title: Concomitant injury of the annular ligament in fractures of the coronoid process and the supinator crest.
abstract: BACKGROUND
  Fractures of the coronoid process or the supinator crest, as well as arthroscopic resection of osteophytes around the coronoid process, can endanger the attachment of the annular ligament (AL) to the proximal ulna. The purpose of this study was to investigate the corresponding insertional areas of the AL within this context.
  
  
  METHODS
  In 30 embalmed human cadaveric elbow specimens, the insertional area of the AL at the anterior and posterior margin of the sigmoid notch was characterized. The distances and relations of the AL insertion anteriorly to the coronoid surface, the coronoid tip, and the depth of the coronoid process, as well as posteriorly to the supinator crest, were evaluated macroscopically.
  
  
  RESULTS
  The mean distance of the anterior insertion area was 1.9 ± 0.6 mm (range, 1.0-3.1 mm) to the coronoid articular surface and 6.2 ± 1.7 mm (range, 2.9-10.2 mm) to the tip of the coronoid. The distance of the anterior insertion in relation to the depth of the coronoid process was 44% ± 11% (range, 30%-69%). The distance of the posterior insertion area to the level of the sigmoid notch measured from 3.5 ± 1.5 mm (range, 0.5-6.5 mm) to 17.7 ± 2.9 mm (range, 13.1-25.4 mm).
  
  
  CONCLUSIONS
  Coronoid fractures involving 44% or more of the coronoid process and anterolaterally oriented fractures where one-third of the anterolateral facet is affected are accompanied by a complete anterior bony disruption of the AL. Arthroscopic resection of the coronoid tip should be limited to 1 mm distal to the coronoid articular surface to avoid injury to the AL. Fractures of the upper half of the supinator crest place the AL at risk at its posterior insertion.
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany. Electronic address: tim.leschinger@uk-koeln.de.
authors.forename: Tim
authors.initials: T
authors.lastname: Leschinger
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Lars Peter
authors.initials: LP
authors.lastname: Müller
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hackl
authors.affiliation: Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany; Institute of Anatomy II, University of Cologne, Cologne, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Scaal
authors.affiliation: Department of Trauma and Orthopaedic Surgery, Berufsgenossenschaftliche Unfallklinik, Frankfurt am Main, Germany.
authors.forename: Kay
authors.initials: K
authors.lastname: Schmidt-Horlohé
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Kilian
authors.initials: K
authors.lastname: Wegmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D004551:Elbow Joint / Q000033:anatomy & histology*; D004838:Epiphyses / Q000033:anatomy & histology / Q000293:injuries; D005260:Female; D006801:Humans; D008023:Ligaments, Articular / Q000033:anatomy & histology* / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D014458:Ulna Fractures / Q000150:complications / Q000473:pathology*
keywords: Annular ligament; concomitant injury; coronoid fracture; iatrogenic injury; insertion areas; sigmoid notch; supinator crest