Peroneal artery injury potential due to different syndesmosis screw placement options: a simulation study with lower extremity computed tomography angiography

Abstract

Introduction: The aim of this study is to assess the risk of peroneal artery injury of hardware placement at the fixation of syndesmotic injuries.

Materials and methods: The lower extremity computed tomography angiography was used to design the study. The syndesmosis screw placement range was simulated every 0.5 cm, from 0.5 to 5 cm proximal to the ankle joint. The screw axes were drawn as 20°, 30° or individual angle according to the femoral epicondylar axis. The proximity between the screw axis and the peroneal artery was measured in millimeters. Potential peroneal artery injury was noted if the distance between the peroneal artery to the axis of the simulated screw was within the outer shaft radius of the simulated screw. The Pearson chi-square test was used and a p-value < 0.05 was considered significant.

Results: The potential for injury to the peroneal artery increased as the syndesmosis screw level rose proximally from the ankle joint level or as the diameter of the syndesmosis screw increasds. In terms of syndesmosis screw trajection, the lowest risk of injury was observed with the syndesmosis screw angle of 20°. Simulations with a screw diameter of 3.5 mm exhibited the least potential for peroneal artery injury.

Conclusion: Thanks to this radiological anatomy simulation study, we believe that we have increased the awareness of the peroneal artery potential in syndesmosis screw application. Each syndesmosis screw placement option may have different potential for injury to the peroneal artery. To decrease the peroneal artery injury potential, we recommend the followings. If individual syndesmosis screw angle trajection can be measured, place the screw 1.5 cm proximal to the ankle joint using a 3.5 mm screw shaft. If not, fix it with 30° trajection regardless of the screw diameter at the same level. If the most important issue is the peroneal artery circulation, use the screw level up to 1 cm proximal to the ankle joint regardless of the screw angle trajection and screw diameter.

Keywords: Computed tomography angiography; Iatrogenic injury; Peroneal artery; Syndesmosis screw.

Fig. 1

The 10 different placement levels of the simulated syndesmosis screws. Please note that every level has three different syndesmosis screw angle option, each with three different screw shaft diameter option

Fig. 2

The necessary axes for the syndesmosis screw placement and the relation of the axes and peroneal artery. The arrows show the peroneal artery. At the b, c and e, the three different diameter screw options have potential for damage to the peroneal artery. a The transepicondylar femoral axes. b The axis of the 20° syndesmosis screw angle. The level is 2.5 cm proximal to the ankle joint line. The closest distance of axis to the peroneal artery is 0.9 mm. c The axis of the 30° syndesmosis screw angle. The level is 2.5 cm proximal to the ankle joint line. The figure points out the overlapping of the simulated syndesmosis screw axis and peroneal artery. d The individual syndesmosis screw angle perpendicular to the incisura fibularis. The level is 0.5 cm proximal to the ankle joint line. e The individual syndesmosis screw angle parallel to the interosseous ligament above 3 cm to the ankle joint. Please note the proximity of the peroneal artery to the syndesmosis screw axis. The syndesmosis screw axis passes tangent to the peroneal artery