{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T06:20:42Z","timestamp":1773642042300,"version":"3.50.1"},"reference-count":25,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T00:00:00Z","timestamp":1773619200000},"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. Physiol."],"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>This study investigated the dose-dependent impact of femoral distraction length on knee joint integrity and characterized the molecular mechanisms driving cartilage degeneration in a rat distraction osteogenesis (DO) model.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Thirty-six Sprague-Dawley rats underwent femoral DO and were randomly assigned to three groups: Control (5 mm), Group A (10 mm), and Group B (20 mm). Following a consolidation phase, knee joint morphology and subchondral bone microstructure were evaluated using digital radiography and micro-computed tomography. Histological assessment included H&amp;amp;E, Safranin O-Fast Green, and Masson\u2019s trichrome staining. Furthermore, immunohistochemical analysis quantified the expression of catabolic (IL-1\u03b2, MMP-13, RANKL) and anabolic (COL-II, SOX9, OPG) biomarkers in the articular cartilage and subchondral bone.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Radiographic and histological findings demonstrated successful osseointegration and physiological tolerance in the Control and Group A. Conversely, Group B exhibited severe osteoarthritis-like pathology, including cartilage erosion, proteoglycan depletion and subchondral sclerosis. Quantitative analysis confirmed significantly elevated bone mineral density and bone volume fraction in the subchondral bone of Group B (\n                      <jats:italic>P<\/jats:italic>\n                      &amp;lt; 0.05). Molecularly, Group B showed significant upregulation of catabolic biomarkers (IL-1\u03b2, MMP-13 and RANKL) with concurrent downregulation of anabolic biomarkers (COL-II, SOX9 and OPG;\n                      <jats:italic>P<\/jats:italic>\n                      &amp;lt; 0.05).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Extensive distraction (20 mm, \u223c50% of original length) surpasses the physiological adaptive capacity of the knee joint, triggering irreversible degeneration via IL-1\u03b2\/MMP-13-mediated sterile inflammation and OPG\/RANKL-driven osteochondral uncoupling. While moderate distraction (10 mm, \u223c25% length) remains compensatory, this pathological transition highlights the critical necessity of joint protection strategies when limb lengthening targets exceed \u223c25% of the original bone length.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fphys.2026.1779440","type":"journal-article","created":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T05:23:05Z","timestamp":1773638585000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of distraction length on the morphology of knee cartilage in a rat model of femoral distraction osteogenesis"],"prefix":"10.3389","volume":"17","author":[{"given":"Caifeng","family":"Wu","sequence":"first","affiliation":[{"name":"Department of Orthopaedics, The Affiliated Hospital of Southwest Medical University","place":["Luzhou, Sichuan, China"]},{"name":"Department of Hand and Foot Microsurgery, Qingdao University Affiliated Hospital","place":["Qingdao, Shandong, China"]},{"name":"Department of Trauma and Microreconstructive Surgery, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, Xinjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuanxin","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics, The Affiliated Hospital of Southwest Medical University","place":["Luzhou, Sichuan, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanshi","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics, The Affiliated Hospital of Southwest Medical University","place":["Luzhou, Sichuan, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lian","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics, The Affiliated Hospital of Southwest Medical University","place":["Luzhou, Sichuan, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoheng","family":"Ding","sequence":"additional","affiliation":[{"name":"Department of Hand and Foot Microsurgery, Qingdao University Affiliated Hospital","place":["Qingdao, Shandong, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aihemaitijiang","family":"Yusufu","sequence":"additional","affiliation":[{"name":"Department of Trauma and Microreconstructive Surgery, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, Xinjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kai","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics, The Affiliated Hospital of Southwest Medical University","place":["Luzhou, Sichuan, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,3,16]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1186\/s10195-019-0527-1","article-title":"Ilizarov bone transport and treatment of critical-sized tibial bone defects: a narrative review","volume":"20","author":"Aktuglu","year":"2019","journal-title":"J. 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