gms | German Medical Science

76. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

04.05. - 08.05.2005, Erfurt

Clinical investigation and simulation at the finite element model of the human skull to elucidate mechanisms of the isolated orbital floor fracture

Meeting Abstract

  • corresponding author Christoph Punke - HNO-Klinik der Universität Rostock, Rostock
  • B Kramp - HNO-Klinik der Universität Rostock, Rostock
  • A Fritsche - Institut für Biomedizinische Technik der Universität Rostock, Rostock
  • H Martin - Institut für Biomedizinische Technik der Universität Rostock, Rostock
  • A Fischer - Institut für Biomedizinische Technik der Universität Rostock, Rostock
  • K Schmitz - Institut für Biomedizinische Technik der Universität Rostock, Rostock
  • H Pau - HNO-Klinik der Universität Rostock, Rostock

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie. 76. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V.. Erfurt, 04.-08.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05hno550

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/hno2005/05hno204.shtml

Veröffentlicht: 22. September 2005

© 2005 Punke et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Background: Isolated orbital floor fractures are a significant part of facial injuries. Their mechanism of injury is not yet completely defined. Two theories have been described: According to the Hydraulic-Pressure Theory, the incompressible eye tissue transfers the kinetic energy of the blow to the floor of the orbita, which in turn fractures. In contradiction to that, the Buckling-Force Theory explains fractures of the orbital floor with bending and shear stress due to kinetic energy directly attacing the orbital rim.

Study design and Methods: In the clinical part of this study 163 cases of Orbital floor fracture were examined with respect to epidemiologic data symptoms, concurring injuries and types of fracture. In the experimental part we constructed a simplified Finite-Element Model of the human orbita by 3D optical scanning of a human skull. To elucidate the mechanism of injury we created a generic approximation model based on empiric data from femor fractures. Several experiments tested the aforementioned hypothesis by direct and indirect application of kinetic energy.

Results: 75% of patients were between 10 and 40 years of age, with a mean age of 30 years. 90% of patients were male. 50% of fractures were caused by human violence, 10% each by falls, sports/leisure activities and traffic accidents, respectivly. At least 33% of patients suffered their injuries under the influence of alcohol. Common symptoms included disorders of eye movement, double vision, “Monokel hematoma”, epistaxis, swelling, bulbus contusion, sensory deficits and enophthalmus. Clinical data mostly suggested a direct and superficial energy transfer to the bulbus, in some cases the orbital rim seemed to be the primary point of impact. With the Finite-Element Model of the skull we simulated different Types of shear stress. The calculated points of maximum pressure were all within the orbital floor.

Conclusion: Retrospective analysis as well as simulation support both theories describing methods of injury. Simulation. The calculated points of maximum pressure in the simulation were all within the orbital floor, where the majority of clinical fractures occured. Further examinations concerning mechanical attributes of the involved structures as well as the acquisition optical scans of different skulls are needed to further evaluate this model.