avascular necrosis

Advanced Avascular Necrosis

AVN results in death and collapse of the subchondral bone of the femoral head. Initially the articular cartilage and acetabulum are not affected. In this radiograph there is collapse of the femoral head subchondral bone plate but preservation of the joint space. The large area of necrotic bone is visible in the femoral head and the tidemark of new bone formation can be seen.

Late Avascular Necrosis

Later in the disease secondary osteoarthrosis results in loss of articular cartilage and changes in the acetabulum.

Progression of Avascular Necrosis

0 months

Avascular necrosis can develop very quickly in the femoral head leading to a rapidly progressive arthritis of the hip. These X-rays were taken 6 months apart and show the change from a relatively normal hip with preserved joint space to a hip with complete loss of joint space. This patient had a more rapid onset of pain and disability compared to the typical patient who has osteoarthritis.

6 months

Gross Pathology

Photograph of the sectioned femoral head removed at hip replacement surgery shows the area of avascular (dead) bone in the weight bearing area.