{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T13:06:57Z","timestamp":1789391217439,"version":"build-2803163510"},"reference-count":24,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T00:00:00Z","timestamp":1789344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Clin. Med.","JCM"],"abstract":"<jats:p>Background: The Rockwood classification is the most widely used radiographic framework for grading acromioclavicular (AC) joint dislocations. However, native anatomical variation may be associated with differences in the radiographic appearance of AC joint dislocations. Purpose: To evaluate the association between the acromioclavicular joint coronal orientation angle (AJCO) and Rockwood grade and to characterize the relationship between native coronal orientation and radiographic grade. Methods: This retrospective observational radiographic study included 198 adults with acute AC joint dislocations classified as Rockwood II, III, or V on standardized bilateral Zanca radiographs. AJCO was measured on the contralateral, uninjured side as the angle between the AC joint orientation line and a vertical reference. Two blinded orthopedic surgeons performed measurements independently, with reliability assessed using intraclass correlation coefficients. AJCO was compared across Rockwood groups, its monotonic association with grade was evaluated using Spearman correlation, and exploratory receiver operating characteristic analysis was performed for the tested binary contrast. Results: AJCO differed significantly across Rockwood injury grades, decreasing progressively from type II to type V injuries (median [IQR]: type II, 18.3\u00b0 [14.6\u201326.0\u00b0]; type III, 15.3\u00b0 [12.0\u201321.3\u00b0]; type V, 14.0\u00b0 [8.6\u201318.0\u00b0]; p &lt; 0.001). Consistent with this finding, AJCO demonstrated an inverse weak-to-moderate association with Rockwood grade (Spearman \u03c1 = \u22120.338, 95% CI \u22120.453 to \u22120.214; p &lt; 0.001). AJCO showed limited ability to discriminate higher-grade injuries (Rockwood \u2265 III), with an AUC of 0.694 (95% CI, 0.612\u20130.777; p &lt; 0.001), characterized by high specificity but low sensitivity at the optimal threshold. Furthermore, lower AJCO values remained significantly associated with higher Rockwood grades after adjustment for age and sex (OR = 0.899 per degree increase, 95% CI, 0.864\u20130.935; p &lt; 0.001). Conclusions: Lower AJCO values were associated with higher Rockwood grades in this cohort, but the magnitude of association and discriminatory performance were limited. These findings support AJCO as a morphology-related contextual variable associated with Rockwood grade rather than as a stand-alone diagnostic or treatment-guiding measure.<\/jats:p>","DOI":"10.3390\/jcm15187116","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T12:09:51Z","timestamp":1789387791000},"page":"7116","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Native Coronal Acromioclavicular Joint Orientation Is Associated with Rockwood Grade in Acute Acromioclavicular Joint Dislocations"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9788-6578","authenticated-orcid":false,"given":"Hakan Batuhan","family":"Kaya","sequence":"first","affiliation":[{"name":"Department of Orthopedics and Traumatology, \u00dcmraniye Training and Research Hospital, University of Health Sciences, Elmal\u0131kent Mahallesi Adem Yavuz Cad. No:1, Istanbul 34764, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-6235-1900","authenticated-orcid":false,"given":"Mehmet Talha","family":"Ayd\u0131n","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Traumatology, \u00dcmraniye Training and Research Hospital, University of Health Sciences, Elmal\u0131kent Mahallesi Adem Yavuz Cad. No:1, Istanbul 34764, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6268-9910","authenticated-orcid":false,"given":"Murat","family":"Birinci","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Traumatology, \u00dcmraniye Training and Research Hospital, University of Health Sciences, Elmal\u0131kent Mahallesi Adem Yavuz Cad. No:1, Istanbul 34764, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6577-3491","authenticated-orcid":false,"given":"Alper","family":"D\u00fcnki","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Traumatology, \u00dcmraniye Training and Research Hospital, University of Health Sciences, Elmal\u0131kent Mahallesi Adem Yavuz Cad. No:1, Istanbul 34764, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"project-administration","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"given":"Sava\u015f","family":"\u00c7amur","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Traumatology, \u00dcmraniye Training and Research Hospital, University of Health Sciences, Elmal\u0131kent Mahallesi Adem Yavuz Cad. No:1, Istanbul 34764, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9545-7454","authenticated-orcid":false,"given":"Mahmut Enes","family":"Kayaalp","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Traumatology, Fatih Sultan Mehmet Research and Training Hospital, University of Health Sciences, Hastane Sokak No:1\/9, Istanbul 34752, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"project-administration","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6275-8250","authenticated-orcid":false,"given":"Serdar Kamil","family":"\u00c7epni","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Traumatology, \u00dcmraniye Training and Research Hospital, University of Health Sciences, Elmal\u0131kent Mahallesi Adem Yavuz Cad. No:1, Istanbul 34764, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,14]]},"reference":[{"key":"ref_1","first-page":"219","article-title":"Minimally Invasive Techniques for the Treatment of Acute and Chronic Acromioclavicular Joint Instabilities","volume":"161","author":"Vetter","year":"2023","journal-title":"Z. Orthop. Unfall."},{"key":"ref_2","first-page":"251","article-title":"The treatment of acute Rockwood type III acromio-clavicular joint dislocations by two different surgical techniques","volume":"86","author":"Biz","year":"2015","journal-title":"Acta Biomed."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2192","DOI":"10.1007\/s00167-014-3436-0","article-title":"Inter- and intraobserver reliability of the Rockwood classification in acute acromioclavicular joint dislocations","volume":"24","author":"Schneider","year":"2016","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"538","DOI":"10.1016\/j.jse.2017.09.021","article-title":"Interobserver and intraobserver reliability of radiographic classification of acromioclavicular joint dislocations","volume":"27","author":"Ringenberg","year":"2018","journal-title":"J. Shoulder Elb. