{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T18:51:23Z","timestamp":1793472683896,"version":"4.5.0"},"reference-count":55,"publisher":"SAGE Publications","issue":"7","license":[{"start":{"date-parts":[[2025,4,30]],"date-time":"2025-04-30T00:00:00Z","timestamp":1745971200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Am J Sports Med"],"published-print":{"date-parts":[[2025,6]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>The J-sign is a marker of abnormal patellar tracking and is associated with bony abnormalities. When patella alta is present, distal tibial tubercle osteotomy (dTTO) can enable the patella to engage in a more distal\/deeper groove, often eliminating the J-sign.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose:<\/jats:title>\n                    <jats:p>To determine which anatomic findings are associated with a persistent J-sign after medial patellofemoral ligament reconstruction (MPFL-R) and dTTO in patients with recurrent lateral patellar dislocations and patella alta.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Study Design:<\/jats:title>\n                    <jats:p>Cohort study; Level of evidence, 4.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>A retrospective cohort study of 93 knees (77 patients) with recurrent lateral patellar dislocations and the J-sign, treated by a single surgeon with MPFL-R and dTTO without trochleoplasty, was conducted. Demographic, imaging, and surgical data were obtained from medical records. The following measurements were obtained: Caton-Deschamps index (CDI), patellotrochlear index, tibial tubercle\u2013trochlear groove (TT-TG) distance, patellar tendon\u2013lateral trochlear ridge (PT-LTR) distance, lateral patellar tilt, tibiofemoral joint rotation (TFJR), lateral trochlear inclination (LTI), trochlear depth, sulcus angle, and sagittal bump height. The postoperative J-sign was assessed. Patients were categorized into the resolved J-sign group or persistent J-sign group. Binary logistic regression was performed to identify significant predictors of a postoperative J-sign. Cutoff values were determined by receiver operating characteristic curve analysis using the Youden index. The Fisher exact test was used to compare frequencies.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>The J-sign was not observed postoperatively in 56 cases (60.2%) and was thus considered resolved. Preoperative characteristics revealed differences between the resolved J-sign and persistent J-sign groups for mean lateral patellar tilt, PT-LTR distance, TFJR, sulcus angle, trochlear depth, TT-TG distance, sagittal bump height, and LTI. The mean amount of distalization, patellotrochlear index, and preoperative and postoperative CDI were similar between the groups. Logistic regression identified TFJR, PT-LTR distance, and LTI as significant predictors of a persistent J-sign. An increased risk of a persistent J-sign was found for a TFJR \u22656\u00b0 (odds ratio [OR], 14.9 [95% CI, 5.4-41.6]), PT-LTR distance \u226513 mm (OR, 12.3 [95% CI, 4.3-35.5]), and LTI \u226410\u00b0 (OR, 4.1 [95% CI, 1.6-10.4]). The frequency of a persistent J-sign was 3.8% for cases with no risk factors above the threshold value, 10.5% with 1 risk factor, 63.0% with 2 risk factors, and 87.5% with all 3 risk factors present.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>A persistent J-sign was associated with imaging measurements of a more lateralized extensor mechanism (greater PT-LTR distance), trochlear dysplasia (lower LTI), and increased external TFJR.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/03635465251336162","type":"journal-article","created":{"date-parts":[[2025,4,30]],"date-time":"2025-04-30T06:37:56Z","timestamp":1745995076000},"page":"1554-1562","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":11,"title":["Anatomic Factors Influencing a Persistent J-Sign After Medial Patellofemoral Ligament Reconstruction and Distal Tibial Tubercle Osteotomy in Patients With Recurrent Patellar Dislocations and Patella Alta: A Retrospective Cohort Study"],"prefix":"10.1177","volume":"53","author":[{"given":"Raimundo","family":"Vial Irarrazaval","sequence":"first","affiliation":[{"name":"Department of Orthopedic Surgery, Pontifical Catholic University of Chile, Santiago, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefan","family":"Turkula","sequence":"additional","affiliation":[{"name":"Teton Valley Health Care, Driggs, Idaho, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marc","family":"Tompkins","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julie","family":"Agel","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6944-7332","authenticated-orcid":false,"given":"Elizabeth","family":"Arendt","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2025,4,30]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1177\/18632521221149055"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-642-05424-2_21"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1177\/0363546518803936"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00167-016-4117-y"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00167-016-4365-x"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00167-005-0015-4"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00167-009-0824-y"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00167-014-3195-y"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1177\/0363546516652894"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1148\/radiology.216.2.r00au07582"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1097\/JSA.0000000000000150"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.knee.2023.07.003"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.2106\/00004623-199305000-00007"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.asmr.2020.06.009"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF01552649"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1177\/03635465980260012701"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.2106\/JBJS.M.00688"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1177\/0363546519835800"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1177\/0363546503260788"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.arthro.2018.10.109"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF01623337"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1097\/00003086-199804000-00021"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1097\/JSM.0000000000000997"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00167-018-5065-5"},{"issue":"3","key":"e_1_3_2_26_2","article-title":"How reliable is a J-sign severity scale when assessing lateral patellar instability?","volume":"5","author":"Klimenko O","year":"2023","unstructured":"Klimenko O, Sousa TC, Baker R, et al. 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