{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T07:05:13Z","timestamp":1779433513232,"version":"3.53.1"},"reference-count":31,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T00:00:00Z","timestamp":1779408000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Bioeng. Biotechnol."],"abstract":"<jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>To characterize tibiofemoral contact mechanics in a rat knee under progressive varus loading, evaluate whether a statistical shape and appearance model (SSAM) can reproduce specimen-specific biomechanical behavior, and assess whether this meniscus-deficient computational-experimental framework can serve as a controlled preclinical platform for studying load redistribution.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Three-dimensional rat knee models were reconstructed from micro-CT images of 10 hind limbs from 5 male Sprague Dawley rats. Each limb model was alternately designated as the target, while the remaining limb models served as the training dataset for principal component analysis (PCA) to develop the SSAM. Finite element analysis (FEA) was used to assess maximum contact pressure and contact area in the medial and lateral compartments under simulated standing posture at 0%, 50%, and 100% varus loading. Because the finite element model did not include the menisci, experimental validation was performed in a matched meniscus-deficient setting using a custom biomechanical testing apparatus. Analysis of variance (ANOVA) was used to compare biomechanical outcomes among loading conditions and model types.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Both FEA and experimental results demonstrated consistent patterns in maximum contact pressure and contact area across varus loading levels. Compared with 0% varus, 50% and 100% varus loading increased medial maximum contact pressure and contact area by up to 0.55\u00a0MPa and 1.28\u00a0mm\n                      <jats:sup>2<\/jats:sup>\n                      , respectively. The lateral compartment showed reductions, with maximum decreases of 0.43\u00a0MPa and 1.76\u00a0mm\n                      <jats:sup>2<\/jats:sup>\n                      . No statistically significant differences were detected between the specimen-specific FEA models and the corresponding SSAM-predicted models across the tested loading conditions (P &amp;gt; 0.05).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Progressive varus loading shifted contact mechanics toward the medial compartment in both FEA and experimental tests, and the SSAM reproduced these trends with good agreement to specimen-specific models. These findings support the use of the present SSAM-FEA framework as a controlled biomechanical tool for investigating varus-induced contact redistribution in a rat meniscus-deficient knee. However, because the model excludes the menisci, uses simplified material assumptions, and applies static loading, the results should be interpreted primarily within a post-meniscectomy biomechanical context rather than as a direct surrogate for naturally occurring human knee osteoarthritis.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fbioe.2026.1741621","type":"journal-article","created":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T06:09:58Z","timestamp":1779430198000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["A validated SSAM-FEA framework for the rat knee reproduces varus-induced contact redistribution in a meniscus-deficient setting"],"prefix":"10.3389","volume":"14","author":[{"given":"Ke","family":"Lu","sequence":"first","affiliation":[{"name":"Department of Orthopedics, Affiliated Kunshan Hospital of Jiangsu University","place":["Suzhou, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu-Rong","family":"Tao","sequence":"additional","affiliation":[{"name":"School of Health Science and Engineering, University of Shanghai for Science and Technology","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shao-Han","family":"Guo","sequence":"additional","affiliation":[{"name":"Department of Orthopedics, Affiliated Kunshan Hospital of Jiangsu University","place":["Suzhou, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chong","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Orthopedics, Kunshan Hospital Affiliated to Nanjing University of Chinese Medicine","place":["Suzhou, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xue-Lian","family":"Gu","sequence":"additional","affiliation":[{"name":"School of Health Science and Engineering, University of Shanghai for Science and Technology","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bo","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,22]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"802","DOI":"10.1002\/jor.21359","article-title":"Post-traumatic osteoarthritis: improved understanding and opportunities for early intervention","volume":"29","author":"Anderson","year":"2011","journal-title":"J. Orthop. Res."