Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0932
    Keywords: Key words Spine ; Spine ; bone ; plates ; Spine ; screws ; Spine ; biomechanics ; Spine ; implant ; testing ; Spine ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of this combined study was to evaluate the stability and safety of a new monocortical screw-plate system for anterior cervical fusion and plating (ACFP) according to Caspar in comparison with classical bicortical fixation. In the biomechanical part of the study two groups, each comprising six fresh human cadaveric spines (C4–C7), matched for bone mineral density, additionally resulting in almost the same mean age, were used. Range of motion and neutral zone were analyzed in flexion-extension, rotation (left, right) and lateral bending (left, right) using pure moments of ± 2.5 Nm for each specimen in the intact state, after discectomy at C5/6 and after discectomy at C 5/6 followed by bone grafting plus plating (Caspar plates), with either monocortical or bicortical screws. For all three motion planes, no significant difference could be found between the new monocortical and the bicortical fixation techniques. The clinical part of the study was performed as a prospective study on 30 patients suffering from symptomatic degenerative cervical disc disease in one segment. At the latest follow-up, no hardware- or graft-related complications were seen in any of the patients. Following these findings monocortical screw fixation can be recommended for the majority of anterior cervical fusion and plating procedures in degenerative disease, making the procedure quicker, easier, and safer. Bicortical screw fixation still has specific indications for multilevel stabilization, poor bone quality (osteoporosis, rheumatoid disease – as bicortical oversized rescue screw), unstable spines (trauma, tumour) and in particular for the realignment of kyphotic deformities (restoration of the normal lordotic curve). Due to the design of the study the results apply only to surgical treatment of monosegmental degenerative disc disease at the time.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Archives of orthopaedic and trauma surgery 91 (1978), S. 129-135 
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zwischen Osteosyntheseschraube und -platee treten Reibemomente auf, die zu einer ausgeprägten Oberflächenbeschädigung mit der Gefahr der Reibkorrosion und zu einer Verringerung der Schraubenzugkraft führen. Beschichteten wir die Schraubenköpfe mit PTFE- oder Graphit-Gleitlack, so ließ sich die Reibung signifikant verringern und die Schraubenzugkraft um 40% erhöhen. Rasterelektronenmikroskopisch konnte dabei eine Verminderung der Oberflächenschäden nachgewiesen werden. Zur Überprüfung der Gewebeverträglichkeit wurden Gleitlacke und Lackextrakte mit fötalem Kälber-serum und mit Dimethylsulfoxid Fibroblastenkulturen zugesetzt. Als Maß für die Toxizität diente die DNS-Syntheserate, die autoradiographisch ermittelt wurde. Diese wurde durch Zusatz von Gleitlack und Kälber-serum-Lackextrakt nicht herabgesetzt. Auch bei in-vivo-Versuchen an Ratten, in die gleitlackbeschichtete Teflonplättchen implantiert wurden, konnte eine gute lokale und systemische Gewebeverträglichkeit festgestellt werden.
    Notes: Summary The screws and plates used in operative treatment of fractures cause moments of friction between the bone screw head and the bone plate hole during the tightening of the screws. This results in hidden damage to the grinding metal surfaces, with the danger of erosion corrosion and in a reduction in the screw force. By covering the screw heads with the lubricating sprays PTFE or graphite friction was significantly reduced, the screw force increased by 40% and extensive damage to the surfaces avoided. Lubricating sprays or their extracts, in fetal calf serum or in dimethylsulfoxide, were added to fibroblast cultures. Toxicity was manifest as changes in the synthesis of DNA, as measured by autoradiography. Sprays or spray extracts in fetal calf serum did not inhibit cell proliferation. In vivo experiments in rats reflected the in vitro results, there being no evidence that toxic substances were released from the sprays by physiological solvents: There was a lack of histopathological changes in the inner organs and a local encapsulation of implants which was essentially like that in a teflon control group.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1437-2320
    Keywords: Biomechanical study ; cervical spine instability ; cervical spondylodesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a comparative experimental biodynamic study using thirty-two human cervical spines of cadavers the primary stabilization effect of different types of spondylodesis was examined. Whereas in flexion stress all methods showed a sufficient stability, the rotation tests proved, that in case of a dorsal instability of the lower cervical spine, posterior interlaminar wiring or anterior plate stabilization showed no reliable stabilization effect. However, the compression clamps by Roosen and Trauschel as well as the hook-plates by Magerl are suitable dorsal stabilization methods with excellent rotation stability. In case of dorsal instability of the lower cervical spine a posterior spondylodesis is necessary and sufficient.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Biomaterials 6 (1995), S. 99-104 
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: A major problem in fracture treatment by external fixation is screw loosening, which often results in reduced stability and can lead to prolonged treatment. A load-carrying experiment was conducted to determine whether coating implants with bioactive hyroxyapatite (HA) increases screw stability. Twelve HA-coated ASIF screws with 3 different macroporosities were inserted in 12 sheep that had already been fitted with a 6-pin external fixator for the treatment of a tibial osteotomy. The same number of uncoated polished steel screws served as controls. Although initial stability was not different for HA-coated screws, average removal torque after a 9-week implantation period increased with increasing macroporosity of the HA coating (p 〈.002). Instability of some screws was accompanied by histologic findings of cartilagenous tissue and proliferation of periosteal callus. Near the threads in the tibial cortex and in the shaft area of the screw were seen large numbers of HA particles that had been sheared off during implantation as well as during screw removal because of high contract forces between the HA coating and bone. Particulate debris of HA particles as well as the release of small bone fragments during explantation is likely to be unavoidable since HA adherence to bone is greater than adherence to steel after several weeks of implantation. © 1995 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Biomaterials 6 (1995), S. 35-41 
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: In ligament replacement cases where the artificial ligament has worn and partially or totally ruptured, the released wear particles have been associated with a chronic synovitis that inhibits integration of the ligament and contributes to the ultimate failure of the device. In this study, the biological response to ligament wear particles from nine different artificial ligaments was quantitatively evaluated in vivo. Wear particles, the majority of which were 〈7 μm, were generated in vitro. These particles were injected into rabbit knee joints, and the biological response as well as the systemic migration of the particles were evaluated histologically after 4 weeks. The extent of the inflammatory reaction to the ligament wear particles was found to be significantly (p 〈 0.05) influenced by the type of material implanted. No particles were found in the regional lymph nodes or in the spleen, liver, kidney, or lung. © 1995 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...