Table 3.

Key features of subchondral insufficiency fracture

Most commonly seen in elderly osteoporotic females. Radiographs are often unremarkable and MRI is imaging modality of choice. Marrow oedema with irregular, disconnected subchondral fracture line which is convex to articular surface is characteristic MRI finding. Osteonecrosis of femoral head and transient osteoporosis are important differentials.