Biomechanical effects of position and angle of insertion for all-suture anchors in arthroscopic Bankart repair.

Background: The biomechanical properties of all-suture anchor for labral repair depending on the insertion angle and location are lacking. The purpose of this study was to quantify the biomechanical fixation characteristics of the anchor position and insertion angle of all-suture anchors for arthroscopic Bankart repair.

Methods: Twenty-four fresh frozen cadaveric glenoid were used. All-suture anchors with 1.5-mm diameter were randomly inserted at 2:30, 4:00, and 5:30 o'clock positions on the glenoid edge, with either 30°, 45° or 60° insertion angles to the mediolateral axis of the glenoid. Anchors were preloaded to 5 N and cyclically loaded from 5 N to 20 N for 10 cycles, followed by a load to failure test at 60 mm/min. Permanent, non-recoverable displacement was quantified at the end of the cyclic loading test to yield load.

Findings: All-suture anchors implanted at the 2:30 o'clock position of the glenoid provided greater stiffness, yield load, and ultimate load than those inserted at the 4:00 and 5:30 o'clock positions, regardless of the insertion angle. Displacement at yield and ultimate load were similar among the positions and insertion angles (yield load, vs. 4:00, p = 0.01; vs. 5:30, p = 0.045; ultimate load, vs. 4:00, p < 0.01; vs. 5:30, p < 0.01). The insertion angles of 30°, 45° and 60° did not influence mechanical stability between the 4:00 and 5:30 o'clock positions.

Interpretation: The insertion angle of all-suture anchors does not significantly affect the stability at antero-inferior quadrant of the glenoid.