REVIEW article
Front. Bioeng. Biotechnol.
Sec. Biomechanics
This article is part of the Research TopicAddressing Aging-related Orthopaedic Disorders: Innovative Strategies for Spine and Joint HealthView all 6 articles
The Mediating Role of Sacral Slope in the Relationship between Lumbar Lordosis and Knee Alignment in Knee Osteoarthritis: An Imaging Study
Provisionally accepted
Binghua Zhang*
Youyue Pang
Yicong Bai
Shilin Yin
Yuntao Yan
Xi LiXiang Wang
Yongwang ZhangChang Wang
Shuang Qing Du- Hebei Province Traditional Chinese Medicine Hospital, Hebei, China
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Objective: This study aimed to investigate the association between lumbar lordosis (LL) and the sagittal hip-knee-ankle angle (sHKA) in patients with knee osteoarthritis (KOA) and to quantify the mediating effect of the sacral slope (SS). Methods: This study enrolled 507 participants (left-side 302, right-side 205). Lateral full-length X-ray films of the lower extremities in weight-bearing position were collected from the research participants to measure radiological parameters such as lumbar lordosis (LL), sacral slope (SS), and sagittal hip-knee-ankle angle (sHKA), and SF-12(12-items Short Form Health Survey) and WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scores were also collected. Correlation analysis and Bootstrap mediation effect analysis were performed. Results: Among the 507 KOA participants, LL was positively correlated with SS, HKA, sHKA, and SF-12 scores, and negatively correlated with JLCA and WOMAC scores. The mediation analysis revealed that SS accounted for 10.74% of the total association of LL on sHKA. Conclusion: In patients with KOA, LL is closely related to sHKA, and this statistical association may be partially mediated by SS. This highlights the importance of adopting a "spine-pelvis-knee" perspective when assessing and treating KOA.
Keywords: Imaging study, knee osteoarthritis, Mediation, Sacral slope, Sagittal force line
Received: 04 Dec 2025; Accepted: 28 Jan 2026.
Copyright: © 2026 Zhang, Pang, Bai, Yin, Yan, Li, Wang, Zhang, Wang and Du. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Binghua Zhang
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