Concomitant osteochondral lesions of the talus affect the stair descent biomechanics of patients with chronic ankle instability: A pilot study

Anterior Talofibular Ligament Repair in Combination With Anterior Tibiofibular Ligament Distal Fascicle Transfer for The Treatment of Chronic Lateral Ankle Instability: A Finite Element Analysis

In recent years, anterior tibiofibular ligament-distal fascicle transfers for anterior talofibular ligament augmentation repair have proposed. However, a comprehensive biomechanical study on the anterior tibiofibular ligament-distal fascicle transfer is still lacking. We are established four distinct groups, namely the normal, the anterior talofibular ligament rupture, the anterior talofibular ligament repair, and the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer. We assessed the anterior drawer test and varus stress test of the ankle in each group. Moreover, we employed the model to simulate and compute the total displacement and von-Mises stress of the talus cartilage at varying gait phases, including foot strike, tibia vertical, and toe-off phases. The results of the anterior drawer test and varus stress test revealed that the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer group exhibited greater closeness to the normal group. Regarding von-Mises stress in cartilage, the three gait instants had higher values in the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer group than the other groups. Nevertheless, regarding total displacement, the toe-off phases exhibited higher values in the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer group than the other groups. Using ATiFL-DF transfer to augment ATFL repair is a potential feasible procedure. However, this procedure could potentially compromise the anterior tibiofibular ligament's contribution to the dynamic stability of the ankle. Therefore, we recommend conducting further in-depth research to ensure the suitability and success of this technique in a clinical environment.

Functional effects of arthroscopic modified Broström procedure on lateral ankle instability: A pilot study

BACKGROUND

This study aims to assess the mechanical and functional effects of the arthroscopic modified Broström procedure (AMBP) on patients with lateral ankle instability.

METHODS

Eight patients with unilateral ankle instability treated with AMBP and eight healthy subjects were recruited. Healthy subjects, preoperative and one-year postoperative patients were assessed using outcome scales and the Star Excursion Balance Test (SEBT) for dynamic postural control. One-dimensional statistical parametric mapping was performed to compare ankle angle and muscle activation curve during stair descent.

RESULTS

The patients with lateral ankle instability showed good clinical outcomes and increased posterior lateral reach during the SEBT after the AMBP (p = 0.046). The medial gastrocnemius activation after initial contact was reduced (p = 0.049), and the peroneal longus activation after initial contact was promoted (p = 0.014).

CONCLUSION

The AMBP has functional effects of promoting dynamic postural control and peroneal longus activation within one year of follow-up, which can benefit patients with functional ankle instability. However, the medial gastrocnemius activation was unexpectedly reduced post operation.