gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie, 75. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 97. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 52. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie

25. - 28.10.2011, Berlin

A novel technique for simplified distal interlocking of IM nails to reduce radiation exposure

Meeting Abstract

  • L. Fliri - AO Research Institute, Davos, Switzerland
  • J. Schroeder - AO Research Institute, Davos, Switzerland
  • G. Richards - AO Research Institute, Davos, Switzerland
  • M. Windolf - AO Research Institute, Davos, Switzerland

Deutscher Kongress für Orthopädie und Unfallchirurgie. 75. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 97. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 52. Tagung des Berufsverbandes der Fachärzte für Orthopädie. Berlin, 25.-28.10.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocGR16-718

DOI: 10.3205/11dkou488, URN: urn:nbn:de:0183-11dkou4887

Veröffentlicht: 18. Oktober 2011

© 2011 Fliri 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

Questionnaire: The common practice for insertion of distal locking screws of intramedullary (IM) nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure to patient and surgical personnel. A new technique is introduced which guides the surgeon by landmarks on the X-ray projection. It was the aim of this study to investigate the newly developed guided freehand technique on human cadaveric below-knee specimens in an OR like environment and to compare it with the commonly used freehand technique in terms of operating time and radiation exposure.

Methods: 10 fresh frozen human below-knee specimens (incl. soft tissue) were used in the study. Each specimen was instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland) and was mounted on an OR-table providing an experimental setting close to surgical practice. Two distal interlocking techniques (freehand / guided freehand) were performed by an orthopedic resident surgeon in a random order. The newly developed guided freehand technique, generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the X-ray image. A computer program plans the drilling trajectory by 2D-3D conversion and provides said guiding landmarks in real-time. Interlocking holes can be drilled by visually aligning the drill to the planned trajectory. No additional tracking or navigation equipment is needed. A Siemens ARCADIS C-arm system (Siemens AG, Munich, Germany) was used as imaging means for all procedures. All four distal screws (2 mediolateral, 2 anteroposterior) were placed for each interlocking procedure. Each specimen was operated twice by either the freehand or the guided freehand technique. The nail was retrieved by 4-5 cm after the first procedure and was operated again. Operating time, number of taken X-rays and radiation time were recorded per procedure and for each single screw. Data was statistically evaluated using non-parametric tests.

Results and Conclusions: In total 8 procedures were performed with the freehand technique and 10 with the guided freehand technique. A 58% reduction in number of taken X-rays per screw was found for the guided freehand technique (7.4±3.4 X-rays) compared to the freehand technique (17.6±10.3 X-rays) (p<0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique (17.1±3.7 s) compared to the freehand technique (37.9±9.1 s) (p=0.001). Operating time (from first shot to screw tight) per screw was on average 3.2±1.2 min for the guided freehand technique and 4.1±2.1 min for the freehand technique (−22%, p=0.018). In an experimental setting, the newly developed guided freehand technique has proven to markedly reduce radiation exposure when compared to the conventional freehand technique. The method enhances established clinical workflows and does not require cost intensive add-on devices or extensive training.