition fixation on protein retention during fixation of tissue with formalin and glutaraldehyde have been determined and compared with those of standard aqueous fixation using these fixatives. It has been shown that retention of protein in tissue during phase partition fixation was as good or better than during aqueous fixation. Improved retention provides further evidence that phase partition fixation may be a useful alternative to aqueous fixation.

  7. [Establishment of loop-mediated isothermal amplification technique for rapid detection of NDM-1 gene].

    PubMed

    Zhang, Yuanyi; Wu, Na; Zhu, Baoli; Chen, Lei; Zhu, Yuzhuo

    2011-08-01

    We established a rapid detection method of New Delhi Metallo-beta-Lactamase Gene (NDM-1) based on Loop-mediated Isothermal Amplification (LAMP). With the application of LAMP, we designed four sets of LAMP premiers, using NDM-1 gene as the target sequence, and selected the set of optimal primers. Meanwhile, we established optimal reaction systems and conditions to carry out the sensitivity and specificity experiments. The experiment results showed that the whole detection process took only one hour and could be observed visually. In the experiment of sensitivity, NDM-1 gene had a detection limit of 6 copies in each reaction. In the experiment of specificity, we detected NDM-1 gene in 4 pathogen strains (Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae), and the total DNA from intestinal microbes and the total DNA from soil microbes. We had not detected the amplification reactions. The detection method established could rapidly detect NDM-1 gene and visualize the experiment result. The method is easy to operate and has high sensitivity and specificity and thus has great application value in basic research laboratories, emergent detection and spot detection.

  8. 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

  9. The anchor-away technique: rapid, conditional establishment of yeast mutant phenotypes.

    PubMed

    Haruki, Hirohito; Nishikawa, Junichi; Laemmli, Ulrich K

    2008-09-26

    The anchor-away (AA) technique depletes the nucleus of Saccharomyces cerevisiae of a protein of interest (the target) by conditional tethering to an abundant cytoplasmic protein (the anchor) by appropriate gene tagging and rapamycin-dependent heterodimerization. Taking advantage of the massive flow of ribosomal proteins through the nucleus during maturation, a protein of the large subunit was chosen as the anchor. Addition of rapamycin, due to formation of the ternary complex, composed of the anchor, rapamycin, and the target, then results in the rapid depletion of the target from the nucleus. All 43 tested genes displayed on rapamycin plates the expected defective growth phenotype. In addition, when examined functionally, specific mutant phenotypes were obtained within minutes. These are genes involved in protein import, RNA export, transcription, sister chromatid cohesion, and gene silencing. The AA technique is a powerful tool for nuclear biology to dissect the function of individual or gene pairs in synthetic, lethal situations.

  10. Latarjet Fixation

    PubMed Central

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

    2016-01-01

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

  11. 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.

  12. Establishment of the genomic in situ hybridization (GISH) technique for analysis in interspecific hybrids of Passiflora.

    PubMed

    Melo, C A F; Silva, G S; Souza, M M

    2015-03-27

    The genomic in situ hybridization (GISH) technique was applied to Passiflora interspecific F1 HD13-133 hybrids (Passiflora sublanceolata x Passiflora foetida) and HD15-101 (Passiflora gardineri x Passiflora gibertii), and the backcrossed hybrids (BC1) HD18-106 and HD18-113 (Passiflora sublanceolata x HD13-133). GISH was performed using genomic probes prepared with the DNA from the paternal genitor, whereas the maternal DNA was used as blocking DNA and employed at various concentrations (20X, 40X, 60X, and 100X) in relation to the probe concentration. At the same time, GISH was applied with the use of simultaneous probes from both genomes, paternal and maternal, that were detected with avidin-FITC and anti-digoxigenin-rhodamine, respectively. Both methodologies allowed the distinguishing of the maternal and paternal genomes, thus confirming the hybrid nature of all the analyzed genotypes. Furthermore, the presence of recombinant chromosomes in BC1 hybrids revealed the occurrence of meiotic recombination in HD13 hybrids. This application of the GISH technique is an important step towards genomic analyses of Passiflora hybrids: it can broaden the phylogenetic and evolutionary studies of the genus and, at the same time, contribute to breeding programs.

  13. Transmission Electron Microscopy for Nanomedicine: Novel Applications for Long-established Techniques

    PubMed Central

    2016-01-01

    During the last twenty years, the research in nanoscience and nanotechnology has dramatically increased and, in the last decade, the interest has progressively been oriented towards biomedical applications, giving rise to a new field termed nanomedicine. Transmission electron microscopy is a valuable technique not only for the thorough physico-chemical characterization of newly synthesized nanoparticulates, but especially to explore the effects of nanocomposites on biological systems, providing essential information for the development of efficient therapeutic and diagnostic strategies. Thus, for the progress of nanotechnology in the biomedical field, experts in cell biology, histochemistry and ultramicroscopy should always support the chemists, physicists and pharmacologists engaged in the synthesis and characterization of innovative nanoconstructs. PMID:28076938

  14. The effectiveness of two novel techniques in establishing the mechanical and contractile responses of biceps femoris.

    PubMed

    Ditroilo, Massimiliano; Hunter, Angus M; Haslam, Samuel; De Vito, Giuseppe

    2011-08-01

    Portable tensiomyography (TMG) and myotonometry (MMT) devices have been developed to measure mechanical and contractile properties of skeletal muscle. The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris (BF) muscle as a result of change in knee joint angle (i.e. muscle length). BF responses were assessed in 16 young participants (23.4 ± 4.9 years), at three knee joint angles (0°, 45° and 90°), for maximal isometric torque (MIT) along with myo-electrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the TMG and MMT was also assessed. MIT changed significantly (p < 0.01) across the three angles, so did stiffness and other parameters measured with MMT (p < 0.01). Conversely, TMG could detect changes only at two knee angles (0° and 45°, p < 0.01), when there is enough tension in the muscle. Reliability was overall insufficient for TMG whilst absolute reliability was excellent (coefficient of variation < 5%) for MMT. The ability of MMT more than TMG to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness.

  15. 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

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

    PubMed

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

    2016-01-01

    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. 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. 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. 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.

  17. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Finite element analysis of posterior cervical fixation.

    PubMed

    Duan, Y; Wang, H H; Jin, A M; Zhang, L; Min, S X; Liu, C L; Qiu, S J; Shu, X Q

    2015-02-01

    Despite largely, used in the past, biomechanical test, to investigate the fixation techniques of subaxial cervical spine, information is lacking about the internal structural response to external loading. It is not yet clear which technique represents the best choice and whether stabilization devices can be efficient and beneficial for three-column injuries (TCI). The different posterior cervical fixation techniques (pedicle screw PS, lateral mass screw LS, and transarticular screw TS) have respective indications. A detailed, geometrically accurate, nonlinear C3-C7 finite element model (FEM) had been successfully developed and validated. Then three FEMs were reconstructed from different fixation techniques after C4-C6 TCI. A compressive preload of 74N combined with a pure moment of 1.8 Nm in flexion, extension, left-right lateral bending, and left-right axial rotation was applied to the FEMs. The ROM results showed that there were obvious significant differences when comparing the different fixation techniques. PS and TS techniques can provide better immediate stabilization, compared to LS technique. The stress results showed that the variability of von Mises stress in the TS fixation device was minimum and LS fixation device was maximum. Furthermore, the screws inserted by TS technique had high stress concentration at the middle part of the screws. Screw inserted by PS and LS techniques had higher stress concentration at the actual cap-rod-screw interface. The research considers that spinal surgeon should first consider using the TS technique to treat cervical TCI. If PS technique is used, we should eventually prolong the need for external bracing in order to reduce the higher risk of fracture on fixation devices. If LS technique is used, we should add anterior cervical operation for acquire a better immediate stabilization. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. Open reduction and internal fixation of OTA type C2-C4 fractures of the calcaneus with a triple-plate technique.

    PubMed

    Brunner, Alexander; Müller, Jochen; Regazzoni, Pietro; Babst, Reto

    2012-01-01

    The purpose of this study was to present a surgical technique of open reduction and internal fixation of displaced intra-articular calcaneal fractures with 3 AO mini-fragment plates and to evaluate the clinical and radiological outcome of a consecutive group of patients after a mean follow-up of 41.7 months. A series of 54 patients (16 women and 38 men) with 62 calcaneal fractures were treated over a period of 6.5 years. Forty-five patients with 50 calcaneal fractures were completely clinically and radiologically followed up. Clinical follow-up included assessment of range of motion, pain according to a visual analogue scale, the American Orthopaedic Foot and Ankle Society hindfoot score, and the short-form 36 health survey. Radiological follow-up included plain axial and lateral radiographs and measurement of the Böhler's angle and Gissane's angle. Independent Student's t test and paired Student's t test were used alongside the chi-square test to compare clinical and radiological data and score values between different groups of patients. Eleven patients showed breakage of the osteosynthesis material during the healing process and 2 patients sustained deep wound infection requiring revision surgery. At the final follow-up all fractures had healed. The average range of motion was supination 26.4° (range 0° to 50°; SD 11.6°), pronation 15.4° (range 0° to 30°; SD 6.4°), dorsal extension 14.3° (range -10° to 30°; SD 8.0°), and plantarflexion 39.6° (range 20° to 65°; SD 11.7°). Patients with OTA type C4 fractures achieved significantly lower supination (p < .01) and plantarflexion (p < .01) compared with other fracture types. The mean visual analog scale pain score was 3.6 (range 0 to 8; SD 2.3) points, average American Orthopaedic Foot and Ankle Society hindfoot score was 70.8 (range 33 to 100; SD 17.1) points, and the mean short-form 36 score was 60.98 (range 22.9 to 93.0; SD 18.4) points. The mean postoperative Böhler's angle was 28.9° (range 8

  20. Establishment of temporomandibular joint puncture technique in rats using in vivo micro-computed tomography (R_mCT®)

    PubMed Central

    Kameoka, S; Matsumoto, K; Kai, Y; Yonehara, Y; Arai, Y; Honda, K

    2010-01-01

    The aim of the report was to establish puncture techniques for the temporomandibular joint (TMJ) cavity in rats. The experimental sample comprised 30 male Sprague–Dawley rats. Under general anaesthesia the superior joint cavity of the rat was punctured either laterally (lateral puncture technique (LPT), n = 11), anteriorly (anterosuperior puncture technique (ASPT), n = 13) or anteroinferior puncture technique (AIPT), n = 6) using a 27-gauge needle. After the tip of the needle was confirmed by micro-CT (R-mCT®, Rigaku, Tokyo, Japan) located on the mandibular fossa, 0.05 ml of contrast media was injected under micro-CT fluoroscopic guidance. After confirmation that the joint cavity was filled with contrast media, micro-CT imaging was carried out. The puncture for LPT was accurate in 5 of the 11 animals. The ASPT was accurate in all 13 animals. The AIPT punctured 3 of the 6 animals. Furthermore, the ASPT and AIPT demonstrated improved preservation of the needle; it was harder to detach the needle, which led to greater stability. These results suggest that ASPT assisted by R-mCT® is useful for basic research, including drug discovery and pathogenesis of TMJ diseases. PMID:20841463

  1. Establishment of temporomandibular joint puncture technique in rats using in vivo micro-computed tomography (R_mCT®).

    PubMed

    Kameoka, S; Matsumoto, K; Kai, Y; Yonehara, Y; Arai, Y; Honda, K

    2010-10-01

    The aim of the report was to establish puncture techniques for the temporomandibular joint (TMJ) cavity in rats. The experimental sample comprised 30 male Sprague-Dawley rats. Under general anaesthesia the superior joint cavity of the rat was punctured either laterally (lateral puncture technique (LPT), n = 11), anteriorly (anterosuperior puncture technique (ASPT), n = 13) or anteroinferior puncture technique (AIPT), n = 6) using a 27-gauge needle. After the tip of the needle was confirmed by micro-CT (R-mCT®, Rigaku, Tokyo, Japan) located on the mandibular fossa, 0.05 ml of contrast media was injected under micro-CT fluoroscopic guidance. After confirmation that the joint cavity was filled with contrast media, micro-CT imaging was carried out. The puncture for LPT was accurate in 5 of the 11 animals. The ASPT was accurate in all 13 animals. The AIPT punctured 3 of the 6 animals. Furthermore, the ASPT and AIPT demonstrated improved preservation of the needle; it was harder to detach the needle, which led to greater stability. These results suggest that ASPT assisted by R-mCT® is useful for basic research, including drug discovery and pathogenesis of TMJ diseases.

  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. Comparative study on the treatment of Rockwood type III acute acromioclavicular dislocation: Clinical results from the TightRope(®) technique vs. K-wire fixation.

    PubMed

    Horst, K; Garving, C; Thometzki, T; Lichte, P; Knobe, M; Dienstknecht, T; Hofman, M; Pape, H-C

    2017-04-01

    The aim of this study was to address the inconsistency regarding the operative treatment of Rockwood type III acromioclavicular joint separation. We compared results after single- and double TightRope(®) reduction with results after acromioclavicular transfixation via K-wires only and additional ligament augmentation in acute acromioclavicular (AC) joint separations graded Rockwood type III, and hypothesized that the TightRope(®) technique leads to better clinical and radiological results. We conducted a retrospective clinical cohort study and included 42 consecutive patients (mean age 43 years [24-66]) diagnosed and operatively treated between 2004 and 2012 (mean follow-up was 54.6 months [15-118]). Specific shoulder scores as well as scores reflecting the patients' overall mental and physical health status were used. Radiological evaluation was also performed. The SF12 test revealed comparability between all subgroups. Specific shoulder tests and a visual analogue scale demonstrated comparable results. Radiographic measurements showed a significant reduction in the AC distance and CC distance after surgery in all subgroups. The early complication rate was 9.5% for all patients, while late complications occurred in 14.3% of all cases. Compared to the established methods, the operative TightRope(®) procedures represent a safe alternative in Rockwood III injuries. All investigated techniques predominantly led to good and excellent clinical results in acute Rockwood type III AC joint instabilities. Avoidance of material removal and shorter hospital stays appear to speak in favour for the TightRope(®) technique. IV. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. 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

  5. Minimally invasive (sinus tarsi) approach for open reduction and internal fixation of intra-articular calcaneus fractures in children: surgical technique and case report of two patients.

    PubMed

    Abdelgawad, Amr A; Kanlic, Enes

    2015-01-01

    Calcaneus fractures in children differ from those in adults. Most calcaneus fractures in children can be managed nonoperatively, with good long-term results expected. The width and height of the calcaneus can remodel with time in children. Recently, there has been a trend toward operative treatment of displaced intra-articular fractures of the calcaneus in children to correct the articular deformity. Studies of calcaneal fracture fixation in children used an extended lateral approach, with its possible complications. In the present report, we describe the operative treatment of 2 children (12 and 13 years old), who had a displaced intra-articular fracture of the calcaneus, using a minimally invasive sinus tarsi approach. Adequate reduction was obtained in both cases with no soft tissue complications or implant discomfort. Fixation was obtained using 3.5-mm cortical screws. Anatomic joint alignment was restored. The children were followed up until they had both resumed their full activities with no complications. We recommend this approach for operative treatment of displaced intra-articular fractures of the calcaneus, because it addresses the intra-articular displacement, which is the most important element of the deformity in children.

  6. The Establishment of an On-Campus Neurotraining Center at a Small University: Internship Experience Using Neuropsychological Techniques

    PubMed Central

    Schicatano, Edward J.; Bohlander, Robert

    2016-01-01

    In 2015, Wilkes University’s Neuroscience Program and Psychology Department established a unique training and learning center on a small liberal arts undergraduate campus - The NeuroTraining & Research Center. This paper shares the purpose of the Center, as a learning tool for Neuroscience majors who engage in internships and research opportunities, and as a means of promoting well-being on the campus by offering training in techniques such as Neurofeedback, Biofeedback and Audio-Visual Entrainment to the college community. The role that the center plays in connecting real world applications to concepts in Neuroscience, and the approach that the authors have taken to assess student learning is presented in this article. PMID:27980472

  7. α -decay chain of the short-lived isotope 220Pa established using a digital pulse processing technique

    NASA Astrophysics Data System (ADS)

    Huang, T. H.; Zhang, W. Q.; Sun, M. D.; Liu, Z.; Wang, J. G.; Liu, X. Y.; Ding, B.; Gan, Z. G.; Ma, L.; Yang, H. B.; Zhang, Z. Y.; Yu, L.; Jiang, J.; Wang, K. L.; Wang, Y. S.; Liu, M. L.; Li, Z. H.; Li, J.; Wang, X.; Lu, H. Y.; Lin, C. J.; Sun, L. J.; Ma, N. R.; Ren, Z. Z.; Zhang, F. S.; Zou, W.; Zhou, X. H.; Xu, H. S.; Xiao, G. Q.

    2017-07-01

    The decay properties of the short-lived isotope 220Pa were re-investigated via the reaction 40Ar+187Re at the gas-filled recoil separator Spectrometer for Heavy Atoms and Nuclear Structure. The digital pulse processing technique was applied to resolve the evaporation residues-α (ER -α ) pileup signals in the decay of 220Pa. The α -decay chain of 220Pa leading to the well-known 216Ac isotope was established for the first time. The α energy and half-life were measured to be Eα=9.520 (16 ) MeV and T1 /2=0.90 (13 ) μ s , respectively. The spin parity of the ground state of 220Pa was assigned to be 1-, based on the reduced α -decay width.

  8. Mouse tissue fixation.

    PubMed

    Cardiff, Robert D; Miller, Claramae H; Munn, Robert J

    2014-05-01

    One of the primary goals of fixation is to stop postmortem changes that degrade the tissue and allow optimal preservation of morphologic and cytological detail as well as nucleic acid integrity. Following death, tissues soon undergo autolysis, and if organisms from the gastrointestinal, urinary, or respiratory tracts are present, their colonization can soon cause putrefaction. Time is of the essence because warmer temperatures accelerate both types of degradation. Placing the tissue into a fixative stops the postmortem changes. Fixatives have their effect on tissue by cross-linking, coagulation, or a combination of both. This article outlines the basic tissue fixation procedure and offers guidance on choosing an appropriate fixative, the timing and duration of fixation, sample storage, and quality issues.

  9. Iris fixation of posterior chamber intraocular lenses.

    PubMed

    Yazdani-Abyaneh, Alireza; Djalilian, Ali R; Fard, Masoud Aghsaei

    2016-12-01

    We introduce a technique for iris fixation of a posterior chamber intraocular lens (IOL) in which most of the procedure is done outside the eye. This minimizes intraocular manipulation, maximizes corneal endothelial preservation, and avoids the risk for IOL drop into the vitreous cavity intraoperatively. The IOL is fixated to the most peripheral part of the iris, resulting in a rounder pupil. Sutures are placed at exact positions on the haptics, resulting in a well-centered IOL.

  10. Establishment of an operating room committee and a training program to improve aseptic techniques for rodent and large animal surgery.

    PubMed

    Héon, Hélène; Rousseau, Nathalie; Montgomery, Jane; Beauregard, Gilles; Choiniére, Manon

    2006-11-01

    Investigators of our research facility generally accept the concept of asepsis as an important component of adequate surgical care for animals. However, they experience difficulties putting it into practice, especially in the case of rodents. The reasons for this are inconvenience, cost, and lack of training. To better assist investigators in the implementation of aseptic surgical techniques in their laboratories, we have created an Operating Room (OR) Committee modeled after OR committees found in human hospitals. A reconstructive surgeon, a veterinarian, a research scientist, a nurse involved in the training of OR personnel, interns, graduate students, and an animal health technician were chosen as committee members in light of their OR and animal care expertise. The first task of the OR Committee was to establish institutional guidelines for aseptic surgery, taking into account the costs imposed on research budgets by these procedures. The OR Committee also supports a complete training program in aseptic surgery techniques, which consists of lectures, a training manual, videos, and a practical course. Furthermore, when experimental procedures require specialized equipment, the OR Committee collaborates with researchers to develop strategies to achieve asepsis. This OR Committee and the training program proved to be important tools to promote and improve the quality of animal care during surgery.

  11. 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

    2015-01-06

    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.

  12. Fixation, Counting, and Manipulation of Heterotrophic Nanoflagellates

    PubMed Central

    Bloem, Jaap; Bär-Gilissen, Marie-José B.; Cappenberg, Thomas E.

    1986-01-01

    Quantitative effects of several fixatives on heterotrophic nanoflagellates (HNAN) and phototrophic nanoflagellates (PNAN) were investigated by hemacytometer and epifluorescence counting techniques. Counts of Monas sp. cultures before and after fixation with unbuffered 0.3% glutaraldehyde and 5% formaldehyde showed no loss of cells during fixation, and cell concentrations remained constant for several weeks after fixation. Buffering of fixatives with borax caused severe losses, up to 100% within 2 h. Field samples from Lake Vechten showed no decline of HNAN and total nanoflagellate concentrations for at least 1 week after fixation with 5% formaldehyde and with 1% glutaraldehyde. With 1% glutaraldehyde, the chlorophyll autofluorescence of PNAN was much brighter than with 5% formaldehyde, although it was lost after a few days and thus limited the storage time of samples. However, when primulin-stained slides were prepared soon after fixation and stored at −30°C, the loss of autofluorescence was prevented and PNAN and HNAN concentrations were stable for at least 16 weeks. Effects of filtration and centrifugation on HNAN were also studied. Filtration vacuum could not exceed 3 kPa since 10 kPa already caused losses of 15 to 20%. Similar losses were caused by centrifugation, even at low speed (500 × g). PMID:16347232

  13. Endotracheal tube fixation methods for optimal stability: a comparison of adhesive tape, suture, and tape-suture fixation.

    PubMed

    Farbod, Frank; Tuli, Puneet; Robertson, Bernard F; Jackson, Ian T

    2010-07-01

    Accidental extubation of an intubated patient is a serious consideration in the surgical patient. Adequate fixation in the intubated patient is essential to prevent potentially life-threatening complications. Several methods of endotracheal tube fixation have been described in the literature. In this study, we examine 3 common methods of fixation: adhesive tape alone, suture, and tape-suture. Testing occurred in a laboratory setting with 2 fresh cadavers. Endotracheal tubes were inserted, using the methods of fixation in question. We subjected each fixation technique to progressively increasing weight to determine which technique is most resistant to accidental removal. We found that fixation of the tube by combining tape around the tube with a suture through the tape is the best noninvasive technique of the 3 methods evaluated in cases where movement of the head is anticipated.

  14. Ab externo scleral fixation of intraocular lens.

    PubMed

    Slade, D Snow; Hater, Michael A; Cionni, Robert J; Crandall, Alan S

    2012-08-01

    We describe an ab externo technique that facilitates IOL scleral fixation and reduces the risk associated with previous ab externo scleral fixation techniques. This technique uses a microvitreoretinal blade and an internal limiting membrane forceps to create sclerotomies and retrieve the suture, respectively. Dr. Cionni is a consultant to Morcher GmbH, Stuttgart, Germany. Dr. Crandall is a consultant to Alcon Laboratories, Inc., Ft. Worth, Texas, USA. No other author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  15. 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

  16. Complications of halo fixation of the cervical spine.

    PubMed

    Hayes, Victor M; Silber, Jeff S; Siddiqi, Farhan N; Kondrachov, Dmitriy; Lipetz, Jason S; Lonner, Baron

    2005-06-01

    Halo fixators play an integral role in stabilizing the cervical spine. They are most widely used after upper cervical to midcervical spine fractures and dislocations and as a supplement to various surgical fixation techniques. Compared with supine cervical traction techniques, halo fixators allow early patient mobilization and shorten hospital stays. The incidence of halo-fixator complications remains high. Minor complications include pin loosening, localized infection, periorbital edema, superficial pressure sores, and unsightly scars. Major complications include pin penetration, osteomyelitis, subdural abscess, nerve palsies, fracture overdistraction, and persistent instability. Many of these potential complications can be avoided with proper pin placement and meticulous pin care.

