Osteonecrosis Femoral head LSBU

Description: ACR-code 443-441 Clinical presentation: 63 year old caucasian man with recent pain and restricted movement of the right hip. He is a known case of Non-Hodgkin lymphoma and had been receiving a combination of high dose chemotherapy and steroids.
The image shows loss of the normal curve of the head of the right femur and an interruption to its cortical outline. There is separation of a fragment from the supero-medial portion of the head. Its cortical margin shows a line with a dark line below it. There is, in comparison with the left side, a reduction in the bone density immediately adjacent to the bone fragment. This does not correspond to the density of the acetabular margin and indicates osteoporosis in the adjacent (more normal?) bone.