},{"key":"B2","doi-asserted-by":"publisher","first-page":"101602","DOI":"10.1016\/j.bonr.2022.101602","article-title":"Contribution of joint tissue properties to load-induced osteoarthritis","volume":"17","author":"Ayobami","year":"2022","journal-title":"Bone Rep."},{"key":"B3","doi-asserted-by":"publisher","first-page":"979032","DOI":"10.1155\/2011\/979032","article-title":"Biomechanical influence of cartilage homeostasis in health and disease","volume":"2011","author":"Bader","year":"2011","journal-title":"Arthritis"},{"key":"B4","doi-asserted-by":"publisher","first-page":"967","DOI":"10.3389\/fbioe.2020.00967","article-title":"A review on finite element modeling and simulation of the anterior cruciate ligament reconstruction","volume":"8","author":"Benos","year":"2020","journal-title":"Front. Bioeng. Biotechnol."},{"key":"B5","doi-asserted-by":"publisher","first-page":"47","DOI":"10.1016\/j.medengphy.2019.02.009","article-title":"The effect of articular geometry features identified using statistical shape modelling on knee biomechanics","volume":"66","author":"Clouthier","year":"2019","journal-title":"Med. Eng. Phys."},{"key":"B6","doi-asserted-by":"publisher","first-page":"953","DOI":"10.1016\/j.jbiomech.2009.10.047","article-title":"Compressive axial mechanical properties of rat bone as functions of bone volume fraction, apparent density and micro-CT based mineral density","volume":"43","author":"Cory","year":"2010","journal-title":"J. Biomechanics"},{"key":"B7","doi-asserted-by":"publisher","first-page":"1419","DOI":"10.1016\/j.joca.2014.07.014","article-title":"Rapid, automated imaging of mouse articular cartilage by microCT for early detection of osteoarthritis and finite element modelling of joint mechanics","volume":"22","author":"Das Neves Borges","year":"2014","journal-title":"Osteoarthr. Cartil."},{"key":"B8","doi-asserted-by":"publisher","first-page":"109","DOI":"10.1243\/PIME_PROC_1996_210_399_02","article-title":"The influence of loading time and lubricant on the friction of articular cartilage","volume":"210","author":"Forster","year":"1996","journal-title":"Proc. Inst. Mech. Eng. H."},{"key":"B9","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1186\/s40634-020-00224-y","article-title":"Accuracy of 3D-planned patient specific instrumentation in high tibial open wedge valgisation osteotomy","volume":"7","author":"Fucentese","year":"2020","journal-title":"J. Exp. Orthop."},{"key":"B10","doi-asserted-by":"publisher","first-page":"041013","DOI":"10.1115\/1.4024541","article-title":"Finite element modeling of the contact geometry and deformation in biomechanics Applications1","volume":"8","author":"Gantoi","year":"2013","journal-title":"J. Comput. Nonlinear Dyn."},{"key":"B11","doi-asserted-by":"publisher","first-page":"1216","DOI":"10.1016\/j.jbiomech.2013.01.009","article-title":"Changes in in vitro compressive contact stress in the rat tibiofemoral joint with varus loading","volume":"46","author":"Gardner-Morse","year":"2013","journal-title":"J. Biomech."},{"key":"B12","doi-asserted-by":"publisher","first-page":"230","DOI":"10.1111\/j.1749-6632.2009.05240.x","article-title":"Articular cartilage and subchondral bone in the pathogenesis of osteoarthritis","volume":"1192","author":"Goldring","year":"2010","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"B13","doi-asserted-by":"publisher","first-page":"136","DOI":"10.1115\/1.3138397","article-title":"A joint coordinate system for the clinical description of three-dimensional motions: application to the knee","volume":"105","author":"Grood","year":"1983","journal-title":"J. Biomech. Eng."},{"key":"B14","doi-asserted-by":"publisher","first-page":"325","DOI":"10.1002\/jor.25358","article-title":"Assessment of reporting practices and reproducibility potential of a cohort of published studies in computational knee biomechanics","volume":"41","author":"Halloran","year":"2023","journal-title":"J. Orthop. Res."},{"key":"B15","doi-asserted-by":"publisher","first-page":"309","DOI":"10.3899\/jrheum.120589","article-title":"A new approach to prevention of knee osteoarthritis: reducing medial load in the contralateral knee","volume":"40","author":"Jones","year":"2013","journal-title":"J. Rheumatol."},{"key":"B16","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1302\/2046-3758.71.BJR-2017-0143.R1","article-title":"A computational simulation study to determine the biomechanical influence of posterior condylar offset and tibial slope in cruciate retaining total knee arthroplasty","volume":"7","author":"Kang","year":"2018","journal-title":"Bone Jt. Res."},{"key":"B17","doi-asserted-by":"publisher","first-page":"1472","DOI":"10.1002\/jor.23763","article-title":"Sagittal plane walking patterns are related to MRI changes over 18-months in people with and without mild-moderate hip osteoarthritis","volume":"36","author":"Kumar","year":"2018","journal-title":"J. Orthop. Res."