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Lukas Konstantinidis, Benjamin Schmidt, Anke Bernstein, Anja Hirschmüller, Steffen Schröter, Norbert Paul Südkamp, Peter Helwig
Osteosynthesis of periprosthetic femur fractures by screw fixation around the implanted prosthetic stem is currently regarded as the biomechanically superior option compared with cerclage. The aim of this biomechanical study was damage analysis of the cement mantle after revision screw insertion. A prosthetic stem (Bicontact) was implanted in 20 cadaveric femora in cemented technique. A locking compression plate (Synthes) was then applied to the lateral femur at the level of the prosthetic stem. The method of plate fixation to the femur was assigned randomly to three groups: bicortical non-locking screws, monocortical locking screws, and bicortical locking screws...
December 1, 2016: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
I Damlar, O F Arpağ, U Tatli, A Altan
The aim of this study was to investigate effects of the Hypericum perforatum (St John's Wort) on bone healing in rabbit calvarium. Ten male New Zealand rabbits each had three bicortical defects made in the calvarial bones, which were filled with xenograft, xenograft+H perforatum oil extract, and autogenous graft. Four weeks postoperatively all rabbits were killed and the bony defects examined histomorphometrically. Tissue compartments including new bone (p<0.001), marrow space (p<0.001), and residual bone grafts (p=0...
December 19, 2016: British Journal of Oral & Maxillofacial Surgery
George M Ghobrial, Fadi Al-Saiegh, Daniel Franco, Joshua Heller
Minimally invasive surgical techniques may decrease length of stay, operative duration and blood loss, and postoperative pain. Numerous technical challenges and concerns surround the placement of percutaneous pedicle screws at the lumbosacral level. Maximization of screw triangulation, bicortical purchase, and rostral bias toward the sacral promontory has been shown repeatedly to stabilize lumbosacral segment instrumentation and maximize pullout strength. Because of the unique anatomy, conventional anteroposterior (AP) and lateral radiographic views are relatively less reliable at determining screw depth and penetration of the sacral cortex...
December 13, 2016: Clinical Spine Surgery
Ahmet Karakaşlı, Nihat Acar, Mehmet Hilal Özcanhan, Fatih Ertem
OBJECTIVES: This study aims to assess five different cortical screw types using artificial femurs, under equated testing conditions. MATERIALS AND METHODS: We investigated the maximum force needed to cause deformation at screw-bone interface using fourth generation composite femurs by conducting separate pullout tests for each screw type. We normalized obtained results with traditional methods and cross-comparison. To conduct pullout tests dependent on screw dimensions, we eliminated the effect of bicortical bone thickness by equalizing the conditions of screw insertion...
December 2016: Eklem Hastalıkları Ve Cerrahisi, Joint Diseases & related Surgery
Elinor J Field, Kevin Parsons, Julie A Etches, Katie Hamilton, Neil J Burton
OBJECTIVES: To evaluate the effect of varying the number and configuration of locking bicortical and monocortical screws on a plate-rod construct using a mid-diaphyseal femoral ostectomy model. METHODS: Thirty Greyhound femurs were assigned to six groups (A-F). An intramedullary pin was placed in each bone following which a 3.5 mm locking plate was applied with six differing locking screw configurations. Groups A to C had one bicortical screw in the most proximal and distal plate holes and one to three monocortical locking screws in the proximal and distal fragments...
November 23, 2016: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
Devin Ganesh, Ben Service, Brian Zirgibel, Kenneth Koval
OBJECTIVES: To assess the utility of the dorsal tangential view (DTV) in detecting intraoperative dorsal screw penetration in distal radius fractures treated with volar locked plating. DESIGN: Retrospective cohort study. SETTING: Academic level 1 trauma center. PATIENTS/PARTICIPANTS: Skeletally mature patients where open reduction internal fixation with volar locked plating was the definitive treatment. A total of twenty-six patients were evaluated...
November 2016: Journal of Orthopaedic Trauma
Mark Lenz, Karl Stoffel, Heike Kielstein, Keith Mayo, Gunther O Hofmann, Boyko Gueorguiev
INTRODUCTION: Proximal plate fixation in periprosthetic femur fractures can be improved by plate anchorage in the greater trochanter (lateral tension band principle) or bicortical locking screw placement beside the prosthesis stem in an embracement configuration. Both concepts were compared in a biomechanical test using a femoral hook plate (hook) or a locking attachment plate (LAP). METHODS: After bone mineral density (BMD) measurement in the greater trochanter, six pairs of fresh frozen human femora were assigned to two groups and instrumented with cemented hip endoprostheses...
