Anatomic Fixation of Supination External Rotation Type IV Equivalent Ankle Fractures

Abstract

OBJECTIVES: To compare radiographic and clinical outcomes of supination external rotation type IV equivalent (SER IV E) ankle fractures (AO/OTA classification 44-B2.1) treated with transsyndesmotic screw fixation with those treated with deltoid and posterior inferior tibiofibular ligament (PITFL) repair. DESIGN: Case series and single-surgeon retrospective analysis of a prospective database. SETTING: Academic level I trauma center. PATIENTS: Forty-five SER IV E ankle fractures fulfilled all inclusion/exclusion criteria with at least 12 months of radiographic follow-up. INTERVENTION: Deltoid and PITFL repair in addition to lateral malleolus fixation compared with transsyndesmotic screw fixation. MAIN OUTCOME MEASUREMENTS: Syndesmotic reduction compared with contralateral extremity on a postoperative computed tomography scan and maintenance of reduction based on final postoperative radiographs [medial clear space (MCS) and tibiofibular clear space (TCS)]. RESULTS: There was no significant difference in mean postoperative TCS, MCS, or change in TCS or MCS between the cohorts. The anatomic treatment group had significantly better postoperative syndesmotic reduction compared with the transsyndesmotic cohort (7.4% vs. 33.3%; P = 0.02). Fourteen patients in the transsyndesmotic screw cohort underwent removal compared with 3 patients in the anatomic cohort who required secondary procedures. The transsyndesmotic screw cohort had statistically significant better mean dorsiflexion of ankle (mean 20 vs. 17 degrees; P = 0.02). CONCLUSIONS: This comparison of treatment strategies for SER IV E ankle fractures has shown an improvement in immediate postoperative syndesmotic reduction and the elimination of reoperation for removal of transsyndesmotic screws in patients treated with PITFL repair. Previous research has shown a good correlation between functional outcomes and syndesmotic reduction; however, further investigation into the functional outcomes of these patients is necessary to determine the future clinical impact of this anatomic fixation strategy. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.