The Neviaser portal for superior glenoid anchor insertion: an anatomic study

Purpose. To measure the angular relationship between the Neviaser portal and the superior glenoid labrum in 60 cadaveric specimens to determine whether this portal can be used for reliable anchor placement. Methods. The Neviaser portal of 30 left and 30 right unpaired dry cadaveric scapulae with clavicles were measured by a single observer using an analogue vernier caliper. The angular relationship between the Neviaser portal and the 12 o'clock position of the glenoid labrum was calculated. Results. 13 of the 60 scapulae were excluded from analysis, because the Neviaser portal was medial to the glenoid rim making safe anchor insertion unfeasible. For the remaining 47 scapulae, the mean angles alpha and beta were 58.2 degrees and 57.9 degrees, respectively. Compared with the ideal angles alpha and beta of 30 degrees and 0 degrees, respectively, all the 47 Neviaser portals were more posterior (relative to the 12 o'clock position) and closer to the transverse plane, making insertion of suture anchors in the optimum position unfeasible, except for one that was within 10 degrees of the ideal angles in both planes. Conclusion. Reliable insertion of suture anchors at the 12 o'clock position of the glenoid labrum through the Neviaser portal is unfeasible in most patients.