title: Coronoid fracture height in terrible-triad injuries.
abstract: OBJECTIVE
  The coronoid fractures that occur in the terrible-triad pattern of traumatic elbow instability (posterior dislocation with fractures of the radial head and coronoid) usually are small transverse fragments. Attempts to classify these fragments according to height as suggested by Regan and Morrey have been inconsistent and contentious. The purpose of this study was to quantify coronoid fracture height in terrible-triad injuries.
  
  
  METHODS
  The height of the coronoid process of the ulna and the coronoid fracture fragment were measured on computed tomography scans of 13 patients with terrible-triad-pattern elbow injuries. Two observers performed the measurements with excellent intraobserver and interobserver reliability.
  
  
  RESULTS
  The total height of the coronoid process of the ulna averaged 19 mm. The average height of the coronoid fracture fragment was 7 mm. This corresponds to an average of 35% of the total height of the coronoid process.
  
  
  CONCLUSIONS
  The transverse coronoid fractures associated with terrible-triad elbow injuries have a variable height that may not be easy to classify according to the system of Regan and Morrey. Classification of coronoid fractures according to fracture morphology and injury pattern may be preferable.
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Harvard Medical School, Boston, MA, USA.
authors.forename: Job N
authors.initials: JN
authors.lastname: Doornberg
authors.forename: Joppe
authors.initials: J
authors.lastname: van Duijn
authors.forename: David
authors.initials: D
authors.lastname: Ring
mesh_terms: D000328:Adult; D000368:Aged; D004551:Elbow Joint / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D004204:Joint Dislocations / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011885:Radius Fractures / Q000145:classification / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014458:Ulna Fractures / Q000145:classification / Q000150:complications / Q000000981:diagnostic imaging*; D000092464:Elbow Injuries