Open versus minimally invasive fixation of a simulated syndesmotic injury in a cadaver model.

BACKGROUND

Malreduction of unstable syndesmotic ankle fractures is common. This study compared the reduction quality of an anterolateral open technique (OT) versus a conventional minimally invasive technique (MIT).

METHODS

Fourteen fresh-frozen lower torso specimens with 28 matched lower extremities underwent computed tomography (CT) to measure syndesmosis position before dissection. Reduction was performed using direct visualization and fluoroscopy for the OT group (right-sided specimens) and fluoroscopy only for the MIT group (left-sided specimens). Fixation was achieved with 2 cortical screws. Measurements were repeated with postfixation CT scans. Statistical analysis used a two-tailed t test (α = 0.05).

RESULTS

Mean posterior fibula-tibia distance decreased after OT by 0.3 ± 0.5 mm and increased after MIT by 0.7 ± 0.6 mm (P = 0.025 for difference between techniques). Mean anterior fibula-tibia distance decreased after OT by 0.4 ± 0.2 mm (P = 0.007) and did not change significantly after MIT (- 0.01 ± 0.4 mm (P = 0.686). Mean anterior translation after OT was 0.04 ± 0.4 mm (P = 0.856), and mean posterior translation after MIT was 0.3 ± 0.7 mm (P = 0.434). Mean medialization after OT was 0.3 ± 0.4 mm (P = 0.132), and mean lateralization after MIT was 0.2 ± 0.6 mm (P = 0.446).

CONCLUSIONS

Both techniques produced near-anatomic reduction of the fibula, with MIT producing significantly more internal rotation malreduction than OT. OT appears to restore near-anatomic fibula position, although this did not differ significantly from the results of MIT. We conditionally recommend OT when closed reduction of the syndesmosis cannot be obtained.