  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. Guide to radiation fixatives

    SciTech Connect

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

    1983-11-01

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

  19. Cell fixatives for immunostaining.

    PubMed

    Jamur, Maria Célia; Oliver, Constance

    2010-01-01

    Fixation is one of the most critical steps in immunostaining. The object of fixation is to achieve good morphological preservation, while at the same time preserving antigenicity. Tissue blocks, sections, cell cultures or smears are usually immersed in a fixative solution, while in other situations, whole body perfusion of experimental animals is preferable. Fixation can be accomplished by either chemical or physical methods. The chemical methods include cross-linking agents such as formaldehyde, glutaraldehyde and succinimide esters as well as solvents such as acetone and methanol, which precipitate proteins. Of the physical methods, freezing tissue and air drying are most widely used. This chapter deals with the chemical fixation methods most commonly used for light microscopy.

  20. When femoral fracture fixation fails: salvage options.

    PubMed

    Petrie, J; Sassoon, A; Haidukewych, G J

    2013-11-01

    Most hip fractures treated with modern internal fixation techniques will heal. However, failures occasionally occur and require revision procedures. Salvage strategies employed during revision are based on whether the fixation failure occurs in the femoral neck, or in the intertrochanteric region. Patient age and remaining bone stock also influence decision making. For fractures in young patients, efforts are generally focused on preserving the native femoral head via osteotomies and repeat internal fixation. For failures in older patients, some kind of hip replacement is usually selected. Disuse osteopenia, deformity, bone loss, and stress-risers from previous internal fixation devices all pose technical challenges to successful reconstruction. Attention to detail is important in order to minimise complications. In the majority of cases, good outcomes have been reported for the various salvage strategies.

  1. Systematic comparison of tissue fixation with alternative fixatives to conventional tissue fixation with buffered formalin in a xenograft-based model.

    PubMed

    Nietner, Thorben; Jarutat, Tiantom; Mertens, Alfred

    2012-09-01

    In our study we systematically compared the alternative fixatives acidified formal alcohol (AFA), PAXgene®, HOPE®, and combinations of AFA or formalin with ultrasound treatment to standard (buffered) formalin fixation. We examined general morphology and detectability of protein structures by immunohistochemistry of the membrane receptors epidermal growth factor receptor (EGFR), insulin-like growth factor 1 receptor (IGF-1R), and phosphorylated human epidermal growth factor receptor 2 (phospho-HER2). In order to allow for stringent comparability of different fixation techniques, we used matched mouse xenograft tumor samples from three different human cancer cell lines (colon, ovarian, and non-small cell lung cancer), either fixed conventionally with formalin or an alternative fixative. Tissue morphology after fixation with AFA and PAXgene® was comparable to formalin-fixed paraffin-embedded tissue (FFPET) morphology. Ultrasound fixations resulted in slightly inferior morphology and HOPE® fixation preserved morphology only poorly compared to FFPET in this system. None of the tested alternative fixatives enabled immunohistochemical detectability of all three targets in the same manner as FFPET. Pronounced staining was possible for EGFR and IGF-1R with all alternative fixatives but HOPE®, and phospho-HER2 staining was only noteworthy with formalin-ultrasound-fixed tissue. Therefore, the use of alternative fixatives comes with the need for careful validation of obtained IHC results individually for each target.

  2. Establishing a rabbit model of malignant esophagostenosis using the endoscopic implantation technique for studies on stent innovation

    PubMed Central

    2014-01-01

    Background Stents are recommended in patients with dysphagia caused by esophageal stricture, but an ideal stent does not currently exist. Thus, studies on new esophageal stents are necessary, and suitable animal models are desperately needed for these studies. The aim of this study was to establish a model of malignant esophageal stricture in rabbit for studies on stent innovation. Methods A total of 38 New Zealand white rabbits were used in this study. Using the endoscopic submucosal injection technique, VX2 fragments were inoculated into the submucosal layer of the rabbit thoracic esophagus, and an endoscopic follow-up was subsequently performed to observe the tumor development and progression. The self-expandable metal stents were randomly deployed in rabbits with severe esophageal stricture to investigate the safety and feasibility of the animal models for stenting. Results An endoscopic implantation procedure for VX2 tumors was completed in 34/38 rabbits, and tumor development was confirmed in 30/34 animals. The success rate of the endoscopic implantation and tumor development were 89.4% (95% CI, 79.6% to 99.2%) and 88.2% (95% CI, 76.9% to 99.5%) respectively. During the endoscopic follow-up period, severe esophageal stricture occurred in 22/30 rabbits with a rate of 73.3% (95% CI, 57.5% to 89.1%), and 12/22 models received stent placement. During and after stent implantation, no severe stent-related complication or mortality occurred in the animal models. The rabbits that received stent placement survived longer than those without stent implantation (the mean survival time: 53.9 days versus 40.3 days, P = 0.016). Conclusion The endoscopic method is a safe and effective method for establishing a malignant esophagostenosis model in rabbits. This model can simulate the human body environment for stent deployment and is an excellent tool for the study of stent innovation for the treatment of esophageal cancer. PMID:24507720

  3. Expert training with standardized operative technique helps establish a successful penile prosthetics program for urologic resident education.

    PubMed

    King, Ashley B; Klausner, Adam P; Johnson, Corey M; Moore, Blake W; Wilson, Steven K; Grob, B Mayer

    2011-10-01

    The challenge of resident education in urologic surgery programs is to overcome disparity imparted by diverse patient populations, limited training times, and inequalities in the availability of expert surgical educators. Specifically, in the area of prosthetic urology, only a small proportion of programs have full-time faculty available to train residents in this discipline. To examine whether a new model using yearly training sessions from a recognized expert can establish a successful penile prosthetics program and result in better outcomes, higher case volumes, and willingness to perform more complex surgeries. A recognized expert conducted one to two operative training sessions yearly to teach standardized technique for penile prosthetics to residents. Each session consisted of three to four operative cases performed under the direct supervision of the expert. Retrospective data were collected from all penile prosthetic operations before (February, 2000 to June, 2004: N = 44) and after (July, 2004 to October, 2007: N = 79) implementation of these sessions. Outcomes reviewed included patient age, race, medical comorbidities, operative time, estimated blood loss, type of prosthesis, operative approach, drain usage, length of stay, and complications including revision/explantation rates. Statistical analysis was performed using Student's t-tests, Fisher's tests, and survival curves using the Kaplan-Meier technique (P value ≤ 0.05 to define statistical significance). Patient characteristics were not significantly different pre- vs. post-training. Operative time and estimated blood loss significantly decreased. Inflatable implants increased from 19/44 (43.2%, pre-training) to 69/79 (87.3%, post-training) (P < 0.01). Operations per year increased from 9.96 (pre-training) to 24 (post-training) (P < 0.01). Revision/explantation occurred in 11/44 patients (25%, pre-training) vs. 7/79 (8.9%, post-training) (P < 0.05). These data demonstrate that yearly sessions with a

  4. 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…

  5. 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…

  6. [Visualization for Traditional Quality Management Techniques--Characterization Method for Spikenard of INUBUSHI SEIYAKU Established in the Edo Period].

    PubMed

    Ito, Ken; Inubushi, Soichiro; Moriwaki, Takafumi; Matsunaga, Kazuhiro; Takahashi, Kyoko; Ueda, Takahiro; Hashizume, Setsuya; Takemoto, Hiroaki; Kobayashi, Yoshinori; Ota, Tomoe; Nakamura, Seiko; Matsuda, Hisashi

    2015-01-01

    INUBUSHI SEIYAKU, a Japanese pharmaceutical company established in 1807, manufactures KEISHIN-TAN. This is an original drug developed by the company, and consists of 14 exotic natural medicines, spikenard, oriental bezoar, musk, agarwood, etc. It has been used for adjusting the autonomic nervous system and physical conditions. We studied the original methods of the traditional quality management techniques handed down within INUBUSHI SEIYAKU in selecting the appropriate spikenard (Nardostachys chinensis) for medicinal use. Currently, spikenards are mainly used as incense rather than medicine. KEISHIN-TAN is a rare case in that the bulk powder of the spikenards is used for pharmaceutical products in Japan. We examined the morphological characteristics and made an analysis of the component of spikenards selected by traditional methods. The raw material of the spikenards was purchased from the Japanese market, and was classified into two categories-superior, fit for medicinal use and defective, to be discarded-by traditional methods of INUBUSHI SEIYAKU. The methods of the characterization of the spikenard by INUBUSHI SEIYAKU were investigated. As a result, only thick spikenard roots over 2.0 cm in length and approximately 0.5 cm in diameter were found to be used, and the total weight of the superior was only 15% of the raw material. By comparing the weights of hexane extracts and GC-MS analyses, the content of calarene--main sedative compound in spikenards--in the superior material was 2.8 times higher than the raw material and 4.3 times higher than the defective material. The ways to devise how to enhance the pharmacological effects of spikenards may be contained in this method. These results revealed the traditional spikenard selection criteria, and may show the indications of using spikenard or its compounds for medicinal purposes.

  7. Surgical management of symptomatic os odontoideum with posterior screw fixation performed using the magerl and harms techniques with intraoperative 3-dimensional fluoroscopy-based navigation.

    PubMed

    Weng, Chong; Tian, Wei; Li, Zhi-Yu; Liu, Bo; Li, Qin; Wang, Yong-Qing; Sun, Yu-Zhen

    2012-10-01

    Retrospective case series. To evaluate the accuracy of screw fixation using intraoperative three-dimensional fluoroscopy-based navigation (ITFN) and to assess the clinical outcomes of this treatment regimen. The surgical management of symptomatic os odontoideum poses considerable difficulties due to the highly variable anatomy of the upper cervical spine and surrounding neurovascular structures. Various methods have been described for the treatment of symptomatic os odontoideum, all of which have limitations. Nineteen patients with symptomatic os odontoideum were investigated. Pain scores were assessed using the visual analogue scale. Myelopathy was assessed using the Nurick scale and Odom's criteria. Radiological imaging was carried out in all patients for diagnosis and to assess the atlantodens interval, space available for cord, and presence of intramedullary hyperintensity signals on T2-weighted images at the C1-C2 level. Posterior stabilization was performed for all patients by using ITFN. The mean Nurick score improved from 2.3 before surgery to 0.7 at the time of follow-up. The mean follow-up period was 34.7 months (range, 12-65 mo). According to Odom's criteria, outcomes were as follows: excellent, 47%; good, 37%; fair, 11%; and poor, 5%. All patients with preoperative neck pain had symptom relief or improvement, with all of these patients having more than 83.7% improvement in visual analogue scale scores. The mean preoperative space available for cord value of 9.3 mm improved to 17.7 mm. Solid fusion and reduction of atlantoaxial dislocation were achieved in every patient without screw failure. Sixty screws were placed in 19 patients. Two C2 polyaxial screws in 2 patients and 1 transarticular screw in 1 patient slightly penetrated the transverse foramen with no vascular injury and clinical sequelae. ITFN is a safe, accurate, and effective tool for screw placement in patients with symptomatic os odontoideum.

  8. Arthroscopic Control for Safe and Secure Seating of Suspensory Devices for Femoral Fixation in Anterior Cruciate Ligament Reconstruction Using Three Different Techniques

    PubMed Central

    Kang, Seo Goo; Lee, Yong Seuk

    2017-01-01

    Purpose The purpose of this study was to evaluate the efficacy of our technique that allows direct visualization of seating of suspensory devices in anterior cruciate ligament (ACL) reconstruction. Materials and Methods Three different suspensory devices (TightRope RT, RetroButton, and EndoButton) were used in ACL reconstruction using 3 different techniques (outside-in, anteromedial [AM] portal, and transtibial techniques). Positioning of a guiding material and seating pattern of the suspensory devices were evaluated according to the surgical technique and suspensory device used. Results On the transtibial technique, 21 of total 26 cases (81%) of single bundle reconstructions and 22 of total 22 cases (100%) of double bundle reconstructions required superolateral capsulotomy where buttons were found in 21 of total 21 cases (100%) and 17 of 22 cases (77%), respectively. On the AM portal technique, all patients required capsulotomy and the button was found in only 18 of total 32 cases (56%) even after capsulotomy. On the outside-in technique, all patients required capsulotomy and the button was found in 86 of total 86 cases (100%). Conclusions Our technique for direct visualization of seating of the suspensory devices was more effective in outside-in and single bundle transtibial ACL reconstruction. However, it was less effective in double bundle transtibial and AM portal ACL reconstructions. PMID:28231646

  9. The halo fixator.

    PubMed

    Bono, Christopher M

    2007-12-01

    The halo fixator may be used for the definitive treatment of cervical spine trauma, preoperative reduction in the patient with spinal deformity, and adjunctive postoperative stabilization following cervical spine surgery. Halo fixation decreases cervical motion by 30% to 96%. Absolute contraindications include cranial fracture, infection, and severe soft-tissue injury at the proposed pin sites. Relative contraindications include severe chest trauma, obesity, advanced age, and a barrel-shaped chest. In children, a computed tomography scan of the head should be obtained before pin placement to determine cranial bone thickness. Complications of halo fixation include pin loosening, pin site infection, and skin breakdown. A concerning rate of life-threatening complications, such as respiratory distress, has been reported in elderly patients. Despite a paucity of contemporary data, recent retrospective studies have demonstrated acceptable results for halo fixation in managing some upper and lower cervical spine injuries.

  10. Photographic fixative poisoning

    MedlinePlus

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

  11. Fixation-based filtering

    NASA Astrophysics Data System (ADS)

    Olson, Thomas J.; Lockwood, Robert J.

    1992-11-01

    Fixation and visual attention are central themes in active vision research, and are closely related. In this paper we discuss one of several ways in which they interact. We describe filtering methods that allow an agent to selectively extract features of the object it is fixating and suppress features of foreground and background objects. The methods are essentially depth filters; they use disparity or motion information to suppress image features that are far from the fixation point in depth. They share a simple computational structure based on the Laplacian pyramid, and are readily amenable to hardware implementation. We present the filters and the properties of fixation geometry that allow them to work, and discuss their behavior. We present methods of implementing them in real time and describe ways of extending them to other features besides depth.

  12. A new femoral fixation device for anterior cruciate ligament reconstruction using the outside-in technique and hamstring tendon graft: A comparison between two devices in cadaveric human knee models.

    PubMed

    Chong, Suri; Kwak, Dai-Soon; Balasubramanian, Dhanasekaraprabu; Song, Young Dong; Na, Young Gon; Kim, Tae Kyun

    2017-10-01

    A new device (T-anchor) was developed for ACL reconstruction and is implanted via the outside-in technique using hamstring grafts. The purpose of this study was to compare the T-anchor with the EndoButton Direct. This study was conducted on 30 cadaveric knees (15 matched pairs). There were two groups of 15 each in the T-anchor and EndoButton Direct groups. After the harvest of grafts, fixation site profile and graft length were measured by loading the grafts onto both devices. They were then tested on a universal testing machine to assess elongation after cyclic loading, load to failure, ultimate load, and mode of failure. The fixation site profile was lower in the T-anchor group than in the EndoButton Direct group (2.3±0.4mm vs. 4.7±1.0mm, P<0.001). The length of the graft-device complex of the T-anchor specimens was longer than that of the EndoButton Direct specimens (125.0±8.9mm vs. 115.0±8.7mm, P<0.001). The mean cyclic elongation was lower for the T-anchor group when compared with the EndoButton Direct group (2.4±0.6mm vs. 3.9±2.6mm, P=0.015). There was no statistically significant difference in ultimate load and load to failure between the T-anchor and EndoButton Direct groups. For mode of failure, the T-anchor fared better (P=0.013) with all failures attributed to specimens. In this cadaveric study, the new device, T-anchor, performed better than the EndoButton Direct with respect to the above-mentioned study parameters except for ultimate load and load to failure. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Management of paediatric tibial fractures using two types of circular external fixator: Taylor spatial frame and Ilizarov circular fixator.

    PubMed

    Tafazal, Suhayl; Madan, Sanjeev S; Ali, Farhan; Padman, Manoj; Swift, Simone; Jones, Stanley; Fernandes, James A

    2014-05-01

    The use of circular fixators for the treatment of tibial fractures is well established in the literature. The aim of this study was to compare the Ilizarov circular fixator (ICF) with the Taylor spatial frame (TSF) in terms of treatment results in consecutive patients with tibial fractures that required operative management. A retrospective analysis of patient records and radiographs was performed to obtain patient data, information on injury sustained, the operative technique used, time duration in frame, healing time and complications of treatment. The minimum follow-up was 24 months. Ten patients were treated with ICF between 2000 and 2005, while 15 patients have been treated with TSF since 2005. Two of the 10 treated with ICF and 5 of the 15 treated with TSF were open fractures. All patients went on to achieve complete union. Mean duration in the frame was 12.7 weeks for ICF and 14.8 weeks for the TSF group. Two patients in the TSF group had delayed union and required additional procedures including adjustment of fixator and bone grafting. There was one malunion in the TSF group that required osteotomy and reapplication of frame. There were seven and nine pin-site infections in the ICF and TSF groups, respectively, all of which responded to antibiotics. There were no refractures in either group. In an appropriate patient, both types of circular fixator are equally effective but have different characteristics, with TSF allowing for postoperative deformity correction. Of concern are the two cases of delayed union in the TSF group, all in patients with high-energy injuries. We feel another larger study is required to provide further clarity in this matter. Level II-comparative study.

  14. Treating Somatic Fixation: A Biopsychosocial Approach

    PubMed Central

    McDaniel, Susan H.; Campbell, Thomas; Seaburn, David

    1991-01-01

    Somatic fixation occurs when the patient or physician focuses exclusively on the biomedical aspects of a complex illness. Individual, family, and cultural factors promote the expression of emotional experience through physical symptoms. The physician or treatment team establishes a collaborative relationship with the patient and family, integrating biomedical and psychosocial evaluations and respecting the patient's defenses. PMID:21228995

  15. 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.

  16. Bone Plug Versus Suture-Only Fixation of Meniscal Grafts

    PubMed Central

    Wang, Hongsheng; Gee, Albert O.; Hutchinson, Ian D.; Stoner, Kirsten; Warren, Russell F.; Chen, Tony O.; Maher, Suzanne A.

    2014-01-01

    Background Meniscus allograft transplantation (MAT) is primarily undertaken to relieve the symptoms associated with meniscal deficiencies. However, its ability to restore normal knee joint contact mechanics under physiological loads is still unclear. Purpose To quantify the dynamic contact mechanics associated with 2 commonly used fixation techniques in MAT of the medial compartment: transosseous suture fixation via bone plugs and suture-only fixation at the horns. Study Design Controlled laboratory study. Methods Physiological loads to mimic gait were applied across 7 human cadaveric knees on a simulator. A sensor placed on the medial tibial plateau recorded dynamic contact stresses under the following conditions: (1) intact meniscus, (2) MAT using transosseous suture fixation via bone plugs at the anterior and posterior horns, (3) MAT using suture-only fixation, and (4) total medial meniscectomy. A “remove-replace” procedure was performed to place the same autograft for both MAT conditions to minimize the variability in graft size, geometry, and material property and to isolate the effects of the fixation technique. Contact stress, contact area, and weighted center of contact stress (WCoCS) were quantified on the medial plateau throughout the stance phase. Results Knee joint contact mechanics were sensitive to the meniscal condition primarily during the first half of the gait cycle. After meniscectomy, the mean peak contact stress increased from 4.2 ± 1.2 MPa to 6.2 ± 1.0 MPa (P = .04), and the mean contact area decreased from 546 ± 132 mm2 to 192 ± 122 mm2 (P = .01) compared with the intact meniscus during early stance (14% of the gait cycle). After MAT, the mean contact stress significantly decreased with bone plug fixation (5.0 ± 0.7 MPa) but not with suture-only fixation (5.9 ± 0.7 MPa). Both fixation techniques partially restored the contact area, but bone plug fixation restored it closer to the intact condition. The location of WCoCS in the

  17. 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

  18. The surgical correction of mandibular prognathism using rigid internal fixation--a report of a new technique together with its long-term stability.

    PubMed Central

    Reitzik, M.

    1988-01-01

    A historical review of the literature for the surgical correction of mandibular prognathism is presented, together with a list of ideal conditions for the successful treatment of this condition. This is a report of a new surgical technique which satisfies the majority of these principles and demonstrates stability at the osteotomy site. PMID:3207331

  19. [A study on the appropriate fixation for the procedures for the better preservation of cellular antigenicity and morphology of the blood smear in immunocytochemistry: an improvement of the immunostain technique using alkaline-phosphatase (ALP) as a labeling enzyme].

    PubMed

    Aoki, J; Sasaki, N; Hino, N; Nanba, K

    1991-01-01

    The authors previously reported a new coloration method which utilized hexazotized newfuchsin as a coupler for the immuno-enzyme-cytochemistry. This procedure used alkaline-phosphatase (ALP) as the labeling enzyme. The insolubility of the reaction product to organic solvents made it possible to prepare permanent slides. However, this suffered from several drawbacks, due to the fixation procedures, in the preservation of better morphology and antigenicity of the cell. The present study was undertaken to overcome such problems by modifying the fixation procedure. The study utilized twenty monoclonal and polyclonal antibodies commonly used in immunohematological staining. Various fixative solutions and timing of fixation were evaluated. The results indicated that; 1) the best fixative solution was a mixture of buffered paraformaldehyde (PFA) and acetone (10 ml 40% PFA solution, 10 ml pH 6.6 0.02 M phosphate buffer, 20 ml distilled water, 60 ml acetone, with pH adjusted to 6.6-7.4 with HCl) and 2) the fixation should be performed just before the immunostain. The results further showed that unstained smear slides, when freshly air dried and stored in a desicator, could maintain various differentiation antigens (CD2, 3, 4, 5, 8, 10, 14, 15, 16, 19, 25, L26, HLA-DR) for at least 4 weeks without any change in the immuno-reactivity. Thus, we conclude that this improved fixation procedure is an optimum fixative and should be used in routine application of the immunostain method for blood smears.

  20. [Exposed distal radio-ulnar dislocation by dog bite. Reconstructive surgical technique using a soft tissue graft and a syndesmotic fixation implant. Case report].

    PubMed

    Vélez-de Lachica, J C; Brambila-Botello, C A; Valdez-Jiménez, L A

    2015-01-01

    The main function of the forearm is the supination, which is achieved largely through the biomechanical characteristics and stability of the distal radio-ulnar joint. There are several surgical techniques for the treatment of distal radio-ulnar dislocations isolated or associated with a fracture. We report the case of a canine trainer who was bitten at the wrist and distal forearm that came to the emergency department in where distal ulnar dislocation with muscle tendon exposure was diagnosed. Due to the offending agent and multiple soft tissue injuries the treatment with standard techniques was impossible. We describe the technique of treatment of this patient by placing autologous gracilis tendon graft, platelet rich plasma and two anchoring systems for ankle syndesmosis. Immobilization was maintained for six weeks with a subsequent rehabilitation and posterior valuation at 12, 18 and 28 weeks by the scale of MAYO, PRWE and DASH and finding a good result which implies the return to work and daily activities of the patient with minimal pain and limitation.

