Scapular notch, spinoglenoid notch, and scapular dimensions: implications on the safe zone of the suprascapular nerve

The suprascapular nerve corresponds to one of the supraclavicular branches of the brachial plexus, and its route exposes it to being injured during some surgical procedures. Morphometric analysis of the scapula has been proposed as a tool for preventing injuries to the suprascapular nerve. The present investigation aimed to determine the safe distances for approaching the suprascapular nerve at the level of the scapular notch (SPN) and spinoglenoid notch, in addition to establishing its relationship with the type of SPN and with two scapular dimensions: major longitudinal axis (MLA) and major transverse axis (MTA). For this purpose, a descriptive-correlative, quantitative, non-experimental and transversal study was carried out, in which 82 dry scapulae from adult individuals of Chilean origin were investigated. The main results of this study found that prevalences were highest for SPNs types II (36.2%), I (29.3%), and III (26.0%), with average distances that were considered safe in all types of SPNs. Furthermore, there was a positive correlation, with P<0.05, between the MTA (r=0.526; r=0.634), MLA (r=0.284) and the safe distances for the suprascapular nerve at the level of the SPN and incisura spinoglenoid of the scapulae studied. Scapular dimensions such as the MTA and the MLA could, therefore, be used to predict a safe zone for the suprascapular nerve, potentially contributing to a reduction in the current rate of injury of the suprascapular nerve in surgical procedures involving the deltoid and scapular regions.