Suture Retensioning and an Additional Posteroinferior Anchor Increases Stiffness and Decreases Elongation on Cyclic Bankart Repair Biomechanics in a Human Cadaveric Model.

Abstract

To evaluate the isolated and combined biomechanical effect of suture retensioning and the addition of a posteroinferior (PI) anchor during Bankart repair. Ten fresh-frozen cadaveric shoulders (age, 61.3 ± 5.1 years; sex, 90.0% males) were tested in the present study. After preconditioning, Bankart lesions were created, and each shoulder underwent 4 different repair states using knotless soft body anchors: (1) 3-anchor Bankart repair (5:30, 4:30, and 3:30 o'clock), (2) 4-anchor Bankart repair with a PI anchor (6:30 o'clock), (3) 3-anchor Bankart repair with suture retensioning, and (4) 4-anchor Bankart repair with a PI anchor and suture retensioning. Repair sutures were passed through 1 cm of capsulolabral tissue and tensioned to 50 N. Retensioning of each suture was performed to 50 N twice. Stiffness and elongation were evaluated before and after 100 cycles of cyclic loading to 25 N. Stiffness after cyclic loading was highest in the 4-anchor Bankart repair with suture retensioning and was significantly stiffer than the 3-anchor and the 4-anchor Bankart repair (P = .013 and .040, respectively). It was not significantly stiffer than the 3-anchor Bankart repair with suture retensioning (P > .127). Elongation after cyclic loading was lowest in the 4-anchor Bankart repair with suture retensioning and was significantly lower than the 3-anchor and 4-anchor Bankart repair (P = .042 and .020, respectively). It was not significantly different than the 3-anchor Bankart repair with suture retensioning (P > .232). The addition of suture retensioning and a PI anchor to the Bankart repair showed a modest increase in stiffness and a reduction in elongation after cyclic loading. Adding both suture retensioning and a PI anchor to the Bankart repair may decrease the risk for instability recurrence.