Fixation of the Ankle Syndesmosis – Is There a Best Way?

Objectives:
Ankle fractures are one of the commonest fractures in the orthopedic practice, responsible for 10.2% of the fractures 1. 10% of all ankle fractures sustain an associated syndesmotic injury 2. Historically syndesmosis immobilization was done using a single or a double screw. These screws have to be removed 8-12 weeks after the primary surgery and before weight baring is allowed. Suture- button device (Tightrope) is a relatively new technique for syndesmosis fixation, characterized by a non-absorbable stitch held tight between two cortical metal buttons. The main benefits of the tightrope device are that it does not require removal and it allows weight baring.

The aim of this study was to compare the functional outcome of both screw and tightrope fixation for syndesmotic injuries and conclude whether there is a preferred way to treat syndesmotic injuries.

Methods:
Using the hospital registry archive, we collected the patients who underwent surgery for ankle fracture and extracted the patients who had syndesmosis fixation. Patients were evaluated using functional questionnaires (SF 12, AOFAS) and VAS pain index. Physical examination was conducted in several patients. The two groups were compared for their physical examination results, functional questionnaires score and general satisfaction. Patients’ evaluation was done physically or via telephone call.

Results:
70 patients who underwent Open Reduction Internal Fixation surgery for ankle fracture between the years 2012 and 2020 – had a concomitant syndesmotic injury. 21 patients were available for the study. 12 males and 9 females. The average follow-up was 3 years post the last surfery.11 patients had syndesmotic fixation using a screw , 10 patients using a tightrope.

For the SF 12 - The syndesmotic screw group received an average score of 28.6 while the tightrope group received an average score of 28.3. The average of AOFAS score for the Tightrope group was 84.5 compares to 74.55 in the screw group (p=0.041). The average VAS pain index for the tightrope group was 1.4 compares to 3.2 in the screw group (p=0.206). Physical examination showed similar range of motion and stability.

None of the patients had positive syndesmotic injury tests. Second surgery was needed in 11 patients in the screw group but only in one patient in the TR group. complication rate was similar.

Conclusion:
Syndesmosis fixation using Tightrope device show significantly better results in the AOFAS score and lower Pain score. It also has fewer second surgery for device removal. These results correlate to the recent literature. We conclude that tightrope should be consider the standard method for syndesmosis injury fixation.