  1. Arthroscopically assisted percutaneous fixation of Bennett fractures.

    PubMed

    Culp, Randall W; Johnson, Jeff W

    2010-01-01

    Arthroscopic-assisted reduction and fixation of Bennett-type fractures of the thumb metacarpal allow for the confirmation of reduction as well as the assessment of the degree of chondral damage. With use of a 1.9-mm arthroscope and a traction tower, direct visualization and reduction is possible. Traditional methods of fixation are used to secure the fracture fragment. Postoperative rehabilitation follows the usual protocol used in both open and percutaneous techniques. However, the potential to obtain and confirm a more accurate articular reduction may reduce the incidence of late arthritis of the thumb carpometacarpal articulation.

  2. 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

  3. 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.

  4. Fixation of tendo Achilles avulsion fracture.

    PubMed

    Lui, T H

    2009-01-01

    Achilles tendon ruptures occur commonly in the midsubstance of the tendon, usually 2-6 cm proximal to the insertion to the calcaneus. Ruptures near its insertion into the calcaneus are less common and mostly found in hyperpronators with a heel spur (Haglund's deformity). Avulsion of the bony insertion of the Achilles tendon at the calcaneus is infrequent and is diagnosed by radiography. Open reduction and internal fixation is indicated to achieve bone to bone healing and restoration of the function and continuity of the triceps surae mechanism. Screw fixation is not effective to resist the pull out tension of the triceps surae. Moreover, the prominent screw head may cause skin impingement. More secure fixation method is necessary in order to allow early functional rehabilitation. We describe a technique to fix the avulsed fragment of Achilles tendon insertion with 2 suture anchors. This can neutralize the pull of the triceps surae and early post-operative rehabilitation programme is allowed.

  5. A technique to re-establish dose distributions for previously treated brain cancer patients in external beam radiotherapy

    SciTech Connect

    Yue, Ning J.; Knisely, Jonathan; Studholme, Colin; Chen Zhe; Bond, James E.; Nath, Ravinder

    2004-03-31

    Tumor recurrences or new tumors may develop after irradiation of local lesion(s) in the brain, and additional radiotherapy treatments are often needed for previously treated patients. It is critical to re-establish the dose distributions delivered during the previous treatment in the current patient geometry, so that the previous dose distributions can be accurately taken into consideration in the design of the current treatment plan. The difficulty in re-establishing the previous treatment dose distributions in the current patient geometry arises from the fact that the patient position at the time of reirradiation is different from that at the previous treatment session. Simple re-entry of the previous isocenter coordinates, gantry, and couch and collimator angles into the new treatment plan would result in incorrect beam orientations relative to the new patient anatomy, and therefore incorrect display of the previous dose distributions on the current patient anatomy. To address this issue, a method has been developed so that the previous dose distributions can be accurately re-established in the framework of the current brain treatment. The method involves 3 matrix transformations: (1) transformation of beams from machine coordinate system to patient coordinate system in the previous treatment; (2) transformation of beams from patient coordinate system in the previous treatment to patient coordinate system in the current treatment; and (3) transformation of beams from patient coordinate system in the current treatment to machine coordinate system. The transformation matrices used in the second transformation are determined by registration using a mutual information-based algorithm with which the old and new computed tomography (CT) scan sets are registered automatically without human interpretation. A series of transformation matrices are derived to calculate the isocenter coordinates, the gantry, couch, and collimator angles of the beams for the previous

  6. Establishing the Concepts and Techniques of Performance-Oriented Training in Army Training Centers: A Summary Report

    DTIC Science & Technology

    1975-06-01

    Military Police), (d) qcIf-pacing of instruction in supply and heavy equipment courses, ,e NCO leadership and instructor training courses, and ( f ) training...for Reserve Components: and I f ) NCO Leadership /instructor Training. When specifi" projects were undertaken, attempts were made to establish a...and heavy equipment courses; (e) NCO leadership and instructor training courses; and ( f ) Training for Reserv. Components. Performance training and

  7. Periosteal Fixation Procedures in the Management of Incomitant Strabismus

    PubMed Central

    Saxena, Rohit; Phuljhele, Swati; Sharma, Pradeep; Pinto, C. N.

    2015-01-01

    Managing a case of incomitant strabismus from nerve palsy or extraocular muscle loss is a major challenge. Among possible management options are globe or extraocular muscle fixation to the orbital wall coupled with weakening or strengthening of the relevant antagonist. Extraocular muscle fixation to the orbital wall can also be used in cases of abnormal synkinesis to eliminate the abnormal eye movements of a misfiring extraocular muscle, which thereby allows the use of standard paralytic strabismus surgery techniques. This review article summarizes indications and techniques of periosteal fixation procedures for incomitant strabismus. PMID:26180470

  8. Ganglion cysts of the shoulder: technique of arthroscopic decompression and fixation of associated type II superior labral anterior to posterior lesions.

    PubMed

    Westerheide, Kenneth J; Karzel, Ronald P

    2003-10-01

    Ganglion cysts of the shoulder and concomitant suprascapular nerve compression should be considered in the differential diagnosis of shoulder pain. They are associated commonly with labral tears, most commonly SLAP lesions. MRI has become commonplace in evaluating shoulder pain and has led to the increased awareness of shoulder cysts. MRI accurately demonstrates the size and location of ganglions, which is critical when planning surgical intervention. It also has shown the frequent association of intra-articular pathology with these cysts. Despite that MRI can detect atrophy, the diagnosis of suprascapular nerve compression can be confirmed only by EMG/NCS, because the presence of a cyst does not necessarily mean the nerve is compressed. Likewise, a positive EMG does not confirm that the compression is caused by a ganglion cyst. EMG/NCVs are necessary for confirming the diagnosis and evaluating nerve and muscle function. A trial of nonoperative management is warranted; however, this is associated with a high failure rate. Aspiration techniques are successful for decompression of the cysts and initial pain relief; however, the intra-articular pathology is not addressed and there is a higher rate of recurrence. Open resection of the ganglion cyst is successful; however, the intra-articular labral tears are not addressed, which can lead to recurrence and the morbidity of the cyst excision is not warranted. Shoulder arthroscopy has led to the identification of associated intra-articular pathology such as SLAP lesions. These were not appreciated previously with open surgery and therefore were not addressed. Arthroscopic techniques have evolved to allow decompression of the ganglion cysts and repair of the labral lesions. This should decrease the possibility of recurrence of the cyst by eliminating the cyst and the pathologic lesion that created it. Arthroscopic excision also avoids much of the morbidity of the open approach and allows intra-articular pathology to be

  9. 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,…

  10. 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)

  11. The Fixation of Nitrogen.

    ERIC Educational Resources Information Center

    Andrew, S. P. S.

    1978-01-01

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

  12. Revision of Minimally Invasive Sacroiliac Joint Fixation: Technical Considerations and Case Studies Using Decortication and Threaded Implant Fixation

    PubMed Central

    Fielding, Louis C

    2017-01-01

    Background Sacroiliac joint (SIJ) disease is increasingly recognized as a common source of low back pain. Arthrodesis of the SIJ has been shown to be clinically effective for this condition. In the last decade, minimally invasive (MI) SIJ fusion procedures have been developed to achieve the clinical effectiveness of open fusion procedures, with lower operative morbidity and faster recovery. However, SIJ fusion patients occasionally present with symptomatic nonunions necessitating revision. Methods Four patients who previously underwent MI SIJ arthrodesis returned with complaints of SIJ related pain confirmed by examination. Radiographic assessment showed lucency after fixation with triangular titanium interference implants. Loose implants were removed, and the patients were revised with a different MI SIJ fusion system that utilizes decortication, placement of autograft and graft extender, and fixation with cannulated threaded implants. The trajectory of the revision implants was in a more ventral-to-dorsal and caudal-to-cranial trajectory to place the implants perpendicularly through the articular portion of the SIJ. Results The triangular implants typically exhibited haloing lucency on radiographs and CT scans, and most were easily removed using the manufacturer’s instrumentation; only one implant was left in place as it was well-fixed. The removed implants exhibited little or no bony ongrowth. Decortication of the SIJ was performed, followed by placement of local autograft and fixation with 12.5 mm or 14.5mm diameter implants, as required. A more ventral-todorsal and caudal-to-cranial trajectory was established for the revision implants through the center of the articular region of the joint in order to maximize implant purchase in residual bone stock and achieve bony fusion through the articular portion of the SIJ. By six to twelve months post-revision, the presenting symptoms were successfully resolved in all patients. Conclusions Patients demonstrating

  13. Biomechanical advantages of robot-assisted pedicle screw fixation in posterior lumbar interbody fusion compared with freehand technique in a prospective randomized controlled trial-perspective for patient-specific finite element analysis.

    PubMed

    Kim, Ho-Joong; Kang, Kyoung-Tak; Park, Sung-Cheol; Kwon, Oh-Hyo; Son, Juhyun; Chang, Bong-Soon; Lee, Choon-Ki; Yeom, Jin S; Lenke, Lawrence G

    2017-05-01

    There have been conflicting results on the surgical outcome of lumbar fusion surgery using two different techniques: robot-assisted pedicle screw fixation and conventional freehand technique. In addition, there have been no studies about the biomechanical issues between both techniques. This study aimed to investigate the biomechanical properties in terms of stress at adjacent segments using robot-assisted pedicle screw insertion technique (robot-assisted, minimally invasive posterior lumbar interbody fusion, Rom-PLIF) and freehand technique (conventional, freehand, open approach, posterior lumbar interbody fusion, Cop-PLIF) for instrumented lumbar fusion surgery. This is an additional post-hoc analysis for patient-specific finite element (FE) model. The sample is composed of patients with degenerative lumbar disease. Intradiscal pressure and facet contact force are the outcome measures. Patients were randomly assigned to undergo an instrumented PLIF procedure using a Rom-PLIF (37 patients) or a Cop-PLIF (41), respectively. Five patients in each group were selected using a simple random sampling method after operation, and 10 preoperative and postoperative lumbar spines were modeled from preoperative high-resolution computed tomography of 10 patients using the same method for a validated lumbar spine model. Under four pure moments of 7.5 Nm, the changes in intradiscal pressure and facet joint contact force at the proximal adjacent segment following fusion surgery were analyzed and compared with preoperative states. The representativeness of random samples was verified. Both groups showed significant increases in postoperative intradiscal pressure at the proximal adjacent segment under four moments, compared with the preoperative state. The Cop-PLIF models demonstrated significantly higher percent increments of intradiscal pressure at proximal adjacent segments under extension, lateral bending, and torsion moments than the Rom-PLIF models (p=.032, p=.008, and p

  14. The limited anterior approach of the elbow for open reduction and internal fixation of capitellum fractures. Surgical technique and clinical experience in 2 cases with more than 2 years follow-up.

    PubMed

    Ballesteros-Betancourt, J R; Fernández-Valencia, J A; García-Tarriño, R; Domingo-Trepat, A; Sastre-Solsona, S; Combalia-Aleu, A; Llusá-Pérez, M

    Fractures involving the capitellum can be treated surgically by excision of the fragment, or by reduction and internal fixation with screws, with or without heads. The lateral Kocher approach is the most common approach for open reduction. We believe that the limited anterior approach of the elbow, could be a valid technique for treating these fractures, as it does not involve the detachment of any muscle group or ligament, facilitating the recovery process. A description is presented of the surgical technique, as well as of 2cases with a Bryan-Morrey type 1 fracture (Dubberley type 1A). Two different final quality of life evaluation questionnaires were completed by telephone: the EuroQol Five Dimensions Questionnaire (EQ-5D), and the patient part of the Liverpool Elbow Score (PAQ-LES) questionnaire. The 2patients showed favourable clinical progress at 36 and 24 months, respectively, with an extension/flexion movement arc of -5°/145° and -10°/145°, as well as a pronosupination of 85°/80° and 90°/90°. The 2patients showed radiological consolidation with no signs of osteonecrosis. The EQ-5D score was 0.857 and 0.910 (range: 0.36-1), and a PAQ-SLE of 35 and 35 (range: 17-36), respectively. We believe that the limited anterior approach of the elbow is a technical option to consider for the open surgical treatment of a capitellum fracture, although further studies are needed to demonstrate its superiority and clinical safety compared to the classical lateral Kocher approach. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Comparison of modern and conventional imaging techniques in establishing multiple myeloma-related bone disease: a systematic review.

    PubMed

    Regelink, Josien C; Minnema, Monique C; Terpos, Evangelos; Kamphuis, Marjolein H; Raijmakers, Pieter G; Pieters-van den Bos, Indra C; Heggelman, Ben G F; Nievelstein, Rutger-Jan; Otten, Rene H J; van Lammeren-Venema, Danielle; Zijlstra, Josee M; Arens, Anne I J; de Rooy, Jacky W; Hoekstra, Otto S; Raymakers, Reinier; Sonneveld, Pieter; Ostelo, Raymond W; Zweegman, Sonja

    2013-07-01

    This systematic review of studies compared magnetic resonance imaging (MRI), (18) F-fluorodeoxyglucose positron emission tomography (FDG-PET), FDG-PET with computerized tomography (PET-CT) and CT with whole body X-Ray (WBXR) or (whole body) CT in order to provide evidence-based diagnostic guidelines in multiple myeloma bone disease. A comprehensive search of 3 bibliographic databases was performed; methodological quality was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria (score 1-14). Data from 32 directly comparative studies were extracted. The mean QUADAS score was 7·1 (3-11), with quality hampered mainly by a poor description of selection and execution criteria. All index tests had a higher detection rate when compared to WBXR, with up to 80% more lesions detected by the newer imaging techniques; MRI (1·12-1·82) CT (1·04-1·33), PET (1·00-1·58) and PET-CT (1·27-1·45). However, the modern imaging techniques detected fewer lesions in the skull and ribs. In a direct comparison CT and MRI performed equally with respect to detection rate and sensitivity. This systematic review supports the International Myeloma Working Group guidelines, which recommend that WBCT can replace WBXR. In our opinion, the equal performance of MRI also indicates that it is a valuable alternative. As lesions of the skull and ribs are underdiagnosed by modern imaging techniques we advise additional X-rays of these regions. The consequences of this approach are discussed. © 2013 John Wiley & Sons Ltd.

  16. 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

  17. Percutaneous fixation of hand fractures using locked K-wires: mechanical analysis and clinical application.

    PubMed

    De Spirito, Daniele

    2013-09-01

    Closed percutaneous wire fixation of hand fractures frequently requires protection with external splintage. This splintage increases the risk of joint stiffness, prolongs recovery time, and increases therapy input. We have developed a method of linking external Kirschner wires (K-wires), using a metal clamp, after their insertion, so as to increase the security of fixation and facilitate postoperative mobilization. The mechanical properties of this method have been assessed in vitro and compared with conventionally fixed, unlinked, K-wires. We have been able to establish that the linked K-wire system is better able to resist loosening. This work proposes that linkage of K-wires permits omission of all additional external splintage, with no detriment to management. The technique has been applied in clinical cases over the past 8 years and results of treatments were evaluated mainly to detect unexpected complications. We report a low rate of complications and good results in terms of bone healing and recovery of function.

  18. [Fixation of cells for analysis by laser microdissection--comparative studies in forensic trace material].

    PubMed

    Fischer, Elisabeth J; Laberke, Patrick J; Kübler, Eric; Balitzki, Beate

    2012-01-01

    This paper is focused on the preparation of samples for laser microdissection (LM) in forensic casework. In forensic genetics, it is essential to preserve and separate cellular traces during sample preparation, as they are usually gathered in very small amounts and are often contaminated with undesired cells. This is made possible by laser microdissection, a technique developed to cut cells or tissue of a certain type from a microscopical specimen by UV laser and catapult them directly into a PCR reactor. This method minimizes the risk of getting inconclusive, mixed DNA profiles due to contamination by foreign DNA and also supplies information about the cellular origin of a DNA profile. A method for optimized fixation and staining of spermatozoa for laser microdissection was established. Four different fixation methods combined with two staining methods were tested on two different microscope slides. Moreover, the effect of a blocker pen to contain the specimen on the slide was investigated.

  19. Percutaneous K-wire fixation versus palmar plating with locking screws for Colles' fractures.

    PubMed

    Hollevoet, Nadine; Vanhoutie, Tom; Vanhove, Wim; Verdonk, René

    2011-04-01

    Different methods exist to treat distal radius fractures. A prospective randomized study was conducted to establish whether palmar plate fixation with locking screws gave better results than percutaneous K-wire fixation in patients over 50 years of age. Only fractures with dorsal displacement after a simple fall were included in the study. Twenty wrists were treated with K-wires and 20 with a plate. Radiological parameters were measured on preoperative radiographs and at five weeks postoperatively. Clinical results and DASH scores were determined at three months postoperatively and at more than one year. No significant difference in radial inclination, palmar tilt, clinical outcome and DASH score was found between plating and K-wires, but the mean difference in ulnar variance between pre- and postoperative radiographs was significantly better with plates. It can be concluded that plates were superior to K-wires in restoring ulnar variance, but functional outcome was similar with both techniques.

  20. A systematic review on dynamic versus static distal tibiofibular fixation.

    PubMed

    Inge, S Y; Pull Ter Gunne, A F; Aarts, C A M; Bemelman, M

    2016-12-01

    In the last couple of years dynamic fixation for syndesmosis injuries, using a suture-button technique, raised more interest due to its advantages over the static fixation. In the current systematic review suture-button fixation is compared to the traditionally applied static fixation in unstable ankle fractures accompanied with distal tibiofibular syndesmosis injury, including the functional outcome, post-operative complications, reoperation rate, recurrent diastasis and financial aspects. A computerized literature search using PubMed/MEDLINE and EMBASE was conducted in search of suitable articles between January 2006 and February 2016. A total of 4 suture-button studies, 5 suture-button vs. static fixation studies and 1 study discussing the financial aspects were identified. The AOFAS of 104 patients treated with the suture-button device was 91.08 points with an average study-follow up of 24.85 months. The AOFAS of 106 patients treated with a static fixation device was 87.95 with an average follow-up of 24.78 months. Removal of the suture-button device was reported in 10.5% of 229 patients and removal of the screws in 38.5%. Dynamic fixation demonstrated to be a viable alternative to the static fixation device, with lower reoperation rates and less complications. They can accurately stabilize the ruptured syndesmosis without device breakage or loss of reduction. 1A economic/decision. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2016-06-01

    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. 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). 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. 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.

  2. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

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

  3. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

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

  4. LIVER ULTRASONOGRAPHY IN DOLPHINS: USE OF ULTRASONOGRAPHY TO ESTABLISH A TECHNIQUE FOR HEPATOBILIARY IMAGING AND TO EVALUATE METABOLIC DISEASE-ASSOCIATED LIVER CHANGES IN BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS).

    PubMed

    Seitz, Kelsey E; Smith, Cynthia R; Marks, Stanley L; Venn-Watson, Stephanie K; Ivančić, Marina

    2016-12-01

    The objective of this study was to establish a comprehensive technique for ultrasound examination of the dolphin hepatobiliary system and apply this technique to 30 dolphins to determine what, if any, sonographic changes are associated with blood-based indicators of metabolic syndrome (insulin greater than 14 μIU/ml or glucose greater than 112 mg/dl) and iron overload (transferrin saturation greater than 65%). A prospective study of individuals in a cross-sectional population with and without elevated postprandial insulin levels was performed. Twenty-nine bottlenose dolphins ( Tursiops truncatus ) in a managed collection were included in the final data analysis. An in-water ultrasound technique was developed that included detailed analysis of the liver and pancreas. Dolphins with hyperinsulinemia concentrations had larger livers compared with dolphins with nonelevated concentrations. Using stepwise, multivariate regression including blood-based indicators of metabolic syndrome in dolphins, glucose was the best predictor of and had a positive linear association with liver size (P = 0.007, R(2) = 0.24). Bottlenose dolphins are susceptible to metabolic syndrome and associated complications that affect the liver, including fatty liver disease and iron overload. This study facilitated the establishment of a technique for a rapid, diagnostic, and noninvasive ultrasonographic evaluation of the dolphin liver. In addition, the study identified ultrasound-detectable hepatic changes associated primarily with elevated glucose concentration in dolphins. Future investigations will strive to detail the pathophysiological mechanisms for these changes.

  5. Chromium and its speciation in water samples by HPLC/ICP-MS--technique establishing metrological traceability: a review since 2000.

    PubMed

    Markiewicz, Barbara; Komorowicz, Izabela; Sajnóg, Adam; Belter, Magdalena; Barałkiewicz, Danuta

    2015-01-01

    Chromium holds a special position among living organisms because depending on its species it can be either essential or toxic. Cr(VI) even at very low concentrations is harmful and carcinogenic, while Cr(III) is a necessary microelement for cellular metabolism. Therefore, a simple analysis of Cr concentration in collected samples will not be able to distinguish these differences effectively: for a proper chemical analysis we need to perform a reliable detection and quantification of Cr species. Separation and detection of chromium can be accomplished with high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC/ICP-MS) in a one-step. Our review assembles articles published since 2000 regarding chromium speciation in water samples with the use of HPLC/ICP-MS. It addresses the following issues: chromium chemistry, the possibilities of dealing with interferences, metrological aspects, analytical performance and speciated isotope dilution mass spectrometry (SIDMS) which is a definitive measurement method. The authors would like to advocate this hyphenated advanced technique as well as the metrological approach in speciation analysis of chromium. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. The sterile insect technique for the management of the spotted wing drosophila, Drosophila suzukii: Establishing the optimum irradiation dose.

    PubMed

    Lanouette, Geneviève; Brodeur, Jacques; Fournier, François; Martel, Véronique; Vreysen, Marc; Cáceres, Carlos; Firlej, Annabelle

    2017-01-01

    The spotted wing drosophila Drosophila suzukii Matsumura (Diptera: Drosophilidae), a pest of berries stone fruits, invaded North America and Europe in 2008. Current control methods rely mainly on insecticides. The sterile insect technique (SIT) has potential as an additional control tactic for the integrated management of D. suzukii. As a step towards the development of the SIT, this study aimed at finding the optimum irradiation dose to sterilize D. suzukii under controlled laboratory conditions. Four-day-old D. suzukii pupae were irradiated 12 to 24 hours prior to adult emergence in a 60Co Gamma Cell 220 and in a 137Cs Gamma Cell 3000 with doses of 30, 50, 70, 80, 90, 100 or 120 Gy. Emergence rate (88.1%), percent of deformed flies (4.0%) and survival curves were not affected by the tested irradiation doses. However, some reproductive parameters of the flies were affected by irradiation. Females irradiated with a dose of 50 Gy or more had almost no fecundity. When non-irradiated females were mated with irradiated males, egg hatch decreased exponentially with irradiation dose from 82.6% for the untreated control males to 4.0% for males irradiated with 120 Gy. Mortality of F1 individuals from the irradiated treatment also occurred during larval and pupal stages, with an egg to adult survival of 0.2%. However, descendants produced by the irradiated generation were fertile. These results are an encouraging first experimental step towards the development of the SIT for the management of D. suzukii populations.

  7. 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

  8. 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

  9. Biomechanical comparison of lumbosacral fixation using Luque-Galveston and Colorado II sacropelvic fixation: advantage of using locked proximal fixation.

    PubMed

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

    2005-06-15

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

  10. 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.

