The Augmentation Technique for Anatomical Reduction of Shortened Lateral Ligament Complex in Modified Broström Procedure

Abstract

Category: Ankle, Sports Introduction/Purpose: The modified Broström procedure(MBP) is clinically standard surgical treatment of lateral ankle instability with or without subfibular ossicle. But if there is a large ossicle or distal malposition of lateral ligament complex(LLC), it can result in a lack of remnant ligamentous tissue and leave gap that may not be approximated. Thus, we have proposed an augmentation technique for anatomical reduction of shortened LLC in MBP and evaluated radiologic and clinical findings. Methods: From December 2013 to February 2018, fifty two of fifty six patients who had shortened LLC treated with the augmentation technique with MBP using absorbable suture material. LLC(anterior talofibular ligament(ATFL) and calcaneofibular ligament(CFL)) was exposed after inferior extensor retinaculum(IER) was incised. Then, we identified shortened LLC. Then, we incised just distal part of connecting soft tissue of ATFL and CFL additionally for reduction to anatomic footprint. After confirmation of reduction, 4 or 5 bone tunnels were made and deep fiber of LLC was repaired tightly with foot in neutral dorsiflexion and 5° eversion by using horizontal mattress and simple stitch. Then, superficial fiber with capsule of LLC was repaired by priorly tied suture without cutting. Finally, IER was reinforced. Results: Mean AOFAS scores improved from 59.2 to 91.4 at final follow-up. Mean Karlsson scores also improved from 61.3 to 89.5 at final follow-up. Mean talar tilt angles were 13.4° preoperatively and 5.8° postoperatively. Mean anterior talar translations were 9.1 mm preoperatively and 5.7 mm postoperatively. There was significant improvement between preoperative & final follow- up in all parameters (all p < .05). During follow up, no clinical symptom like experience of instability or irritation of skin were encountered after surgery, and no patient underwent revision lateral ligament surgery. Conclusion: Augmentation technique of LLC flap in MBP enabled anatomical reduction of shortened LLC to footprint, and provided good clinical and radiographic outcomes. If further comparative and mechanical study is supported, this technique would be a good treatment option.