{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T00:32:48Z","timestamp":1759969968958,"version":"build-2065373602"},"reference-count":29,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T00:00:00Z","timestamp":1759881600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T00:00:00Z","timestamp":1759881600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J Orthop Surg Res"],"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>The relationship between surgical duration and length of hospital stay (LOS) in total knee arthroplasty (TKA) remains incompletely understood. We investigated the potential associations and modulating factors influencing LOS.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods<\/jats:title>\n            <jats:p>In this retrospective cohort study, we analyzed 2,394 patients undergoing primary unilateral total knee arthroplasty at Singapore General Hospital (2013\u20132014). Surgical duration served as the primary exposure, with LOS as the principal outcome. We employed multivariable linear regression models, including piecewise linear regression, to elucidate the relationship between surgical duration and LOS.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>A significant non-linear association emerged between surgical duration and LOS. A critical inflection point was identified at 115\u00a0min, beyond which LOS increased substantially (adjusted <jats:italic>\u03b2<\/jats:italic>\u2009=\u20090.047, 95% CI: 0.018\u20130.076, <jats:italic>P<\/jats:italic>\u2009=\u20090.0015). Stratified analyses revealed nuanced effect modifications by anemia status and American Society of Anesthesiologists Physical Status (ASA-PS) scores. Patients with moderate-to-severe anemia and higher ASA-PS scores demonstrated markedly different response patterns, with more pronounced increases in hospitalization duration.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusion<\/jats:title>\n            <jats:p>Our findings demonstrate a complex, non-linear relationship between surgical duration and LOS in TKA. Anemia status and physiological reserve significantly modulate this association, suggesting the need for personalized perioperative management strategies. These insights may optimize surgical planning and resource allocation in orthopedic interventions.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/s13018-025-06267-0","type":"journal-article","created":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T09:11:22Z","timestamp":1759914682000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Non-linear association between surgical duration and length of hospital stay in primary unilateral total knee arthroplasty: a secondary analysis based on a retrospective cohort study in Singapore"],"prefix":"10.1186","volume":"20","author":[{"given":"Jianxiang","family":"Zhu","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zengbing","family":"Xia","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jikang","family":"Min","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wenlin","family":"Hu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Heng","family":"Li","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chao","family":"Mei","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2025,10,8]]},"reference":[{"key":"6267_CR1","doi-asserted-by":"publisher","first-page":"1102371","DOI":"10.3389\/fsurg.2023.1102371","volume":"10","author":"B Zhu","year":"2023","unstructured":"Zhu B, Zhang D, Sang M, Zhao L, Wang C, Xu Y. Establishment and evaluation of a predictive model for length of hospital stay after total knee arthroplasty: A single-center retrospective study in China. Front Surg. 2023;10:1102371.","journal-title":"Front Surg"},{"issue":"12","key":"6267_CR2","doi-asserted-by":"publisher","first-page":"7185","DOI":"10.1007\/s00402-023-05013-7","volume":"143","author":"TL Chen","year":"2023","unstructured":"Chen TL, Buddhiraju A, Seo HH, Shimizu MR, Bacevich BM, Kwon YM. Can machine learning models predict prolonged length of hospital stay following primary total knee arthroplasty based on a National patient cohort data. Arch Orthop Trauma Surg. 2023;143(12):7185\u201393.","journal-title":"Arch Orthop Trauma Surg"},{"key":"6267_CR3","doi-asserted-by":"publisher","first-page":"121","DOI":"10.1016\/j.jor.2022.05.018","volume":"32","author":"M Mannani","year":"2022","unstructured":"Mannani M, Motififard M, Farajzadegan Z, Nemati A. Length of stay in patients undergoing total knee arthroplasty. 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In accordance with the institutional guidelines for retrospective studies involving anonymized medical records, the CIRB waived the requirement for individual patient informed consent. The study protocol was implemented in strict adherence to the ethical principles outlined in the Declaration of Helsinki and local institutional regulations governing medical research.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"876"}}