  11. 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

  12. 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

  13. Calibration and standardization of microwave ovens for fixation of brain and peripheral nerve tissue.

    PubMed

    Login, G R; Leonard, J B; Dvorak, A M

    1998-06-01

    Rapid and reproducible fixation of brain and peripheral nerve tissue for light and electron microscopy studies can be done in a microwave oven. In this review we report a standardized nomenclature for diverse fixation techniques that use microwave heating: (1) microwave stabilization, (2) fast and ultrafast primary microwave-chemical fixation, (3) microwave irradiation followed by chemical fixation, (4) primary chemical fixation followed by microwave irradiation, and (5) microwave fixation used in various combinations with freeze fixation. All of these methods are well suited to fix brain tissue for light microscopy. Fast primary microwave-chemical fixation is best for immunoelectron microscopy studies. We also review how the physical characteristics of the microwave frequency and the dimensions of microwave oven cavities can compromise microwave fixation results. A microwave oven can be calibrated for fixation when the following parameters are standardized: irradiation time; water load volume, initial temperature, and placement within the oven; fixative composition, volume, and initial temperature; and specimen container shape and placement within the oven. Using two recently developed calibration tools, the neon bulb array and the agar-saline-Giemsa tissue phantom, we report a simple calibration protocol that identifies regions within a microwave oven for uniform microwave fixation. Copyright 1998 Academic Press.

  14. [Use of zinc-containing dehydrating fixatives for neurohistological studies].

    PubMed

    Korzhevskiĭ, D E; Grigor'ev, I P; Otellin, V A

    2006-01-01

    The suitability of zinc-containing dehydrating fixatives for neurohistological study of paraffin sections using Nissl staining and immunocytochemical techniques was examined. It was found that zinc-containing dehydrating fixatives (zinc-ethanol-formaldehyde and zinc-acetone-isopropanol-formaldehyde) had a capacity for good preservation of both structure and antigenic properties of the nervous tissue and could be recommended for application in neurohistological studies.

  15. Morphology of the fetal rat testis preserved in different fixatives.

    PubMed

    Howroyd, Paul; Hoyle-Thacker, Renee; Lyght, Otis; Williams, Delorise; Kleymenova, Elena

    2005-01-01

    Histopathological examination of the testes of exposed fetuses and neonates is important in assessing the developmental effects of environmental toxins, including sex hormone modulators. Modified Davidson's fluid (mDF) has been suggested as a superior substitute for Bouin's fluid for fixation of adult animal testes. We compared the morphology of fetal rat testes stained with hematoxylin and eosin (H&E) or immunochemically after fixation in 10% neutral buffered formalin (NBF), Bouin's fluid, or mDF. Fixation in mDF resulted in more sharply defined nuclear detail and better preservation of cellular cytoplasm on H&E-stained sections of rat testes on gestation day 19. Use of Bouin's fluid did not allow satisfactory detection of apoptotic cells by fluorescent terminal deoxynucleotide transferase-mediated deoxy-UTP nick labeling. Staining with the immunoperoxidase system and the conventional chromogen diaminobenzidine tetrahydrochloride to visualize 5-bromo-2-deoxyuridine-positive cells demonstrated that the number of positive nuclei and intensity of staining were similar with all 3 fixatives. Immunostaining for cytoskeletal protein vimentin was more intense and provided better details of the Sertoli cell cytoplasm with formalin fixation than with mDF. Our study demonstrates that fixation in mDF provided better morphologic detail in the fetal rat testis compared with 10% NBF and Bouin's fluid and illustrates the importance of establishing the correct fixation conditions for each immunostaining protocol.

  16. 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.

  17. A biomechanical comparison of facet screw fixation and pedicle screw fixation: effects of short-term and long-term repetitive cycling.

    PubMed

    Ferrara, Lisa A; Secor, Jessica L; Jin, Byung-Ho; Wakefield, Andrew; Inceoglu, Serkan; Benzel, Edward C

    2003-06-15

    A biomechanical study was conducted to assess the stabilization performance of transfacet pedicle screw fixation. To compare the biomechanical effects of short-term and long-term cyclic loading on lumbar motion segments instrumented with either a pedicle screw or a transfacet pedicle screw construct. Facet screw fixation is an alternative to pedicle screw fixation that permits the use of a minimally invasive strategy. It is not known whether facet screw fixation can provide stability equivalent to pedicle screw fixation during cyclical loading. Therefore, transfacet pedicle screw fixation and standard pedicle screw fixation techniques were compared biomechanically. Lumbar motion segments were tested under short-term and long-term cyclic loading conditions. For the short-term phase, specimens were tested intact for six cycles (to 400 N or 4 Nm) in compression, flexion, extension, lateral bending, and torsion. The specimens then were instrumented with bilateral semicircular interbody spacers and pedicle screw instrumentation or transfacet pedicle screws, and the testing sequence was repeated. For the long-term phase, 12 specimens were instrumented in a similar manner and loaded to 6 Nm of flexion bending for 180,000 cycles. For the short-term phase, both fixation systems had significantly greater stiffness and reduced range of motion, as compared with the intact state. No differences were observed between the fixation systems except in flexion, wherein transfacet pedicle screw specimens were significantly stiffer than traditional pedicle screw specimens. For the long-term phase, the stiffness and range of motion did not significantly increase or decrease over repetitive cycling of the instrumented specimens. Furthermore, no significant difference between the fixation systems was observed. The stability provided by both transfacet pedicle screw fixation and traditional pedicle screw fixation was not compromised after repetitive cycling. In this model, transfacet

  18. Ensuring precision in lower limb deformity correction through a combination of temporary external fixation followed by internal fixation: Results of a retrospective study

    PubMed Central

    Ganjwala, Dhiren; Shah, Shrenik; Shah, Snehal

    2014-01-01

    Background: It is important to plan preoperatively when contemplating internal fixation following deformity correction. Surgeons often find it difficult to retain the achieved correction till the end of internal fixation. To maintain precise correction we used hybrid technique which uses both external and internal fixation. The objective of the study was to evaluate the effectiveness of this hybrid technique in achieving and retaining desired correction. Materials and Methods: In this retrospective study, we evaluated the magnitude of deformity with radiological parameters. We compared correction which was planned and correction which was achieved. The technique was used during surgery for corrective osteotomies. Before carrying out the osteotomy, rail fixator with two swivel clamps was applied. After osteotomy swivel clamps were loosened. Desired correction was achieved. While fixator held the fragments in corrected position, definitive internal fixation was carried out. External fixator was removed after completion of internal fixation. Position of mechanical axis ratio, mechanical lateral distal femoral angle and mechanical medial proximal tibial angle were measured before and 12 weeks after surgery. Student t-test was used to analyze the difference between correction which was planned and correction which was achieved. Results: There was no statistical difference between the desired correction and the correction achieved. Conclusions: Temporary use of external fixator while correcting angular deformities of lower limb allows to achieve accurate correction. PMID:25298557

  19. External fixators in haemophilia.

    PubMed

    Lee, V; Srivastava, A; PalaniKumar, C; Daniel, A J; Mathews, V; Babu, N; Chandy, M; Sundararaj, G D

    2004-01-01

    External fixators (EF) are not commonly used for patients with haemophilia. We describe the use of EF (Ilizarov, AO- uni- and bi-planar fixators and Charnley clamp) in nine patients (mean age: 19.2 years; range: 9-37) with haemophilia for the following indications - arthrodesis of infected joints, treatment of open fractures and osteoclasis. EF required an average of nine skin punctures [range: 4-17 were maintained for a period of 15 weeks (range: 8-29.5), without regular factor replacement, till bone healing was adequate and were removed with a single dose of factor infusion]. The mean preoperative factor level achieved was 85% (range: 64-102%). Much lower levels were subsequently maintained till wound healing. The average total factor consumption was 430 IU kg(-1) (range: 240-870), administered over a period of 17 days (range: 9-44). There were no major complications related to EF except in a patient who developed inhibitors. In conclusion, EF can be used safely in haemophilic patients who do not have inhibitors and does not require prolonged factor replacement.

  20. 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.

  1. 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

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

    PubMed

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

    2015-01-01

    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. Nine general surgeons performed 36 open IPOM fixation procedures in porcine model. Each surgeon conducted two mechanical (using ETHICON SECURESTRAP ™ 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. 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. Mechanical fixation with ETHICON SECURESTRAP ™ 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.

  3. 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

  4. Subbrow blepharoplasty using supraorbital rim periosteal fixation.

    PubMed

    Kim, Yeon Soo

    2014-02-01

    Subbrow blepharoplasty (SBB) addresses lateral hooding of the upper eyelid skin, a shortcoming of classical upper blepharoplasty. Therefore, SBB is widely used by plastic surgeons in Korea and Japan. The aim of this study is to improve postoperative results and to minimize a relapse of existing SBB by the use of a supraorbital rim periosteal suture fixation technique. An upper incision is made along the inferior margin of the eyebrow. A lower incision, which is determined according to necessary amount of skin excision, is made vertically, deep to the posterior fascia of the obicularis oculi muscle (OOM). Then, skin, OOM, and posterior fascia of the OOM are excised en bloc. An upper skin flap dissection is extended to the width of 1 cm. The posterior fascia of the OOM in the inferior flap is pulled up and three transverse 5-0 nylon sutures are placed to fix it to the periosteum and the sub-brow fat of the supraorbital rim temporally to the supraorbital nerve. A margin of upper flap level is usually a suitable position for fixation. Thirty-six patients underwent SBB using the supraorbital rim periosteal suture fixation technique from July 2007 to June 2012. Thirty-six patients underwent SBB and were followed up for an average of 27 months. The follow-up period ranged from 8 months to 6 years. Their mean age at the time of surgery was 55 years. Thirty-four patients (94.4 %) were satisfied with the surgical results, however, two patients (5.6 %) complained about dimpling at the periosteal suture fixation point. Administration of two focal injections of triamcinolone acetonide resulted in relief and disappearance of the dimpling. We report our experience with a subbrow blepharoplasty using suture fixation of the OOM in the inferior flap to the supraorbital rim periosteum at the margin of the upper flap after an elliptical excision of subbrow skin. Our method of SBB has the advantage of ensuring the continuance of surgical results and minimizing the risk of relapse

  5. Slipknot for scleral fixation of intraocular lenses.

    PubMed

    Lee, S C; Tseng, S H; Cheng, H C; Chen, F K

    2001-05-01

    We describe a simple, quick technique to construct a slipknot that can be snared around the haptic of an intraocular lens (IOL) during transscleral fixation of a posterior chamber IOL or repositioning of a dislocated IOL. An in vitro experiment showed that the time required for the slipknot method was significantly less than that for the traditional triple-knot method. An additional advantage is that the slipknot technique can be performed by a single surgeon using standard ophthalmic instrumentation. In addition, the slipknot is as secure as a triple knot.

  6. 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

  7. 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.

  8. Effects of different fixatives on beta-galactosidase activity.

    PubMed

    Ma, Wenbin; Rogers, Keith; Zbar, Berton; Schmidt, Laura

    2002-10-01

    beta-Galactosidase (beta-Gal) staining is widely used to demonstrate specific gene expression during evaluation of gene targets in vivo. This technique is extremely sensitive to fixation. Optimal fixation conditions are necessary to obtain the maximal beta-Gal activity. In this experiment, Carnoy's and three different aldehyde fixatives were used at different temperatures and over different time points. Kidneys from LacZ-stop-human alkaline phosphatase (ZA/P) double reporter mice were used to generate positive material for the experiment. The results show that glutaraldehyde combinative solution (LacZ) produced the most consistent and reliable results. Paraformaldehyde and formaldehyde were effective as fixatives only at 4C for a period of less than 4 hr, and Carnoy's solution destroyed beta-Gal activity.

  9. Compression capability of cerclage fixation systems. A biomechanical study.

    PubMed

    Shaw, J A; Daubert, H B

    1988-08-01

    Cerclage wire or tension band techniques are frequently complicated by broken wires or inadequate bony stabilization. The fixation capabilities of various cerclage systems were defined in this study by measuring the maximum compression forces generated by the different methods as well as their ultimate strengths. Parham bands and swage-lock titanium cables were found to exhibit the greatest fixation potential and highest ultimate strengths. Cerclage fixation using stainless steel wire was found to be enhanced by using a modified square knot. Mersilene tape was found to have fixation capabilities of similar magnitude to 20 guage stainless wire secured with a twist knot. The polypropylene and nylon cable ties tested showed no advantage when compared to the other systems.

  10. Fixation of distal radial epiphyseal fracture: Comparison of K-wire and prebent intramedullary nail.

    PubMed

    Cai, Haoqi; Wang, Zhigang; Cai, Haiqing

    2016-02-01

    To compare the use of crossed K-wire and prebent intramedullary nail techniques for the fixation of distal radius metaphyseal fracture in children. Intraoperative and follow-up data for children with distal radius metaphyseal fracture, treated using crossed K-wire or prebent intramedullary nail fixation, were retrospectively analysed. Patient groups were matched for age, sex and clinical parameters (fracture location, affected side, fracture type). Patients treated using prebent intramedullary nail fixation (n = 52) had significantly shorter surgery duration, fewer intraoperative X-radiographs, and lower prevalence of postoperative redisplacement and malalignment deformity than those treated using crossed K-wire fixation (n = 52). Both techniques resulted in similar postoperative complications and recovery of forearm rotation. Prebent intramedullary nail fixation has a better functional outcome than crossed K-wire fixation in the treatment of distal radial epiphyseal fracture in children. © The Author(s) 2015.

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

    PubMed Central

    Lareau, Craig R.; Daniels, Alan H.; Vopat, Bryan G.; Kane, Patrick M.

    2015-01-01

    Unstable ankle fractures and impacted tibial pilon fractures often benefit from provisional external fixation as a temporizing measure prior to definitive fixation. Benefits of external fixation include improved articular alignment, decreased articular impaction, and soft tissue rest. Uniplanar external fixator placement in the Emergency Department (ED ex-fix) is a reliable and safe technique for achieving ankle reduction and stability while awaiting definitive fixation. This procedure involves placing transverse proximal tibial and calcaneal traction pins and connecting the pins with two external fixator rods. This technique is particularly useful in austere environments or when the operating room is not immediately available. Additionally, this bedside intervention prevents the patient from requiring general anesthesia and may be a cost-effective strategy for decreasing valuable operating time. The ED ex-fix is an especially valuable procedure in busy trauma centers and during mass casualty events, in which resources may be limited. PMID:25709258

  12. 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

  13. Establishment and rapid detection of a heterozygous missense mutation in the CACNA1F gene by ARMS technique with double-base mismatched primers.

    PubMed

    Yang, W C; Zhu, L; Zhou, B X; Tania, S; Zhou, Q; Khan, M A; Fu, X L; Cheng, J L; Lv, H B; Fu, J J

    2015-09-25

    Retinitis pigmentosa (RP) is a retinal degenerative disorder that often causes complete blindness. Mutations of more than 50 genes have been identified as associated with RP, including the CACNA1F gene. In a recent study, by employing next-generation sequencing, we identified a novel mutation in the CACNA1F gene. In this study, we used the amplification refractory mutation system (ARMS) and identified a single nucleotide change c.1555C>T in exon 13 of the CACNA1F gene, leading to the substitution of arginine by tryptophan (p.R519W) in a Chinese individual affected by RP. This study actually confirms this novel mutation, and establishes the ARMS technique for the detection of mutations in RP.

  14. Risk factors for loss of fixation in pediatric supracondylar humeral fractures.

    PubMed

    Sangkomkamhang, Thananit; Singjam, Udomsin; Leeprakobboon, Duangjai

    2014-09-01

    The aim of this study was to determine the risk factors for loss of fixation in pediatric supracondylar humeral fractures. The data were analyzed regarding assessed loss of fixation in 256 supracondylar fractures from January 2010 to December 2012, all of which were treated by closed or open reduction and Kirschner wire fixation. The confounding factors that were thought to cause loss of reduction were collected. Multivariate logistic regression analysis was performed to predict risk factors. Reduction was lost in 14.8% of the patients. Poor surgical technique was significantly higher in the cases with lost reduction (odds ratio: 15.21). Additionally, cases with only lateral pins placement (odds ratio: 2.57), Gartland type 3 fractures (odds ratio: 2.38), and, obesity with a BMI ≥ 25 (odds ratio: 14.35) had a significantly higher risk of losing reduction and fixation. Other factors including age, energy type of injury, time of surgery, and time to surgery were not associated with risk. The loss of reduction following fracture fixation is associated with poor surgical technique,fixation with lateral pinning only, Gartland type 3 fractures, and pediatric obesity (BMI > 25). The stability of fracture fixation in pediatric supracondylar fractures is largely dependent on the use of effective fixation techniques. Cross pinning provides a more stabile fixation than lateral pinning.

  15. Multiplanar Fixation for Patella Fractures Using a Low-Profile Mesh Plate.

    PubMed

    Lorich, Dean G; Warner, Stephen J; Schottel, Patrick C; Shaffer, Andre D; Lazaro, Lionel E; Helfet, David L

    2015-12-01

    Patella fractures are challenging orthopaedic injuries. Many commonly used fixation techniques can be ineffective and lead to poor clinical outcomes even with satisfactory reductions and fracture healing. In this investigation, we present the technique of cage plate fixation of patella fractures and the clinical outcomes of 9 initial patients surgically treated at our institution. This technique allows direct visualization of the articular reduction, provides multiplanar fixation, effectively stabilizes inferior pole comminution, and reduces the risk of patella vascular disruption. Using this technique, we have achieved excellent functional and radiographic outcomes.

  16. A graduated method of tip graft fixation in rhinoplasty.

    PubMed

    Papel, I D

    1995-06-01

    Projection of the nasal tip has gained increased recognition as a measurable and visual characteristic that has an impact on the results of aesthetic rhinoplasty. Autologous cartilage tip grafts have been used in many techniques to increase tip projection and contour the tip during rhinoplasty. This article introduces a graduated method of tip graft fixation correlated with specific clinical measurements related to tip projection. After careful analysis of tip projection and contour, a predictable graft fixation technique can be selected to obtain the desired degree of nasal tip projection and sculpting.

  17. Neuronal control of fixation and fixational eye movements

    PubMed Central

    2017-01-01

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

  18. [Biomechanical performance of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability].

    PubMed

    Liu, Tie-long; Yan, Wang-jun; Han, Yu; Ye, Xiao-jian; Jia, Lian-shun; Li, Jia-shun; Yuan, Wen

    2010-05-01

    To compare the biomechanical performances of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability, and test the effect of different fixation strengths and fixation approaches on the surgical outcomes. Six specimens of the atlantoaxial complex (C0-C3) were used to establish models of the normal complex, unstable complex (type II odontoid fracture) and fixed complex. On the wd-5 mechanical testing machine, the parameters including the strength and rigidity of anti-rotation, change and strength of stress, and stability were measured for the normal complex, atlantoaxial instability complex, the new type titanium cable fixation system, Atlas titanium cable, Songer titanium cable, and stainless wire. The strength and rigidity of anti-rotation, change and strength of stress, stability of flexion, extension and lateral bending of the unstable atlantoaxial complex fixed by the new double locking titanium cable fixation system were superior to those of the Songer or Atlas titanium cable (P<0.05) and medical stainless wire (P<0.05). Simultaneous cable fastening on both sides resulted in better fixation effect than successive cable fastening (P<0.05). Better fixation effect was achieved by fastening the specimen following a rest (P<0.05). The fixation effects can be enhanced by increased fastening strengths. The new type double locking titanium cable fixation system has better biomechanical performance than the conventional Songer and Atlas titanium cables. Fastening the unstable specimens after a rest following simultaneous fastening of the specimen on both sides produces better fixation effect.

  19. 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

  20. Limits of internal fixation in long-bone fracture.

    PubMed

    Nieto, H; Baroan, C

    2017-02-01

    Alternatives to internal fixation of long-bone fracture comprise, depending on location, external fixation or joint replacement. Limitations comprise risk of infection and functional outcome quality, which vary according to technique. The present study examines these limitations, based on comparative or large-scale studies from which certain significant results emerge. Four main questions are dealt with: (1) the present role of locking plates; (2) conditions for intramedullary nailing in Gustilo grade IIIb open fracture; (3) the limitations of conversion from external fixation to intramedullary nailing in open lower leg fracture; (4) and the limitations of definitive anterograde femoral nailing in multiple trauma. Locking plate fixation has yet to prove clinical superiority in any of the anatomic sites for which good-quality comparative analyses are available. Infection risk in Gustilo grade IIIb open lower leg fracture is equivalent when treated by intramedullary nailing or external fixation, if wound care and debridement are effective, antibiotherapy is initiated rapidly and skin cover is restored within 7days. Conversion from primary external fixation to intramedullary nailing is possible if the external fixator was fitted less than 28days previously and skin cover was restored within 7days. The pulmonary and systemic impact of peripheral lesions or definitive anterograde intramedullary nailing of femoral fracture in multiple trauma calls for caution and what is known as "damage-control orthopedics" (DCO), a term covering the general consequences of both the initial trauma and its treatment. Femoral intramedullary nailing is thus contraindicated in case of hemorrhagic shock (blood pressure<90mmHg), hypothermia (<33°C), coagulation disorder (platelet count<90,000) or peripheral lesions such as multiple long-bone fractures, crushed limb or primary pulmonary contusion. In such cases, external fixation or retrograde nailing with a small-diameter nail and without

  1. Treatment of infected non-unions with segmental defects with a rail fixation system.

    PubMed

    Mudiganty, Srikanth; Daolagupu, Arup Kumar; Sipani, Arun Kumar; Das, Satyendra Kumar; Dhar, Arijit; Gogoi, Parag Jyoti

    2017-04-01

    We conducted this study to evaluate the use of rail fixation system in infected gap non-union of femur and tibia as an alternative to the established Ilizarov circular fixator technique. Prospective study. The study was done in the Department of Orthopaedic surgery in a medical school and level I trauma center to which the authors are/were affiliated. Between June 2010 and June 2015, 40 patients with infected gap non-union of femur and tibia were treated with the rail fixation system. Patients who were willing to undergo surgery and participate in the post-operative rehabilitation were included in the study. After radical debridement, the system was applied and corticotomy done. For closure of bone gap, acute docking and distraction was done in 18 cases and segmental bone transport in 22 cases. Early mobilization of patient was done along with aggressive physiotherapy. Bone and functional results were calculated according to ASAMI scoring system, and complications were classified according to Paley classification. The mean follow-up period was 22.56 months (range 8-44). Bone union with eradication of infection was achieved in all but 1 case (97.5%). Bone results were excellent in 57.5%, good 40%, fair 0% and poor in 2.5% cases, while functional result was excellent in 32.5%, good 65%, fair 0% and poor in 2.5% cases. The rail fixation system is an excellent alternative method to treat infected gap non-union of femur and tibia. It is simple, easy to use and patient-friendly.

  2. Transit fixatives: an innovative study.

    PubMed

    M, Rajanikanth; A, Ravi Prakash; G, Sreenath; Jk, Sonia Bai; Ndvn, Shyam

    2015-03-01

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

  3. 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)

  4. 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)

  5. Extensive hydrogen supersaturations in the western South Atlantic Ocean suggest substantial underestimation of nitrogen fixation

    NASA Astrophysics Data System (ADS)

    Moore, Robert M.; Kienast, Markus; Fraser, Michael; Cullen, John J.; Deutsch, Curtis; Dutkiewicz, Stephanie; Follows, Michael J.; Somes, Christopher J.

