Quantitative ultrasound evaluation of medial compartment knee osteoarthritis under standing weight-bearing condition
- 1Department of Orthopaedic Surgery, The Second Affiliated Hospital of Chongqing Medical University, No.74, Linjiang Road, Yuzhong District, Chongqing, 400010 China
- 2Department of Orthopaedic Surgery, Chongqing Orthopedic Hospital of Traditional Chinese Medicine, No.19, Fuhua Road, Yuzhong District, Chongqing, 400043 China
- 3Department of Orthopaedic Surgery, People’s Hospital of Yichun City, Yichun, Jiangxi Province China
Abstract
Purpose: To evaluate the diagnostic value of ultrasound for joint space width in knee osteoarthritis under standing weight-bearing conditions and identify reliable sonographic parameters for osteoarthritis severity grading, especially end-stage knee osteoarthritis.
Methods: This cross-sectional study enrolled 256 patients with knee pain and suspected knee osteoarthritis from June to December 2025. All participants underwent standing weight-bearing radiography and ultrasound of the affected knee at 20° and 45° flexion. Radiographic assessments (Kellgren-Lawrence grading, joint space width, minimal joint space width) were performed by two senior orthopedists, while ultrasound evaluations (joint space width, total femoral and tibial osteophyte height, medial meniscal extrusion) were conducted by another two experienced orthopedists blinded to radiographic findings. Interrater reliability was analyzed using the weighted kappa coefficient and intraclass correlation coefficient. The Pearson product-moment correlation coefficient quantified the correlation between sonographic and radiographic measurements, and receiver operating characteristic curve analysis determined the diagnostic efficacy of ultrasound parameters for Kellgren-Lawrence grading.
Results: Participants had a mean age of 55.9 ± 11.7 years, mean body mass index of 25.22 ± 4.32 kg/m², and 81.6% were female. Interrater reliability for all measurements was moderate to excellent (intraclass correlation coefficient/weighted kappa: 0.54–0.92). With increasing Kellgren-Lawrence grades, radiographic and ultrasound joint space width decreased, while total femoral and tibial osteophyte height and medial meniscal extrusion increased. A total of 29 patients (11.3%) were reclassified to higher Kellgren-Lawrence grades at 45° versus 20° flexion. High correlations were observed between radiographic and sonographic measurements. For differentiating Kellgren-Lawrence Grade 3 from 4, ultrasound joint space width at 45° flexion had a higher area under the curve (0.839, 95% confidence interval: 0.766–0.912; cutoff: 1.75 mm) than at 20° (0.825, 95% confidence interval: 0.745–0.905; cutoff: 1.95 mm).
Conclusions: Sonographic joint space width measured at 20° and 45° knee flexion under standing weight-bearing conditions yielded AUC values similar to those obtained from weight-bearing radiographs for diagnosing medial compartment KOA. Ultrasound may act as a potential supplementary imaging alternative to conventional standing radiograph for grading the severity of medial compartment KOA.
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BibTeX
@article{jiang2026quantitative,
title = {{Quantitative ultrasound evaluation of medial compartment knee osteoarthritis under standing weight-bearing condition}},
author = {Qilong Jiang and Yajun Li and Yan Xiao and Na Wang and Junming Lin and Chang Liu and Mingbo Wu and Yusong Liu and Mao Nie and Xianding Sun},
journal = {BMC Medical Imaging},
year = {2026},
month = jul,
doi = {10.1186/s12880-026-02638-z},
url = {https://doi.org/10.1186/s12880-026-02638-z},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Quantitative ultrasound evaluation of medial compartment knee osteoarthritis under standing weight-bearing condition
AU - Qilong Jiang
AU - Yajun Li
AU - Yan Xiao
AU - Na Wang
AU - Junming Lin
AU - Chang Liu
AU - Mingbo Wu
AU - Yusong Liu
AU - Mao Nie
AU - Xianding Sun
PY - 2026
DA - 2026/07/31
JO - BMC Medical Imaging
DO - 10.1186/s12880-026-02638-z
UR - https://doi.org/10.1186/s12880-026-02638-z
AB - Purpose: To evaluate the diagnostic value of ultrasound for joint space width in knee osteoarthritis under standing weight-bearing conditions and identify reliable sonographic parameters for osteoarthritis severity grading, especially end-stage knee osteoarthritis. Methods: This cross-sectional study enrolled 256 patients with knee pain and suspected knee osteoarthritis from June to December 2025. All participants underwent standing weight-bearing radiography and ultrasound of the affected knee at 20° and 45° flexion. Radiographic assessments (Kellgren-Lawrence grading, joint space width, minimal joint space width) were performed by two senior orthopedists, while ultrasound evaluations (joint space width, total femoral and tibial osteophyte height, medial meniscal extrusion) were conducted by another two experienced orthopedists blinded to radiographic findings. Interrater reliability was analyzed using the weighted kappa coefficient and intraclass correlation coefficient. The Pearson product-moment correlation coefficient quantified the correlation between sonographic and radiographic measurements, and receiver operating characteristic curve analysis determined the diagnostic efficacy of ultrasound parameters for Kellgren-Lawrence grading. Results: Participants had a mean age of 55.9 ± 11.7 years, mean body mass index of 25.22 ± 4.32 kg/m², and 81.6% were female. Interrater reliability for all measurements was moderate to excellent (intraclass correlation coefficient/weighted kappa: 0.54–0.92). With increasing Kellgren-Lawrence grades, radiographic and ultrasound joint space width decreased, while total femoral and tibial osteophyte height and medial meniscal extrusion increased. A total of 29 patients (11.3%) were reclassified to higher Kellgren-Lawrence grades at 45° versus 20° flexion. High correlations were observed between radiographic and sonographic measurements. For differentiating Kellgren-Lawrence Grade 3 from 4, ultrasound joint space width at 45° flexion had a higher area under the curve (0.839, 95% confidence interval: 0.766–0.912; cutoff: 1.75 mm) than at 20° (0.825, 95% confidence interval: 0.745–0.905; cutoff: 1.95 mm). Conclusions: Sonographic joint space width measured at 20° and 45° knee flexion under standing weight-bearing conditions yielded AUC values similar to those obtained from weight-bearing radiographs for diagnosing medial compartment KOA. Ultrasound may act as a potential supplementary imaging alternative to conventional standing radiograph for grading the severity of medial compartment KOA.
SN - 1471-2342
ER -