Arthroscopic Evaluation of Syndesmotic Instability and Malreduction.

Ankle fractures are a common injury treated by orthopaedic surgeons. The distal tibiofibular syndesmosis can be injured during these fractures as well as in isolation. They pose a significant challenge with regard to the diagnosis of instability as well as evaluating reduction after fixation. Multiple studies have demonstrated that traditional radiographic analysis fails to accurately identify syndesmotic diastasis, instability, or malreduction. Ankle arthroscopy has been proposed as an alternative way to evaluate the syndesmosis. Ten transtibial amputation cadavers were utilized for this study. Two distinct analyses were undertaken. The first, analysis of instability, utilized 2 dissection groups, a superficial dissection only and a partial disruption instability model. The second analysis was of syndesmotic malreduction. For this, all 10 specimens underwent complete disruption of the syndesmosis and subsequent fixation in either anatomic alignment or malreduction. Both analyses were performed by surgeons blinded to the condition of the syndesmosis. Two groups of surgeons were able to identify syndesmotic instability a combined 75% of the time. Malreduction diagnosis was mixed with a 100% accurate diagnosis of sagittal plane displacement but only 50% accuracy for rotation and 17% for an anatomic reduction. Syndesmotic injury during ankle fracture presents a significant problem to the treating surgeon. Ankle arthroscopy has been shown in the literature to be highly sensitive for diagnosing instability but has not been evaluated in diagnosing malreduction. The current study shows moderate success in diagnosing both malreduction and instability.

LEVELS OF EVIDENCE: Therapeutic, Level V: Basic Science.