{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T00:32:12Z","timestamp":1793233932446,"version":"4.5.0"},"reference-count":99,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T00:00:00Z","timestamp":1772496000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82172447"],"award-info":[{"award-number":["82172447"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Beijing Natural Science Foundation Haidian Joint Project","award":["24L20439"],"award-info":[{"award-number":["24L20439"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Osteoarthritis (OA) is a prevalent degenerative joint disease which affects millions of patients across the globe. The infrapatellar fat pad (IPFP) harbors diverse cell types with intricate intercellular interactions. Its mesenchymal stem cells (MSCs) and extracellular vesicles (EVs) possess significant biological functions and hold promising applications in regenerative medicine. IPFP exhibits active secretory capacity, releasing adipokines including leptin and adiponectin, along with various cytokines. Furthermore, it contains a rich neural network playing a crucial role in knee pain perception and sensation. Moreover, IPFP and synovium can be considered an integrated unit, exhibiting interactions both with each other and with cartilage. In imaging applications, IPFP is gaining widespread attention as an emerging biomarker. In clinical practice, the decision to resect or preserve IPFP remains a controversial topic. This article will review the latest research regarding the mechanism of IPFP in OA, and discuss its clinical applications, providing a theoretical basis for the prevention and treatment of OA.<\/jats:p>","DOI":"10.3390\/ijms27052369","type":"journal-article","created":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T15:22:21Z","timestamp":1772551341000},"page":"2369","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["The Infrapatellar Fat Pad in Osteoarthritis: From Pathophysiology to a Novel Therapeutic Target"],"prefix":"10.3390","volume":"27","author":[{"given":"Qianshuo","family":"Wang","sequence":"first","affiliation":[{"name":"Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dingge","family":"Liu","sequence":"additional","affiliation":[{"name":"Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-9729-8361","authenticated-orcid":false,"given":"Fan","family":"Hu","sequence":"additional","affiliation":[{"name":"Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Langran","family":"Wang","sequence":"additional","affiliation":[{"name":"Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhihua","family":"Zhang","sequence":"additional","affiliation":[{"name":"Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuhao","family":"Yan","sequence":"additional","affiliation":[{"name":"Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Zhang","sequence":"additional","affiliation":[{"name":"Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1007\/s00167-004-0592-7","article-title":"The infrapatellar fat pad: Anatomy and clinical correlations","volume":"13","author":"Gallagher","year":"2005","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"117364","DOI":"10.1016\/j.biopha.2024.117364","article-title":"The biphasic role of the infrapatellar fat pad in osteoarthritis","volume":"179","author":"Yue","year":"2024","journal-title":"Biomed. Pharmacother."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1038\/s41514-024-00159-z","article-title":"The infrapatellar fat pad in inflammaging, knee joint health, and osteoarthritis","volume":"10","author":"Wang","year":"2024","journal-title":"NPJ Aging"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jmbbm.2016.11.024","article-title":"Investigation of biomechanical response of Hoffa\u2019s fat pad and comparative characterization","volume":"67","author":"Fontanella","year":"2017","journal-title":"J. Mech. Behav. Biomed. Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"51","DOI":"10.2165\/11595680-000000000-00000","article-title":"Evaluation and treatment of disorders of the infrapatellar fat pad","volume":"42","author":"Dragoo","year":"2012","journal-title":"Sports Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1097\/BOR.0000000000000763","article-title":"Role of adipose tissues in osteoarthritis","volume":"33","author":"Eymard","year":"2021","journal-title":"Curr. Opin. Rheumatol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1136\/ard-2024-225928","article-title":"Cell and transcriptomic diversity of infrapatellar fat pad during knee osteoarthritis","volume":"84","author":"Peters","year":"2025","journal-title":"Ann. Rheum. Dis."