title: The safe zone for avoiding suprascapular nerve injury during shoulder arthroscopy: an anatomical study on 500 dry scapulae.
abstract: OBJECTIVE
  Suprascapular nerve injury may be a complication during shoulder arthroscopy. Our aim was to verify the reliability of the existing data, assess the differences between scapulae in the 2 genders and in the same subject, obtain a safe zone useful to avoid iatrogenic nerve lesions, and analyze the existing correlations between the scapular dimensions and the safe zone.
  
  
  METHODS
  We examined 500 dried scapulae, measuring 6 distances for each one, referring to the scapular body, glenoid, and the course of the suprascapular nerve, also catalogued according to gender and side. Differences due to gender were assessed comparing mean ± sd of each distance in males and females; paired t test was used to compare distances deriving from each couple. Successively, we calculated our safe zone and Pearson's correlation.
  
  
  RESULTS
  We found nonsignificant differences between the right and left distances deriving from each couple; differences due to gender were stated. We defined 3 kinds of safe zones referring to: 500 scapulae; males (139 scapulae) and females (147 scapulae). The correlation indexes calculated between the axis of the scapular body and glenoid, and the posterosuperior distance (referring to the suprascapular nerve) were 0.624, 0.694, 0.675, 0.638; while those with the posterior distance were 0.230, 0.294, 0.232, 0.284.
  
  
  CONCLUSIONS
  Knowledge of the safe zone, for avoiding suprascapular nerve injury, is important; gender and specific scapular dimensions should be evaluated, as they influence the dimensions of the safe zone. The linear predictors should be used to obtain specific values of the posterosuperior limit in each patient.
authors.affiliation: Department of Orthopaedics and Traumatology, University of Rome Sapienza, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Gumina
authors.forename: Paolo
authors.initials: P
authors.lastname: Albino
authors.forename: Marco
authors.initials: M
authors.lastname: Giaracuni
authors.forename: Annarita
authors.initials: A
authors.lastname: Vestri
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ripani
authors.forename: Franco
authors.initials: F
authors.lastname: Postacchini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001182:Arthroscopy / Q000379:methods*; D001917:Brachial Plexus / Q000033:anatomy & histology* / Q000601:surgery; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D059348:Peripheral Nerve Injuries / Q000209:etiology / Q000517:prevention & control*; D015203:Reproducibility of Results; D012540:Scapula / Q000294:innervation* / Q000601:surgery; D012782:Shoulder / Q000033:anatomy & histology / Q000601:surgery*; D012785:Shoulder Joint / Q000294:innervation / Q000601:surgery; D055815:Young Adult