title: Normal glenoid rim anatomy and the reliability of shoulder instability measurements based on intrasite correlation.
abstract: OBJECTIVE
  To evaluate the glenoid shape and to evaluate if the contralateral glenoid can be used as size reference.
  
  
  METHODS
  Two independent investigators prospectively analysed shoulder computer-tomographies of 90 patients. The glenoids were positioned in a true "en face" view and evaluated for size and shape. The intraindividual correlation of these parameters between left and right side were assessed.
  
  
  RESULTS
  In the 90 computer tomographically evaluated shoulder pairs a significant intraindividual correlation of size and shape was seen (P < 0.001). The intraindividual difference in glenoid surface area averaged 1.8% of the total glenoid surface. The shape of the inferior hemisphere correlated 100%. We found all the inferior glenoids to be circular.
  
  
  CONCLUSIONS
  Our study clearly shows that the inferior glenoid in healthy individuals has the shape of a circle. The high side-to-side correlation of the glenoid surface area can be applied when measuring bony defects by evaluation of the contralateral side.
authors.affiliation: Department of Traumatology and Sports Medicine, Innsbruck Medical University, Anichstrasse 35, 6020, Innsbruck, Austria. hans.jeske@i-med.ac.at
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Jeske
authors.forename: Martina
authors.initials: M
authors.lastname: Oberthaler
authors.forename: Michael
authors.initials: M
authors.lastname: Klingensmith
authors.forename: Christian
authors.initials: C
authors.lastname: Dallapozza
authors.forename: Vinzenz
authors.initials: V
authors.lastname: Smekal
authors.forename: Markus
authors.initials: M
authors.lastname: Wambacher
authors.forename: Franz
authors.initials: F
authors.lastname: Kralinger