{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T16:26:02Z","timestamp":1784823962302,"version":"3.55.0"},"reference-count":41,"publisher":"Springer Science and Business Media LLC","issue":"9","license":[{"start":{"date-parts":[[2023,4,13]],"date-time":"2023-04-13T00:00:00Z","timestamp":1681344000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2023,4,13]],"date-time":"2023-04-13T00:00:00Z","timestamp":1681344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Universit\u00e4tsklinikum Freiburg"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Arch Orthop Trauma Surg"],"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Introduction<\/jats:title>\n                <jats:p>The recovery of periarticular strength is a major criterion in return-to-play testing. The rationale of the study was to assess the impact of the  delay\u00a0of surgery (\u2206 between injury and surgery) on knee extensor and knee flexor strength of anterior cruciate ligament (ACL)-deficient patients six months after reconstruction.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Materials and methods<\/jats:title>\n                <jats:p>In a retrospective cohort study, all patients with ACL ruptures between 03\/2015 and 12\/2019 were analyzed. Inclusion criteria were isolated ACL rupture without any associated lesions undergoing a reconstruction using ipsilateral hamstring tendon autograft and adherence to isokinetic strength testing before and at 5\u20137\u00a0months postoperatively. These patients were then clustered into three groups: EARLY reconstruction (\u2206\u2009&lt;\u200942\u00a0days), DELAYED reconstruction (\u220642-180d), and CHRONIC (\u2206\u2009&gt;\u2009180d). Knee extensor and flexor strength of the ipsi- and contralateral leg were analyzed by concentric isokinetic measurement (60\u00b0\/s). Primary outcomes were the maximal knee extension and flexion torque, hamstrings-to-quadriceps ratio (H\/Q) ratio), and the corresponding limb symmetry indices.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p><jats:italic>n<\/jats:italic>\u2009=\u2009444 patients met the inclusion criteria. From EARLY to DELAYED to CHRONIC, a progressive reduction in postoperative strength performance was observed in knee extension (1.65\u2009\u00b1\u20090.45 to 1.62\u2009\u00b1\u20090.52 to 1.51\u2009\u00b1\u20090.5 Nm\/kg resp.) and flexion (1.22\u2009\u00b1\u20090.29 to 1.18\u2009\u00b1\u20090.3 to 1.13\u2009\u00b1\u20090.31 Nm\/kg resp.) strength on the ACL reconstructed leg. This general\u00a0loss in periarticular strength was already apparent in the preoperative performance\u00a0even on the healthy side. When controlling for the preoperative performance using ANCOVA analysis, EARLY performed significantly better than DELAYED (extension <jats:italic>p<\/jats:italic>\u2009=\u20090.001, flexion <jats:italic>p<\/jats:italic>\u2009=\u2009.02) and CHRONIC (extension <jats:italic>p<\/jats:italic>\u2009=\u20090.005, flexion <jats:italic>p<\/jats:italic>\u2009&lt;\u20090.001). Also, there were significantly higher values for H\/Q ratio in the injured leg across all groups where the H\/Q ratio increased from EARLY to CHRONIC and from pre- to postoperative values.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>With respect to the force generating capacity when returning-to-play, it is advantageous to seek for an early ACL reconstruction within the first 12\u00a0weeks after the injury. The increasing loss of thigh muscle strength observed in delayed or chronic cases affects the injured and also the non-injured leg.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Level of Evidence<\/jats:title>\n                <jats:p>III, retrospective cohort study.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1007\/s00402-023-04863-5","type":"journal-article","created":{"date-parts":[[2023,4,13]],"date-time":"2023-04-13T07:14:54Z","timestamp":1681370094000},"page":"5741-5750","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Early ACL reconstruction shows an improved recovery of isokinetic thigh muscle strength compared to delayed or chronic cases"],"prefix":"10.1007","volume":"143","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3929-2317","authenticated-orcid":false,"given":"Markus","family":"Wenning","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marlene","family":"Mauch","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Albrecht H.","family":"Heitner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gerrit","family":"Bode","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ghislain","family":"Sofack","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ramona","family":"Ritzmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2023,4,13]]},"reference":[{"key":"4863_CR1","doi-asserted-by":"publisher","first-page":"989","DOI":"10.1007\/s00402-017-2704-0","volume":"137","author":"C Domnick","year":"2017","unstructured":"Domnick C, Garcia P, Raschke MJ et al (2017) Trends and incidences of ligament-surgeries and osteotomies of the knee: an analysis of German inpatient records 2005\u20132013. 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