25dkou623 10.3205/25dkou623 urn:nbn:de:0183-25dkou6235 Meeting Abstract Roshardt Roshardt Jose J

Department of Orthopaedic Surgery, Inselspital, University of Bern, Bern, Schweiz

author Meier Meier Malin M

University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University of Bern, Bern, Schweiz

author Lerch Lerch Till T author Ruckli Ruckli Adrian A

Department of Orthopaedic Surgery, Inselspital, University of Bern, Bern, Schweiz

author Gerber Gerber Nicolas N

Department of Orthopaedic Surgery, Inselspital, University of Bern, Bern, Schweiz

author Tannast Tannast Moritz M

Department of Orthopaedic Surgery, Inselspital, University of Bern, Bern, Schweiz

author Steppacher Steppacher Simon Damian SD

Department of Orthopaedic Surgery, Inselspital, University of Bern, Bern, Schweiz

author Schmaranzer Schmaranzer Florian F

Radiology Department, Balgrist University Hospital, Zürich, Schweiz

author German Medical Science GMS Publishing House

Düsseldorf

610 20251031 engl This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). M0634 623 Deutsche Gesellschaft für Orthopädie und Unfallchirurgie Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie Deutsche Gesellschaft für Unfallchirurgie Berufsverband für Orthopädie und Unfallchirurgie Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2025) Abstracts | AE; Deutsche Rheuma-Liga | Spezielle Aspekte bei rheumatoider Arthritis Berlin 20251028 20251031 AV32-3146 TextObjective and research question: Coxa profunda sign has traditionally been used as a radiographic parameter of increased lateral acetabular coverage. However, it is also observed in hip dysplasia, suggesting that it does not reflect acetabular coverage. Artificial intelligence (AI)-powered 3D MRI segmentation now enables precise evaluation of lunate surface size.The objective of this study is to evaluate whether a positive coxa profunda sign reflects increased lunate surface size using an AI-based automatic 3D analysis.Material and methods: This retrospective study included 98 patients (100 hips) with symptomatic hip deformities who underwent 3T MR arthrography between January 2020 and October 2021 (mean age 30 ± 9 years; 64% female). The imaging protocol included proton-density-weighted turbo spin-echo (PD-w TSE) and axial-oblique 3D T1 MP2RAGE sequences. Anteroposterior pelvic radiographs were assessed for the coxa profunda sign and standard parameters. Patients were stratified into acetabular morphology groups based on the lateral center-edge angle (LCE): dysplasia (LCE < 23°), normal coverage (LCE 23–33°), overcoverage (LCE 33–39°), severe overcoverage (LCE > 39°), and retroversion (retroversion index > 30%). AI-based segmentation evaluated lunate surface size, normalized to femoral head size, with statistical analyses using Fisher’s exact test for prevalence and unpaired t-tests for morphological relationships.Results: Positive coxa profunda was found in 65% of cases (dysplasia: 68%, normal: 63%, retroversion: 45%, overcoverage: 83%, severe overcoverage: 75%), with no statistically significant difference between groups (p = 0.156). By contrast, the relative size of the lunate surface differed significantly across groups, with dysplastic hips showing the smallest area (28 ± 3%) and severe overcoverage the largest (35 ± 3%; p < 0.001). Lunate surface size (31 ± 3% vs. 31 ± 3%; p = 0.462) and lateral coverage parameters (LCE: 30 ± 10° vs. 29 ± 9°; p = 0.633, acetabular index: 3 ± 6° vs. 4 ± 6°; p = 0.504) showed no difference between coxa profunda-positive and -negative individuals. However, those with positive coxa profundahad significantly higher acetabular version (18 ± 6° vs. 15 ± 6°; p = 0.026) and lower retroversion index (11 ± 16% vs. 21 ± 20%; p = 0.006).Discussion and coclusion: The coxa profunda sign is highly prevalent and does not reflect the size of the lunate surface. Therefore, it should not be relied upon for diagnosing acetabular coverage. However, it might be an indicator of increased acetabular version. 0 0 0 0