Mechanical instability after acute ankle ligament injury: randomized prospective comparison of two forms of conservative treatment.

Objective: This trial has the objective to investigate the incidence of mechanical ankle instability after the conservative treatment of first episode, severe ankle ligamentar lesions. This common lesion affects young, professional and physical active patients, causing important personal and economic consequences. There are difficulties related to adequate diagnosis and treatment for these lesions.

Method: 186 patients with severe ankle ligament lesions were included in this trial. They were randomized in two treatment options. In group A patients were treated using ankle long orthoosis, weight bearing allowed as confortable, pain care, ice, elevation with restricted joint mobilization for three weeks. After that they were maintained in short, functional orthosis (air cast), starting the reabilitation program. In group B patients were immobilized using a functional orthosis (air cast), following the same other sequences that patients in group A.

Results: We did not find significant differences in relation to the residual mechanical ankle instability between both groups. We did not find differences in the intensity of pain, but the functional evaluation using AOFAS score system showed better results in the functional treatment group.

Conclusion: The functional treatment (Group B) had better AOFAS score and few days off their professional activities, comparing with patients treated with rigid orthosis (Group A), without increased chance in developing ankle mechanical instability.