    2014-07-01

    The nitrogen cycle is fundamental to Earth's biogeochemistry. Yet major uncertainties of quantification remain, particularly regarding the global oceanic nitrogen fixation rate. Hydrogen is produced during nitrogen fixation and will become supersaturated in surface waters if there is net release from diazotrophs. Ocean surveys of hydrogen supersaturation thus have the potential to illustrate the spatial and temporal distribution of nitrogen fixation and to guide the far more onerous but quantitative methods for measuring it. Here we present the first transect of high resolution measurements of hydrogen supersaturations in surface waters along a meridional 10,000 km cruise track through the Atlantic. We compare measured saturations with published measurements of nitrogen fixation rates and also with model-derived values. If the primary source of excess hydrogen is nitrogen fixation and has a hydrogen release ratio similar to Trichodesmium, our hydrogen measurements would point to similar rates of fixation in the North and South Atlantic, roughly consistent with modeled fixation rates but not with measured rates, which are lower in the south. Possible explanations would include any substantial nitrogen fixation by newly discovered diazotrophs, particularly any having a hydrogen release ratio similar to or exceeding that of Trichodesmium; undersampling of nitrogen fixation south of the equator related to excessive focus on Trichodesmium; and methodological shortcomings of nitrogen fixation techniques that cause a bias toward colonial diazotrophs relative to unicellular forms. Alternatively, our data are affected by an unknown hydrogen source that is greater in the southern half of the cruise track than the northern.

  6. The pathologist's guide to fixatives.

    PubMed

    Qidwai, Kiran; Afkhami, Michelle; Day, Christina E

    2014-01-01

    Proper tissue fixation is essential to ensure the highest level of specimen evaluation. Pathologists and laboratory staff are frequently consulted by clinical counterparts regarding what fixative should be used for different tissues or to enable a diagnosis of a specific condition. It is vital for the patient that the pathologist provides accurate information to ensure proper fixation. Frequently, once a tissue has been fixed inadequately or inappropriately, remedial changes may no longer be possible. Most often formalin is an adequate choice, if not the optimal one; however, there are certain situations when placing the tissue in formalin may limit the ability to reach a definitive diagnosis. It is imperative for pathologists to have the knowledge to communicate which fixative is optimal. Furthermore, as we move into a world of personalized medicine, where ancillary testing has both diagnostic and specific therapeutic implications, knowledge about how different fixatives affect immunohistochemistry, cytogenetics, and molecular studies becomes even more significant. This chapter provides practical information regarding common fixatives, their mechanism of action and optimal uses.

  7. 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

  8. Bilateral sagittal split osteotomy and temporomandibular disorders: rigid fixation versus wire fixation.

    PubMed

    Nemeth, D Z; Rodrigues-Garcia, R C; Sakai, S; Hatch, J P; Van Sickels, J E; Bays, R A; Clark, G M; Rugh, J D

    2000-01-01

    The effects of orthognathic surgery on temporomandibular disorders may be related to the surgical method that is used. Specifically, it has been suggested that the choice of stabilization technique may play a major role in the functional outcome of mandibular advancement surgery. The purpose of this study was to prospectively compare long-term (2 years) signs and symptoms of temporomandibular disorders after orthognathic surgery with bilateral sagittal split osteotomy in 127 patients randomized to receive rigid or wire fixation. Signs and symptoms of temporomandibular disorders were evaluated before and 2 years after surgery by means of the overall craniomandibular index (CMI), dysfunction index (DI), and muscle index (MI). Patients also reported subjective symptoms of temporomandibular disorders by marking areas of pain on a standard drawing of the head and rating the pain in each area on a scale ranging from 1 (very mild) to 7 (very extreme). Subjective pain was also assessed through use of the Oral Health Status Questionnaire and by a rating of the difficulty in opening the mouth because of pain. There were no statistically significant differences in the CMI, MI, or DI change scores between the wire and rigid fixation groups (mean CMI(wire) = 0.05, mean CMI(rigid) = 0.04; mean DI(wire) = 0.02, mean DI(rigid) = 0. 01; mean MI(wire) = 0.08, mean MI(rigid) = 0.08) 2 years after surgery. Temporomandibular joint sounds also demonstrated no significant differences between the two fixation methods. Subjective pain reports were consistent with the clinical examinations. On average, both wire and rigid scores decreased slightly, but the change scores were not significantly different between groups. These findings suggest that the long-term (2 years) effects of wire and rigid internal fixation methods on the signs and symptoms of temporomandibular disorders do not differ. Earlier concerns about increased risk for temporomandibular disorders with rigid fixation were not

  9. 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

  10. Biomechanics of external fixation and limb lengthening.

    PubMed

    Younger, Alastair S E; Morrison, James; MacKenzie, William G

    2004-09-01

    Surgeons who use external fixators for foot and ankle conditions need to understand the biomechanical principles to ensure good outcomes. Fixators can be used for fracture fixation, correction of contractures, distraction osteogenesis, and distraction arthroplasty. A two-ring fixator with wire fixation remains the gold standard with which all other frames are compared. Small changes in mechanical characteristics can have major implications on new bone or cartilage formation.

  11. Microwave-Assisted Tissue Preparation for Rapid Fixation, Decalcification, Antigen Retrieval, Cryosectioning, and Immunostaining

    PubMed Central

    2016-01-01

    Microwave irradiation of tissue during fixation and subsequent histochemical staining procedures significantly reduces the time required for incubation in fixation and staining solutions. Minimizing the incubation time in fixative reduces disruption of tissue morphology, and reducing the incubation time in staining solution or antibody solution decreases nonspecific labeling. Reduction of incubation time in staining solution also decreases the level of background noise. Microwave-assisted tissue preparation is applicable for tissue fixation, decalcification of bone tissues, treatment of adipose tissues, antigen retrieval, and other special staining of tissues. Microwave-assisted tissue fixation and staining are useful tools for histological analyses. This review describes the protocols using microwave irradiation for several essential procedures in histochemical studies, and these techniques are applicable to other protocols for tissue fixation and immunostaining in the field of cell biology. PMID:27840640

  12. Endoscopically assisted reduction and fixation of condylar neck/base fractures--The learning curve.

    PubMed

    Loukota, R A

    2006-12-01

    Following the introduction of a new technique for fixation of fractures of the condylar neck and base in our department, the operative times were compared with those for the traditional and frequently used method of open reduction and internal fixation. A distinct learning curve was seen.

  13. The role of external fixation and emergency fracture management in bovine orthopedics.

    PubMed

    Adams, S B

    1985-03-01

    External fixation is a very useful method of treating selected fractures in cattle. The economics of therapy and the availability of the techniques to all veterinarians will continue to make external fixation the most frequently used method of fracture repair in cattle.

  14. Robotic mitral valve repair for all prolapse subsets using techniques identical to open valvuloplasty: establishing the benchmark against which percutaneous interventions should be judged.

    PubMed

    Suri, Rakesh M; Burkhart, Harold M; Daly, Richard C; Dearani, Joseph A; Park, Soon J; Sundt, Thoralf M; Li, Zhuo; Enriquez-Sarano, Maurice; Schaff, Hartzell V

    2011-11-01

    Recent reports have shown that robotic mitral valve repair is effective in treating posterior leaflet disease; however, comparison with trans-sternal (open) valvuloplasty for all prolapse categories has not been performed. Moreover, data from the recently published EVEREST II trial infer that adverse event rates after mitral valve repair for degenerative disease are high. We therefore compared early outcomes of robotic versus open mitral valve repair for patients with mitral valve prolapse. Among 745 consecutive patients undergoing open or robotic mitral repair for degenerative disease, 95 propensity-matched pairs were identified. Leaflet prolapse categories were similar between groups. Complete mitral valve repair was performed using identical techniques. Median crossclamp and bypass times were longer in the robotic group but decreased significantly over time (P < .001). There were no conversions to open sternotomy, repair rate and early survival were 100%, dismissal mitral regurgitation grade was similar (P = 1.00), and all patients in the robotic group had mild or less mitral regurgitation at 1 month after repair. There were no differences in adverse events (5% open vs 4% robotic, P = 1.00). Patients in the robotic group had shorter postoperative ventilation time, intensive care unit stay, and hospital stay. Robotic mitral valve repair allows complete anatomic correction of all categories of leaflet prolapse using techniques identical to open approaches. Robotic repair effectively corrects mitral regurgitation, offers excellent freedom from adverse events, and facilitates rapid weaning from ventilation, translating into earlier hospital dismissal. Safety and efficacy after both open and robotic mitral valve repair are higher than recently reported in the EVEREST II trial and establish a benchmark against which nonsurgical therapies should be evaluated. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  15. [Establishment of a three-dimensional pancreas model for simulating surgical resection of pancreatic tail carcinoma using virtual-reality technique].

    PubMed

    Fang, Chi-Hua; Liu, Yu-Bin; Tang, Yun-Qiang; Pan, Jia-Hui; Peng, Feng-Ping; Lu, Chao-Min; Bao, Su-Su

    2008-06-01

    To assess the feasibility of visual-reality technique for simulating surgical resection of pancreatic tail carcinoma using a 3-dimensional pancreas model reconstructed on the basis of the CT data. The original image data of 64-slice spiral CT was obtained from a patient with pancreatic tail carcinoma. Using adaptive region growing algorithm, the serial CT images were segmented and automatically extracted for 3-dimensional reconstruction of the pancreas and the anatomically related structures with a self-designed program. The model was then processed with Freeform Modeling System for image modification and smoothing. With the assistance of GHST SDK and PHANTOM software systems, preoperative simulation of surgical resection of the carcinoma was performed on the basis of the established pancreatic model. The reconstructed 3-dimensional pancreatic model with the related structures clearly visualized the 3-dimensional structures of the pancreas, the pancreatic tail compromised by the carcinoma, and the adjacent organs, displaying also the distribution, courses and the anatomical relations of the ductal systems including the main pancreatic duct, abdominal aorta, portal vein system, and the biliary tract. During simulated surgery for pancreatic tail carcinoma resection, the GHOST SDK system allowed effective application of the virtual surgical instruments, and the use of PHANTOM software produced a surgical experience with high resemblance of that from an actual operation. The serial CT data-based reconstruction of 3-dimensional pancreas model and simulated operation on this model using virtual-reality technique has great potentials for application in individualized surgical planning and surgical risk assessment in cases of pancreatic tail carcinoma, and also facilitates clinical training of the surgeons.

  16. A biomechanical experiment and clinical study of the use of figure of eight plus circular wiring fixation for the treatment of olecranon fractures

    PubMed Central

    WANG, WULIAN; WU, GUANGWEN; SHEN, FUER; ZHANG, YIYUAN; LIU, XIANXIANG

    2012-01-01

    The aim of the present study was to evaluate the stability of the figure of eight plus circular wiring fixation technique compared with four common internal fixation techniques and to provide experimental data for the selection of internal fixation techniques clinically. A total of 20 fresh cadaveric elbow joints were used as transverse, oblique and comminuted olecranon fracture models. Five techniques of internal fixation were investigated: circular wiring, figure of eight wiring, circular plus figure of eight wiring, Kirschner wire (K-wire) and screw fixation. The elbow joints were flexed at 90°. The fixation performance was tested using a high-precision displacement sensor. Displacement-load curves revealed that the strength of internal fixation was weakest when using circular wiring alone and that circular wiring plus figure of eight wiring fixation was stronger than that of figure of eight wiring or screw fixation. The difference was statistically significant (P<0.05). There were no significant differences between circular wiring plus figure of eight wiring fixation and K-wire fixation in the transverse and oblique fracture models (P>0.05). However, figure of eight plus circular wiring fixation was superior to K-wire fixation in the comminuted fracture model, with a tensile force of 67.42±2.17 vs. 58.52±2.17 N, respectively (P<0.05). All 152 patients with olecranon fractures who received circular wiring plus figure of eight wiring fixation recovered and 108 were included in the follow-up for an average of 12 months. The rate of excellent/fairly good recovery was 98.10%. Due to its reliability, simple surgery, lower invasiveness and lower cost, figure of eight plus circular wiring fixation is an ideal choice for the internal fixation of olecranon fractures, particularly comminuted fractures, compared with circular wiring, figure of eight wiring or screw fixation. PMID:23226778

  17. The influence of alternative plant propagation and stand establishment techniques on survival and growth of eastern cottonwood (Populus deltoides Bartr.) clones.

    SciTech Connect

    Kaczmarek, Donald J.; et. al.,

    2014-02-09

    Four eastern cottonwood clones, including standard operational clone ST66 and three advanced clonal selections were produced and included in a test utilizing five different plant propagation methods. Despite relatively large first-year growth differences among clones, all clones demonstrated similar responses to the treatments and clone 9 cutting treatment interactions were generally non-significant. The effects of changing cutting lengths are consistent with previous studies which indicated the potential for increased plant survival and growth with increased cutting lengths. Differences in stored carbohydrate reserves alone do not appear to completely control first-year growth and development of cuttings. First-year growth of 51 cm long cuttings planted 30.5 cm deep was greater than the same cuttings planted 48 cm deep. Stem form of plants derived from whip-tip propagation did not differ from plants derived from standard, unrooted cuttings. This propagation method offers the potential of far greater production capacity from a cutting orchard and rapid bulk-up of new or limited clones. Stand uniformity assessments suggest that surviving trees of each individual cutting treatment exhibit similar levels of growth variation. Optimization of plantation establishment techniques has the potential to increase growth of young Populus plantations.

  18. Comparing the effectiveness of "plasma knife" tonsillectomy with two well-established tonsillectomy techniques: cold dissection and bipolar electrocautery. A prospective randomized study.

    PubMed

    Sadikoglu, Fatih; Kurtaran, Hanifi; Ark, Nebil; Ugur, K Serife; Yilmaz, Turker; Gozdemir, Muhammed; Mutlu, Cemil; Aktas, Davut

    2009-09-01

    To evaluate the effectiveness of a new device "plasma knife" for tonsillectomy by comparing to two well-established tonsillectomy techniques: cold dissection, and bipolar electrocautery. A prospective, randomized study conducted on 110 patients undergoing tonsillectomy. Subjects were randomized to plasma knife (PKT), cold dissection (CDT) and bipolar electrocautery (BET) groups. Operative time, intraoperative blood loss and postoperative complications were recorded. Pain/discomfort level of patients and healing time of the tonsillar fossae were assessed postoperatively. Data were recorded and statistically analyzed. Operative time with plasma knife and bipolar electrocautery were associated with a significant decrease in operative time compared to cold dissection (p<0.05). Intraoperative blood loss was significantly decreased with plasma knife, compared to cold dissection and bipolar electrocautery (p<0.05). Less postoperative pain was observed with plasma knife compared to bipolar electrocautery but more postoperative pain was observed with both compared to CDT (p<0.05). Postoperative healing time was longer with plasma knife and bipolar electrocautery, compared to cold dissection (p<0.05). Plasma knife is a useful and safe device in tonsillectomy. Its use reduces intraoperative blood loss and provides a fast tonsillectomy with acceptable morbidity.

  19. Mini-plate fixation versus suture suspensory fixation in cervical laminoplasty

    PubMed Central

    Liu, Feng-Yu; Ma, Lei; Huo, Li-Shuang; Cao, Yan-Xiang; Yang, Da-Long; Wang, Hui; Yang, Si-Dong; Ding, Wen-Yuan

    2017-01-01

    Abstract Background: Both the mini-plate fixation and suture suspensory fixation techniques are extensively applied in cervical laminoplasty, but which technique is superior has not been ascertained. The purpose of this meta-analysis is to compare the results between mini-plate fixation and suture suspensory fixation in cervical laminoplasty for the patients with multilevel cervical compressive myelopathy. Methods: PubMed, Embase, the Cochrane library, CNKI, and WANFANG were searched for studies that compared mini-plate fixation and suture suspensory fixation in cervical laminoplasty up to November 1, 2016. We calculated odds ratio (OR) with 95% confidence interval (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes. Review Manager 5.3 was used for the statistical analyses. Results: A total of 25 studies, involving 1603 participants, were included in this review. The results of this meta-analysis indicated that there were statistically significant differences in postoperative Japanese Orthopedic Association (JOA) scores (MD = 0.67, 95% CI: 0.34–0.99, P < 0.001), JOA scores improvement rate (MD = 4.00, 95% CI: 2.51–5.50, P < 0.001), postoperative Visual Analogue Score (VAS) (MD = −0.81, 95% CI: −1.36 to −0.26, P = 0.004), postoperative range of motion (ROM) (MD = 4.15, 95% CI: 2.06–6.23, P < 0.001), postoperative cervical lordosis (MD = 3.1, 95% CI: 2.02–4.18, P < 0.001), postoperative anteroposterior diameter of the spinal canal (MD = 1.53, 95% CI: 0.11–2.95, P = 0.03), postoperative open angle (MD = 1.93, 95% CI: 0.14–3.71, P = 0.03), postoperative cross-sectional area of the spinal canal (MD = 37.10, 95% CI: 26.92–47.29, P < 0.001), axial symptoms (OR = 0.28, 95% CI: 0.20–0.37, P < 0.001), operation time (MD = 4.46, 95% CI: 0.74–8.19, P = 0.02), and blood loss (MD = 9.24, 95% CI: 6.86–11.62, P < 0.001). However

  20. 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

  1. Bovine rumenotomy: comparison of four surgical techniques.

    PubMed Central

    Dehghani, S N; Ghadrdani, A M

    1995-01-01

    Rumenotomy in cattle is a routine procedure for treatment and diagnostic purposes. A comparative study of different rumenotomy techniques is lacking in the veterinary literature. Four rumenotomy techniques were compared in 20 cattle: skin suture fixation, Weingarth's ring, stay suture, and skin clamp fixation. Results indicated that skin suture fixation was superior to Weingarth's ring and the stay suture techniques. Skin clamp fixation was comparable with skin suturing and required a shorter operative time. Rumenotomy using the stay suture technique was followed by postoperative inflammatory complications, as indicated by significant (P < 0.05) increases in mean body temperature and total white blood cell counts of 39.3, s = 0.56 degrees C and 12.6 x 10(9), s = 1.57 x 10(9)/L, respectively, on day 4. Therefore, rumenotomy using the skin clamp fixation technique could be considered as an alternative to the more commonly used skin suture fixation technique. PMID:8590423

  2. Climatic controls of moss-associated nitrogen fixation in the Subarctic

    NASA Astrophysics Data System (ADS)

    Rousk, Kathrin; Michelsen, Anders

    2017-04-01

    Nitrogen (N2) fixation performed by moss-associated cyanobacteria is one of the main sources of new N input in pristine, high latitude ecosystems like boreal forests and subarctic tundra. However, N2 fixation in mosses is strongly influenced by climatic conditions, in particular, moisture and temperature. Previous attempts to temporally scaling up N2 fixation in mosses from low frequency in situ measurements to several weeks, months or even the entire growing season without taking into account changes in abiotic conditions could not capture the variation in moss-associated N2 fixation. We therefore aimed to estimate moss-associated N2 fixation throughout the snow-free period in subarctic tundra in field experiments simulating climate change: willow (Salix myrsinifolia) and birch (Betula pubescens spp. tortuosa) litter addition, and warming. The litter additions were sought to simulate shrub expansion in high latitude ecosystems. We established relationships between measured in situ N2 fixation rates and soil moisture and soil temperature and used high-resolution measurements of soil moisture and soil temperature (hourly from May - October) to model N2 fixation. The modelled N2 fixation rates were highest in the warmed (2.8 ±0.3 kg N ha-1) and birch litter addition plots (2.8 ±0.2 kg N ha-1), and lowest in the plots receiving willow litter (1.6 ±0.2 kg N ha-1). The control plots had intermediate rates (2.2 ±0.2 kg N ha-1). Our findings suggest that a longer snow-free period and increased temperatures in a future climate will likely lead to higher N2 fixation rates in mosses. Yet, the consequences of increased litter fall on moss-associated N2 fixation due to shrub expansion in the Arctic will depend on the shrub species' litter traits. To follow up on the strong dependence of moss-associated N2 fixation on moisture and temperature, we collected mosses along a precipitation gradient in subarctic tundra, Northern Sweden and exposed the mosses to different

  3. 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.

  4. Outcomes of C1 and C2 posterior screw fixation for upper cervical spine fusion.

    PubMed

    De Iure, F; Donthineni, R; Boriani, S

    2009-06-01

    To achieve stable fixation of the upper cervical spine in posterior fusions, the occiput is often included. With the newer techniques, excluding fixation to the occiput will retain the occiput-cervical motion, while still allowing a stable fixation. Harms's technique has been adapted at our institution and its effectiveness for indications such as C2 complex fractures and tumors using C1 or C2 as endpoints of a posterior fixation are reviewed. Fourteen cases were identified, consisting of one os odontoideum; four acute fractures and four non-unions of the odontoid; three tumors and two complex fractures of C2 vertebral body, and one C2-C3 post-traumatic instability. One misplaced screw without clinical consequences was the only complication recorded. Screw loosening or migration was not observed at follow-up, showing a stable fixation.

  5. Transarticular fixation with a bioabsorptive screw for cervical spondylolisthesis.

    PubMed

    Kim, Kyongsong; Isu, Toyohiko; Omura, Tomoko; Morimoto, Daijiro; Kobayashi, Shiro; Teramoto, Akira

    2014-01-01

    Patients with cervical instability and intramedullary signal intensity changes on preoperative magnetic resonance imaging scans may benefit from not only cervical decompression but also from fusion surgery. Transarticular screw (TAS) fixation is a useful technique for posterior fixation. We first report treating a patient with cervical spondylosis and instability by cervical laminoplasty with TAS fixation using a bioabsorptive screw. A 66-year-old woman who had undergone surgery for carcinoma of the tongue via the anterior approach experienced cervical myelopathy. Radiologic findings showed severe cervical canal stenosis with myelomalacia and spondylolisthesis at C4/C5 with instability. We performed laminoplasty of C3 to C7 and TAS fixation of C4/C5 using a bioabsorptive poly-L-lactide screw that contained hydroxyapatite. Her postoperative course was uneventful, and at 1 year after treatment we confirmed C4/C5 fusion. Our method has advantages over metal instrumentation. The treated area can be evaluated with the use of magnetic resonance imaging, and the space left after screw absorption is filled by newly formed bone. Because our screw contains hydroxyapatite, it is osteoconductive. This may increase the fusion rate and induce substitution with new bone. To our knowledge this is the first patient treated by cervical posterior TAS fixation via the use of a bioabsorptive screw. Our method is safe and economical and free of the complications elicited by the use of metal parts. TAS fixation with a bioabsorptive screw may be appropriate for one fixation in patients without severe instability. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Trochanteric osteotomy and fixation during total hip arthroplasty.

    PubMed

    Archibeck, Michael J; Rosenberg, Aaron G; Berger, Richard A; Silverton, Craig D

    2003-01-01

    Once used routinely, trochanteric osteotomy in total hip arthroplasty now is usually limited to difficult primary and revision cases. There are three types: the standard trochanteric osteotomy and its variations, the trochanteric slide, and the extended trochanteric osteotomy. Each has unique indications, fixation techniques, and complications. Primary total hip arthroplasty procedures requiring the enhanced exposure provided by trochanteric osteotomy may be needed in patients with hip ankylosis or fusion, protrusio acetabuli, proximal femoral deformities, developmental dysplasia, or abductor muscle laxity. Trochanteric osteotomies in revision arthroplasties, primarily the extended trochanteric osteotomy, facilitate the removal of well-fixed femoral components, provide direct access to the diaphysis for distal fixation, and enhance acetabular exposure.

  7. Prevention and management of external fixator pin track sepsis.

    PubMed

    Ferreira, Nando; Marais, Leonard Charles

    2012-08-01

    Pin track-associated complications are almost universal findings with the use of external fixation. These complications are catastrophic if it leads to the failure of the bone-pin interface and could lead to pin loosening, fracture non-union and chronic osteomyelitis. Strategies proposed for the prevention and management of pin track complications are diverse and constantly changing. Prevention of external fixation pin track infection is a complex and ongoing task that requires attention to detail, meticulous surgical technique and constant vigilance.

