title: The superior-medial shoulder arthroscopy portal is safe.
abstract: OBJECTIVE
  The superior-medial (SM) shoulder arthroscopic portal (Neviaser portal) is the portal anatomically closest to the suprascapular nerve, and any potential benefits of this portal would be mitigated if risk of suprascapular nerve injury were significant. The purpose of this study is to determine the safety of the SM arthroscopic shoulder portal. We hypothesize that the SM shoulder arthroscopic portal is safe.
  
  
  METHODS
  Twelve fresh cadaveric shoulders were securely positioned to simulate shoulder arthroscopy in the beach-chair position with the arm at the patient's side in neutral rotation. An SM portal was established 1 cm medial to the acromion and 1 cm posterior to the clavicle, and a 5.5-mm burr sheath was oriented toward the acromioclavicular joint. The skin and trapezius were resected, the supraspinatus was retracted, and the suprascapular nerve was identified. The distance between the sheath and the nerve was measured by 2 independent observers with calipers. A safe distance was defined as 10 mm.
  
  
  RESULTS
  The measured distances between the nerve and burr ranged from 18.5 to 35.7 mm, with a mean of 24.2 +/- 5 mm. The distance is significantly greater than the safe distance of 10 mm (P < .0001).
  
  
  CONCLUSIONS
  This study shows that the SM portal is safe. The distance between an instrument oriented toward the acromioclavicular joint via the SM portal and the suprascapular nerve was 18.5 mm or greater in all specimens.
  
  
  CONCLUSIONS
  Our study has clinical relevance because the SM portal is useful for arthroscopic rotator cuff repair, arthroscopic superior labrum repair, and arthroscopic distal clavicle excision.
authors.affiliation: Taos Orthopaedic Institute Research Foundation, Taos, New Mexico 87571, USA.
authors.forename: Shane K
authors.initials: SK
authors.lastname: Woolf
authors.forename: Dan
authors.initials: D
authors.lastname: Guttmann
authors.forename: Michael M
authors.initials: MM
authors.lastname: Karch
authors.forename: Robert D
authors.initials: RD
authors.lastname: Graham
authors.forename: John B
authors.initials: JB
authors.lastname: Reid
authors.forename: James H
authors.initials: JH
authors.lastname: Lubowitz
mesh_terms: D001182:Arthroscopy / Q000379:methods*; D002102:Cadaver; D006801:Humans; D012785:Shoulder Joint / Q000033:anatomy & histology* / Q000294:innervation