Segond Fractures on MRI may only be seen as an area of bone marrow oedema rather than the classic fracture fragment seen on x-ray. It is not related to an iliotibial band avulsion and the area to look for it is posterior to the Ilio Tibial Band insertion. Here is a quick review of what it looks like and where to look for it.
Image Above: X-ray shows fracture fragment ( yellow arrow) adjacent to lateral tibial plateau. ITB ( yellow arrow) is intact and normal. Bone marrow oedema ( blue arrow) low signal fracture line seen posterior to ITB insertion.
Image Above: Segond Fracture normal ITB ( yellow arrow). Fracture of the lateral cortex ( blue arrows) posterior to ITB insertion.