Arthroscopic Suture Anchor Repair of the Lateral Ligament Ankle Complex A Cadaveric Study

Background: Operative treatment of mechanical ankle instability is indicated for patients with multiple sprains and continued episodes of instability. Open repair of the lateral ankle ligaments involves exposure of the attenuated ligaments and advancement back to their anatomic insertions on the fibula using bone tunnels or suture implants. Hypothesis: Open and arthroscopic fixation are equal in strength to failure for anatomic Brostrom repair. Study Design: Controlled laboratory study. Methods: Seven matched pairs of human cadaveric ankle specimens were randomized into 2 groups of anatomic Brostrom repair: open or arthroscopic. The calcaneofibular ligament and anterior talofibular ligament were excised from their origin on the fibula. In the open repair group, 2 suture anchors were used to reattach the ligaments to their anatomic origins. In the arthroscopic repair group, identical suture anchors were used for repair via an arthroscopic technique. The ligaments were cyclically loaded 20 times and then tested to failure. Torque to failure, degrees to failure, initial stiffness, and working stiffness were measured. A matched-pair analysis was performed. Power analysis of 0.8 demonstrated that 7 pairs needed to show a difference of 30%, with a 15% standard error at a significance level of = .05. Results: There was no difference in the degrees to failure, torque to failure, or stiffness for the repaired ligament complex. Nine of 14 specimens failed at the suture anchor. Conclusion: There is no statistical difference in strength or stiffness of a traditional open repair as compared with an arthroscopic anatomic repair of the lateral ligaments of the ankle. Clinical Relevance: An arthroscopic technique can be considered for lateral ligament stabilization in patients with mild to moderate mechanical instability.