124. INJURY OF THE SUPRASCAPULAR NERVE DURING ARTHROSCOPIC REPAIR OF SUPERIOR LABRAL TEARS: AN ANATOMIC STUDY

Abstract

Purpose: Due to its proximity to the glenohumeral joint, the suprascapular nerve may be at risk of iatrogenic nerve injury during arthroscopic labral repair. Our primary objective is to evaluate the risk of suprascapular nerve injury during standard drilling techniques utilized in arthroscopic superior labral repairs. Secondarily, we evaluated the correlation between this risk and scapular size.

Method: Forty-two cadaveric shoulders were dissected to isolate their scapulae. A surgical drill and guide was used to create suture anchor holes in 3 locations in the superior rim of the glenoids as typically done in arthroscopic superior labral repairs. The orientation of these drill holes correspond to common shoulder arthroscopic portals. The suprascapular nerve was then dissected from the suprascapular notch to the spinoglenoid notch. The presence of drill perforations through the medial cortex of the glenoid vault was recorded along with the corresponding hole depth and distance to the suprascapular nerve.

Results: Medial glenoid vault perforations occurred in 8/21(38%) cadavers with a total of 18/126(14%) perforations. The suprascapular nerve was in line of the drill path in 5/18(28%) perforations. Female specimens and smaller scapulae had a statistically higher risk of having a perforation (p< 0.05).

Conclusion: The results of this anatomic study suggest that there is a substantial risk of medial glenoid vault perforation. When a perforation does occur, the suprascapular nerve appears to be at high risk for injury especially with more posterior drill holes. The risk is significantly higher in females and in smaller scapulae.