{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T15:07:37Z","timestamp":1785337657331,"version":"3.55.0"},"reference-count":37,"publisher":"Wiley","issue":"11","license":[{"start":{"date-parts":[[2022,4,18]],"date-time":"2022-04-18T00:00:00Z","timestamp":1650240000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2022,4,18]],"date-time":"2022-04-18T00:00:00Z","timestamp":1650240000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.springer.com\/tdm"},{"start":{"date-parts":[[2022,4,18]],"date-time":"2022-04-18T00:00:00Z","timestamp":1650240000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.springer.com\/tdm"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Knee surg. sports traumatol. arthrosc."],"published-print":{"date-parts":[[2022,11]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>To evaluate the intra\/inter\u2010rater and diagnostic reliability of the sagittal plane adjusted patellar instability ratios (PIRs) compared to tibial tubercle\u2010trochlear groove (TT\u2013TG) distance alone while employing a matched case\u2013control analysis for age and sex to minimize a potential confounding effect.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>A retrospective case\u2013control study was performed of all knee MRI studies of patients diagnosed with patellar instability, between 2005 and 2020 at a regional tertiary medical centre. Using a 1:1 case\u2013control matching of sex and age at the time of the diagnosis, one control subject was assigned to each case of patellar instability. Measurements of TT\u2013TG distance, sagittal patellar length (PL), sagittal patellar tendon length (PTL), TT\u2013TG\/PL ratio, and TT\u2013TG\/PTL ratio were conducted. Two orthopaedic surgery residents and a senior musculoskeletal radiologist were assigned to assess the intra\u2010 and inter\u2010rater reliability. Inter\u2010class coefficients were calculated (ICC). The receiver operating characteristic (ROC) curve and area under curve (AUC) for each parameter were compared to evaluate for diagnostic reliability. Odds ratios (OR) and their 95% confidence intervals (CI) were calculated and a multivariable logistic regression model was performed to control for possible confounders.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The study included 324\u00a0individuals (162 case\u2013control matched pairs). In terms of intra\u2010 and inter\u2010rater reliability, TT\u2013TG\/PL and TT\u2013TG\/PTL ratios showed an excellent correlation within and between readers (TT\u2013TG\/PL; intra\u2010rater ICC 0.94 and inter\u2010rater ICC 0.92, TT\u2010TG\/PTL; intra\u2010rater ICC 0.91 and inter\u2010rater ICC 0.88). The ROC curve showed a slightly greater AUC of the TT\u2010TG\/PL ratio compared to TT\u2010TG distance alone (0.75 vs 0.73, <jats:italic>p\u2009<\/jats:italic>&lt;\u20090.001).<\/jats:p><jats:p>When applying the pathologic cutoff of TT\u2013TG\u2009\u2265\u200920\u00a0mm and TT\u2013TG\/PL\u2009\u2265\u20090.5; the calculated odds ratios for the above cutoff were as follows; TT\u2013TG distance alone had an OR of 14 (95% CI 1.8\u2013106.5, <jats:italic>p\u2009<\/jats:italic>=\u20090.011) and OR for TT\u2013TG\/PL ratio was 23 (95% CI 3.1\u2013170.3, <jats:italic>p\u2009<\/jats:italic>=\u20090.002). In the multivariable analysis, while controlling for height and weight, only the association between TT\u2013TG\/PL ratio and patellar dislocation remained statistically significant with an adjusted OR of 2.7 (CI 1.3\u20135.4, <jats:italic>p\u2009<\/jats:italic>=\u20090.006), compared to TTTG distance alone (OR\u2009=\u20091.9, n.s.).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Patellar instability ratios are significantly more reliable compared to TT\u2013TG distance alone for the evaluation of patellar instability. Patellar instability ratios present superior diagnostic reliability, sensitivity and specificity, and intra\\inter rater reliability. Thus, patellar instability ratios could function as a valuable diagnostic tool for the evaluation of patellar instability.<\/jats:p><\/jats:sec><jats:sec><jats:title>Level of evidence<\/jats:title><jats:p>III.<\/jats:p><\/jats:sec>","DOI":"10.1007\/s00167-022-06979-4","type":"journal-article","created":{"date-parts":[[2022,4,18]],"date-time":"2022-04-18T15:04:01Z","timestamp":1650294241000},"page":"3644-3650","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Individualized tibial tubercle\u2013trochlear groove distance\u2010to\u2010patellar length ratio (TT\u2013TG\/PL) is a more reliable measurement than TT\u2013TG alone for evaluating patellar instability"],"prefix":"10.1002","volume":"30","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6309-5639","authenticated-orcid":false,"given":"Ahmad","family":"Essa","sequence":"first","affiliation":[{"name":"<!--<label>1<\/label>--> Department of Orthopaedics, Shamir Medical Center (Assaf Harofeh) POB 2007 48810 Zerifin Kfar\u2010Qassim Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dror","family":"Lindner","sequence":"additional","affiliation":[{"name":"<!--<label>1<\/label>--> Department of Orthopaedics, Shamir Medical Center (Assaf Harofeh) POB 2007 48810 Zerifin Kfar\u2010Qassim Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Salah","family":"Khatib","sequence":"additional","affiliation":[{"name":"<!--<label>1<\/label>--> Department of Orthopaedics, Shamir Medical Center (Assaf Harofeh) POB 2007 48810 Zerifin Kfar\u2010Qassim Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ron","family":"Gilat","sequence":"additional","affiliation":[{"name":"<!--<label>1<\/label>--> Department of Orthopaedics, Shamir Medical Center (Assaf Harofeh) POB 2007 48810 Zerifin Kfar\u2010Qassim Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nogah","family":"Shabshin","sequence":"additional","affiliation":[{"name":"<!--<label>3<\/label>--> Department of Radiology Carmel Medical Center Haifa Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eran","family":"Tamir","sequence":"additional","affiliation":[{"name":"<!--<label>1<\/label>--> Department of Orthopaedics, Shamir Medical Center (Assaf Harofeh) POB 2007 48810 Zerifin Kfar\u2010Qassim Israel"},{"name":"<!--<label>2<\/label>--> Faculty of Medicine Tel Aviv University Tel Aviv Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriel","family":"Agar","sequence":"additional","affiliation":[{"name":"<!--<label>1<\/label>--> Department of Orthopaedics, Shamir Medical Center (Assaf Harofeh) POB 2007 48810 Zerifin Kfar\u2010Qassim Israel"},{"name":"<!--<label>2<\/label>--> Faculty of Medicine Tel Aviv University Tel Aviv Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yiftah","family":"Beer","sequence":"additional","affiliation":[{"name":"<!--<label>1<\/label>--> Department of Orthopaedics, Shamir Medical Center (Assaf Harofeh) POB 2007 48810 Zerifin Kfar\u2010Qassim Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2022,4,18]]},"reference":[{"key":"e_1_2_10_2_2","unstructured":"AckermannJ HaslerJ GrafDN FucenteseSF VlachopoulosLThe effect of native knee rotation on the tibial\u2010tubercle\u2010trochlear\u2010groove distance in patients with patellar instability: an analysis of MRI and CT measurements.Arch Orthop Trauma 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