Anterior Talofibular Ligament Ruptures, Part 1

Abstract

Background: The concept of utilizing nonabsorbable suture tape fixed directly to bone to augment Broström repairs of the anterior talofibular ligament (ATFL) has been proposed. No biomechanical studies of this technique are available. Hypothesis: We hypothesized that suture tape augmentation alone and Broström repair with suture tape augmentation would have similar biomechanical properties to the intact ATFL at time zero in a cadaveric model. Study Design: Controlled laboratory study. Methods: Eighteen fresh-frozen cadaveric ankles were randomized into 3 groups of 6 specimens each: (1) intact ATFL, (2) suture tape augmentation, and (3) Broström repair with suture tape augmentation. The specimens were loaded to failure to determine the strength and stiffness of each construct. Results: The mean ultimate load to failure of suture tape augmentation (315.5 ± 66.8 N) was significantly higher than that of the intact ATFL (154.0 ± 63.7 N) (P = .017). The mean ultimate load of the Broström repair with suture tape augmentation (250.8 ± 122.7 N) was not significantly different from that of the intact ATFL. The mean stiffness of augmentation alone (31.4 ± 9.9 N/mm) was significantly higher than that of the intact ATFL (14.5 ± 4.4 N/mm) (P = .008). The mean stiffness of the Broström repair with augmentation (21.1 ± 9.1 N/mm) was not significantly different from that of the intact ATFL. Conclusion: The ATFL with suture tape augmentation is at least as strong and stiff as the native ATFL at time zero in a fresh-frozen cadaveric model. Clinical Relevance: The Broström repair for lateral ankle ligament ruptures is often unsuccessful in circumstances of poor tissue quality. Augmentations, such as with suture tape, have been proposed for these situations. Suture tape used alone or in combination with the Broström repair provided increased strength and stiffness compared with the standard Broström repair, which produced an immediate strength of less than 50% of the intact ATFL. Adding strength to the Broström repair may be valuable in patients with generalized ligamentous laxity, in large patients or elite athletes, or when graft reconstruction is not feasible.