Evaluation of a method for digital definition of bone shapes

Philipp Peloschek, Georg Langs, Martin Urschler, J. Sailer, M. Uffmann, T. Schlager, Franz Kainberger, Horst Bischof

Research output: Contribution to conferenceAbstractpeer-review


Purpose: To examine the influence of posterior instrumentation on content and distribution of subchondral mineralization as a correlate of a long-term load acting on adjacent and transfixed facets.
Materials and Methods: 23 patients with thoraco-lumbar fractures had CTs and received posterior fixation. Patients were divided into group A (second CT on an average of 7.3 days) and group B (second CT on an average of 17 months after
implant removal). CT-OAM was performed. Facet joints were separated on each CT-slice and 3D-reconstructed. The subchondral bone plate in each slice was isolated and reconstructed. In the density image summarized HU were represented by false colors. Finally, the density images were projected onto the 3D images. The resulting pictures were used to evaluate intra-individual changes in mineralization of paired facets joints by visual and quantitative analysis.
Results: There were significant differences between groups A and B with an overall mineralization decrease in group A and an increase in group B. In group A no significant differences between adjacent and transfixed facets were found, in group B the suprajacent joints showed a significantly higher mineralization increase than the transfixed joints.
Conclusion: Decrease in subchondral mineralization indicates reduced load upon the facets. This finding in patients with early follow-up seems to be caused by reduced activity until implant removal. In patients with longer follow-up intervals
higher loads are shown which might be caused by unphysiological long-term stress induced by stabilization. Whether these changes lead to spondylarthritis has to be the subject of further studies.
Original languageEnglish
Publication statusPublished - 2005
EventEuropean Congress of Radiology: ECR 2005 - Wien, Austria
Duration: 4 Mar 20057 Mar 2005


ConferenceEuropean Congress of Radiology
Abbreviated titleECR

Fields of Expertise

  • Information, Communication & Computing

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