December 2016: Injury
Brian Brighton, Joshua M Abzug, Christine Ann Ho, Todd F Ritzman
Pediatric supracondylar humerus fractures are the most commonly encountered type of elbow fractures in children that require surgical fixation. Many pediatric supracondylar humerus fractures can be treated with closed reduction and percutaneous skeletal fixation. In difficult fractures, adjunct pin techniques, such as joystick wires and leverage pins, can be used to help attain a satisfactory and stable reduction before an open approach is used. After the fracture is reduced, optimal pinning, with the use of either crossed or lateral-entry techniques, and fixation that achieves maximal spread at the fracture site as well as bicortical engagement in both fragments are essential to maintain reduction and avoid complications that are associated with malunion...
February 15, 2016: Instructional Course Lectures
Denty Paul Vaughn, Jason Alan Syrcle, John E Ball, Steven H Elder, Jennifer Michele Gambino, Russell L Griffin, Ronald M McLaughlin
OBJECTIVE: Monocortical screws are commonly employed in locking plate fixation, but specific recommendations for their placement are lacking and use of short monocortical screws in metaphyseal bone may be contraindicated. Objectives of this study were to evaluate axial pullout strength of two different lengths of monocortical screws placed in various regions of the canine humerus compared to bicortical screws, and to derive cortical thickness and bone density values for those regions using quantitative computed tomography analysis (QCT)...
November 23, 2016: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
Jessica Lee, Chad Williams, Charles Lowrey, Greg Gould, Ronald Markert, Richard Laughlin
: Introduction Flexor hallucis longus (FHL) tendon transfer to the calcaneus is commonly used in the surgical treatment of chronic Achilles tendinopathy. This study assesses the integrity of FHL tendon biotenodesis screw fixation with respect to 2 variables: incorporation of a terminal whipstitch and tunnel depth. Materials and methods A total of 60 fresh-frozen cadaver FHL tendons and 28 calcanei were harvested for analysis in 4 sets of fixation constructs; 14 whipstitched tendons were compared against their nonwhipstitched paired tendon via pull-out strength load testing, and 16 tendon pairs were randomized for fixation in either a full-depth tunnel (bicortical) or a 25-mm partial tunnel (unicortical)...
September 7, 2016: Foot & Ankle Specialist
Ho-Chyul Han, Hyun-Chang Lim, Ji-Youn Hong, Su-Jin Ahn, Ji-Young Han, Seung-Il Shin, Jong-Hyuk Chung, Yeek Herr, Seung-Yun Shin
PURPOSE: The aim of this study was to determine the influence of anatomical conditions on primary stability in the models simulating posterior maxilla. METHODS: Polyurethane blocks were designed to simulate monocortical (M) and bicortical (B) conditions. Each condition had four subgroups measuring 3 mm (M3, B3), 5 mm (M5, B5), 8 mm (M8, B8), and 12 mm (M12, B12) in residual bone height (RBH). After implant placement, the implant stability quotient (ISQ), Periotest value (PTV), insertion torque (IT), and reverse torque (RT) were measured...
August 2016: Journal of Periodontal & Implant Science
Claudia Wittkowske, Stefan Raith, Maximilian Eder, Alexander Volf, Jan S Kirschke, Benjamin König, Christoph Ihle, Hans-Günther Machens, Stefan Döbele, Laszlo Kovacs
A semi-automated workflow for evaluation of diaphyseal fracture treatment of the femur has been developed and implemented. The aim was to investigate the influence of locking compression plating with diverse fracture-specific screw configurations on interfragmentary movements (IFMs) with the use of finite element (FE) analysis. Computed tomography (CT) data of a 22-year-old non-osteoporotic female were used for patient specific modeling of the inhomogeneous material properties of bone. Hounsfield units (HU) were exported and assigned to elements of a FE mesh and converted to mechanical properties such as the Young's modulus followed by a linear FE analysis performed in a semi-automated fashion...
August 30, 2016: Biomedizinische Technik. Biomedical Engineering
James R Meadows, Matthew M Diesselhorst, Jonathan T Finnoff, Britta L Swanson, Kyle E Swanson
Use of a cortical button for proximal biceps tenodesis has demonstrated strength comparable to that of other types of fixation in biomechanical models, but few studies have evaluated the clinical outcome of such fixation. In the study reported here, 18 patients who underwent open subpectoral biceps tenodesis with a bicortical button were assessed, at minimum 12-month follow-up, with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, a pain scale, physical examination, biceps supination strength testing, and ultrasonographic evaluation (to determine tenodesis integrity and proximity of the button to the axillary nerve)...
