title: Anatomic study of the coracoid process: safety margin and practical implications.
abstract: OBJECTIVE
  The aim of this study was to define a safety margin for coracoid process osteotomy that does not compromise the coracoclavicular ligaments and that can be used in the coracoid transfer procedures.
  
  
  METHODS
  Thirty shoulders from 15 cadavers were dissected, exposing the coracoid process and attached anatomic structures. The distance of the insertion of these structures to the coracoid process apex was measured.
  
  
  RESULTS
  The average length of the coracoid process was 4.26 ± 0.26 cm. The average width and height at the tip were 2.11 ± 0.2 and 1.49 ± 0.12 cm, respectively. The average distance from the tip to the anterior and posterior margin of the pectoralis minor was 0.1 ± 1.17 and 1.59 ± 0.27 cm, respectively. The average distance from the tip to the posterior margin of the coracoacromial ligament was 2.79 ± 0.33 cm. The average distance from the apex to the most anterior part of the trapezoid ligament was 3.33 ± 0.38 cm. We obtained a constant value of 0.85 cm for this measure, and the value increased with each 1.0-cm increase in the distance from the tip to the posterior margin of the pectoralis minor. The safety margin for osteotomy (i.e., available bone distance for the coracoid process transfer) was 2.64 cm.
  
  
  CONCLUSIONS
  This study established a safety margin of 2.64 cm for the osteotomy of the coracoid process and its relation with the posterior margin of the pectoralis minor. The anatomic descriptions of bone and soft tissue, as well as a measure of correlation for the safety margin of the coracoid, provide tools for surgeons performing anatomic surgical procedures to correct glenohumeral instability with significant bone loss.
  
  
  CONCLUSIONS
  Knowing the safety margin allows the surgeon to perform a safe osteotomy without direct visualization of the coracoclavicular ligaments attachments, thereby making procedures more anatomic.
authors.affiliation: Department of Orthopaedic Surgery and Sports Medicine, Federal University of São Paulo, Brazil. bernardomed@hotmail.com
authors.forename: Bernardo Barcellos
authors.initials: BB
authors.lastname: Terra
authors.forename: Benno
authors.initials: B
authors.lastname: Ejnisman
authors.forename: Eduardo Antônio
authors.initials: EA
authors.lastname: de Figueiredo
authors.forename: Carina
authors.initials: C
authors.lastname: Cohen
authors.forename: Gustavo Cará
authors.initials: GC
authors.lastname: Monteiro
authors.forename: Alberto
authors.initials: A
authors.lastname: de Castro Pochini
authors.forename: Carlos Vicente
authors.initials: CV
authors.lastname: Andreoli
authors.forename: Moises
authors.initials: M
authors.lastname: Cohen
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D002102:Cadaver; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control; D008023:Ligaments, Articular / Q000033:anatomy & histology; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods; D012540:Scapula / Q000033:anatomy & histology* / Q000601:surgery; D012785:Shoulder Joint / Q000601:surgery; D055815:Young Adult