The valid diagnostic parameters in static CT scan to predict unstable syndesmotic injury with ankle fracture

Abstract

Introduction/Purpose:

The purpose of this study is to evaluate valid and reasonable parameters to predict syndesmotic injury in ankle fracture.

Methods:

Seventy patients who underwent preoperative bilateral CT scans were enrolled retrospectively. On preoperative x-ray, tibiofibular overlap (TFO) and tibiofibular clear space (TFCS) were measured. On preoperative CT scan, anterior fibular distance (AFD), posterior fibular distance (PFD), anterior translation distance (AT), fibular diastasis (FD), anterior-posterior translation (APT), fibular length (FL), surface area of syndesmosis (SAS), surface area of syndesmosis of 1.5 cm above the ankle joint line (SAS1.5) were measured. Those measured values were divided with those of uninjured side, in order to minimize the differences among the individuals.

Results:

Statistically significant differences has been shown between The measurements of ratio (Injured/Uninjured) of TFO, PFD, APT, Diastasis, and SAS of groups which required transfixation have shown statistically significant difference, compared to those of groups which did not require transfixation. Other measurements were not showing significant difference. Furthermore, using ROC curve analysis, a ratio of measurement which is the most reasonable to predict transfixation was SAS (95% confidence interval = 0.598 – 0.869, cut of value = 1.555)

Conclusion:

Measuring TFO, PFD, APT, Diastasis, and SAS from CT scans and comparing with uninjured side preoperatively can provide surgeon an reasonable evidence to perform transfixation intraoperatively