Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs

Yavuz Yüksel; Özkan Köse

doi:10.17343/sdutfd.1771453

Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs

Abstract

Objective: The posterior tibial slope (PTS) is a critical anatomical parameter influencing knee biomechanics and ligamentous stability. Despite its clinical relevance, no consensus exists on the most reliable radiographic method for measuring PTS. This study aimed to evaluate the inter- and intra-observer reliability and agreement of four radiographic techniques for PTS measurement on standard lateral knee radiographs. Material and Method: A retrospective analysis was conducted on 70 adult patients with high-quality true lateral knee radiographs. Four commonly used methods were applied to measure the PTS: the fibular shaft axis (FSA), anterior cortical line (ACL), posterior cortical line (PCL), and proximal anatomical axis (PAA). Two experienced observers performed all measurements twice, 15 days apart, using a standardized protocol. Intraclass correlation coefficients (ICCs) were calculated to assess reliability, and Pearson correlation coefficients were used to evaluate the agreement between measurements and demographic characteristics. Results: All four methods showed excellent intra-observer reliability (ICC, range 0.916–0.975) and good-to-excellent inter-observer reliability (ICC, range 0.813–0.968). Mean PTS values differed by method: ACL 12.4° ± 3.2°, PCL 7.2° ± 3.1°, FSA 10.1° ± 3.2°, PAA 9.6° ± 3.0° (p = 0.001). Pairwise correlations were strong for all methods (p < 0.001). PTS showed no significant association with age, sex, height, weight, or body mass index. Conclusions: Although reliability was high for all techniques, differences in absolute values indicate that methods are not interchangeable. Standardized reference axes should be specified to ensure consistent reporting across clinical and research settings.

Keywords

Ethical Statement

Alaaddin Keykubat University Ethics Committee approved the study protocol. Date:11.06.2025 Issue:10-2. The study was conducted in line with the principles of the "Helsinki Declaration".

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Details

Primary Language

English

Subjects

Orthopaedics, Radiology and Organ Imaging

Journal Section

Research Article

Authors

Yavuz Yüksel
0000-0002-3805-4245
Türkiye

Özkan Köse ^*
0000-0002-7679-9635
Türkiye

Publication Date

December 1, 2025

Submission Date

August 24, 2025

Acceptance Date

October 31, 2025

Published in Issue

Year 2025 Volume: 32 Number: 4

DOI

https://doi.org/10.17343/sdutfd.1771453

IZ

https://izlik.org/JA75ST34ZT

Cite

RIS / Bibtex

APA

Yüksel, Y., & Köse, Ö. (2025). Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs. Medical Journal of Süleyman Demirel University, 32(4), 327-335. https://doi.org/10.17343/sdutfd.1771453

AMA

1.Yüksel Y, Köse Ö. Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs. Med J SDU. 2025;32(4):327-335. doi:10.17343/sdutfd.1771453

Chicago

Yüksel, Yavuz, and Özkan Köse. 2025. “Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs”. Medical Journal of Süleyman Demirel University 32 (4): 327-35. https://doi.org/10.17343/sdutfd.1771453.

EndNote

Yüksel Y, Köse Ö (December 1, 2025) Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs. Medical Journal of Süleyman Demirel University 32 4 327–335.

IEEE

[1]Y. Yüksel and Ö. Köse, “Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs”, Med J SDU, vol. 32, no. 4, pp. 327–335, Dec. 2025, doi: 10.17343/sdutfd.1771453.

ISNAD

Yüksel, Yavuz - Köse, Özkan. “Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs”. Medical Journal of Süleyman Demirel University 32/4 (December 1, 2025): 327-335. https://doi.org/10.17343/sdutfd.1771453.

JAMA

1.Yüksel Y, Köse Ö. Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs. Med J SDU. 2025;32:327–335.

MLA

Yüksel, Yavuz, and Özkan Köse. “Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs”. Medical Journal of Süleyman Demirel University, vol. 32, no. 4, Dec. 2025, pp. 327-35, doi:10.17343/sdutfd.1771453.

Vancouver

1.Yavuz Yüksel, Özkan Köse. Reliability and Agreement of Four Radiographic Methods for Measuring Posterior Tibial Slope on Lateral Knee Radiographs. Med J SDU. 2025 Dec. 1;32(4):327-35. doi:10.17343/sdutfd.1771453

Cited By

Radiographic Posterior Tibial Slope Measurement in Medial Unicompartmental Knee Arthroplasty: A Retrospective Validation Study Using Digital Volume Tomography of Tibial Resectates

Journal of Clinical Medicine

https://doi.org/10.3390/jcm15062095