Background: Minimal information exists regarding the sub-supraspinatus recess superior to the labrum and inferior to the supraspinatus. Furthermore, movement of the superior labrum during glenohumeral range of motion has not previously been defined. The objectives of this arthroscopic study were to describe the (i) sub-supraspinatus recess dimensions and (ii) superior labral motion.
Methods: Forty-four patients were enrolled and underwent standardized arthroscopic assessment. Analysis consisted of static measurement of the sub-supraspinatus recess depth, as well as the amount of labral motion during passive shoulder motion. Labral movement was categorized relative to the glenoid rim (lateral to the rim, to the rim, or medial to the rim).
Results: All patients had a well-defined sub-supraspinatus recess varying from a depth of 0 mm to 5 mm (n = 10; 22.7%), 5 mm to 10 mm (n = 23; 52.3%) or >10 mm (n = 11; 25%). External rotation in abduction demonstrated the greatest labral movement (p < 0.001) with 28 (80%) shoulders moving medial to the rim.
Conclusions: The sub-supraspinatus recess is consistently present with an average depth of 5 mm to 10 mm. Superior labral motion is present in most patients and is most pronounced in external rotation in abduction. This finding likely has clinical implications for superior labral repair surgery, especially for overhead athletes and laborers who require external rotation in an abducted position for a successful outcome.
Keywords: SLAP; arthroscopy; labrum; shoulder.