title: The variable morphology of suprascapular nerve and vessels at suprascapular notch: a proposal for classification and its potential clinical implications.
abstract: OBJECTIVE
  The most common place for suprascapular nerve entrapment is the suprascapular notch. The aim of the study was to determine the morphological variation of the location of the suprascapular nerve, artery and vein, and measure the reduction in size of the suprascapular opening in each type of the passage.
  
  
  METHODS
  A total of 106 human formalin-fixed cadaveric shoulders were included in the study. After dissection of the suprascapular region, the topography of the suprascapular nerve, artery and vein was evaluated. Additionally, the area of the suprascapular opening was measured using professional image analysis software.
  
  
  RESULTS
  Four arrangements of the suprascapular vein, artery and nerve were distinguished with regard to the superior transverse scapular ligament: type I (61.3 %) (suprascapular artery was running above ligament, while suprascapular vein and nerve below it), type II (17 %) (both vessels pass above ligament, while nerve passes under it), type III (12.3 %) (suprascapular vessels and nerve lie under ligament) and type IV (9.4 %), which comprises the other variants of these structures. Statistically significant differences regarding the suprascapular opening were observed between the specimens with types II and III. Anterior coracoscapular ligaments were present in 55 from 106 shoulders.
  
  
  CONCLUSIONS
  The morphological variations described in this study are necessary to better understand the possible anatomical conditions which may promote suprascapular nerve entrapment (especially type III). They may be useful during open and endoscopic procedures at the suprascapular notch to prevent such complications as unexpected bleeding.
authors.affiliation: Department of Angiology, Medical University of Łódź, Narutowicza 60, 90-136, Łódź, Poland. michal.polguj@umed.lodz.pl.
authors.forename: Michał
authors.initials: M
authors.lastname: Polguj
authors.affiliation: Department of Neurology, Medical University of Łódź, Łódź, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Rożniecki
authors.affiliation: Clinic of Orthopedic and Pediatric Orthopedics, Medical University of Łódź, Łódź, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Sibiński
authors.affiliation: Clinic of Orthopedic and Pediatric Orthopedics, Medical University of Łódź, Łódź, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Grzegorzewski
authors.affiliation: Department of Radiology, Medical University of Łódź, Łódź, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Majos
authors.affiliation: Department of Normal and Clinical Anatomy, Medical University of Łódź, Łódź, Poland.
authors.forename: Mirosław
authors.initials: M
authors.lastname: Topol
mesh_terms: D001158:Arteries / Q000033:anatomy & histology*; D002102:Cadaver; D006801:Humans; D008023:Ligaments, Articular / Q000098:blood supply / Q000294:innervation; D009408:Nerve Compression Syndromes / Q000145:classification*; D010525:Peripheral Nerves / Q000033:anatomy & histology*; D012540:Scapula / Q000033:anatomy & histology*; D012782:Shoulder / Q000098:blood supply / Q000294:innervation