{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:44:18Z","timestamp":1760150658655,"version":"build-2065373602"},"reference-count":27,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2023,12,21]],"date-time":"2023-12-21T00:00:00Z","timestamp":1703116800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: The original description of boxer\u2019s knuckle injury of the fifth ray mentions that the injury occurs between the extensor digitorum communis (EDC) and the extensor digiti minimi (EDM). Subsequent reports claim similar findings. Anatomical studies show that the EDC of the fifth ray is absent in most patients, while the EDM is generally composed of two slips. We present a modification of the current description of boxer\u2019s knuckle injury of the little finger based on the correlation between advanced preoperative 3D imaging and intraoperative findings. Methods: Five patients were investigated preoperatively using high-resolution ultrasound and 3D tendon reconstruction-based MR arthrography. Surgical exploration identified the lesion site relative to the EDM and EDC. Results: All patients had two slips of the EDM and no EDC to the fifth ray. The injury appeared as a longitudinal tear of the EDM between its two slips. The mean gap was 7.8 mm (range 4.5\u201310 mm) on the pathological side vs. 1.3 mm (range 1\u20132 mm) on the healthy contralateral side. Conclusions: We believe that previous descriptions of boxer\u2019s knuckle of the fifth ray are inaccurate. High-resolution ultrasound and 3D reconstructions based on MR arthrography are reliable diagnostic tools allowing to locate the injury with precision.<\/jats:p>","DOI":"10.3390\/jcm13010046","type":"journal-article","created":{"date-parts":[[2023,12,21]],"date-time":"2023-12-21T03:36:17Z","timestamp":1703129777000},"page":"46","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["New Insights into Boxer\u2019s Knuckle Injury of the Little Finger"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3753-1222","authenticated-orcid":false,"given":"S\u00e9bastien","family":"Durand","sequence":"first","affiliation":[{"name":"Department of Hand Surgery, Lausanne University Hospital, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2292-811X","authenticated-orcid":false,"given":"Thierry","family":"Christen","sequence":"additional","affiliation":[{"name":"Department of Hand Surgery, Lausanne University Hospital, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jean-Baptiste","family":"Ledoux","sequence":"additional","affiliation":[{"name":"Department of Diagnostic and Interventional Radiology, Lausanne University Hospital, University of Lausanne, CH-1011 Lausanne, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Romain","family":"Baillot","sequence":"additional","affiliation":[{"name":"Department of Hand Surgery, Lausanne University Hospital, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1016\/0002-9610(57)90828-0","article-title":"Boxer\u2019s knuckle; a preliminary report","volume":"93","author":"Gladden","year":"1957","journal-title":"Am. J. Surg."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/0363-5023(89)90011-7","article-title":"Boxer\u2019s knuckle\u2014Dorsal capsular rupture of the metacarpophalangeal joint of a finger","volume":"14","author":"Posner","year":"1989","journal-title":"J. Hand Surg. Am."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1054\/JHSB.2001.0656","article-title":"Treatment of soft tissue injuries to the dorsum of the metacarpophalangeal joint (Boxer\u2019s knuckle)","volume":"27","author":"Arai","year":"2002","journal-title":"J. Hand Surg. Br."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1645","DOI":"10.1249\/01.MSS.0000089340.89660.EB","article-title":"Traumatic Extensor Tendon Dislocation in a Boxer: A Case Study","volume":"35","author":"Bents","year":"2003","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1097\/00005131-200203000-00013","article-title":"Traumatic divergent dislocation of the extensor tendons over the metacarpophalangeal joint","volume":"16","author":"Heirweg","year":"2002","journal-title":"J. Orthop. Trauma"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"464","DOI":"10.1016\/S0363-5023(96)80364-9","article-title":"Dislocation of the extensor tendons over the metacarpophalangeal joints","volume":"21","author":"Inoue","year":"1996","journal-title":"J. Hand Surg. Am."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1105","DOI":"10.1177\/1753193420934072","article-title":"An unusual presentation of Boxer\u2019s knuckle in the little finger: A case report","volume":"45","author":"Lam","year":"2020","journal-title":"J. Hand Surg. Eur."},{"key":"ref_8","first-page":"273","article-title":"Traumatic luxation of the extensor apparatus of the dorsum of the metacarpophalangeal joint of the little finger. Six cases","volume":"10","author":"Ebelin","year":"1991","journal-title":"Ann. Chir. Main Memb. Super."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1162","DOI":"10.1177\/17531934221123139","article-title":"Extensor hood injuries in elite boxers: Injury characteristics, surgical technique and outcomes","volume":"47","author":"Matharu","year":"2022","journal-title":"J. Hand Surg. Eur."