Extensor retinaculum augmentation reinforces anterior talofibular ligament repair

Repair of the anterior talofibular ligament often is augmented with the inferior extensor retinaculum because it is thought to reinforce the primary ligament repair. The additional dissection and suturing extend the duration of surgery, and not all surgeons routinely include inferior extensor retinaculum augmentation in anterior talofibular ligament repairs. To determine whether there is a reasonable basis for this surgery, we ascertained the degree to which inferior extensor retinaculum augmentation reinforced the primary anterior talofibular ligament repair. Matched pairs of cadaveric ankles had controlled inversion while monitoring resistance to inversion, first with the anterior talofibular ligament sectioned, then with primary anterior talofibular ligament repair alone or with inferior extensor retinaculum augmentation. The resistance to ankle inversion was greater at 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 25 degrees rotation in ankles that had inferior extensor retinaculum augmentation. Anterior talofibular ligament failure occurred at similar inversion angles in both treatment groups, but the primary anterior talofibular ligament repair required more torque to fail in the augmented group. With these ankle loading conditions, inferior extensor retinaculum augmentation provided protection to the primary anterior talofibular ligament repair, indicating that broader clinical use of augmentation may be warranted.