# Ins and Outs of the Ankle Syndesmosis from a 2D to 3D CT Perspective
## 4 Discussion  
A broad set of measurements exists to evaluate syndesmotic integrity [46]. However, these measurements are scattered across the literature. Therefore, this topical review compiled the current evidence available in the literature, with the aim of providing a comprehensive overview of which 2D/3D measurements are at hand. No systematic review was obtained because of the heterogeneity of the trials. This made it difficult to compare the results of the trials. Secondly, the aim was to look at newer and emerging techniques. These are usually described in individual trials, so a systematic review was not possible. Although the majority of ICC values for 2D measurements indicate high reliability, specific measurements that involve multiple steps show lower ICC values, likely due to the learning curve. The 3D measurement techniques are emerging as promising alternatives and could replace 2D measurements in the future, but they have not yet been integrated into daily clinical practice. Regarding 2D measurements, there are several techniques to quantify mediolateral translation, anteroposterior translation, rotation, and area. The mediolateral tibiofibrular translation measurements were the most commonly used [5; 6; 13; 18; 20; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32]. Interobserver reliability was good to excellent for all measurements. There was also no significant difference between bilateral ankles, which can be compared to assess syndesmotic integrity [6; 31]. No studies have shown a significant increase in width between non-weight-bearing and weight-bearing conditions, but the average of the means was greater in weight-bearing conditions for each measurement [20; 29]. Greater distances have been shown for each measurement when comparing normal and injured ankles in non-weight-bearing conditions. In weight-bearing conditions, only a significant difference has been shown for one mediolateral translation measurement: MTFW [22; 26; 32; 33; 47]. Studies have reported cut-off values for ATFW, MTFW, and MxTFW with varying sensitivity and specificity [5; 18; 32]. For each  
Figure 8: Distal tibiofibrular joint anatomy in a documented syndesmotic lesion (**top**) versus the mean control distal tibiofibrular joint anatomy, derived from a statistical shape model (**bottom**). The statistical shape model-based ligament modeling framework was able to detect an increase of anterior inferior tibiofibrular ligament distance by 170%, resulting in an anterior “open-book” injury. measure, there are studies that demonstrate that the measure is adequate to discriminate between normal and injured ankles, but more research is needed to formulate a consensus on cut-off values. The anteroposterior translation of the fibula relative to the tibia can be assessed using two commonly used measurements [5; 28; 38]. The anterior Phisitkul is the most commonly used translational parameter [5; 13; 20; 23; 26; 28; 29; 38; 39]. Unfortunately, most studies only include normal ankles, and just one study evaluated injured ankles in both non-weight-bearing and weight-bearing conditions [39]. An excellent AUC value was achieved in non-weight-bearing conditions (0.894), suggesting that the anterior Phisitkul could be an excellent parameter in the diagnosis of syndesmotic injuries [26]. [PERSON]'s translational parameter is an interesting method but is only used in three studies with normal ankles [5; 20; 28]. Comparative studies are needed to assess whether this parameter can be used in the diagnosis of syndesmotic injury. Other studies have also described measurements of anteroposterior translation, but as these measurements were rarely used and lacked validation, they were not discussed in this review [26; 27; 33]. The main rotation measurements were the fibula rotation parameter by [PERSON] et al. [34]. With respect to this measurement, our findings suggest that the mean rotation of the fibula under weight-bearing conditions was 12.3\({}^{\circ}\) internal rotation, as compared to 7.39\({}^{\circ}\) in the presence of lesions.