  8. Establishment of the 1st World Health Organization International Standard for Plasmodium falciparum DNA for nucleic acid amplification technique (NAT)-based assays

    PubMed Central

    Padley, David J; Heath, Alan B; Sutherland, Colin; Chiodini, Peter L; Baylis, Sally A

    2008-01-01

    Background In order to harmonize results for the detection and quantification of Plasmodium falciparum DNA by nucleic acid amplification technique (NAT)-based assays, a World Health Organization (WHO) collaborative study was performed, evaluating a series of candidate standard preparations. Methods Fourteen laboratories from 10 different countries participated in the collaborative study. Four candidate preparations based upon blood samples parasitaemic for P. falciparum were evaluated in the study. Sample AA was lyophilized, whilst samples BB, CC and DD were liquid/frozen preparations. The candidate standards were tested by each laboratory at a range of dilutions in four independent assays, using both qualitative and quantitative NAT-based assays. The results were collated and analysed statistically. Results Twenty sets of data were returned from the participating laboratories and used to determine the mean P. falciparum DNA content for each sample. The mean log10 "equivalents"/ml were 8.51 for sample AA, 8.45 for sample BB, 8.35 for sample CC, and 5.51 for sample DD. The freeze-dried preparation AA, was examined by accelerated thermal degradation studies and found to be highly stable. Conclusion On the basis of the collaborative study, the freeze-dried material, AA (NIBSC code No. 04/176) was established as the 1st WHO International Standard for P. falciparum DNA NAT-based assays and has been assigned a potency of 109 International Units (IU) per ml. Each vial contains 5 × 108 IU, equivalent to 0.5 ml of material after reconstitution. PMID:18652656

  9. Biomechanical comparison of lag screw versus self-drilling screw fixation of oblique metatarsal osteotomy.

    PubMed

    Rabenhorst, Brien M; Smith, Michael P; James, C Roger; Grimes, Jerry S

    2011-08-01

    Several fixation methods for a Weil metatarsal osteotomy have been proposed. Lag screw fixation has been described as the preferred fixation technique. The self-drilling screw has been introduced and can be used for fixation of the Weil osteotomy. The current study compared self-drilling screws with lag screw fixation. A Weil metatarsal osteotomy was performed on the second, third, and fourth metatarsals of five matched pairs of fresh frozen cadaver feet. The feet of each pair were randomly assigned ical to fixation with either a 2.0-mm cortical lag screw or a 2.0-mm self-drilling screw. The second metatarsals were stressed using cantilever bending. The third and fourth metatarsals were stressed under a shear force. Yield load, deformation at yield load, structural stiffness, and energy stored at yield load were recorded. There were no statistically significant differences (p < 0.05) noted. However, there was a trend toward greater biomechanical stability with the lag screw. There were no significant differences in the stability of fixation of the self-drilling screw and lag screw. There was a trend toward the lag screw fixation being more stable. The clinical significance of this trend is uncertain but suggests there is not a large difference between the two methods of fixation.

  10. Studies of chemical fixation effects in human cell lines using Raman microspectroscopy.

    PubMed

    Meade, Aidan D; Clarke, Colin; Draux, Florence; Sockalingum, Ganesh D; Manfait, Michel; Lyng, Fiona M; Byrne, Hugh J

    2010-03-01

    The in vitro study of cellular species using Raman spectroscopy has proven a powerful non-invasive modality for the analysis of cell constituents and processes. This work uses micro-Raman spectroscopy to study the chemical fixation mechanism in three human cell lines (normal skin, normal bronchial epithelium, and lung adenocarcinoma) employing fixatives that preferentially preserve proteins (formalin), and nucleic acids (Carnoy's fixative and methanol-acetic acid). Spectral differences between the mean live cell spectra and fixed cell spectra together with principal components analysis (PCA), and clustering techniques were used to analyse and interpret the spectral changes. The results indicate that fixation in formalin produces spectral content that is closest to that in the live cell and by extension, best preserves the cellular integrity. Nucleic acid degradation, protein denaturation, and lipid leaching were observed with all fixatives and for all cell lines, but to varying degrees. The results presented here suggest that the mechanism of fixation for short fixation times is complex and dependent on both the cell line and fixative employed. Moreover, important spectral changes occur with all fixatives that have consequences for the interpretation of biochemical processes within fixed cells. The study further demonstrates the potential of vibrational spectroscopy in the characterization of complex biochemical processes in cells at a molecular level.

  11. Development of titanium fixation screw for hydroxyapatite osteosynthesis (APACERAM).

    PubMed

    Tanaka, Yoshihide

    2008-11-01

    Cranioplasty using custom-made HAP ceramic implants is a common procedure for skull defects. However, miniplate fixation using commercially available screws to stabilize the HAP flap is associated with several problems due to characteristic brittleness. The authors have thus developed a suitable screw for this procedure. Hydroxyapatite blocks (porosity, 40%; thickness, 5 mm) were prepared. Holes were created using a phi 1.4-mm drill. Five types of screw were evaluated for HAP condition after insertion, fixation strength on pull-out test, and fasten plate strength based on maximum torque. Based on this evaluation, the most effective screws were cylindrical style in shape, 4.8 mm in effective length, phi 1.6 mm in effective diameter, and 0.2 mm in edge height. A novel screw with high fixation potential for the miniplate technique was developed in this study.

  12. A Comparison of Screw Fixation and Suture-Button Fixation in a Syndesmosis Injury in an Ankle Fracture.

    PubMed

    Kim, Jung-Han; Gwak, Heui-Chul; Lee, Chang-Rack; Choo, Hye-Jeung; Kim, Jeon-Gyo; Kim, Dae-Yoo

    2016-01-01

    The present study compared the quality of reduction and the clinical assessment between screw fixation and suture-button fixation with an ankle fracture accompanied by syndesmosis injury. We studied the clinical and radiologic findings 1 year postoperatively through retrospective examination of 24 patients who had undergone screw fixation from January 2011 to December 2012 and prospective examination of 20 patients who had undergone suture button fixation from January 2013 to May 2014. Regarding the tibiofibular clear space, tibiofibular overlap, and medial clear space, the screw fixation group had improvement from a preoperative mean of 6.97 (range 2.79 to 15.81) mm, 4.43 (range 0 to 7.87) mm, 7.90 (range 4.24 to 19.50) mm to a postoperative mean of 4.95 (range 2.72 to 9.08) mm, 6.29 (range 0 to 10.37) mm, and 4.32 (range 1.98 to 6.57) mm, respectively. The corresponding improvement for the suture-button fixation group was from a preoperative mean of 6.65 (range 3.94 to 13.73) mm, 5.39 (range 0 to 9.44) mm, 7.27 (range 4.04 to 16.00) mm to a postoperative mean of 5.15 (range 2.93 to 7.30) mm, 7.21 (range 2.15 to 10.30) mm, and 4.25 (range 2.97 to 5.71) mm. No statistically significant difference was found between the 2 techniques. Both suture-button and metal screw fixation are effective treatment methods for an ankle fracture accompanied by syndesmosis injury. However, a long-term and prospective analysis is needed. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  13. Complications in operative fixation of calcaneal fractures

    PubMed Central

    Li, Ying; Bao, Rong-Hua; Jiang, Zhi-Qiang; Wu, Huo-Yan

    2016-01-01

    Objective: The purpose of this study focused on a number of factors that have been implicated in calcaneal complications and find the incidence of wound complications. Methods: This was a retrospective study. A total of 162 patients (176 feet) who underwent calcaneal fractures between 2007 and 2012 were included. The patient’s personal details, age, time from injury to surgery, cause of injury, type of fracture, operative details, operating and tourniquet times were collected from hospital computers and paper records. Evidence of complications including wound infection, wound necrosis, pain, malunion, nonunion, impingement, loss of fixation, ect were studied. Results: Forty-seven of one hundred and seventy-six fractures (26.704%) had complications, wound infection was noted in seven fractures (3.977%), twelve fractures developed necrosis (6.818%), 14 fractures (7.955%) developed pain. Malunion was found in five fractures (2.841%), nonunion in two fractures (1.136%) and loss of fixation in four fractures (2.272%). Three neurologic injury was also seen in our study (1.705%). Operating time, time from injury to surgery and type of fracture had some association with complications in operative fixation of calcaneal fractures, which showed a statistically significant improvement (P=0.000, 0.031, 0.020, respectively), but there were no evidence that age and tourniquet time affect the incidence of complication after calcaneal fracture surgery (P=0.119, 0.682, respectively). Conclusions: Despite developments in the surgical treatment of calcaneal fracture, wound complications still remain inevitable. Advanced imaging techniques, less invasive surgical procedures, wealth of anatomical knowledge, surgical experience and better postoperative care should be ensured. PMID:27648028

  14. 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.

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

    DOE PAGES

    Willner, Marian; Fior, Gabriel; Marschner, Mathias; ...

    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

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

    PubMed

    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.

  17. 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

  18. Internal fixation of mandibular angle fractures: a meta-analysis.

    PubMed

    Regev, Eran; Shiff, Jacob S; Kiss, Alex; Fialkov, Jeffrey A

    2010-06-01

    The degree of rigidity of internal fixation required for the treatment of mandibular angle fractures has long been at the center of debate in the literature. A statistical comparison between rigid fixation and monocortical fixation has been difficult because of multiple terms, definitions, and technical variations. The purpose of this study was to use the meta-analysis tool to combine information from multiple studies and to compare complication rates for different fixation methods. An English language literature search was conducted for articles on mandibular angle fractures. Information was collected on four variables of interest: compression/noncompression technique, monocortical/bicortical screws, number of plates, and location of plates. Five outcome rates were analyzed: infection, reoperation, hardware removal, malunion, and nonunion. Meta-analyses were run using Comprehensive Meta Analysis, version 2.2.03. Twenty-four studies with relevant data on the variables and outcomes of interest met the inclusion criteria. Significantly higher rates of infection, reoperation, and hardware removal were found for compression compared with noncompression, two plates compared with one plate, and for plates located on both the inferior and superior borders as compared with superior or inferior only. There were also significantly higher infection rates for bicortical screws compared with monocortical screws and higher malunion rates for compression compared with noncompression plating techniques. The results of this meta-analysis found lower complication rates with the use of noncompression, monocortical, and single-plate fixation, supporting the trend toward a single, superiorly placed, monocortical miniplate for fixation of mandibular angle fractures.

  19. Evaluation and comparison of clinical results of femoral fixation devices in arthroscopic anterior cruciate ligament reconstruction.

    PubMed

    Aydin, Deniz; Ozcan, Mert

    2016-03-01

    Several femoral fixation devices are available for hamstring tendon autograft in anterior cruciate ligament (ACL) reconstruction, but the best technique is debatable. We hypothesised that different suspensory femoral fixation techniques have no superiority over each other. The aim of this study was to evaluate and compare the clinical results of different suspensory femoral fixation devices in arthroscopic ACL reconstruction. This was a Level III, retrospective, comparative study. A total of 100 consecutive patients who underwent arthroscopic ACL reconstruction in a single institution with a mean follow-up time of 40 months (12-67 months) were divided into three groups according to femoral fixation devices as 'Endobutton' (n=34), 'Transfix' (n=35) and 'Aperfix' (n=31). The length of painful period after surgery, time to return to work and sporting activities, final range of motion, anterior drawer and Lachman tests, knee instability symptoms, International Knee Documentation Committee (IKDC) subjective knee evaluation score, Short Form 36 (SF-36) score, Lysholm knee score and Tegner point of the patients were evaluated and compared between groups. There were no significant differences between the groups. All techniques led to significant recovery in knee instability tests and symptoms. In this study, the clinical results of different suspensory femoral fixation techniques were found to be similar. We believe that different femoral fixation techniques have no effect on clinical results provided that the technique is correctly applied. The surgeon must choose a technique appropriate to his or her experience. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. 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.

  1. 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 ...

  2. Transit Fixatives: An Innovative Study

    PubMed Central

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

    2015-01-01

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

  3. Binocular Fixation Disparity in Single Word Displays

    ERIC Educational Resources Information Center

    Paterson, Kevin B.; Jordan, Timothy R.; Kurtev, Stoyan

    2009-01-01

    It has been claimed that the recognition of words displayed in isolation is affected by the precise location at which they are fixated. However, this putative role for fixation location has yet to be reconciled with the finding from reading research that binocular fixations are often misaligned and, therefore, more than 1 location in a word is…

  4. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls...

  5. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls...

  6. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls...

  7. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls...

  8. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls...

  9. 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. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Tunnel widening after ACL reconstruction with aperture screw fixation or all-inside reconstruction with suspensory cortical button fixation: Volumetric measurements on CT and MRI scans.

    PubMed

    Mayr, Raul; Smekal, Vinzenz; Koidl, Christian; Coppola, Christian; Fritz, Josef; Rudisch, Ansgar; Kranewitter, Christof; Attal, René

    2017-10-01

    Tunnel widening after anterior cruciate ligament reconstruction (ACLR) is influenced by the surgical and fixation techniques used. Computed tomography (CT) is the most accurate image modality for assessing tunnel widening, but magnetic resonance imaging (MRI) might also be reliable for tunnel volume measurements. In the present study tunnel widening after ACLR using biodegradable interference screw fixation was compared with all-inside ACLR using button fixation, with tunnel volume changes being measured on CT and MRI scans. Randomized controlled trial; Level of evidence, 2. Thirty-three patients were randomly assigned to hamstring ACLR using a biodegradable interference screw or all-inside cortical button fixation. CT and MRI scanning were done at the time of surgery and six months after. Tunnel volume changes were calculated and compared. On CT, femoral tunnel volumes changed from the postoperative state (100%) to 119.8% with screw fixation and 143.2% with button fixation (P=0.023). The changes in tibial tunnel volumes were not significant (113.9% vs. 117.7%). The changes in bone tunnel volume measured on MRI were comparable with those on CT only for tunnels with interference screws. Tibial tunnels with button fixation were significantly underestimated on MRI scanning (P=0.018). All-inside ACLR using cortical button fixation results in increased femoral tunnel widening in comparison with ACLR with biodegradable interference screw fixation. MRI represents a reliable imaging modality for future studies investigating tunnel widening with interference screw fixation. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The time course of contextual influences during lexical ambiguity resolution: evidence from distributional analyses of fixation durations.

    PubMed

    Sheridan, Heather; Reingold, Eyal M

    2012-10-01

    In the lexical ambiguity literature, it is well-established that readers experience processing difficulties when they encounter biased homographs in a subordinate-instantiating prior context (i.e., the subordinate bias effect). To investigate the time course of this effect, the present study examined distributional analyses of first-fixation durations on 60 biased homographs that were each read twice: once in a subordinate-instantiating context and once in a dominant-instantiating context. Ex-Gaussian fitting revealed that the subordinate context distribution was shifted to the right of the dominant context distribution, with no significant contextual differences in the degree of skew. In addition, a survival analysis technique showed a significant influence of the subordinate versus dominant contextual manipulation as early as 139 ms from the start of fixation. These results indicate that the contextual manipulation had a fast-acting influence on the majority of fixation durations, which is consistent with the reordered access model's assumption that prior context can affect the lexical access stage of reading.

  12. Outcome of iris fixation of subluxated intraocular lenses.

    PubMed

    Michaeli, Adi; Soiberman, Uri; Loewenstein, Anat

    2012-09-01

    The aim of this study was to evaluate the efficacy of iris fixation of subluxated intraocular lenses (IOLs). A retrospective study of 44 consecutive cases of subluxated IOLs that underwent iris fixation of the IOL. Demographic information, data regarding surgery, and follow-up were retrieved from patient files. All eyes were operated on in a similar fashion by the same anterior segment surgeon (A.M.) utilizing the McCannel suture technique and/or the Siepser slipknot technique. The main outcome measures were visual acuity improvement, surgically induced astigmatism, and assessment of complications. Ten eyes had a documented complication during primary cataract extraction. Pseudoexfoliation was present in 11 eyes (25 %). History of ocular trauma and high myopia were present in six eyes (each). Excluding eyes with macular disease and very low visual acuity, visual acuity improved from 0.4 (± 0.05) logMAR to 0.24 (± 0.05) logMAR (p = 0.047). Eyes with low pre-operative astigmatism did not worsen post-operatively (R square linear = 0.8, p < 0.01). Pupil ovalization was a major aesthetic complication (21 of 44 eyes). Major hemorrhagic complications were uncommon. One patient developed intermediate uveitis 1 year after IOL fixation. In this study of 44 eyes, iris fixation was proven to be a an effective method for treating subluxated IOLs.

  13. Fixed-angle screws vs standard screws in acetabular prosthesis fixation: a cadaveric biomechanical study.

    PubMed

    Hugate, Ronald R; Dickey, Ian D; Chen, Qingshan; Wood, Christina M; Sim, Franklin H; Rock, Michael G

    2009-08-01

    Secure fixation of acetabular components in total hip arthroplasty can be challenging. The purpose of this study was to perform biomechanical analysis of cup fixation strength using fixed-angle vs standard screw fixation. Multihole, porous-backed acetabular prostheses were implanted in both acetabuli of 8 cadaveric pelves using standard press-fit techniques. Fixed-angle screws were used on the left side, and standard cancellous screws were used in the right. The use of fixed-angle screws enhanced acetabular fixation substantially under subfailure cyclic loading conditions and load-to-failure. The triradiate screw configuration increases the bending moment required to fail the specimens as well. Fixed-angle screws may be useful for achieving rigid fixation of acetabular prostheses in challenging clinical scenarios.

  14. The role of internal fixation for long bone metastasis prior to impending fracture: an experimental model.

    PubMed

    Ibrahim, Mohammad; Terai, Hidetomi; Yamada, Kentaro; Suzuki, Akinobu; Toyoda, Hiromitsu; Nakamura, Hiroaki

    2013-07-01

    Patients with long bone metastasis have many therapeutic options, including surgery. However, the appropriate time for surgical intervention and the use of internal fixation prior to impending fracture remains controversial. The purpose of this study was to establish a long bone metastatic model with internal fixation, and to determine whether prophylactic internal fixation for long bone metastasis prior to impending fracture would affect bone destruction, tumor progression, and mortality. We implanted VX2 tumor cells into the tibiae of 45 rabbits divided equally into three groups: internal fixation, control, and sham groups. Rabbits were monitored by X-ray and computed tomography, and blood serum levels were examined every 2 weeks. Computed tomography data revealed significantly higher bone destruction in rabbit tibiae in the sham and control groups compared with those in the fixation group; there were volumetric bone losses of 0.2, 0.4, and 2.3% in the fixation, sham, and control groups, respectively, at 3 weeks, which increased to 1.2, 2.5, and 6.1% at 5 weeks. Rabbits in the fixation group showed significantly prolonged survival (64.5 ± 13.5 days) in comparison with rabbits in the sham group (50.3 ± 11.6 days) and control group (38.2 ± 4.9 days). Our results suggest that prophylactic internal fixation may hinder bone destruction and tumor progression, thus extending the survival period for patients with long bone metastasis.

  15. Influence of Target Parameters on Fixation Stability in Normal and Strabismic Monkeys

    PubMed Central

    Pirdankar, Onkar H.; Das, Vallabh E.

    2016-01-01

    Purpose The purpose of this study was to assess the effect of fixation target parameters on fixation instability in strabismic monkeys. Methods One normal and three exotropic monkeys were presented with four differently shaped fixation targets, with three diameters, during monocular or binocular viewing. Fixation targets were white on a black background or vice versa. Binocular eye movements were recorded using the magnetic search coil technique and fixation stability quantified by calculating the bivariate contour ellipse area (BCEA). Results Fixation instability was greater in all the strabismic monkeys compared with the normal monkey. During monocular viewing, strabismic monkeys showed significantly greater instability in the covered eye compared to the fixating eye. Multifactorial ANOVA suggested statistically significant target parameter influences, although effect sizes were small. Thus, a disk-shaped target resulted in greater instability than other target shapes in the viewing eyes of the normal monkey and two of three strabismic monkeys. A similar target-shape effect was also observed in the covered eye. Least instability was elicited with a 0.5° target in the normal monkey and a 1.0° target in the strabismic monkeys, both in the viewing and the covered eye. Target/background polarity effects were idiosyncratic. In strabismic monkeys, stability of the fixating eye during binocular viewing was not different from the stability of the same eye during monocular viewing. Conclusions Abnormal drifts and nystagmus contribute to increased fixation instability in strabismic monkeys. Target parameters (shape and size) that influence fixation stability in a normal animal also affected fixation stability in our sample of strabismic monkeys. PMID:26968739

  16. Establishment of buttonhole technique as a puncture alternative for arteriovenous fístulas. experience of a centre over 3years.

    PubMed

    Baena, Laura; Merino, José L; Bueno, Blanca; Martín, Beatriz; Sánchez, Verónica; Caserta, Luca; Espejo, Beatriz; Domínguez, Patricia; Gómez, Alicia; Paraíso, Vicente

    The buttonhole (BH) puncture technique for arteriovenous fistulas is an alternative to the classical staggered puncture. We present 3years' results incorporating the BH puncture technique for arteriovenous fistulas in our dialysis unit. Twenty-two patients were started on BH technique, 15 men and 7 women (mean age: 62 years; SD: 12), with time spent on dialysis when starting the BH technique of 34 months (SD: 34, median: 27, range: 3-136). Seven patients received acenocoumarol and 9 antiplatelet agents. The vascular access median time at the beginning of the technique was 27 months (range: 3-252). Between 5 and 8 consecutive dialysis sessions were necessary to achieve a proper tunnel puncture. No patient suffered major complications. The average time on BH technique until December 2015 was 12 months (SD: 10, median: 9, range: 1-45). By the end of the study, 5patients were performing self-puncture. Haemostasis times post-dialysis were reduced from 18.6min (SD: 8, prior to the BH technique), to 12.2minutes (SD: 3 after BH) (P=.0005). The BH technique is an alternative puncture technique for dialysis patients. Self-puncture and reduction in hemostasis time are potential beneficial aspects. A greater diffusion of this technique in the hemodialysis units would allow it to be better applied. A highly motivated nursing staff is key and a necessary condition for its implementation. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  17. Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients.

