Morphologic changes in the glenoid after arthroscopic Bankart repair using the double-row technique

Arthroscopic Bankart repair (ABR) using the knotless double-row technique, called the knotless double anchor footprint fixation (DAFF), involves inserting anchors into the scapular neck, passing sutures through the anterior inferior glenohumeral ligament complex, and using face anchors to secure the ligament complex under increased tension. In single-row arthroscopic Bankart repair, a postoperative reduction in glenoid width is frequently observed. This phenomenon is associated with mechanical stress shielding at the anterior glenoid rim, particularly in the area situated anterior to the anchor insertion. Few studies have examined morphologic changes in the glenoid after ABR using the double-row technique. The purpose of this study was to investigate the change of glenoid bone morphology following ABR using the knotless DAFF technique.

Thirty patients (26 males, 4 females) with anterior shoulder instability involving a total of 32 shoulders treated with knotless DAFF were included. Of the 32 shoulders, 10 had bony Bankart lesions, and 22 were classified as erosion type. The 1.4 mm JuggerKnot anchors were used as neck anchors, and the GRYPHON BR anchors were used as face anchors. The Rowe score and the glenoid bone loss using the best-fit circle method on 3D-computed tomography scans were evaluated. Statistical analysis was performed using the Wilcoxon rank-sum test, with statistical significance set at P < .05.

The mean patient age was 24.0 years (range, 15-54 years). The mean follow-up period was 25.4 months (range, 24-50 months). One patient experienced apprehension and pain 50 months postoperatively. The mean Rowe score significantly improved from 22.5 ± 6.6 points preoperatively to 95.5 ± 8.8 points postoperatively (P < .0001). Among the 10 cases with a bony fragment, bony union was achieved in all cases. The mean glenoid bone loss significantly decreased from 17.5 ± 7.0% preoperatively to 4.8 ± 4.0% at a mean of 24.7 months postoperatively (P = .004). In the 22 cases without a bony fragment, the mean glenoid bone loss significantly decreased from 12.0 ± 6.3% preoperatively to 10.2 ± 5.5% at a mean of 24.6 months postoperatively (P = .03).

Using the knotless DAFF technique for arthroscopic Bankart repair, fragment-type cases showed that reliable bony union was achieved in fragment-type cases. Erosion-type cases demonstrated either minimal glenoid bone loss or evidence of glenoid remodeling. These results indicate that the knotless DAFF technique may contribute to the preservation of glenoid morphology and consequently reduce the risk of postoperative shoulder instability.