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"455","DOI":"10.1136\/annrheumdis-2011-200372","article-title":"Leptin produced by joint white adipose tissue induces cartilage degradation via upregulation and activation of matrix metalloproteinases","volume":"71","author":"Hui","year":"2012","journal-title":"Ann. Rheum. Dis."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Wisniewska, E., Laue, D., Spinnen, J., Kuhrt, L., Kohl, B., Bu\u00dfmann, P., Meier, C., Schulze-Tanzil, G., Ertel, W., and Jagielski, M. (2023). Infrapatellar Fat Pad Modulates Osteoarthritis-Associated Cytokine and MMP Expression in Human Articular Chondrocytes. Cells, 12.","DOI":"10.3390\/cells12242850"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Emmi, A., Stocco, E., Boscolo-Berto, R., Contran, M., Belluzzi, E., Favero, M., Ramonda, R., Porzionato, A., Ruggieri, P., and De Caro, R. (2022). Infrapatellar Fat Pad-Synovial Membrane Anatomo-Fuctional Unit: Microscopic Basis for Piezo1\/2 Mechanosensors Involvement in Osteoarthritis Pain. Front. Cell Dev. Biol., 10.","DOI":"10.3389\/fcell.2022.886604"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"146","DOI":"10.1111\/joa.12820","article-title":"The infrapatellar fat pad and the synovial membrane: An anatomo-functional unit","volume":"233","author":"Macchi","year":"2018","journal-title":"J. Anat."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.joca.2021.04.020","article-title":"Epidemiology of osteoarthritis","volume":"30","author":"Allen","year":"2022","journal-title":"Osteoarthr. Cartil."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"102100","DOI":"10.1016\/j.mtbio.2025.102100","article-title":"Immunomodulatory biomaterials for osteoarthritis: Targeting inflammation and enhancing cartilage regeneration","volume":"34","author":"Zhao","year":"2025","journal-title":"Mater. Today Bio"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"16072","DOI":"10.1038\/nrdp.2016.72","article-title":"Osteoarthritis","volume":"2","author":"Barr","year":"2016","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1186\/s13075-020-02261-5","article-title":"Meniscal and ligament modifications in spontaneous and post-traumatic mouse models of osteoarthritis","volume":"22","author":"Javaheri","year":"2020","journal-title":"Arthritis Res. Ther."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1093\/jbmr\/zjad009","article-title":"Synovium and infrapatellar fat pad share common mesenchymal progenitors and undergo coordinated changes in osteoarthritis","volume":"39","author":"Li","year":"2024","journal-title":"J. Bone Min. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1397","DOI":"10.1016\/j.joca.2024.07.014","article-title":"Osteoarthritis year in review 2024: Epidemiology and therapy","volume":"32","author":"Courties","year":"2024","journal-title":"Osteoarthr. Cartil."},{"key":"ref_18","unstructured":"(2023). Global, regional, and national burden of osteoarthritis, 1990\u20132020 and projections to 2050: A systematic analysis for the Global Burden of Disease Study 2021. Lancet Rheumatol., 5, e508\u2013e522."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"112950","DOI":"10.1016\/j.exger.2025.112950","article-title":"Exploring senescence markers as potential drivers of osteoarthritis pain in aging adults","volume":"212","author":"Abbas","year":"2025","journal-title":"Exp. Gerontol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1659","DOI":"10.1136\/annrheumdis-2013-203355","article-title":"Incidence and risk factors for clinically diagnosed knee, hip and hand osteoarthritis: Influences of age, gender and osteoarthritis affecting other joints","volume":"73","author":"Judge","year":"2014","journal-title":"Ann. Rheum. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1016\/j.jphys.2021.08.009","article-title":"Knee osteoarthritis","volume":"67","author":"Goff","year":"2021","journal-title":"J. Physiother."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"272","DOI":"10.1080\/03008207.2025.2502591","article-title":"Mechanical insights into fat pads: A comparative study of infrapatellar and suprapatellar fat pads in osteoarthritis","volume":"66","author":"Pettenuzzo","year":"2025","journal-title":"Connect. Tissue Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1186\/s13075-025-03517-8","article-title":"Infrapatellar fat pad as a source of biomarkers and therapeutic target for knee osteoarthritis","volume":"27","author":"Emanuel","year":"2025","journal-title":"Arthritis Res. Ther."