Injury mechanisms of ankle fractures with dislocation and analysis of differences on functional outcome.

Background: In the existing classifications, no importance is given to dislocations accompanying ankle fractures. The present study aims to investigate differences in injury mechanisms of ankle fractures with concomitant dislocation injury in respect of functional outcomes and complications.

Methods: A retrospective evaluation was carried out of 285 patients who underwent surgery in our clinic for an ankle fracture between January 2012 and December 2018. A comparison was made of functional scores and complications between the patients with ankle fracture with dislocation (AF-D group) and patients with ankle fracture without dislocation (AF-WD). The correlation of dislocation with current classifications (Lauge-Hansen and Danis-Weber) and the effects on functional outcomes were also evaluated. In addition to functional scores, a record was also made for each patient of infection during follow-up, soft-tissue defect, malalignment, non-union, arthrosis and Reflex Sympathetic Dystrophy Syndrome (RSD).

Results: The mean age of the patients was 44.7±12.04 years (range, 18-72 years) and the mean follow-up period was 3.2 years. Ankle fracture with dislocation was observed in 88 (30.8%). Similar functional results were determined in the AF-WD and AF-D groups with mean AOFAS 84.05±10.5, and 80.33±9.47, respectively (p=0.379), and mean VAS scores of 1±0.5 and 1.23±0.48, respectively (p=0.117). When the AOFAS values of the dislocation function results were evaluated according to the Lauge-Hansen and Danis-Weber subgroups, no significant difference was observed (p=0.562, 0.723). Arthrosis was seen in two of the AF-WD group and seven of the AF-D group (p=0.004). RSD was determined in two of the AF-WD group and in 10 of the AF-D group (p=0.000). From a medico-legal perspective, patients should be informed about arthrosis, and RSD is another significant problem encountered in this patient group.

Conclusion: Although dislocation accompanying ankle fracture was not seen to worsen functional results, arthrosis and RSD were determined more often in these patients.