},{"key":"B18","doi-asserted-by":"publisher","first-page":"115","DOI":"10.1016\/j.apmr.2020.04.001","article-title":"A systematic review of the incidence, prevalence, costs, and activity and work limitations of amputation, osteoarthritis, rheumatoid arthritis, back pain, multiple sclerosis, spinal cord injury, stroke, and traumatic brain injury in the United States: a 2019 update","volume":"102","author":"Lo","year":"2021","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"B19","doi-asserted-by":"publisher","first-page":"1172","DOI":"10.1002\/art.42089","article-title":"Prevalence trends of site-specific osteoarthritis from 1990 to 2019: findings from the global burden of disease study 2019","volume":"74","author":"Long","year":"2022","journal-title":"Arthritis Rheumatol."},{"key":"B20","doi-asserted-by":"publisher","first-page":"1529","DOI":"10.1002\/jor.24661","article-title":"Similitude of cement-bone micromechanics in cemented rat and human knee replacement","volume":"38","author":"Mann","year":"2020","journal-title":"J. Orthop. Res."},{"key":"B21","doi-asserted-by":"publisher","first-page":"e1009398","DOI":"10.1371\/journal.pcbi.1009398","article-title":"A musculoskeletal finite element model of rat knee joint for evaluating cartilage biomechanics during gait","volume":"18","author":"Orozco","year":"2022","journal-title":"PLoS Comput. Biol."},{"key":"B22","doi-asserted-by":"publisher","first-page":"13","DOI":"10.1016\/0021-9290(94)90028-0","article-title":"The mechanical properties of the two bundles of the human posterior cruciate ligament","volume":"27","author":"Race","year":"1994","journal-title":"J. Biomech."},{"key":"B23","doi-asserted-by":"publisher","first-page":"110","DOI":"10.26502\/josm.511500187","article-title":"Advancing osteoarthritis research: insights from rodent models and emerging trends","volume":"7","author":"Rajalekshmi","year":"2025","journal-title":"J. Orthop. Sports Med."},{"key":"B24","doi-asserted-by":"publisher","first-page":"346","DOI":"10.1016\/j.joca.2012.10.014","article-title":"Chronic in vivo load alteration induces degenerative changes in the rat tibiofemoral joint","volume":"21","author":"Roemhildt","year":"2013","journal-title":"Osteoarthr. Cartil."},{"key":"B25","doi-asserted-by":"publisher","first-page":"1562","DOI":"10.1002\/jor.20936","article-title":"Baseline articular contact stress levels predict incident symptomatic knee osteoarthritis development in the MOST cohort","volume":"27","author":"Segal","year":"2009","journal-title":"J. Orthop. Res."},{"key":"B26","doi-asserted-by":"publisher","first-page":"813","DOI":"10.1016\/j.knee.2019.06.002","article-title":"The influence of knee joint geometry and alignment on the tibiofemoral load distribution: a computational study","volume":"26","author":"Van Rossom","year":"2019","journal-title":"Knee"},{"key":"B27","doi-asserted-by":"publisher","first-page":"e18472","DOI":"10.1111\/jcmm.18472","article-title":"Excessive load promotes temporomandibular joint chondrocyte apoptosis via Piezo1\/endoplasmic reticulum stress pathway","volume":"28","author":"Wang","year":"2024","journal-title":"J. Cell Mol. Med."},{"key":"B28","doi-asserted-by":"publisher","first-page":"217","DOI":"10.1177\/036354659101900303","article-title":"Tensile properties of the human femur-anterior cruciate ligament-tibia complex. The effects of specimen age and orientation","volume":"19","author":"Woo","year":"1991","journal-title":"Am. J. Sports Med."},{"key":"B29","doi-asserted-by":"publisher","first-page":"543","DOI":"10.1016\/s0021-9290(01)00222-6","article-title":"ISB recommendation on definitions of joint coordinate system of various joints for the reporting of human joint motion--part I: ankle, hip, and spine. International society of biomechanics","volume":"35","author":"Wu","year":"2002","journal-title":"J. Biomech."},{"key":"B30","doi-asserted-by":"publisher","first-page":"676","DOI":"10.1136\/annrheumdis-2021-221513","article-title":"Mechanical overloading promotes chondrocyte senescence and osteoarthritis development through downregulating FBXW7","volume":"81","author":"Zhang","year":"2022","journal-title":"Ann. Rheum. Dis."},{"key":"B31","doi-asserted-by":"publisher","first-page":"54","DOI":"10.1186\/s13075-023-03037-3","article-title":"Mechanical overloading-induced miR-325-3p reduction promoted chondrocyte senescence and exacerbated facet joint degeneration","volume":"25","author":"Zhao","year":"2023","journal-title":"Arthritis Res. Ther."}],"container-title":["Frontiers in Bioengineering and Biotechnology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2026.1741621\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T06:09:59Z","timestamp":1779430199000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2026.1741621\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,22]]},"references-count":31,"alternative-id":["10.3389\/fbioe.2026.1741621"],"URL":"https:\/\/doi.org\/10.3389\/fbioe.2026.1741621","relation":{},"ISSN":["2296-4185"],"issn-type":[{"value":"2296-4185","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,22]]},"article-number":"1741621"}}