Novel dynamic syndesmotic stabilization system improves anteroposterior and axial translation in distal tibiofibular joint.

BACKGROUND

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, for example in length-unstable syndesmotic injuries. The aim of this biomechanical study was to investigate whether a novel screw-suture implant addresses such issues compared to suture-button implants while preserving dynamic capabilities.

METHODS

Eight pairs of human cadaveric lower legs were injured by complete syndesmosis and deltoid ligaments cuts, and 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. Following, all specimens were biomechanically tested over 5000 cycles under combined 1400 N axial and ± 15° torsional loading. Anteroposterior, axial/vertical, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via optical motion tracking.

RESULTS

Anteroposterior and axial/vertical movements were significantly smaller and maintained over the cycles in Group 1 compared with Group 2 (p < 0.001). No further significant differences were identified between the groups (p ≥ 0.318).

CONCLUSION

Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior and axial/vertical stability of the distal tibiofibular joint, and maintains it over time under dynamic loading in a cadaveric study design. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions with length-unstable fibula.

LEVEL OF EVIDENCE/ STUDY

DESIGN

Level V, Controlled Laboratory Study.