Biomechanical improvement of anterior talofibular ligament by augmentation repair of ligament advance reinforcement system: a cadaver study

BACKGROUND: Ankle sprain are one of the most frequent sports injuries. Some individuals will develop chronic lateral ankle instability (CLAI) after ankle sprain and suffer from recurrent ankle sprain. Current surgical treatment of CAI with anterior talofibular ligament (ATFL) rupture fails to restore the stability of the native ATFL. Ligament Advance Reinforcement System (LARS) augmentation repair of ATFL was developed to improve its primary stability after repaired. METHODS: This study was performed to evaluate whether LARS augmentation repair of ATFL had similar stability as the modified Broström repair and the intact ATFL to maintain ankle construct stability. Standardized surgical techniques were performed on eighteen fresh frozen cadaver ankle specimens. The intact ATFL group has just undergone an ATFL exploratory surgery. The modified Broström procedure is based on anatomical repair of the ATFL with a 2.9 mm suture anchor, and the LARS procedure is an augmentation procedure of the ATFL using LARS ligaments based on the modified Broström procedure. A dynamic tensile test machine was used to assess load-to-failure testing in the three groups. The ultimate failure load and stiffness were calculated and reported from the load-displacement curve. A one-way analysis of variance was used to detect significant differences (p < 0.05) between the LARS augmentation repair, the modified Broström repair and the intact ATFL, followed by least significant difference (LSD) post-hoc tests. RESULTS: The LARS augmentation repair group showed an increased in ultimate failure to load and stiffness compared to the other two groups. There were no significant differences in ultimate failure to load and stiffness between the modified Broström and the intact ATFL, the LARS ligament for ATFL augmentation allows for improved primary stability after repair and reduced stress on the repaired ATFL, which facilitates healing of the remnant ligament. CONCLUSIONS: The LARS augmentation repair of ATFL represents a stable technique that may allow for the ankle stability to be restored in patients with CAI after surgery.