Hi, this is Sagar Wagle, one of the musculoskeletal radiology fellows at Stanford University. We have a case of a 22-year-old lacrosse player with right ankle pain after collision with another player during a game. These are radiographs from the patient. This is frontal view and this is motis view. In motis view, the x-ray is angled slightly more obliquely so that the lateral clear space of the ankle joint opens up. On motis view, the lateral clear space and the medial clear space should be roughly symmetrical. If there is abnormal widening of the lateral clear space and of the tibiofibular clear space, which is the space between distal tibia and distal fibula, that could indicate high ankle sprain. These are the MRI from the patient. Before we talk about MRI findings in the patient, let's learn about high ankle injury. There are three important ligaments for stability of distal tibia and fibula. These are the anterior inferior tibiofibular ligament, the posterior inferior tibiofibular ligament, and the interosseous membrane. An injury to these ligaments are called high ankle injury. The anterior inferior tibiofibular ligament is the more common one to be injured. Let's look at coronal MRI images. As we go from anterior to posterior, this is distal tibia, distal fibula is coming to view, and these obliquely oriented fibers are the anterior inferior tibiofibular ligament. As we keep going more posteriorly, here we see the interosseous membrane coming into view, and this is interosseous membrane again, and as we keep going more posteriorly, here we see the posterior inferior tibiofibular ligament. So here we see the anterior inferior tibiofibular ligament. Let's look at axial images. This is the interosseous membrane. As we keep going more inferiorly, here we see the anterior inferior tibiofibular ligament and posterior inferior tibiofibular ligament, and here we see those same ligaments again. So for the radiograph of our patient, we do not see any fracture, and we also do not see abnormal widening of the lateral clear space or abnormal widening of the tibiofibular clear space. On the MRI from the patient, we have normal on the right for comparison, and on the normal, we can see this anterior inferior tibiofibular ligament, but we do not see that that ligament in case of our patient. So there is high grade tear of the of this ligament, and looking at the same MRI different sequence, we do not see the ligament in our case versus a normal case, so there is high grade tear of the anterior inferior tibiofibular ligament, and here on coronal image, on normal, we can see this ligament fibers, and here we don't see those fibers, and on a different sequence, ligament should appear dark like this, but again, we don't see the ligament here, so this is high grade tear of the anterior inferior tibiofibular ligament, also a case of a high ankle sprain. Thank you for watching the video.

3rd Edition, Case 02

3rd Edition

Ankle

high ankle sprain

anterior inferior tibiofibular ligament

lacrosse player injury

ligament tear

Stanford University diagnosis