title: The 7-o'clock posteroinferior portal for shoulder arthroscopy.
abstract: BACKGROUND
  Access to the inferior glenohumeral joint of the shoulder is very limited through the traditional 2- or 3-o'clock anterior portals.
  
  
  OBJECTIVE
  The 7-o'clock posteroinferior portal offers an excellent alternative approach.
  
  
  METHODS
  Descriptive anatomic study.
  
  
  METHODS
  Six paired cadaveric shoulders were used to arthroscopically develop and test a 7-o'clock posteroinferior portal. The distances between the portal and the subscapular and axillary nerves were measured with the arm in six different positions, combining flexion, extension, abduction, and adduction.
  
  
  RESULTS
  The distance from the 7-o'clock posteroinferior portal to the axillary nerve was 39 +/- 4 mm and to the suprascapular nerve was 28 +/- 2 mm. There was no statistically significant nerve-to-portal differential distance when the arm was placed in flexion, extension, abduction, or adduction. The inside-to-outside technique produced a 7-o'clock posteroinferior portal approximately 5 mm further from both the axillary and suprascapular nerves than did the outside-to-inside method. The angle of divergence from the 7-o'clock posterior portal skin incision to the axillary nerve was 47 degrees and to the suprascapular nerve was 33 degrees.
  
  
  CONCLUSIONS
  The 7-o'clock portal affords safe, direct working access to the inferior capsular recess of the glenohumeral joint.
  
  
  CONCLUSIONS
  The 7-o'clock portal is a safe and effective technique for use by shoulder surgeons.
authors.affiliation: Tampa Bay Orthopaedic Specialists, St. Petersburg, Florida 33709, USA.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Davidson
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Rivenburgh
mesh_terms: D001182:Arthroscopy / Q000379:methods* / Q000592:standards; D002102:Cadaver; D006801:Humans; D012785:Shoulder Joint / Q000601:surgery*