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.main.2006.03.005","article-title":"Traumatic pseudo-boutonniere of the metacarpophalangeal joint of the little finger. Case report and review of the literature","volume":"25","author":"Monteil","year":"2006","journal-title":"Chir. Main"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1016\/0266-7681_89_90103-4","article-title":"Traumatic dislocation of the extensor tendons over the fifth metacarpo-phalangeal joint","volume":"14","author":"Vercauteren","year":"1989","journal-title":"J. Hand Surg. Br."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1849","DOI":"10.1007\/s00330-009-1383-9","article-title":"Functional anatomy of the dorsal hood or the hand: Correlation of ultrasound and MR findings with cadaveric dissection","volume":"19","author":"Kichouh","year":"2009","journal-title":"Eur. Radiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1002\/ca.20710","article-title":"The anatomical variations of the extensor tendons to the dorsum of the hand","volume":"21","author":"Celik","year":"2008","journal-title":"Clin. Anat."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1002\/ca.20878","article-title":"An anatomic study on the junctura tendinum in the 4th intermetacarpal space and its clinical implication","volume":"23","author":"Jeon","year":"2010","journal-title":"Clin. Anat."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1007\/BF01654629","article-title":"Organization of the extensor complex of the digits","volume":"7","author":"Mestdagh","year":"1985","journal-title":"Anat. Clin."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"103","DOI":"10.2106\/00004623-196446010-00010","article-title":"Variations of the extensor tendons of the fingers: Surgical significance","volume":"46","author":"Schenck","year":"1964","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/S0363-5023(05)80053-X","article-title":"Anatomy of the extensor tendons of the fingers: Variations and multiplicity","volume":"20","author":"Botte","year":"1995","journal-title":"J. Hand Surg. Am."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1097\/00003086-200102000-00010","article-title":"Anatomy and Functional Significance of the Long Extensors to the Fingers and Thumb","volume":"383","author":"Botte","year":"2001","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1097\/01.PRS.0000091163.86851.9C","article-title":"Anatomical Variations of the Extensor Tendons to the Fingers over the Dorsum of the Hand: A Study of 50 Hands and a Review of the Literature","volume":"113","author":"Zilber","year":"2004","journal-title":"Plast. Reconstr. Surg."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1016\/S0363-5023(09)90021-1","article-title":"Anatomy of the juncturae tendinum of the hand","volume":"15","author":"Botte","year":"1990","journal-title":"J. Hand Surg. Am."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1007\/s12565-014-0253-y","article-title":"The prevalence of the extensor digiti minimi tendon of the hand and its variants in humans: A systematic review and meta-analysis","volume":"90","author":"Yammine","year":"2015","journal-title":"Anat. Sci. Int."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1007\/s11552-011-9320-1","article-title":"Investigation of Radialization and Rerouting of the Extensor Digiti Minimi (EDM) in the Abduction Deformity of the Little Finger: A Cadaver Study","volume":"6","author":"Zhu","year":"2011","journal-title":"Hand"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1080\/23320885.2020.1719844","article-title":"Closed extensor tendon rupture following neck fracture of the fifth metacarpal (Boxer\u2019s fracture): A case report","volume":"7","author":"Lardenoye","year":"2020","journal-title":"Case Rep. Plast. Surg. Hand Surg."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"642","DOI":"10.1148\/radiol.2283020833","article-title":"Boxer Knuckle (Injury of the Extensor Hood with Extensor Tendon Subluxation): Diagnosis with Dynamic US\u2014Report of Three Cases","volume":"228","author":"Lee","year":"2003","journal-title":"Radiology"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"150","DOI":"10.2174\/1573405613666171123160609","article-title":"Review on 2D and 3D MRI Image Segmentation Techniques","volume":"15","author":"Shirly","year":"2019","journal-title":"Curr. Med. Imaging Rev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1177\/107110079801900502","article-title":"Peroneus Brevis Tendon Tears: Pathophysiology, Surgical Reconstruction, and Clinical Results","volume":"19","author":"Krause","year":"1998","journal-title":"Foot Ankle Int."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.jhsa.2014.09.024","article-title":"Longitudinal Split Tear of the Extensor Pollicis Brevis Tendon: Report of 2 Cases","volume":"40","author":"Kroonen","year":"2015","journal-title":"J. Hand Surg. Am."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/13\/1\/46\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:39:23Z","timestamp":1760132363000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/13\/1\/46"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,12,21]]},"references-count":27,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2024,1]]}},"alternative-id":["jcm13010046"],"URL":"https:\/\/doi.org\/10.3390\/jcm13010046","relation":{},"ISSN":["2077-0383"],"issn-type":[{"type":"electronic","value":"2077-0383"}],"subject":[],"published":{"date-parts":[[2023,12,21]]}}}