Introduction

The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in full progress. Using suture-button repair devices is one of the dynamic stabilization options; however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues (Fig 1). This implant system provides the fixation of a screw and the flexibility of a suture, addresses the limitations of suture-button constructs related to both the lack of tension control and medial soft-tissue disruption, and enables precise anatomical syndesmotic fixation.

Materials and Methods

Eight pairs of human anatomical specimens, namely lower legs, were scanned by computed tomography (CT) under 700 N single-leg axial loading in five foot positions – neutral, 15° external/internal rotation and 20° dorsiflexion/plantarflexion in three different states: (1) pre-injury (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV as well as supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implant for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond/joint surface (Fig 2).

Results

In each group clear space increased significantly after injury (P ≤ .004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (P ≤ .041). In addition, after reconstruction it was significantly smaller in Group 1 compared with Group 2 (P < .001). Anteroposterior and axial movements were significantly smaller in Group 1 compared with Group 2 (P < .001; Fig 3). No further significant differences were identified nor detected between the two groups (P ≥ .113).

Conclusion

Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior translation and axial stability of the tibiofibular joint and maintains it over time under dynamic loading. Therefore, it can be considered as a valid option for treatment of syndesmotic disruptions.