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

Purpose To evaluate the isolated and combined biomechanical effect of suture retensioning and the addition of a posteroinferior (PI) anchor during Bankart repair. Methods 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. Results 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). Conclusions 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. Clinical Relevance Adding both suture retensioning and a PI anchor to the Bankart repair may decrease the risk for instability recurrence.