gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie
74. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie
96. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie
51. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie

26. - 29.10.2010, Berlin

Comparison of one screw with two screw fixation of Anderson type II DENS fractures – a biomechanical study

Meeting Abstract

  • A.-P. Schulz - Univ.Klinikum S-H, Campus Lübeck, Klinik für Chirurgie des Stütz- und Bewegungsapparats, Lübeck, Germany
  • S. Spuck - UK-SH, Campus Lübeck, Klinik für Neurochirurgie, Lübeck, Germany
  • G. Feng - 2nd Affiliated Hospital, Zhejiang University College of Med, Orthopaedic Department, Hangzhou, China
  • R. Wendlandt - Unversitätsklinikum Schleswig-Holstein, Klinik für Chirurgie des Stütz- und Bewegungsapparates, Labor für Biomechatronik, Lübeck, Germany
  • L. Busch - Universität Lübeck, Anatomisches Institut, Lübeck, Germany
  • C. Jürgens - Direktor, BG Unfallkrankenhaus Hamburg, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie. 74. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 96. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 51. Tagung des Berufsverbandes der Fachärzte für Orthopädie. Berlin, 26.-29.10.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocIN16-1440

DOI: 10.3205/10dkou089, URN: urn:nbn:de:0183-10dkou0891

Veröffentlicht: 21. Oktober 2010

© 2010 Schulz 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 vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: The type II odontoid fracture is the most common type of odontoid fracture, it is inherently unstable. Anterior screw fixation is the best treatment for type II odontoid fracture. Both one- and two-screw techniques have their own merits and demerits. The objective the study is to compare the stability between one and two screw fixation.

Methods: 14 fresh cadaver axes were randomly divided into two groups and fixed with one- or two-screw respectively. Implantation was in the usual technique under radiographic control. The stiffness of intact specimens and after screw fixation in six directions was tested on the universal mechanical testing machine (Zwick) and the corresponding data compared with each other. SPSS v16 was used after the consultation of a biometric statistician.

Results and conclusions: There was no statistically significant difference in any direction between the one and the two screw technique. The results showed that the torque load transmitted to the odontoid by ligaments is around 1/3 (0.53±0.38 Nm) of the maximum physiological load (1.5 Nm) in axial rotation. The torque acting on the occipito-altanto-axial complexes is dominated by the odontoid at smaller rotational angles. At larger rotational angles, the other ligaments that do not attach to the odontoid will join in and react against the torque more. The bone mineral density has statistical significant correlation with shear stiffness loading from anterior and posterior, torsional stiffness loading from left and right of intact specimen.

Both one- and two-screw fixation for type II odontoid fracture can gain the same shear and torsional stiffness. The result indicates that anterior odontoid fixation with one- or two-screw offers similar stability. Both the techniques cannot restore the normal shear and torsional stiffness. The stiffness of the odontoid after one- or two-FCS fixation is much less than that of normal.