    PubMed

    Ito, Hiromu; Neo, Masashi; Sakamoto, Takeshi; Fujibayashi, Shunsuke; Yoshitomi, Hiroyuki; Nakamura, Takashi

    2009-06-01

    The most common cervical abnormality associated with rheumatoid arthritis (RA) is atlantoaxial subluxation, and atlantoaxial transarticular screw fixation has proved to be one of the most reliable, stable fixation techniques for treating atlantoaxial subluxation. Following C1-C2 fixation, however, subaxial subluxation reportedly can bring about neurological deterioration and require secondary operative interventions. Rheumatoid patients appear to have a higher risk, but there has been no systematic comparison between rheumatoid and non-rheumatoid patients. Contributing radiological factors to the subluxation have also not been evaluated. The objective of this study was to evaluate subaxial subluxation after atlantoaxial transarticular screw fixation in patients with and without RA and to find contributing factors. Forty-three patients who submitted to atlantoaxial transarticular screw fixation without any concomitant operation were followed up for more than 1 year. Subaxial subluxation and related radiological factors were evaluated by functional X-ray measurements. Statistical analyses showed that aggravations of subluxation of 2.5 mm or greater were more likely to occur in RA patients than in non-RA patients over an average of 4.2 years of follow-up, and postoperative subluxation occurred in the anterior direction in the upper cervical spine. X-ray evaluations revealed that such patients had a significantly smaller postoperative C2-C7 angle, and that the postoperative AA angle correlated negatively with this. Furthermore, anterior subluxation aggravation was significantly correlated with the perioperative atlantoaxial and C2-C7 angle changes, and these two changes were strongly correlated to each other. In conclusion, after atlantoaxial transarticular screw fixation, rheumatoid patients have a greater risk of developing subaxial subluxations. The increase of the atlantoaxial angel at the operation can lead to a decrease in the C2-C7 angle, followed by anterior

  18. Biomechanical analysis on transverse tibial fixation in anterior cruciate ligament reconstructions☆

    PubMed Central

    Filho, Edmar Stieven; Mendes, Mariane Henseler Damaceno; Claudino, Stephanie; Baracho, Filipe; Borges, Paulo César; da Cunha, Luiz Antonio Munhoz

    2015-01-01

    Objective To verify whether the combination of tibial cross pin fixation and femoral screw fixation presents biomechanical advantages when compared to femoral cross pin fixation and tibial screw fixation for the reconstruction of the anterior cruciate ligament (ACL). Methods Thirty-eight porcine knees and bovine extensor digitorum tendons were used as the graft materials. The tests were performed in three groups: (1) standard, used fourteen knees, and the grafts were fixated with the combination of femoral cross pin and a tibial screw; (2) inverted, used fourteen knees with an inverted combination of tibial cross pin and a femoral screw; (3) control, ten control tests performed with intact ACL. After the grafts fixation, all the knees were subjected to tensile testing to determine yield strength and ultimate strength. Results There was no statistically significant difference in survival techniques in regard to strength, yield load and tension. There was a higher survival compared in the standard curves of yield stress (p < 0.05). Conclusion There is no biomechanical advantage, observed in animal models testing, in the combination of tibial cross pin fixation and femoral screw when compared to femoral cross pin fixation and tibial screw. PMID:26229913

  19. PRESERVATION OF THE ULTRASTRUCTURE OF BACILLUS SUBTILIS BY CHEMICAL FIXATION AS VERIFIED BY FREEZE-ETCHING

    PubMed Central

    Nanninga, N.

    1969-01-01

    The present study on the ultrastructure of Bacillus subtilis was undertaken in order to examine by means of the freeze-etching technique possible structural changes occurring during the chemical fixation procedure (Ryter-Kellenberger (R-K) fixation). Three stages were followed by freeze-etching, viz.: (a) fixation in osmium tetroxide, (b) fixation in osmium tetroxide and posttreatment with uranyl acetate, and (c) fixation in osmium tetroxide, posttreatment in uranyl acetate, and dehydration in a graded series of acetone. Preparations were made after each stage in the presence of 20% glycerol. Good preservation of ultrastructure was observed, after any of the three treatments, of the outer surface of the plasma membrane, and the inner surface of the plasma membrane. No alteration in fracturing properties could be observed. However, if we are to judge by the results of freeze-etching, any of the successive steps of the chemical fixation procedure achieve strong contrast between the nucleoplasmic region and the cytoplasm. Dependent on the quality of fixation, very delicately preserved DNA fibrils or strongly aggregated ones were seen. It appears that R-K fixation is capable of producing more or less distinctly visible changes in the native state of the nucleoplasm in young cells of B. subtilis. PMID:4979363

  20. Stress Modulation of Fracture Fixation Implants.

    PubMed

    Beltran, Michael J; Collinge, Cory A; Gardner, Michael J

    2016-10-01

    Stress modulation is the concept of manipulating bridge plate variables to provide a flexible fixation construct that allows callus formation through uneventful secondary bone healing. Obtaining absolute stability through the anatomic reduction of all fracture fragments comes at the expense of fracture biology, whereas intramedullary nailing, which is more advantageous for diaphyseal fractures of the lower extremity, is technically demanding and often may not be possible when stabilizing many metaphyseal fractures. Overly stiff plating constructs are associated with asymmetric callus formation, early implant failure, and fracture nonunion. Numerous surgeon-controlled variables can be manipulated to increase flexibility without sacrificing strength, including using longer plates with well-spaced screws, choosing titanium or stainless steel implants, and using locking or nonlocking screws. Axially dynamic emerging concepts, such as far cortical locking and near cortical overdrilling, provide further treatment options when bridge plating techniques are used.

  1. Implant fixation by bone ingrowth.

    PubMed

    Kienapfel, H; Sprey, C; Wilke, A; Griss, P

    1999-04-01

    The term osseointegration referred originally to an intimate contact of bone tissue with the surface of a titanium implant; the term bone ingrowth refers to bone formation within an irregular (beads, wire mesh, casting voids, cut grooves) surface of an implant. The section dealing with the historical background describes the development of macroporous, microporous, and textured surfaces with an emphasis on the evolution of porous and textured metal surfaces. The principal requirements for osseointegration and bone ingrowth are systematically reviewed as follows: i) the physiology of osseointegration and bone ingrowth, including biomaterial biocompatibility with respect to cellular and matrix response at the interface; ii) the implant surface geometry characteristics; iii) implant micromotion and fixation modes; and iv) the implant-bone interface distances. Based on current methods of bone ingrowth assessment, this article comparatively reviews and discusses the results of experimental studies with the objective of determining local and systemic factors that enhance bone ingrowth fixation.

  2. Tailor's bunion. Is fixation necessary?

    PubMed

    Pontious, J; Brook, J W; Hillstrom, H J

    1996-02-01

    Tailor's bunion or bunionette are terms that describe a pathologic enlargement occurring laterally on the fifth metatarsophalangeal joint. Regardless of the etiology that precipitates the deformity, the resulting abnormal protrusion of soft tissue or bone can result in pain for the patient. Symptoms can range from mild discomfort to severe, debilitating pain. The patient may present with pain dorsolaterally, laterally, or plantarly. The symptoms are mechanically induced, and are often associated with hyperkeratotic lesions and adventitious bursae. Patients complain most often that they cannot find comfortable shoes. The authors compare the effectiveness of fixated versus nonfixated distal osteotomies of the fifth metatarsal for the correction of tailor's bunion. This study shows that fixation can help control postoperative dorsal displacement of the fifth metatarsal capital fragment (p < 0.0001) and produce less shortening of the metatarsal resulting in fewer complications.

  3. Nitrogen fixation by marine cyanobacteria.

    PubMed

    Zehr, Jonathan P

    2011-04-01

    Discrepancies between estimates of oceanic N(2) fixation and nitrogen (N) losses through denitrification have focused research on identifying N(2)-fixing cyanobacteria and quantifying cyanobacterial N(2) fixation. Previously unrecognized cultivated and uncultivated unicellular cyanobacteria have been discovered that are widely distributed, and some have very unusual properties. Uncultivated unicellular N(2)-fixing cyanobacteria (UCYN-A) lack major metabolic pathways including the tricarboxylic acid cycle and oxygen-evolving photosystem II. Genomes of the oceanic N(2)-fixing cyanobacteria are highly conserved at the DNA level, and genetic diversity is maintained by genome rearrangements. The major cyanobacterial groups have different physiological and ecological constraints that result in highly variable geographic distributions, with implications for the marine N-cycle budget.

  4. Enhanced fixation of implants by bone ingrowth to titanium fiber mesh: effect of incorporation of hydroxyapatite powder.

    PubMed

    Tsukeoka, Tadashi; Suzuki, Masahiko; Ohtsuki, Chikara; Tsuneizumi, Yoshikazu; Miyagi, Jin; Sugino, Atsushi; Inoue, Takayuki; Michihiro, Ryouichi; Moriya, Hideshige

    2005-10-01

    Tight fixation between bone and implant materials is of great importance for a successful outcome of procedures such as total knee arthroplasty (TKA) and total hip arthroplasty (THA). Titanium fiber mesh is an attractive structure for the establishment of tight fixation between bone and implant by bone ingrowth into the spaces among the fibers. Enhancement of bone ingrowth is desired not only for tight fixation but also for a fast recovery. Our hypothesis is that just the presence of hydroxyapatite (HA) particles ensures improved bone ingrowth, and that long-term stability can be obtained by mechanical anchoring of bone in the spaces among titanium fibers. In this study, we examine our hypothesis by in vivo experiment using dog femur. HA particles were incorporated in titanium fiber mesh coated on titanium alloy rod by dipping in a slurry of HA with hydroxy-propyl-cellulose in an ethanol solution. Specimens were implanted for 3, 5, and 8 weeks, and were then compared with the results from specimens without the use of HA. Bonding strength was evaluated by push-out test, and histomorphometric measurements were made with analysis software to calculate the average value of bone ingrowth. A significantly higher bonding strength was observed for the specimens with HA-incorporated implant at 3 and 5 weeks, and larger bone ingrowth deep inside the titanium fiber mesh was measured at 3 weeks. Our proposed method has the additional advantage of not requiring a high temperature that may result in changes in characters of HA powder such as phase transition, grain growth, and decomposition. Moreover, this technique of HA powder incorporation without high-temperature treatment allows the use of several types of metallic fiber mesh, as well as the application to fiber mesh made of organic polymers. We conclude that this simple modification of titanium fiber mesh with HA powder can improve the fixation of implant to bone in the initial stage after operation.

  5. Maxillo Mandibular Fixation in Edentulous Scenarios: Combined MMF Screws and Gunning Splints.

    PubMed

    Chaudhary, Zainab; Sharma, Rakesh; Krishnan, Sriram

    2014-06-01

    A fracture of the maxillary or mandibular bone requires the afflicted to undergo a maxillo mandibular fixation for the establishment of pre traumatic occlusion. This process is quiet tedious and consumes a considerable period of time before any surgical procedure can commence. Such a situation can be complicated in case the individual with maxillomandibular fracture has sparse or absent dentition; for such cases a splint is fabricated or an erstwhile existing denture is used for maintaining a vertical jaw proportion. Stabilizing such splints to the jaw requires various invasive approaches that can bring into harm's way, adjacent soft tissue vital structures. We describe here an innovative technique combining the time tested method of the "gunning splint" and the advanced minimally invasive MMF screws for obtaining closed reduction in edentulous jaw fractures.

  6. STIFF ELBOW TREATMENT BY INTERPOSING ARTHROPLASTY ASSOCIATED TO HINGED EXTERNAL FIXATOR

    PubMed Central

    Miyazaki, Alberto Naoki; Fregoneze, Marcelo; Santos, Pedro Doneux; Silva, Luciana Andrade da; Junior, Nelson Gennaro; Checchia, Sergio Luiz

    2015-01-01

    Objective: Assess the results of the elbow/fascia lata interposing arthroplasty technique associated to the use of a hinged external fixator in the treatment of stiff elbow. Methods: Between 2001 and 2006, five cases of stiff elbow were operated and followed up by the Shoulder and Elbow Group of the Santa Casa Misericórdia de São Paulo Medical Sciences School, establishing the following as inclusion criteria: patients with below-functional elbow range of motion associated to degeneration on that joint, for whom total prosthesis had not been indicated. Patients' ages ranged from 21 to 55 years (mean: 38). Male gender was prevalent (four cases), and, in all cases, the dominant side was operated. Concerning etiology, two cases of infectious arthritis sequels, one post-trauma sequel, and two rheumatoid arthritis were found. Preoperative range of motion ranged from 20° to 30° of flexion-extension; in two cases, fixed contracture existed in flexion at 30° and 65°. The patients were assessed according to Bruce-modified AMA criteria. Results: The mean follow up time was 54 months. All patients showed improvement of the Bruce index, which, preoperatively, was 43.5, increasing to 88.2 postoperatively. We found two excellent cases, one good, one fair, and one poor. Conclusion: Fascia lata interposing arthroplasty associated to the use of a dynamic external fixator on stiff elbows is a feasible alternative for patients not indicated to total elbow arthroplasty. PMID:27022516

  7. Bacteria on External Fixators: Which Prep is Best?

    DTIC Science & Technology

    2012-01-01

    Wenke, PhD, and Joseph R. Hsu, MD, San Antonio, Texas BACKGROUND: There are no established guidelines for the surgical prep of an external fixator in...were then randomized into four treatment groups: chlorhexidine- gluconate (CHG) (4%) scrub , CHG (4%) spray, povidone-iodine (PI) (10%) scrub , and PI...reimaged. Spatial distribution of bacteria and total bacteria counts were compared. RESULTS: There was a similar reduction in bacteria after surgical

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

    PubMed Central

    Okano, Kana; Koshiji, Risako; Funaki, Wakana; Shoji, Nobuyuki

    2016-01-01

    The aims of this randomized observational case control study were to quantify fixation behavior during standard automated perimetry (SAP) with different fixation targets and to evaluate the relationship between fixation behavior and threshold variability at each test point in healthy young participants experienced with perimetry. SAP was performed on the right eyes of 29 participants using the Octopus 900 perimeter, program 32, dynamic strategy. The fixation targets of Point, Cross, and Ring were used for SAP. Fixation behavior was recorded using a wearable eye-tracking glass. All participants underwent SAP twice with each fixation target in a random fashion. Fixation behavior was quantified by calculating the bivariate contour ellipse area (BCEA) and the frequency of deviation from the fixation target. The BCEAs (deg2) of Point, Cross, and Ring targets were 1.11, 1.46, and 2.02, respectively. In all cases, BCEA increased significantly with increasing fixation target size (p < 0.05). The logarithmic value of BCEA demonstrated the same tendency (p < 0.05). A positive correlation was identified between fixation behavior and threshold variability for the Point and Cross targets (ρ = 0.413–0.534, p < 0.05). Fixation behavior increased with increasing fixation target size. Moreover, a larger fixation behavior tended to be associated with a higher threshold variability. A small fixation target is recommended during the visual field test. PMID:27829030

  9. Fixation Strategies For Retinal Immunohistochemistry

    PubMed Central

    Stradleigh, Tyler W.; Ishida, Andrew T.

    2015-01-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons. PMID:25892361

  10. Fixation strategies for retinal immunohistochemistry.

    PubMed

    Stradleigh, Tyler W; Ishida, Andrew T

    2015-09-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons.

  11. The incidence of nonunion after Lapidus arthrodesis using staple fixation.

    PubMed

    Mallette, Jason P; Glenn, Courtney L; Glod, Douglas J

    2014-01-01

    Today's foot and ankle surgeon has multiple options when choosing a fixation device for Lapidus arthrodesis, many of which have well-documented nonunion rates. The present study aimed to fill a void in the current foot and ankle literature by establishing a nonunion rate for staple fixation for the Lapidus procedure. The present retrospective analysis of the medical record focused on nickel-titanium staples that were inserted in a delta configuration to yield a stable construct for first metatarsal-cuneiform fusion. The patients were kept strictly non-weightbearing for the first 6 weeks postoperatively. Weightbearing progressed at that point according to the radiographic findings of each case. The data from 35 consecutive patients were analyzed (25 females, 10 males; mean age 43.1 [range 15 to 72] years in whom a Lapidus arthrodesis was performed using staple fixation in 36 feet. The patients were followed until fusion was noted and pain had resolved. Pain resolution occurred at 6 weeks in the earliest cases and several years in others. The incidence of nonunion was 3 (8.3%) of 36 when staple fixation was used for first metatarsal-medial cuneiform arthrodesis. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  12. Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

    PubMed

    Morsy, Ahmed A; Ng, Wai Hoe

    2015-11-01

    We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery.

  13. [Mechanobiology of fracture healing part 2 : Relevance for internal fixation of fractures].

    PubMed

    Claes, L

    2017-01-01

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

  14. Circular External Fixation as a Primary or Adjunctive Therapy for the Podoplastic Approach of the Diabetic Charcot Foot.

    PubMed

    Short, Daniel J; Zgonis, Thomas

    2017-01-01

    Numerous techniques have been described for surgical management of the diabetic Charcot foot. External fixation has become a main surgical tool for the reconstructive foot and ankle surgeon when dealing with the ulcerated diabetic Charcot foot. In the presence of an open wound and/or osteomyelitis, staged reconstruction with circular external fixation becomes ideal for salvage of the diabetic lower extremity. Also, circular external fixation can provide simultaneous compression and stabilization, correct the underlying osseous or soft tissue deformities, and surgically offload the diabetic Charcot foot. This article describes a variety of circular external fixation applications for the diabetic Charcot foot.

  15. Complement-Fixation Analysis of Four Subtypes of Foot-and-Mouth Disease Virus Type A

    PubMed Central

    Lobo, C. A.; Cowan, K. M.; Hanson, R. P.

    1973-01-01

    Complement-fixation patterns were established for four subtypes of foot-and-mouth disease virus by block assays against homologous and heterologous antiserum. Inhibition of fixation by excess antigen was observed in most homologous systems but rarely in the heterologous systems. The heterologous antibody titers were, in all instances, considerably lower than those for the homologous systems. Although relatively high dilutions of antiserum may be desirable for subtyping, higher concentrations of antibody should be used for determining serological types. PMID:4356470

  16. Fixation Release and the Bone Bandaid: A New Bone Fixation Device Paradigm

    PubMed Central

    Shayesteh Moghaddam, Narges; Jahadakbar, Ahmadreza; Amerinatanzi, Amirhesam; Skoracki, Roman; Miller, Michael; Dean, David; Elahinia, Mohammad

    2017-01-01

    grafted bone in the locked state properly since the maximum resultant gap (21.54 micron) between the graft and host mandible surfaces are in the safe region (less than 300 micron). By considering the von Mises criteria for failure, FE analysis together with experimental studies (i.e., compressive and tensile testing on the inferior and superior fixation devices, respectively) confirm that the proposed fixation devices do not fail, showing safety factor of at least 10.3. Based on the Response Surface Methodology (RSM) technique, the optimal parameter values for the wires are achieved (0.65 mm and 1 mm for the superior and inferior wires, respectively) and the required level of preload on each wire are calculated (369.8 N and 229 N for the inferior and superior wires, respectively). The FE results for stress distribution on the reconstructed mandible during the released state closely match that of a healthy mandible. PMID:28952484

  17. Direct lexical control of eye movements in reading: Evidence from a survival analysis of fixation durations

    PubMed Central

    Reingold, Eyal M.; Reichle, Erik D.; Glaholt, Mackenzie G.; Sheridan, Heather

    2013-01-01

    Participants’ eye movements were monitored in an experiment that manipulated the frequency of target words (high vs. low) as well as their availability for parafoveal processing during fixations on the pre-target word (valid vs. invalid preview). The influence of the word-frequency by preview validity manipulation on the distributions of first fixation duration was examined by using ex-Gaussian fitting as well as a novel survival analysis technique which provided precise estimates of the timing of the first discernible influence of word frequency on first fixation duration. Using this technique, we found a significant influence of word frequency on fixation duration in normal reading (valid preview) as early as 145 ms from the start of fixation. We also demonstrated an equally rapid non-lexical influence on first fixation duration as a function of initial landing position (location) on target words. The time-course of frequency effects, but not location effects was strongly influenced by preview validity, demonstrating the crucial role of parafoveal processing in enabling direct lexical control of reading fixation times. Implications for models of eye-movement control are discussed. PMID:22542804

  18. Two-Pin Fixation of Proximal Interphalangeal Joint Fusion for Hammertoe Correction.

    PubMed

    Boffeli, Troy J; Thompson, Jonathan C; Tabatt, Jessica A

    2016-01-01

    Single-pin external Kirschner wire (K-wire) fixation has traditionally been a mainstay in proximal interphalangeal joint fusion for central hammertoe repair. Concerns over cosmesis, inconvenience, pin tract infection, hardware failure, nonunion, and early hardware removal have led to the development of implantable internal fixation devices. Although numerous implantable devices are now available and represent viable options for hammertoe repair, they are costly and often pose a challenge in the event removal becomes necessary. An alternative fixation option not typically used is a 2-pin K-wire fixation technique. The perceived advantage of obtaining 2 points of fixation compared with 1 across the fusion site is improved stability against the rotational and bending forces, thus decreasing the potential for pin-related complications. A retrospective assessment of 91 consecutive hammertoe repairs consisting of proximal interphalangeal joint fusion with 2-pin fixation in 60 patients was performed. The K-wires were removed at 6 weeks postoperatively, and the overall postoperative follow-up duration was 28.56 (range 1.40 to 86.83) months. Of the 91 digits, 89 (98%) did not encounter a complication postoperatively and 2 (2.20%) had sustained loosened or broken hardware. No postoperative infection was encountered. The low incidence of complications observed supports the 2-pin K-wire fixation technique as a low-cost and viable construct for proximal interphalangeal joint fusion hammertoe repair.

  19. A 3-D CT Analysis of Screw and Suture-Button Fixation of the Syndesmosis.

    PubMed

    Schon, Jason M; Williams, Brady T; Venderley, Melanie B; Dornan, Grant J; Backus, Jonathon D; Turnbull, Travis Lee; LaPrade, Robert F; Clanton, Thomas O

    2017-02-01

    Historically, syndesmosis injuries have been repaired with screw fixation; however, some suggest that suture-button constructs may provide a more accurate anatomic and physiologic reduction. The purpose of this study was to compare changes in the volume of the syndesmotic space following screw or suture-button fixation using a preinjury and postoperative 3-D computed tomography (CT) model. The null hypothesis was that no difference would be observed among repair techniques. Twelve pairs of cadaveric specimens were dissected to identify the syndesmotic ligaments. Specimens were imaged with CT prior to the creation of a complete syndesmosis injury and were subsequently repaired using 1 of 3 randomly assigned techniques: (a) one 3.5-mm cortical screw, (b) 1 suture-button, and (c) 2 suture-buttons. Specimens were imaged postoperatively with CT. 3-D models of all scans and tibiofibular joint space volumes were calculated to assess restoration of the native syndesmosis. Analysis of variance and Tukey's method were used to compare least squares mean differences from the intact syndesmosis among repair techniques. For each of the 3 fixation methods, the total postoperative syndesmosis volume was significantly decreased relative to the intact state. The total mean decreases in volume compared with the intact state for the 1-suture-button construct, 2-suture-button construct, and syndesmotic screw were -561 mm(3) (95% CI, -878 to -244), -964 mm(3) (95% CI, -1281 to -647) and -377 mm(3) (95% CI, -694 to -60), respectively. All repairs notably reduced the volume of the syndesmosis beyond the intact state. Fixation with 1 suture-button was not significantly different from screw or 2-suture-button fixation; however, fixation with 2 suture-buttons resulted in significantly decreased volume compared with screw fixation. The results of this study suggest that the 1-suture-button repair technique and the screw fixation repair technique were comparable for reduction of syndesmosis

  20. A new method for typing bovine major histocompatibility complex class II DRB3 alleles by combining two established PCR sequence-based techniques.

    PubMed

    Takeshima, S-N; Matsumoto, Y; Miyasaka, T; Arainga-Ramirez, M; Saito, H; Onuma, M; Aida, Y

    2011-09-01

    Recently, two polymerase chain reaction sequence-based typing (PCR-SBT) methods were reported for the genotyping of the bovine leukocyte antigen (BoLA)-DRB3. One technique is a single PCR-SBT (sPCR-SBT) method that generates heterozygous sequences that are subsequently analyzed by the haplofinder program, while the other technique is a nested PCR-SBT (nPCR-SBT) method that allows the analysis of heterozygous sequences using the assign 400ATF software. In this study, these techniques were compared and then integrated to produce an improved genotyping method. The primer set used for sPCR-SBT was more accurate than those used for nPCR-SBT. Combining sPCR-SBT with the assign 400ATF software previously reported for nPCR-SBT enables rapid and accurate genotyping of a large number of DNA samples.

