Fig. 6
From: Stress fracture of the pelvis and lower limbs including atypical femoral fractures—a review
A 60-year-old female presenting with groin pain. An AP radiograph of the pelvis (a) shows subtle subchondral flattening of the femoral head suspicious for a stress (insufficiency) fracture (see arrow). Multiple bone islands are noted. Sclerosis and irregularity of the symphysis pubis again suggest bone stress. On radiography alone avascular necrosis also has to be considered as a cause of subchondral flattening; however the femoral head infraction is confirmed with MRI [coronal T1w (b) and T2-FS (c) images] (see arrows) and avascular necrosis (avn) is effectively excluded. This is confirmed with CT imaging (d). These lesions need specialist attention to prevent deterioration to rapidly destructive OA