Abstract
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.
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 language | English |
|---|---|
| Pages | 191-192 |
| Publication status | Published - 2005 |
| Event | European Congress of Radiology: ECR 2005 - Wien, Austria Duration: 4 Mar 2005 → 7 Mar 2005 |
Conference
| Conference | European Congress of Radiology |
|---|---|
| Abbreviated title | ECR |
| Country/Territory | Austria |
| City | Wien |
| Period | 4/03/05 → 7/03/05 |
Fields of Expertise
- Information, Communication & Computing