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1016\/j.jbspin.2016.02.016","article-title":"Inflammation of the infrapatellar fat pad","volume":"83","author":"Eymard","year":"2016","journal-title":"Jt. Bone Spine"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Uekusa, Y., Mukai, M., Tsukada, A., Iwase, D., Aikawa, J., Shibata, N., Ohashi, Y., Inoue, G., Takaso, M., and Uchida, K. (2024). Elevated Netrin-4 Expression and Its Action in Infrapatellar Fat Pad. Int. J. Mol. Sci., 25.","DOI":"10.3390\/ijms252111369"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"e2303614","DOI":"10.1002\/advs.202303614","article-title":"Extracellular Vesicles in Infrapatellar Fat Pad from Osteoarthritis Patients Impair Cartilage Metabolism and Induce Senescence","volume":"11","author":"Cao","year":"2024","journal-title":"Adv. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"102851","DOI":"10.1016\/j.tice.2025.102851","article-title":"Fibrosis of the infrapatellar fat pad induces gradual cartilage degeneration in a rat model","volume":"95","author":"Terada","year":"2025","journal-title":"Tissue Cell"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Li, Z., Huang, Z., and Bai, L. (2021). Cell Interplay in Osteoarthritis. Front. Cell Dev. Biol., 9.","DOI":"10.3389\/fcell.2021.720477"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Belluzzi, E., Macchi, V., Fontanella, C.G., Carniel, E.L., Olivotto, E., Filardo, G., Sarasin, G., Porzionato, A., Granzotto, M., and Pozzuoli, A. (2020). Infrapatellar Fat Pad Gene Expression and Protein Production in Patients with and without Osteoarthritis. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21176016"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"eadf4590","DOI":"10.1126\/scitranslmed.adf4590","article-title":"Single-cell atlas of human infrapatellar fat pad and synovium implicates APOE signaling in osteoarthritis pathology","volume":"16","author":"Tang","year":"2024","journal-title":"Sci. Transl. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"111888","DOI":"10.1016\/j.intimp.2024.111888","article-title":"Single cell transcriptome profiling of infrapatellar fat pad highlights the role of interstitial inflammatory fibroblasts in osteoarthritis","volume":"131","author":"Pu","year":"2024","journal-title":"Int. Immunopharmacol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"7841","DOI":"10.1073\/pnas.141221698","article-title":"Identification of a subpopulation of rapidly self-renewing and multipotential adult stem cells in colonies of human marrow stromal cells","volume":"98","author":"Colter","year":"2001","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Hade, M.D., Suire, C.N., and Suo, Z. (2021). Mesenchymal Stem Cell-Derived Exosomes: Applications in Regenerative Medicine. Cells, 10.","DOI":"10.3390\/cells10081959"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"3609","DOI":"10.1038\/s41598-022-07569-7","article-title":"Human infrapatellar fat pad mesenchymal stem cells show immunomodulatory exosomal signatures","volume":"12","author":"Kouroupis","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"334","DOI":"10.1186\/s13287-023-03532-z","article-title":"The influence of inflammation on the characteristics of adipose-derived mesenchymal stem cells (ADMSCs) and tissue repair capability in a hepatic injury mouse model","volume":"14","author":"Xiao","year":"2023","journal-title":"Stem Cell Res. Ther."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"10864","DOI":"10.1038\/s41598-019-47391-2","article-title":"Infrapatellar fat pad-derived MSC response to inflammation and fibrosis induces an immunomodulatory phenotype involving CD10-mediated Substance P degradation","volume":"9","author":"Kouroupis","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"122296","DOI":"10.1016\/j.biomaterials.2023.122296","article-title":"Converse modulation of Wnt\/\u03b2-catenin signaling during expansion and differentiation phases of Infrapatellar fat pad-derived MSCs for improved engineering of hyaline cartilage","volume":"302","author":"Mahajan","year":"2023","journal-title":"Biomaterials"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"298","DOI":"10.22203\/eCM.v027a21","article-title":"Donor-matched mesenchymal stem cells from knee infrapatellar and subcutaneous adipose tissue of osteoarthritic donors display differential chondrogenic and osteogenic commitment","volume":"27","author":"Lopa","year":"2014","journal-title":"Eur. Cell Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1186\/s12964-021-00815-x","article-title":"Infrapatellar fat pad adipose-derived stem cells co-cultured with articular chondrocytes from osteoarthritis patients exhibit increased chondrogenic gene expression","volume":"20","author":"Mak","year":"2022","journal-title":"Cell Commun. Signal."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1186\/s41232-025-00381-6","article-title":"Stem cell modelling of osteoarthritis using an organ-on-a-chip approach","volume":"45","author":"Fischer","year":"2025","journal-title":"Inflamm. Regen."