[The Significance of Early Reposition in Patients with Visible Malposition of the Upper Ankle Joint]

Background: Protracted dislocation of the upper ankle joint can lead to substantial damage to the surrounding soft tissue, possibly followed by local complications and longer hospitalisation. Although reposition is usually easy to conduct, it is commonly recommended that this should only be performed by an experienced specialist, as long as there is no neurovascular restriction. There are however no exact data or studies on this problem. The aim of the present study is to examine whether early reposition is of benefit for subsequent treatment. Methods: Retrospective study of all patients in a supra-regional trauma centre during the period from January 2009 to July 2015, with either prehospital reposition of the ankle joint because of visible malposition or documented visible malposition on arrival at hospital. Patients with relevant concomitant injuries elsewhere were excluded. Data on the duration of dislocation were matched with diagnostic findings at the time of hospital admission, the kind of primary care, local complications and the time of hospitalisation, using linear regression analysis and ANOVA calculations. Results: Of a total of 391 patients with a dislocation or a fracture dislocation of the ankle joint within this period, 132 fulfilled the inclusion criteria. These patients were divided into 5 groups on the basis of the time of dislocation. Time to reposition was less than one hour for 39 patients, between one and two hours for 29 patients, between two and six hours for 41 patients, between six and 24 hours for 13 patients and more than 24 hours for 10 patients, all with a visible dislocation. The results on admission showed a significant increase in skin bruises and tension bullae with increasing time of dislocation. A longer time of dislocation was associated with more two stage surgical procedures with external fixators and a decreasing number of single stage procedures. While there was immediate definitive treatment of 79.5 % of the patients in the first group, this figure decreased continuously to 10.0 % in the last group. The number of local complications increased significantly in every group with the duration of dislocation. In particular, the incidence of severe swelling, wound healing disorders, skin necrosis and the need for revision surgery and plastic reconstruction exhibit a significant linear increase within the groups (p < 0.05). The incidence of severe swelling rose from 10.3 % in the first group, to 31.0 % in the second group, to 100 % in the last group. The incidence of wound healing disorders rose from 7.7 to 13.8 to 80 % and the incidence of skin necrosis from 2.6 to 3.5 to 30.0 %. The duration of hospitalisation also exhibited a significant linear increase with group affiliation (p < 0.001), from 8.3 days in the first group to 12.5 days in the second group and 30.5 days in the last group. Conclusion: This study shows the importance of conducting reposition of the ankle joint as soon as possible if there is visible malposition, in order to avoid local complications and longer hospitalisation. If there is visible malposition of the ankle joint, the best procedure is immediate - ideally prehospital - reposition and in-axis splinting, in order to preserve soft tissue.