The effect of the Tscherne injury pattern on the outcome of operatively treated Lisfranc fracture dislocations.

BACKGROUND

Lisfranc fracture dislocations cause severe tarso-metatarsal malalignment. The research question of this study was to evaluate the severity of the soft tissue injury on the final clinical outcome and compare that with the effect of various determinants on the disability in daily living activities after open reduction and internal fixation of a Lisfranc injury.

METHODS

This study consisted of a retrospective analysis of patients with Lisfranc fracture dislocations who were treated by open reduction and internal fixation beween 2004 and 2009. Evaluation focused mainly on the severity of the soft tissue injury, age, fracture classification, time to operation, posttraumatic osteoarthritis, and the results were compared with American Foot and Ankle Society (AOFAS) scores, and Foot and Ankle Disability Index (FADI). Eight patients had Tscherne Grade 1, 13 had Grade 2, and 11 had Grade 3 soft tissue injuries. Myerson classification revealed 11 type A, 8 type B and 13 type C fractures. Six patients' operations were delayed beyond 8h.

RESULTS

Of the 38 patients treated in the study period, 32 patients (11 female, 21 male; <30 y-old: 14, >30 y-old: 18) were available for complete follow-up (average, 55.5 months). The comparison of treatment results revealed that those patients with high grade soft tissue injuries had lower AOFAS and FADI scores (43.8±15.9, 53.7±9.4, respectively) when compared to Tscherne Grade 1 injuries (82.8±6.1, 109±13.9, respectively) (p<0.001). The overall negative impact of the severity of soft tissue injury on functional outcomes had similar significance with regard to post-traumatic osteoarthritis, and fracture type. There was also a statistically significant difference between outcome measures and post-reduction quality (p=0.002). Patient age (p=0.9) and delayed surgery (p=0.5) had no statistically significant effect on the final outcome.

CONCLUSIONS

Satisfactory results can be achieved with open reduction for Lisfranc injuries. However, despite this treatment, both the severity of the soft tissue injury and non-anatomic reduction are negative prognostic factors in the treatment of Lisfranc fracture dislocations.