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"3432","DOI":"10.1021\/acs.biomac.5c00048","article-title":"Hydrostatic Pressure Enhances Chondrogenic Differentiation of Mesenchymal Stem Cells in Silk Fibroin-Based 3D Bioprinted Hydrogels","volume":"26","author":"Fritz","year":"2025","journal-title":"Biomacromolecules"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"688","DOI":"10.1186\/s13287-025-04783-8","article-title":"Mesenchymal stem cells and extracellular vesicles for knee osteoarthritis: Clinical application, mechanism exploration and prospect","volume":"16","author":"Li","year":"2025","journal-title":"Stem Cell Res. Ther."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1038\/s41413-025-00484-3","article-title":"Bibliometric and LDA analysis of extracellular vesicles in osteoarthritis","volume":"13","author":"Xie","year":"2025","journal-title":"Bone Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1177\/03635465211072227","article-title":"Infrapatellar Fat Pad Mesenchymal Stromal Cell\u2013Derived Exosomes Accelerate Tendon-Bone Healing and Intra-articular Graft Remodeling After Anterior Cruciate Ligament Reconstruction","volume":"50","author":"Xu","year":"2022","journal-title":"Am. J. Sports Med."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1186\/s12951-024-02795-9","article-title":"Engineering exosomes derived from TNF-\u03b1 preconditioned IPFP-MSCs enhance both yield and therapeutic efficacy for osteoarthritis","volume":"22","author":"Wu","year":"2024","journal-title":"J. Nanobiotechnol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1186\/s13287-024-03681-9","article-title":"Culture of Hoffa fat pad mesenchymal stem\/stromal cells on microcarrier suspension in vertical wheel bioreactor for extracellular vesicle production","volume":"15","author":"Otahal","year":"2024","journal-title":"Stem Cell Res. Ther."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1246","DOI":"10.1097\/CORR.0000000000003067","article-title":"Human Infrapatellar Fat Pad Mesenchymal Stem Cell\u2013derived Extracellular Vesicles Purified by Anion Exchange Chromatography Suppress Osteoarthritis Progression in a Mouse Model","volume":"482","author":"Liu","year":"2024","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Kouroupis, D., Kaplan, L.D., Huard, J., and Best, T.M. (2023). CD10-Bound Human Mesenchymal Stem\/Stromal Cell-Derived Small Extracellular Vesicles Possess Immunomodulatory Cargo and Maintain Cartilage Homeostasis under Inflammatory Conditions. Cells, 12.","DOI":"10.20944\/preprints202305.1465.v1"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Philippon, M., Labib, R., Ley, M.B.R.G., Kaplan, L.D., Mendez, A.J., Best, T.M., and Kouroupis, D. (2025). Characterization of Extracellular Vesicles from Infrapatellar Fat Pad Mesenchymal Stem\/Stromal Cells Expanded Using Regulatory-Compliant Media and Inflammatory\/Hormonal Priming. Cells, 14.","DOI":"10.3390\/cells14100706"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"6624874","DOI":"10.1155\/2021\/6624874","article-title":"Exosomes from Kartogenin-Pretreated Infrapatellar Fat Pad Mesenchymal Stem Cells Enhance Chondrocyte Anabolism and Articular Cartilage Regeneration","volume":"2021","author":"Shao","year":"2021","journal-title":"Stem Cells Int."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Liebmann, K., Castillo, M.A., Jergova, S., Best, T.M., Sagen, J., and Kouroupis, D. (2024). Modification of Mesenchymal Stem\/Stromal Cell-Derived Small Extracellular Vesicles by Calcitonin Gene Related Peptide (CGRP) Antagonist: Potential Implications for Inflammation and Pain Reversal. Cells, 13.","DOI":"10.3390\/cells13060484"},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Stocco, E., Barbon, S., Piccione, M., Belluzzi, E., Petrelli, L., Pozzuoli, A., Ramonda, R., Rossato, M., Favero, M., and Ruggieri, P. (2019). Infrapatellar Fat Pad Stem Cells Responsiveness to Microenvironment in Osteoarthritis: From Morphology to Function. Front. Cell Dev. Biol., 7.","DOI":"10.3389\/fcell.2019.00323"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1784","DOI":"10.1093\/rheumatology\/kex287","article-title":"Infrapatellar fat pad features in osteoarthritis: A histopathological and molecular study","volume":"56","author":"Favero","year":"2017","journal-title":"Rheumatology"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"1317","DOI":"10.14336\/AD.2019.1116","article-title":"Infrapatellar Fat Pad and Knee Osteoarthritis","volume":"11","author":"Zeng","year":"2020","journal-title":"Aging Dis."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"eadt5915","DOI":"10.1126\/sciadv.adt5915","article-title":"Adipose-derived leptin and complement factor D mediate osteoarthritis severity and pain","volume":"11","author":"Collins","year":"2025","journal-title":"Sci. Adv."