title: Radial head button holing: a cause of irreducible anterior radial head dislocation.
abstract: "Buttonholing" of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction.
authors: Department of Radiology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Korea.
authors: Su-Mi
authors: SM
authors: Shin
authors: Department of Radiology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Korea. chaijw@gmail.com.
authors: Jee Won
authors: http://orcid.org/0000-0003-1630-1863
authors: JW
authors: Chai
authors: Department of Radiology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Korea.
authors: Ja Yeon
authors: JY
authors: You
authors: Department of Radiology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Korea.
authors: Jina
authors: J
authors: Park
authors: Department of Orthopedic Surgery, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Korea.
authors: Kee Jeong
authors: KJ
authors: Bae
mesh_terms: D000293:Adolescent; D017760:Bone Malalignment / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D004551:Elbow Joint / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011884:Radius / Q000002:abnormalities* / Q000000981:diagnostic imaging* / Q000293:injuries*; D000092464:Elbow Injuries
keywords: Dislocation; Elbow joint; Fractures; Injuries; MRI; Radius