Evaluation of the Deltoid Complex in Supination External Rotation Ankle Fractures

We present the results of a prospective study of supination external rotation ankle injuries with an isolated fibula fracture on plain radiographs. The purpose of this study was to see if a correlation exists between the preoperative evaluation and the intraoperative arthroscopic evaluation of the deltoid ligament complex in these injuries. Gravity stress radiographs of the ankle were evaluated to assess deltoid ligament competence. If the medial clear space was > 4 millimeters, injury to the deltoid ligament complex was assumed. We correlated stress radiograph measurements of the medial clear space with arthroscopic evaluation of the deltoid ligament at the time of open reduction internal fixation in 19 patients. Arthroscopic findings demonstrated that of the 19 patients that underwent open reduction internal fixation, 2 (10%) had intact deltoid ligaments, 2 (10%) had partial ruptures, and 15 (79%) had complete rupture of the deltoid ligament. After placement of fixation, the medial clear space on stress gravity films was measured again to confirm reduction.