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1007\/s11926-019-0868-z","article-title":"Adipokines: New Therapeutic Target for Osteoarthritis?","volume":"21","author":"Xie","year":"2019","journal-title":"Curr. Rheumatol. Rep."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"2808","DOI":"10.1093\/rheumatology\/keaa719","article-title":"Causal association of adipokines with osteoarthritis: A Mendelian randomization study","volume":"60","author":"Fan","year":"2021","journal-title":"Rheumatology"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"e2021096118","DOI":"10.1073\/pnas.2021096118","article-title":"Adipose tissue is a critical regulator of osteoarthritis","volume":"118","author":"Collins","year":"2021","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"101159","DOI":"10.1016\/j.gendis.2023.101159","article-title":"Novel perspectives on leptin in osteoarthritis: Focus on aging","volume":"11","author":"Liu","year":"2024","journal-title":"Genes. Dis."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"155043","DOI":"10.1016\/j.cyto.2020.155043","article-title":"An update on the association between metabolic syndrome and osteoarthritis and on the potential role of leptin in osteoarthritis","volume":"129","author":"Gao","year":"2020","journal-title":"Cytokine"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1186\/s13287-025-04342-1","article-title":"Modulation of senescent Lepr(+) skeletal stem cells via suppression of leptin-induced STAT3-FGF7 axis activation alleviates abnormal subchondral bone remodeling and osteoarthritis progression","volume":"16","author":"Yu","year":"2025","journal-title":"Stem Cell Res. Ther."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.1038\/s41551-024-01238-y","article-title":"Prevention and treatment of peri-implant fibrosis by functionally inhibiting skeletal cells expressing the leptin receptor","volume":"8","author":"Suhardi","year":"2024","journal-title":"Nat. Biomed. Eng."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1652","DOI":"10.1093\/rheumatology\/keac467","article-title":"Metformin attenuates osteoarthritis by targeting chondrocytes, synovial macrophages and adipocytes","volume":"62","author":"Li","year":"2023","journal-title":"Rheumatology"},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"1761","DOI":"10.1016\/j.joca.2019.08.003","article-title":"The role of leptin and adiponectin as mediators in the relationship between adiposity and hand and knee osteoarthritis","volume":"27","author":"Kroon","year":"2019","journal-title":"Osteoarthr. Cartil."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1492","DOI":"10.1002\/jor.25347","article-title":"Source and hub of inflammation: The infrapatellar fat pad and its interactions with articular tissues during knee osteoarthritis","volume":"40","author":"Zhou","year":"2022","journal-title":"J. Orthop. Res."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1177\/03635465980260060601","article-title":"Conscious neurosensory mapping of the internal structures of the human knee without intraarticular anesthesia","volume":"26","author":"Dye","year":"1998","journal-title":"Am. J. Sports Med."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1016\/j.joca.2015.09.018","article-title":"Magnetic resonance imaging of Hoffa\u2019s fat pad and relevance for osteoarthritis research: A narrative review","volume":"24","author":"Roemer","year":"2016","journal-title":"Osteoarthr. Cartil."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"592","DOI":"10.1007\/s00402-005-0796-4","article-title":"Distribution of substance-P nerves inside the infrapatellar fat pad and the adjacent synovial tissue: A neurohistological approach to anterior knee pain syndrome","volume":"125","author":"Bohnsack","year":"2005","journal-title":"Arch. Orthop. Trauma. Surg."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"1218","DOI":"10.1126\/science.2457950","article-title":"Effect of neuropeptides on production of inflammatory cytokines by human monocytes","volume":"241","author":"Lotz","year":"1988","journal-title":"Science"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"eadk3506","DOI":"10.1126\/scitranslmed.adk3506","article-title":"Synovial fibroblast gene expression is associated with sensory nerve growth and pain in rheumatoid arthritis","volume":"16","author":"Bai","year":"2024","journal-title":"Sci. Transl. Med."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"771","DOI":"10.3899\/jrheum.151068","article-title":"Inflammatory Cells in Patients with Endstage Knee Osteoarthritis: A Comparison between the Synovium and the Infrapatellar Fat Pad","volume":"43","author":"Yusuf","year":"2016","journal-title":"J. Rheumatol."