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"23259671251337470","DOI":"10.1177\/23259671251337470","article-title":"Inter- and Intrarater Reliability of the Acromioclavicular Joint Injury Classification on Anteroposterior Radiographs","volume":"13","author":"Skjaker","year":"2025","journal-title":"Orthop. J. Sports Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"504","DOI":"10.1177\/0363546519831013","article-title":"Horizontal Instability of the Acromioclavicular Joint: A Systematic Review","volume":"48","author":"Aliberti","year":"2020","journal-title":"Am. J. Sports Med."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Pogorzelski, J., Beitzel, K., Ranuccio, F., W\u00f6rtler, K., Imhoff, A.B., Millett, P.J., and Braun, S. (2017). The acutely injured acromioclavicular joint\u2014Which imaging modalities should be used for accurate diagnosis? A systematic review. BMC Musculoskelet. Disord., 18.","DOI":"10.1186\/s12891-017-1864-y"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.arthro.2013.11.005","article-title":"ISAKOS upper extremity committee consensus statement on the need for diversification of the Rockwood classification for acromioclavicular joint injuries","volume":"30","author":"Beitzel","year":"2014","journal-title":"Arthroscopy"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"23259671221149391","DOI":"10.1177\/23259671221149391","article-title":"The Reliability of Acromioclavicular Joint Dislocation Classification Systems: A Comparison Between the Rockwood and Kraus Classifications","volume":"11","author":"Liendo","year":"2023","journal-title":"Orthop. J. Sports Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2325","DOI":"10.1007\/s00167-020-06286-w","article-title":"High degree of consensus achieved regarding diagnosis and treatment of acromioclavicular joint instability among ESA-ESSKA members","volume":"29","author":"Rosso","year":"2021","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1989","DOI":"10.1016\/j.jse.2024.11.028","article-title":"Acromioclavicular joint injuries: Multicenter expert consensus study using the Delphi method","volume":"34","author":"Barnes","year":"2025","journal-title":"J. Shoulder Elb. Surg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"73","DOI":"10.2106\/JBJS.L.00734","article-title":"Management of acromioclavicular joint injuries","volume":"96","author":"Li","year":"2014","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1599","DOI":"10.1016\/j.jse.2019.12.014","article-title":"Improved identification of unstable acromioclavicular joint injuries in a clinical population using the acromial center line to dorsal clavicle radiographic measurement","volume":"29","author":"Karargyris","year":"2020","journal-title":"J. Shoulder Elb. Surg."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1619","DOI":"10.1177\/03635465211003300","article-title":"Evaluation of the Circles Measurement and the ABC Classification of Acromioclavicular Joint Injuries","volume":"49","author":"Murphy","year":"2021","journal-title":"Am. J. Sports Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1007\/s11678-018-0469-x","article-title":"Dynamic instability of the acromioclavicular joint: A new classification for acute AC joint separation","volume":"13","author":"Kraus","year":"2018","journal-title":"Obere Extrem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5962","DOI":"10.1007\/s00167-023-07570-1","article-title":"The V angle compliments radiographic assessment of acute acromioclavicular joint dislocations by differentiating between Rockwood types III versus V and by considering dynamic horizontal translation in coronal radiographs","volume":"31","author":"Vetter","year":"2023","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_17","first-page":"813","article-title":"Complete dislocations of the acromiclavicular joint; the nature of the traumatic lesion and effective methods of treatment with an analysis of forty-one cases","volume":"28","author":"Urist","year":"1946","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1302\/0301-620X.78B2.0780242","article-title":"Patterns of degenerative change in the acromioclavicular joint","volume":"78","author":"Edelson","year":"1996","journal-title":"J. Bone Jt. Surg. Br."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1007\/s00276-003-0155-5","article-title":"Anatomic and biometric study of the acromioclavicular joint by ultrasound","volume":"25","author":"Poncelet","year":"2003","journal-title":"Surg. Radiol. Anat."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"985","DOI":"10.1007\/s00402-013-1748-z","article-title":"Management of acute acromioclavicular joint dislocations: Current concepts","volume":"133","author":"Tauber","year":"2013","journal-title":"Arch. Orthop. Trauma. Surg."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Berthold, D.P., Muench, L.N., Dyrna, F., Mazzocca, A.D., Garvin, P., Voss, A., Scheiderer, B., Siebenlist, S., Imhoff, A.B., and Beitzel, K. (2022). Current concepts in acromioclavicular joint (AC) instability\u2014A proposed treatment algorithm for acute and chronic AC-joint surgery. BMC Musculoskelet. Disord., 23.","DOI":"10.1186\/s12891-022-05935-0"},{"key":"ref_22","first-page":"743","article-title":"Classification of the morphology of the acromioclavicular joint using cadaveric and radiological analysis","volume":"92","author":"Allom","year":"2010","journal-title":"J. Bone Jt. Surg. Br."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1007\/s00167-017-4579-6","article-title":"New quantitative radiographic parameters for vertical and horizontal instability in acromioclavicular joint dislocations","volume":"26","author":"Zumstein","year":"2018","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"646","DOI":"10.1016\/j.jseint.2025.01.012","article-title":"Three-dimensional changes of scapulothoracic orientation in patients with acromioclavicular joint dislocations","volume":"9","author":"Vetter","year":"2025","journal-title":"JSES Int."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/18\/7116\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T12:51:09Z","timestamp":1789390269000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/18\/7116"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,14]]},"references-count":24,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["jcm15187116"],"URL":"https:\/\/doi.org\/10.3390\/jcm15187116","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,14]]}}}