title: Evaluation of the coracoid and coracoacromial arch geometry on Thiel-embalmed cadavers using the three-dimensional MicroScribe digitizer.
abstract: BACKGROUND
  Understanding the geometry of the coracoid and coracoacromial arch will improve surgical intervention in shoulder surgery.
  
  
  METHODS
  Thirty pairs of scapulae from 20 female and 10 male deceased donors, average age of 82 years (range, 62-101 years), were scanned and measurements taken using the 3-dimensional (3D) MicroScribe digitizer (Immersion Corp, San Jose CA, USA) and Rhino software (McNeel North America, Seattle, WA, USA).
  
  
  RESULTS
  The following mean angles were determined: coracoid slope, 44° ± 11°; coracoid deviation, 35° ± 6°; coracoid root to glenoid, 115° ± 14°; coracoid head to glenoid, 110° ± 11°; scapular spine angle, 35° ± 6°; and coracoacromial angle, 63° ± 9°. The following mean distances were also determined: coracoid height, 10 ± 3 mm; coracoacromial distance, 42 ± 7 mm; coracoacromial arch height, 20 ± 5 mm; and coracoid (anterior, 29 ± 6 mm; middle, 20 ± 4 mm; posterior tip, 18 ± 6 mm) to the glenoid fossa. The coracoid root-to-glenoid angle was significantly correlated with the coracoacromial angle. In addition, coracoid slope was significantly correlated with coracoid root-to-glenoid angle and also with coracoid deviation. Left shoulders had a significantly higher coracoid-to-glenoid angle (P < .029) than right shoulders. Women had a significantly higher coracoid root-to-glenoid angle than men (P < .042), and men had a significantly higher coracoid deviation (P < .011), anterior (P < .006) and posterior coracoid-to-glenoid distances (P < .03), and coracoacromial arch height (P < .07) than women.
  
  
  CONCLUSIONS
  This is the first time that the 3D MicroScribe digitizer has been used to evaluate the geometry of the coracoacromial arch and coracoid process.
authors.affiliation: Centre for Anatomy and Human Identification (CAHID), University of Dundee, Dundee, UK; Faculty of Applied Medical Science, Umm Al-Qura University, Makkah, Saudi Arabia. Electronic address: m.alobaidy@dundee.ac.uk.
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Alobaidy
authors.affiliation: Centre for Anatomy and Human Identification (CAHID), University of Dundee, Dundee, UK.
authors.forename: Roger W
authors.initials: RW
authors.lastname: Soames
mesh_terms: D000174:Acromion / Q000033:anatomy & histology; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005260:Female; D061165:Glenoid Cavity / Q000033:anatomy & histology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D012540:Scapula / Q000033:anatomy & histology*; D012737:Sex Factors; D012785:Shoulder Joint / Q000033:anatomy & histology*; D012984:Software
keywords: 3D digitizer; Coracoid; Rhino software; Thiel cadavers; coracoacromial arch; shoulder