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"2165","DOI":"10.1002\/art.38657","article-title":"Induction of an inflammatory and prodegradative phenotype in autologous fibroblast-like synoviocytes by the infrapatellar fat pad from patients with knee osteoarthritis","volume":"66","author":"Eymard","year":"2014","journal-title":"Arthritis Rheumatol."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"e2300897","DOI":"10.1002\/advs.202300897","article-title":"Blockage of Osteopontin-Integrin \u03b23 Signaling in Infrapatellar Fat Pad Attenuates Osteoarthritis in Mice","volume":"10","author":"Dai","year":"2023","journal-title":"Adv. Sci."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"1129","DOI":"10.1007\/s00011-021-01503-9","article-title":"Osteoarthritic infrapatellar fat pad aggravates cartilage degradation via activation of p38MAPK and ERK1\/2 pathways","volume":"70","author":"Zhou","year":"2021","journal-title":"Inflamm. Res."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"544","DOI":"10.1016\/j.joca.2019.12.007","article-title":"The role of macrophages in osteoarthritis and cartilage repair","volume":"28","author":"Wu","year":"2020","journal-title":"Osteoarthr. Cartil."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"1396","DOI":"10.1002\/art.40102","article-title":"Regional Differences Between Perisynovial and Infrapatellar Adipose Tissue Depots and Their Response to Class II and Class III Obesity in Patients with Osteoarthritis","volume":"69","author":"Harasymowicz","year":"2017","journal-title":"Arthritis Rheumatol."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1186\/s13075-016-0983-4","article-title":"From osteoarthritic synovium to synovial-derived cells characterization: Synovial macrophages are key effector cells","volume":"18","author":"Manferdini","year":"2016","journal-title":"Arthritis Res. Ther."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1038\/s41413-024-00375-z","article-title":"Cross-talk of inflammation and cellular senescence: A new insight into the occurrence and progression of osteoarthritis","volume":"12","author":"Han","year":"2024","journal-title":"Bone Res."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.joca.2025.11.004","article-title":"Osteoarthritis year in review 2025: Imaging","volume":"34","author":"Harkey","year":"2026","journal-title":"Osteoarthr. Cartil."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1186\/s13075-025-03513-y","article-title":"Comprehensive comparative analysis of infrapatellar fat pad morphologies in a longitudinal knee osteoarthritis exploratory study: New insights into its role as an independent prognostic marker","volume":"27","author":"Pelletier","year":"2025","journal-title":"Arthritis Res. Ther."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1186\/s13075-024-03367-w","article-title":"Infrapatellar fat pad size and subcutaneous fat in knee osteoarthritis radiographic progression: Data from the osteoarthritis initiative","volume":"26","author":"Lee","year":"2024","journal-title":"Arthritis Res. Ther."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"4718","DOI":"10.1007\/s00330-022-08561-5","article-title":"Quantitative MR evaluation of the infrapatellar fat pad for knee osteoarthritis: Using proton density fat fraction and T2* relaxation based on DIXON","volume":"32","author":"Chen","year":"2022","journal-title":"Eur. Radiol."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"e002565","DOI":"10.1136\/rmdopen-2022-002565","article-title":"Quantitative infrapatellar fat pad signal intensity alteration as an imaging biomarker of knee osteoarthritis progression","volume":"9","author":"Cen","year":"2023","journal-title":"RMD Open"},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"5428","DOI":"10.1093\/rheumatology\/keaf319","article-title":"MRI-based patient-specific nomogram for diagnostic risk stratification of patients with early knee OA","volume":"64","author":"Yang","year":"2025","journal-title":"Rheumatology"},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"103534","DOI":"10.1016\/j.eclinm.2025.103534","article-title":"Development of a multi-task deep learning system for classification of nine common knee abnormalities on MRI: A large-scale, multicentre, stepwise validation study","volume":"89","author":"Xie","year":"2025","journal-title":"EClinicalMedicine"},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"20103","DOI":"10.1038\/s41598-023-47459-0","article-title":"Association between infrapatellar fat pad ultrasound elasticity and anterior knee pain in patients with knee osteoarthritis","volume":"13","author":"Satake","year":"2023","journal-title":"Sci. Rep."