WHAT ARE THEY: Segond Fractures are fractures of the lateral tibial plateau often associated with ACL tears.
WHERE DO THEY OCCUR? Lateral tibial plateau, just posterior to the attachment of the ilio tibial band.
IS IT AN AVULSION FRACTURE OF THE ITB? No. Its related to the tibial insertion of the anterolateral ligament. However this ligament is not distinctly identified on MRI and the best landmark is to look immediately posterior to the ITB insertion.
WHAT DO I LOOK FOR ON X-RAY AND MRI?
- XRAY: A small avulsion/ flake type fracture of the lateral tibial plateau.
- MRI: Bone marrow oedema immediately posterior to the ITB insertion. May only be seen as an area of bone marrow oedema rather than the classic fracture fragment seen on x-ray.
- MRI: Bone fragment or loss of cortical margin immediately posterior to the ITB
Image Above: X-ray shows fracture fragment ( blue arrow)) adjacent to lateral tibial plateau. ITB ( yellow arrow) is intact and normal. MRI third image Bone marrow oedema ( blue arrow) low signal fracture line seen immediately posterior to ITB insertion.
Image Above: Segond Fracture normal ITB insertion ( yellow arrow). Fracture of the lateral cortex ( blue arrows) posterior to ITB insertion