Detaillierte Beitrags-Information
| Beitragstitel | Meniscus sizing using three-dimensional models of the ipsilateral tibia plateau based on CT scans - a new sizing approach |
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| Beitragscode | P048 |
| Autoren | |
| Präsentationsform | Poster |
| Themengebiete |
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| Abstract |
Background: Meniscus allograft transplantation seems to be a reliable option for postmeniscectomy syndrome in young patients. Selection of a meniscus allograft with a similar three-dimensional (3D) size is essential for an optimal distribution of joint pressure and good clinical results. Direct meniscus sizing by MRI scan is not possible in total meniscectomy and indirect sizing by conventional radiography (RX) often inaccurate. Purpose: The purpose of this study was to develop a new indirect sizing method, based on the three-dimensional shape of the ipsilateral tibia plateau, which is independent of the meniscus condition and could be performed fully automatized. Further, we analyzed the accuracy of the method compared to the currently used RX and MRI based sizing methods. Methods: Fifty healthy knee joints with available RX, MRI and computer tomography (CT) scan were used. 3D surface models of the menisci were created by segmentation in MRI scan and 3D bone models of the tibia plateau by semi-automatic segmentation of the corresponding CT scan. For the further analysis, we created 3D bone models of the proximal 10mm of the entire tibia plateau and of the half tibia plateau with and without the intercondylar area in a standardized fashion. For each meniscus, the best fitting “allograft” couple out of all other 49 menisci were assessed 1) by the surface distance of the 3D meniscus (3D-MRI), 2) by the surface distance of the 3D tibia plateau (3D-CT) and 3) by width/length measured in x-ray (2D-RX). Differences between the gold standard (3D-MRI) and the other sizing methods were assessed by mean (MeSD) / maximum surface distance (MaSD), as well as meniscal width, length and height. Results: 3D-CT sizing using the half tibia plateau without the intercondylar area was better than the other 3D-CT sizing methods (p < 0.001). Neither sizing by 3D-CT technique, nor by 2D-RX of the ipsilateral tibia plateau could select the best possible allograft in each case (Differences to 3D-MRI of MeSD 0.18-0.35mm, MaSD 1.25-1.99mm, p < 0.001). 3D-CT sizing was significantly better for medial, but not better for lateral meniscus than 2D-RX sizing. Conclusion: Automatized, indirect meniscus sizing using the 3D bone models of the tibia plateau is feasible and more precise than the previously described 2D-RX method. This method might become the gold-standard after total meniscectomy if 2D-MRI sizing is not possible. However, further technical improvement is needed. |