Absorbable suture anchor and knotless anchor techniques produced similar outcomes in arthroscopic anterior talofibular ligament repair

Purpose The purpose of this study is to compare absorbable suture anchor with knotless anchor techniques for arthroscopic anterior talofibular ligament (ATFL) repair. Method A multicenter retrospective study was performed with 185 patients, who had undergone an arthroscopic ATFL repair procedure using absorbable suture anchor or knotless anchor between May 2017 and October 2019. The follow-up time was a minimum of 18 months. Karlsson-Peterson score, visual analogue scale (VAS), and Cumberland ankle instability tool (CAIT) were evaluated. The complications were also recorded. Results One hundred and seven patients underwent one absorbable suture anchor repair procedure (Group A [A]), and the other seventy-eight patients underwent one knotless anchor repair procedure (Group B [B]). At the final follow-up, both Karlsson-Peterson score (A, pre 61.0 +/- 8.0 vs post 93.5 +/- 5.3, P < 0.001; B, pre 59.5 +/- 8.2 vs post 92.4 +/- 6.3, P < 0.001), VAS score (A, pre 5.0 +/- 1.3 vs post 0.5 +/- 0.7, P < 0.001; B, pre 5.5 +/- 1.2 vs post 0.9 +/- 1.0, P < 0.001), and CAIT score (A, pre 53.1 +/- 12.0 vs post 93.1 +/- 6.6, P < 0.001; B, pre 51.6 +/- 12.0 vs post 93.1 +/- 6.5, P < 0.001) improved significantly in both groups. There was no significant difference between the two groups regarding the Karlsson-Peterson score (A, pre 61.0 +/- 8.0 vs B, pre 59.5 +/- 8.2, n.s; A, post 93.5 +/- 5.3 vs B, post 92.4 +/- 6.3, n.s), CAIT score (A, pre 53.1 +/- 12.0 vs B, pre 51.6 +/- 12.0, n.s; A, post 93.1 +/- 6.6 vs B, post 93.1 +/- 6.5, n.s) and the change ranges of VAS (A, 4.5 +/- 1.0 vs B, 4.6 +/- 1.2, n.s). Anchor complications were easier to occur in Group B (0/107 vs 6/78, P = 0.007). Knot irritation slightly increased in Group A (10/107 vs 0/78, P = 0.006). No significant difference was found regarding total complication rates (A, 10/107 vs B, 6/78, n.s). Conclusion Absorbable suture anchor and knotless anchor for arthroscopic ATFL repair produced similar clinical outcomes. The ankle stability scores increased significantly in both groups. However, the knotless anchor has a higher risk to loosen, deviated direction or break, while the absorbable suture anchor still has a slim chance of knot irritation.