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1148\/radiol.212009","article-title":"MRI-based Texture Analysis of Infrapatellar Fat Pad to Predict Knee Osteoarthritis Incidence","volume":"304","author":"Li","year":"2022","journal-title":"Radiology"},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"6037","DOI":"10.1016\/j.acra.2025.07.024","article-title":"Histogram Parameters of the Infrapatellar Fat Pad Fat Fraction: Associations with Radiographic Severity of Knee Osteoarthritis","volume":"32","author":"Zhao","year":"2025","journal-title":"Acad. Radiol."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"876","DOI":"10.1016\/j.joca.2010.03.014","article-title":"The infrapatellar fat pad should be considered as an active osteoarthritic joint tissue: A narrative review","volume":"18","author":"Clockaerts","year":"2010","journal-title":"Osteoarthr. Cartil."},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"282","DOI":"10.1186\/s13075-022-02971-y","article-title":"Early removal of the infrapatellar fat pad\/synovium complex beneficially alters the pathogenesis of moderate stage idiopathic knee osteoarthritis in male Dunkin Hartley guinea pigs","volume":"24","author":"Afzali","year":"2022","journal-title":"Arthritis Res. Ther."},{"key":"ref_91","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.knee.2025.02.012","article-title":"Resection of pathologically altered infrapatellar fat pads during total knee arthroplasty has a positive impact on postoperative knee function","volume":"54","author":"Xu","year":"2025","journal-title":"Knee"},{"key":"ref_92","doi-asserted-by":"crossref","unstructured":"Park, Y.C., Kim, Y.M., and Joo, Y.B. (2025). Arthroscopic Resection of Infrapatellar Fat Pad Impingement Syndrome: Long-Term Clinical Results at Minimum 10-Year Follow-Up. Medicina, 61.","DOI":"10.3390\/medicina61060997"},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1186\/s13018-024-05114-y","article-title":"Partial excision of infrapatellar fat pad for the treatment of knee osteoarthritis","volume":"19","author":"Liu","year":"2024","journal-title":"J. Orthop. Surg. Res."},{"key":"ref_94","doi-asserted-by":"crossref","unstructured":"Chaiyakit, P., Petcharat, B., and Onklin, I. (2025). Preservation of the infrapatellar fat pad during total knee arthroplasty reduces subacute postoperative anterior knee pain: A randomized controlled trial. BMC Musculoskelet. Disord., 26.","DOI":"10.1186\/s12891-025-09003-1"},{"key":"ref_95","doi-asserted-by":"crossref","unstructured":"Skaik, K., Oulousian, S., Lameire, D.L., Abbas, A., Khalik, H.A., Al-Obaedi, O., and Ravi, B. (2025). Excision Versus Preservation of the Infrapatellar Fat Pad During Total Knee Arthroplasty: A Systematic Review and Meta-Analysis. J. Arthroplast., in press.","DOI":"10.1016\/j.arth.2025.12.015"},{"key":"ref_96","doi-asserted-by":"crossref","unstructured":"Ye, C., Zhang, W., Wu, W., Xu, M., Nonso, N.S., and He, R. (2016). Influence of the Infrapatellar Fat Pad Resection during Total Knee Arthroplasty: A Systematic Review and Meta-Analysis. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0163515"},{"key":"ref_97","doi-asserted-by":"crossref","unstructured":"Michalak, S., \u0141apaj, \u0141., Witkowska-\u0141uczak, A., Chod\u00f3r, P., Zabrzy\u0144ski, J., and Kruczy\u0144ski, J. (2022). Resection of Infrapatellar Fat Pad during Total Knee Arthroplasty Has No Impact on Postoperative Function, Pain and Sonographic Appearance of Patellar Tendon. J. Clin. Med., 11.","DOI":"10.3390\/jcm11247339"},{"key":"ref_98","doi-asserted-by":"crossref","first-page":"ldaf010","DOI":"10.1093\/bmb\/ldaf010","article-title":"Retention of the infrapatellar fat pad does not influence the outcome of total knee arthroplasty: A systematic review","volume":"155","author":"Maffulli","year":"2025","journal-title":"Br. Med. Bull."},{"key":"ref_99","doi-asserted-by":"crossref","first-page":"3657","DOI":"10.1007\/s00402-024-05503-2","article-title":"Hoffa\u2019s fat pad resection during total knee arthroplasty does not affect functioning and gait: A double-blind randomized clinical trial","volume":"144","author":"Benner","year":"2024","journal-title":"Arch. Orthop. Trauma. Surg."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/5\/2369\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T15:22:58Z","timestamp":1772551378000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/5\/2369"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,3]]},"references-count":99,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["ijms27052369"],"URL":"https:\/\/doi.org\/10.3390\/ijms27052369","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,3]]}}}