July 2016: American Journal of Orthopedics
Bart Falter, Johan Abeloos, Calix De Clercq, Nathalie Neyt, Philippe Lamoral, Gwen R J Swennen
PURPOSE: Transoral placement of bicortical screws is a rigid fixation method in orthognathic surgery that is used less often than transbuccal placement. The aim of this study was to examine the postoperative outcome of transoral bicortical screw insertion during orthognathic surgery and to compare it with the more common transbuccal fixation technique. MATERIALS AND METHODS: A retrospective cohort study was conducted. Clinical files of orthognathic surgery patients operated on from January 2010 through December 2012 were reviewed...
July 25, 2016: Journal of Oral and Maxillofacial Surgery
Feiran Wu, Katie Young, Mohammad Shahid, Peter Nightingale, Surabhi Choudhary, Michael Craigen, Rajive Jose, Mark Foster
BACKGROUND: Metacarpal fractures are common, accounting for 40 % of all hand injuries. The use of plates for the fixation of these fractures allows early aggressive hand therapy post-operatively, reducing post-operative stiffness. Traditionally, bicortical fixation is the standard practice, where both dorsal and palmar cortices of the metacarpal are drilled through, with screws engaging both cortices. Recent biomechanical studies have shown that unicortical fixation, where only the near cortex is drilled and engaged by the screw, results in no difference in stiffness, load to failure or failure mechanism, when compared with bicortical fixation...
2016: Trials
Hiroyoshi Moriwaki, Satoshi Yamaguchi, Tamaki Nakano, Yasufumi Yamanishi, Satoshi Imazato, Hirofumi Yatani
PURPOSE: Clarification of the protocol for using short implants is required to enable widespread use of short implants as an available treatment option. The purpose of this study was to investigate the influences of implant length and diameter, bicortical anchorage, and sinus augmentation on peri-implant cortical bone stress by three-dimensional finite element analysis. MATERIALS AND METHODS: For bone models with bone quantity A and C in the maxillary molar region, three-dimensional finite element analysis was performed using different lengths and diameters of implant computer-aided design models, and the degree of maximum principal stress distribution for each model was calculated...
July 2016: International Journal of Oral & Maxillofacial Implants
Angélica Castro Pimentel, Marco Antonio Sanches, Gabriel Cardoso Ramalho, Caio Vinicius Roman-Torres, Marcello Roberto Manzi, Wilson Roberto Sendyk
Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve...
2016: Case Reports in Dentistry
Antonios Giannakos, Peter S Vezeridis, Daniel G Schwartz, Richard Jany, Laurent Lafosse
PURPOSE: To describe the technique of an all-arthroscopic Eden-Hybinette procedure in the revision setting for treatment of a failed instability procedure, particularly after failed Latarjet, as well as to present preliminary results of this technique. METHODS: Between 2007 and 2011, 18 shoulders with persistent instability after failed instability surgery were treated with an arthroscopic Eden-Hybinette technique using an autologous bicortical iliac crest bone graft...
January 2017: Arthroscopy: the Journal of Arthroscopic & related Surgery
Fellippo Ramos Verri, Ronaldo Silva Cruz, Cleidiel Aparecido Araújo Lemos, Victor Eduardo de Souza Batista, Daniel Augusto Faria Almeida, Ana Caroline Gonçales Verri, Eduardo Piza Pellizzer
The aim of study was to evaluate the stress distribution in implant-supported prostheses and peri-implant bone using internal hexagon (IH) implants in the premaxillary area, varying surgical techniques (conventional, bicortical and bicortical in association with nasal floor elevation), and loading directions (0°, 30° and 60°) by three-dimensional (3D) finite element analysis. Three models were designed with Invesalius, Rhinoceros 3D and Solidworks software. Each model contained a bone block of the premaxillary area including an implant (IH, Ø4 × 10 mm) supporting a metal-ceramic crown...
February 2017: Computer Methods in Biomechanics and Biomedical Engineering
Trung T Le, Ha V Vo, Lawrence X Webb
PURPOSE: Locking compression plates (LCP) allow trauma and orthopedic surgeons to have a variety of options for utilizing locking and non-locking screw features. In this study, the hybrid constructs of mixed unicortical and bicortical screws were investigated for humerus midshaft fractures. The locking and non-locking features were also incorporated into the hybrid LCP constructs. Kryptonite™ bone cement is biocompatible with low exothermic properties and strong metal adhesion. This novel bone cement was incorporated into the non-locking screw feature to compare its mechanical effect with that of a traditional locking screw feature...
September 2016: Journal of Orthopaedics
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