  1. Abnormal Fixational Eye Movements in Amblyopia.

    PubMed

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

    2016-01-01

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

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

    PubMed Central

    PEREIRA, Felipe Ladeira; JANSON, Marcos; SANT'ANA, Eduardo

    2010-01-01

    Miniplate and screw fixation has been widely used in bilateral sagittal split osteotomy, but some issues remain unclear concerning its lack of rigidity when compared to Spiessl's bicortical technique. This paper demonstrates the hybrid fixation technique in a case report. A 34-year-old female patient underwent a double jaw surgery with counter-clockwise rotation of the mandible fixed using the hybrid fixation technique. The patient evolved well in the postoperative period and is still under follow up after 14 months, reporting satisfaction with the results and no significant deviation from the treatment plan up to now. No damage to tooth roots was done, maxillomandibular range of motion was within normality and regression of the inferior alveolar nerve paresthesia was observed bilaterally. The hybrid mandibular fixation is clearly visible in the panoramic and cephalometric control radiographs. It seems that the hybrid fixation can sum the advantages of both monocortical and bicortical techniques in lower jaw advancement, increasing fixation stability without significant damage to the mandibular articulation and the inferior alveolar nerve. A statistical investigation seems necessary to prove its efficacy. PMID:20379687

  3. Arthrodesis tarsocrural or tarsometatarsal in 2 dogs using circular external skeletal fixator

    PubMed Central

    Rahal, Sheila C.; Volpi, Reinaldo S.; Hette, Khadije; Teixeira Neto, Francisco J.; Vulcano, Luiz C.

    2006-01-01

    An external fixation technique, using a circular fixator, to obtain arthrodesis was evaluated in 2 dogs with infected open lesions and soft tissue damage. In both cases, articular cartilage was curetted, and devitalized bone and necrotic soft tissue were removed. No bone graft was used. The wounds were maintained open and the dogs received postoperative antibiotic therapy. The arthrodesis site was compressed progressively as needed. Infection was eradicated and bony union was obtained in both dogs. It was concluded that the use of a circular fixator is an effective method to achieve arthrodesis. PMID:17017656

  4. Mechanical considerations in using tensioned wires in a transosseous external fixation system.

    PubMed

    Aronson, J; Harp, J H

    1992-07-01

    Factors that affect wire tension were examined using external mechanical testing units as well as in-line load cells. The circular external fixator with wires supported at each end exhibits a self-stiffening effect such that wire stiffness increases with wire deflection. Mechanical slippage between wire and fixation bolt is the primary reason for loss of wire tension. Slippage can be avoided by adequate torque on the fixation nut (20 N.m). Guidelines are presented for proper and safe tensioning techniques to achieve clinically indicated tensions without risk of breakage.

  5. Pullout strength of fixation screws from polymethylmethacrylate bone cement.

    PubMed

    Flahiff, C M; Gober, G A; Nicholas, R W

    1995-05-01

    Polymethylmethacrylate bone cement is often used to fill voids and increase the strength of osteoporotic and pathological bone. However, it is unclear as to which method of cement augmentation provides optimal screw fixation. This study was conducted to determine which of the current cement augmentation techniques provides the strongest construct when used in association with orthopaedic fixation screws. Pullout strength was determined for screws placed in sawbones with no cement, soft cement, doughy cement and hard cement after drilling and tapping. All cement-screw constructs were significantly stronger than the no cement group. Screws placed in doughy cement had a significantly higher pullout force than those placed in hard cement. Pullout strength of screws placed in soft cement was intermediate between the other cement techniques but not significantly different from either group.

  6. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    PubMed Central

    2012-01-01

    Background To assess the efficacy, clinical outcomes, visual acuity (VA), incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany) were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%), 20/60 or better in 12 eyes (92%), and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method. PMID:23050659

  7. Complications of tracheostomy after anterior cervical spine fixation surgery.

    PubMed

    Romero-Ganuza, Javier; Gambarrutta, Claudia; Merlo-Gonzalez, Victoria Eugenia; Marin-Ruiz, Maria Ángeles; Diez De La Lastra-Buigues, Elena; Oliviero, Antonio

    2011-01-01

    Cervical traumatic spinal cord-injured patients often way require both anterior cervical spine stabilization and tracheostomy in the first few days after the injury. The infectious complication of tracheostomy can interfere with the evolution of the fixation surgery. The aim of our study was to evaluate the safety of tracheostomy performed early after anterior cervical spine stabilization. We reviewed the clinical records of 28 patients admitted to our hospital intensive care unit. In all cases, percutaneous tracheostomy was performed using the percutaneous dilation technique. The average time interval between the fixation surgery and tracheostomy was 8.25 ± 5.57 days. We had complications in tracheostomy in only 3 cases: minor bleeding occurred in 1 patient and stomal infection, not propagated to the fixation surgery wound, was observed in 2 patients. Two patients died without causal relation to these interventions. The early performance of tracheostomy after cervical spinal fixation surgery is safe, still realized early and nearly this, at least if the tracheostomy is performed by percutaneous method. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Resorbable bone fixation alloys, forming, and post-fabrication treatments.

    PubMed

    Ibrahim, Hamdy; Esfahani, Sajedeh Nasr; Poorganji, Behrang; Dean, David; Elahinia, Mohammad

    2017-01-01

    Metallic alloys have been introduced as biodegradable metals for various biomedical applications over the last decade owing to their gradual corrosion in the body, biocompatibility and superior strength compared to biodegradable polymers. Mg alloys possess advantageous properties that make them the most extensively studied biodegradable metallic material for orthopedic applications such as their low density, modulus of elasticity, close to that of the bone, and resorbability. Early resorption (i.e., <3months) and relatively inadequate strength are the main challenges that hinder the use of Mg alloys for bone fixation applications. The development of resorbable Mg-based bone fixation hardware with superior mechanical and corrosion performance requires a thorough understanding of the physical and mechanical properties of Mg alloys. This paper discusses the characteristics of successful Mg-based skeletal fixation hardware and the possible ways to improve its properties using different methods such as mechanical and heat treatment processes. We also review the most recent work pertaining to Mg alloys and surface coatings. To this end, this paper covers (i) the properties and development of Mg alloys and coatings with an emphasis on the Mg-Zn-Ca-based alloys; (ii) Mg alloys fabrication techniques; and (iii) strategies towards achieving Mg-based, resorbable, skeletal fixation devices.

  9. Nitrogen Fixation (Acetylene Reduction) Associated with Duckweed (Lemnaceae) Mats

    PubMed Central

    Zuberer, D. A.

    1982-01-01

    Duckweed (Lemnaceae) mats in Texas and Florida were investigated, using the acetylene reduction assay, to determine whether nitrogen fixation occurred in these floating aquatic macrophyte communities. N2-fixing microorganisms were enumerated by plating or most-probable-number techniques, using appropriate N-free media. Results of the investigations indicated that substantial N2-fixation (C2H2) was associated with duckweed mats in Texas and Florida. Acetylene reduction values ranged from 1 to 18 μmol of C2H4 g (dry weight)−1 day−1 for samples incubated aerobically in light. Dark N2 fixation was always two- to fivefold lower. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea (7 to 10 μM) reduced acetylene reduction to levels intermediate between light and dark incubation. Acetylene reduction was generally greatest for samples incubated anaerobically in the light. It was estimated that 15 to 20% of the N requirement of the duckweed could be supplied through biological nitrogen fixation. N2-fixing heterotrophic bacteria (105 cells g [wet weight]−1 and cyanobacteria (105 propagules g [wet weight]−1 were associated with the duckweed mats. Azotobacter sp. was not detected in these investigations. One diazotrophic isolate was classified as Klebsiella. PMID:16345992

  10. Comparison of different fixation methods of the suture-button implant for tibiofibular syndesmosis injuries.

    PubMed

    Teramoto, Atsushi; Suzuki, Daisuke; Kamiya, Tomoaki; Chikenji, Takako; Watanabe, Kota; Yamashita, Toshihiko

    2011-10-01

    Suture-button fixation for tibiofibular syndesmosis injuries is a relatively new surgical technique thought to provide semirigid dynamic stabilization. However, adequate information is still not available and there are controversies as to whether it provides enough fixation for syndesmosis injuries. Optimally directed suture-button fixation brings physiologic dynamic stabilization of the ankle syndesmosis. Controlled laboratory study. Stabilization of the ankle syndesmosis fixed by a suture-button construct was examined using 6 normal fresh-frozen cadaver legs. After initial tests of intact and injured models, suture-button fixation and screw surgical techniques were performed sequentially for each specimen, with single suture-button fixation, double suture-button fixation, anatomic suture-button fixation, and metal screw. Anterior and medial traction forces, as well as external rotation force, were applied to the tibia; the diastasis of the syndesmosis and the rotational angle of the fibula related to the tibia were measured using a magnetic tracking system. Each traction and rotation force significantly increased the diastasis and fibular rotational angles in the created injury models. With single fixation, the diastases increased significantly compared with the intact model with an anterior traction force (P < .001), a medial traction force (P = .005), and an external rotation force (P = .015). The fibular rotational angles increased significantly with a medial traction force (P = .005) and an external rotation force (P < .001). With double fixation, the diastases increased significantly with a medial traction force (P = .004) and an external rotation force (P = .012). The fibular rotational angles increased significantly with a medial traction force (P = .035) and an external rotation force (P = .002). With anatomic fixation, there were no significant differences compared with the intact model. With the metal screw, the diastases decreased significantly with an

  11. Overcoming fixation with repeated memory suppression.

    PubMed

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

  12. A biomechanical study of conventional acetabular internal fracture fixation versus locking plate fixation

    PubMed Central

    Mehin, Ramin; Jones, Bryn; Zhu, Qingan; Broekhuyse, Henry

    2009-01-01

    Background Conventional internal fixation entails the use of an interfragmentary lag screw along with a plate. Not all acetabular fractures are amenable to the placement of an interfragmentary lag screw, and the fracture may be displaced during tightening of the interfragmentary lag screw. Locking plates are a possible solution. We sought to determine whether a locking plate construct can provide stability equivalent to that provided with a conventional construct for transverse acetabular fractures. Methods We used 5 paired fresh-frozen cadaveric acetabula. We fixed one side with the conventional technique and the other side with a locking plate. We subjected each fixation to a cyclic compressive force up to 500 cycles, followed by compressive force until failure. We monitored 3-dimensional motion of the fracture. Results The average fracture gap at 50 N compressive force after 500 loading cycles was 0.41 (standard deviation [SD] 0.49) mm for the conventional plate and lag screw construct compared with 0.76 (SD 0.62) mm for the locked plate construct (p = 0.46). The force to failure, as defined by 2 mm of fracture gap, was 848 (SD 805) N for the conventional plate and lag screw construct compared with 506 (SD 277) N for the locked plate fixation (p = 0.34). Conclusion The locking plate construct is as strong as the conventional plate plus interfragmentary lag screw construct for fixing transverse acetabular fractures. Locking plates may improve management of acetabular fractures by eliminating the need for placement of an interfragmentary lag screw. Furthermore, they may be helpful in revision hip arthroplasty in patients with pelvic discontinuity. PMID:19503667

  13. Enterocutaneous fistula due to mesh fixation in the repair of lateral incisional hernia: a case report.

    PubMed

    Sistla, Sarath Chandra; Reddy, Rajesh; Dharanipragada, Kadambari; Jagdish, Sadasivan

    2008-12-02

    Enterocutaneous fistula following mesh repair of incisional hernia is usually due to mesh erosion of the underlying viscus and presents late. We describe an early enterocutaneous fistula due to an unusual but a potential mode of bowel injury during mesh fixation. This case is reported to emphasize the need for greater attention to the technique of mesh fixation. We suggest laparoscopic guidance to prevent this serious complication in lateral Incisional hernias with ill defined edges of the defect.

  14. Enterocutaneous fistula due to mesh fixation in the repair of lateral incisional hernia: a case report

    PubMed Central

    Sistla, Sarath Chandra; Reddy, Rajesh; Dharanipragada, Kadambari; Jagdish, Sadasivan

    2008-01-01

    Enterocutaneous fistula following mesh repair of incisional hernia is usually due to mesh erosion of the underlying viscus and presents late. We describe an early enterocutaneous fistula due to an unusual but a potential mode of bowel injury during mesh fixation. This case is reported to emphasize the need for greater attention to the technique of mesh fixation. We suggest laparoscopic guidance to prevent this serious complication in lateral Incisional hernias with ill defined edges of the defect. PMID:19055713

  15. The challenging image-guided abdominal mass biopsy: established and emerging techniques 'if you can see it, you can biopsy it'.

    PubMed

    Sainani, Nisha I; Arellano, Ronald S; Shyn, Paul B; Gervais, Debra A; Mueller, Peter R; Silverman, Stuart G

    2013-08-01

    Image-guided percutaneous biopsy of abdominal masses is among the most commonly performed procedures in interventional radiology. While most abdominal masses are readily amenable to percutaneous biopsy, some may be technically challenging for a number of reasons. Low lesion conspicuity, small size, overlying or intervening structures, motion, such as that due to respiration, are some of the factors that can influence the ability and ultimately the success of an abdominal biopsy. Various techniques or technologies, such as choice of imaging modality, use of intravenous contrast and anatomic landmarks, patient positioning, organ displacement or trans-organ approach, angling CT gantry, triangulation method, real-time guidance with CT fluoroscopy or ultrasound, sedation or breath-hold, pre-procedural image fusion, electromagnetic tracking, and others, when used singularly or in combination, can overcome these challenges to facilitate needle placement in abdominal masses that otherwise would be considered not amenable to percutaneous biopsy. Familiarity and awareness of these techniques allows the interventional radiologist to expand the use of percutaneous biopsy in clinical practice, and help choose the most appropriate technique for a particular patient.

  16. Methanotrophy induces nitrogen fixation during peatland development.

    PubMed

    Larmola, Tuula; Leppänen, Sanna M; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

    2014-01-14

    Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation.

  17. Methanotrophy induces nitrogen fixation during peatland development

    PubMed Central

    Larmola, Tuula; Leppänen, Sanna M.; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

    2014-01-01

    Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation. PMID:24379382

  18. Image recorder with microwave fixation

    SciTech Connect

    Hosono, N.; Isaka, K.

    1984-11-13

    The present invention is directed to improvement in an image recorder for recording developed images or toner images by microwave fixation. According to the invention there is used a novel thermoplastic developer comprising of two components. The first component contains a dielectric material which is able to absorb microwave and generate heat by dielectric loss. The second component contains magnetic loss exothermic material. The microwave absorbing power of the first component is improved by heating the first component with heat generated from the second component.

  19. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, H.L.

    1983-08-16

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

  20. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, Hao-Lin

    1983-01-01

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

  1. Establishing operations

    PubMed Central

    Michael, Jack

    1993-01-01

    The first two books on behavior analysis (Skinner, 1938; Keller & Schoenfeld, 1950) had chapter-length coverage of motivation. The next generation of texts also had chapters on the topic, but by the late 1960s it was no longer being given much treatment in the behavior-analytic literature. The present failure to deal with the topic leaves a gap in our understanding of operant functional relations. A partial solution is to reintroduce the concept of the establishing operation, defined as an environmental event, operation, or stimulus condition that affects an organism by momentarily altering (a) the reinforcing effectiveness of other events and (b) the frequency of occurrence of that part of the organism's repertoire relevant to those events as consequences. Discriminative and motivative variables can be distinguished as follows: The former are related to the differential availability of an effective form of reinforcement given a particular type of behavior; the latter are related to the differential reinforcing effectiveness of environmental events. An important distinction can also be made between unconditioned establishing operations (UEOs), such as food deprivation and painful stimulation, and conditioned establishing operations (CEOs) that depend on the learning history of the organism. One type of CEO is a stimulus that has simply been paired with a UEO and as a result may take on some of the motivative properties of that UEO. The warning stimulus in avoidance procedures is another important type of CEO referred to as reflexive because it establishes its own termination as a form of reinforcement and evokes the behavior that has accomplished such termination. Another CEO is closely related to the concept of conditional conditioned reinforcement and is referred to as a transitive CEO, because it establishes some other stimulus as a form of effective reinforcement and evokes the behavior that has produced that other stimulus. The multiple control of human

  2. Surgical techniques of olecranon fractures.

    PubMed

    Wilkerson, James A; Rosenwasser, Melvin P

    2014-08-01

    Olecranon fractures are common upper extremity injuries. The vast majority are treated with operative fixation. Many treatment techniques have been described including tension band and plating. This review covers the most commonly used fixation techniques in detail, including pearls and pitfalls with case examples of both successful treatments and potential complications. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. ESTABLISHING A STEREOSCOPIC TECHNIQUE FOR DETERMINING THE KINEMATIC PROPERTIES OF SOLAR WIND TRANSIENTS BASED ON A GENERALIZED SELF-SIMILARLY EXPANDING CIRCULAR GEOMETRY

    SciTech Connect

    Davies, J. A.; Perry, C. H.; Harrison, R. A.; Trines, R. M. G. M.; Lugaz, N.; Möstl, C.; Liu, Y. D.; Steed, K.

    2013-11-10

    The twin-spacecraft STEREO mission has enabled simultaneous white-light imaging of the solar corona and inner heliosphere from multiple vantage points. This has led to the development of numerous stereoscopic techniques to investigate the three-dimensional structure and kinematics of solar wind transients such as coronal mass ejections (CMEs). Two such methods—triangulation and the tangent to a sphere—can be used to determine time profiles of the propagation direction and radial distance (and thereby radial speed) of a solar wind transient as it travels through the inner heliosphere, based on its time-elongation profile viewed by two observers. These techniques are founded on the assumption that the transient can be characterized as a point source (fixed φ, FP, approximation) or a circle attached to Sun-center (harmonic mean, HM, approximation), respectively. These geometries constitute extreme descriptions of solar wind transients, in terms of their cross-sectional extent. Here, we present the stereoscopic expressions necessary to derive propagation direction and radial distance/speed profiles of such transients based on the more generalized self-similar expansion (SSE) geometry, for which the FP and HM geometries form the limiting cases; our implementation of these equations is termed the stereoscopic SSE method. We apply the technique to two Earth-directed CMEs from different phases of the STEREO mission, the well-studied event of 2008 December and a more recent event from 2012 March. The latter CME was fast, with an initial speed exceeding 2000 km s{sup –1}, and highly geoeffective, in stark contrast to the slow and ineffectual 2008 December CME.

  4. Treatment of tibial plateau fractures by limited internal fixation.

    PubMed

    Duwelius, P J; Rangitsch, M R; Colville, M R; Woll, T S

    1997-06-01

    Seventy-five adults who sustained 76 tibial plateau fractures were treated according to a prospective protocol using instability in extension as the principal indication for operative fixation. Patients showing instability underwent closed manipulative reduction under fluoroscopic guidance. If significant joint depression persisted after reduction, elevation of the fracture was performed either from below using bone punches through a cortical window or via limited arthrotomy. Iliac crest bone graft was used to buttress depressed fractures. Fixation was then secured using 7-mm cannulated screws with washers or buttress plates and screws. Postoperatively, 58 of 76 knees were managed in a hinged knee brace, allowing the patient early range of motion and protected weightbearing for 8 weeks. Patients who were found to have a stable knee were treated with Bledsoe braces according to the postoperative protocol. In the 75 patients, 18 of the 76 knees were unsuitable for percutaneous screw fixation because of fracture complexity requiring plates, severe open injuries, or inadequate reductions with limited fixation had been done. A minimum followup of 12 months was obtained in 55 patients (range, 12-59 months). All fractures had healed at the time of followup. Eighty-seven percent of the patients at followup had a successful outcome using Rasmussen's criteria. Fourteen of these patients had arthroscopic assisted reduction or evaluation. All seven patients who had poor outcomes had AO Type C3 fracture patterns. Severely depressed or comminuted fractures or fractures with significant metaphyseal diaphyseal extension may not be suitable for this technique and require the addition of an external fixation device or buttress plate to maintain the reduction and allow for early range of motion.

  5. Do Fixation Cues Ensure Fixation Accuracy in Split-Fovea Studies of Word Recognition?

    ERIC Educational Resources Information Center

    Jordan, Timothy R.; Paterson, Kevin B.; Kurtev, Stoyan; Xu, Mengyun

    2009-01-01

    Many studies have claimed that hemispheric processing is split precisely at the foveal midline and so place great emphasis on the precise location at which words are fixated. These claims are based on experiments in which a variety of fixation procedures were used to ensure fixation accuracy but the effectiveness of these procedures is unclear. We…

  6. Management of hangman's fracture with percutaneous transpedicular screw fixation.

    PubMed

    Wu, Yao-Sen; Lin, Yan; Zhang, Xiao-Lei; Tian, Nai-Feng; Sun, Liao-Jun; Xu, Hua-Zi; Chi, Yong-Long; Pan, Zhi-Jun

    2013-01-01

    This study describes a percutaneous technique for C2 transpedicular screw fixation and evaluates its safety and efficacy in the treatment of patients with hangman's fracture. Ten patients with hangman's fracture were treated by percutaneous C2 transpedicular screw fixation. There are six males and four females, who were, based on the classification of Levine and Edwards, sorted as follows: type I fracture, three cases; type II, five cases; type IIa, two cases. The causes of injury were road traffic accident in six patients and falling injury in four patients. Other associated lesions included rib fractures (7 patients), head injuries (4 patients), and fractures of extremities (6 patients). The new technique was performed successfully in all cases. The average operation time was 98 min (range 60-130 min) and the estimated blood loss was 25 ml (range 15-40 ml). No complications such as vascular or neural structures injuries were found intraoperatively. Postoperative CT scans demonstrated that 17 (85 %) of 20 screws were placed satisfactorily, and 3 (15 %) screws showed perforations of the pedicle wall (<2 mm). These patients were asymptomatic and no further intervention was required postoperatively. After 8-25 months follow-up (mean 15.3 months), solid fusion was demonstrated by computed tomography. All cases got well-sagittal alignment and no angulation or dislocation was found at the segment of C2-C3. There was no loss of fixation. Clinical examination showed a full range of motion in the neck in all patients. The fluoroscopically assisted percutaneous C2 transpedicular screw fixation method is a technically feasible and minimally invasive technique for hangman's fracture.

  7. Early appraisal of the fixation probability in directed networks

    NASA Astrophysics Data System (ADS)

    Barbosa, Valmir C.; Donangelo, Raul; Souza, Sergio R.

    2010-10-01

    In evolutionary dynamics, the probability that a mutation spreads through the whole population, having arisen from a single individual, is known as the fixation probability. In general, it is not possible to find the fixation probability analytically given the mutant’s fitness and the topological constraints that govern the spread of the mutation, so one resorts to simulations instead. Depending on the topology in use, a great number of evolutionary steps may be needed in each of the simulation events, particularly in those that end with the population containing mutants only. We introduce two techniques to accelerate the determination of the fixation probability. The first one skips all evolutionary steps in which the number of mutants does not change and thereby reduces the number of steps per simulation event considerably. This technique is computationally advantageous for some of the so-called layered networks. The second technique, which is not restricted to layered networks, consists of aborting any simulation event in which the number of mutants has grown beyond a certain threshold value and counting that event as having led to a total spread of the mutation. For advantageous mutations in large populations and regardless of the network’s topology, we demonstrate, both analytically and by means of simulations, that using a threshold of about [N/(r-1)]1/4 mutants, where N is the number of simulation events and r is the ratio of the mutants’ fitness to that of the remainder of the population, leads to an estimate of the fixation probability that deviates in no significant way from that obtained from the full-fledged simulations. We have observed speedups of two orders of magnitude for layered networks with 10000 nodes.

  8. Establishing an