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Turkish Journal of Medical Sciences

Abstract

Background/aim: Acetabular morphology plays a fundamental role in hip biomechanics by influencing load distribution and maintaining cartilage integrity. Although the Sharp angle, lateral center–edge angle (LCEA), Tönnis angle, and acetabular depth are commonly used radiographic parameters, their independent associations with hip osteoarthritis (OA) and their relative diagnostic performance remain uncertain. This study evaluated these associations and compared their diagnostic utility.

Materials and methods: This retrospective study included standardized anteroposterior pelvis radiographs obtained between January 2021 and December 2024. Hips were classified according to the Kellgren–Lawrence (KL) grading system, with grade 0 hips assigned to the control group and grade ≥2 hips assigned to the OA group; grade 1 hips were excluded from the study. Sharp angle, LCEA, Tönnis angle, and acetabular depth were independently measured by two orthopedic surgeons in two separate sessions, and reproducibility was assessed using intraclass correlation coefficients (ICC). Group comparisons were performed using the Mann–Whitney U test. Univariate and multivariable logistic regression analyses were performed to identify independent predictors of OA, while diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis.

Results: A total of 240 hips (120 OA and 120 control) were analyzed. LCEA was significantly lower, whereas Tönnis and Sharp angles were significantly higher in the OA group (all p < 0.05). Acetabular depth showed no significant between-group difference (p = 0.214). In the multivariable analysis, LCEA (p < 0.001) and the Tönnis angle (p < 0.001) remained independent predictors of OA, whereas the Sharp angle and acetabular depth were not significant predictors. ROC analysis demonstrated the highest diagnostic accuracy for LCEA (area under the curve [AUC] = 0.882), followed by the Tönnis angle (AUC = 0.831). All measurements demonstrated acceptable-togood intraobserver and interobserver reliability (ICC range: 0.76–0.89).

Conclusion: Decreased LCEA and increased Tönnis angle demonstrated the strongest independent associations with hip OA. In contrast, the Sharp angle and acetabular depth provided limited diagnostic value. Incorporating LCEA and Tönnis angle into routine radiographic assessment may facilitate the identification of hips with osteoarthritic changes and support clinical evaluation.

Author ORCID Identifier

NİHAT YİĞİT: 0009-0002-8670-5484

NURİNURİ KORAY ÜLGENULGEN: 0000-0003-0301-3432

HAYRETTİN UNALÜNAL: 0000-0003-1178-4931

ALİALİ SAİD NAZLIGÜLNAZLIGUL: 0000-0003-3451-3691

MEHMETMEHMET ORCUNMEHMET ORÇUN AKKURT: 0000-0003-4935-0143

ARSLANARSLAN KAĞANARSLAN KAGAN ARSLAN: 0000-0002-8156-0565

DOI

10.55730/1300-0144.6397

Keywords

acetabular depth, acetabulum, Hip osteoarthritis, lateral center-edge angle, radiographic measurements, Tönnis angle

First Page

1514

Last Page

1523

Publisher

The Scientific and Technological Research Council of Türkiye (TÜBİTAK)

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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