Snapshot A 56-year-old woman presents to the emergency department with left groin and thigh pain. She reports her pain has progressively worsened over the course of a few days and denies any trauma to the region or history of falls. Medical history is significant for systemic lupus erythematosus (SLE) treated with hydroxychloroquine and was recently placed on a short course of oral prednisone. She has had a number of SLE flairs requiring steroid therapy. On physical exam, there is decreased passive and active range of motion of the hip. Magnetic resonance imaging of the affected area demonstrates serpiginous peripheral sclerosis with inner granulation tissue highly suggestive of osteonecrosis of the left femoral head. Introduction Clinical definition login to view 2 more bullets Epidemiology login to view 5 more bullets Etiology login to view 16 more bullets Pathogenesis login to view 6 more bullets Prognosis login to view 1 more bullet Presentation Symptoms login to view 7 more bullets Physical exam login to view 3 more bullets Imaging Radiographs login to view 2 more bullets Magnetic resonance imaging (MRI) login to view 4 more bullets Studies Making the diagnosis login to view 1 more bullet Differential Stress fracture Degenerative joint disease Treatment Management approach login to view 2 more bullets Complications Collapse of femoral head in cases of femoral involvement Degenerative joint disease Focal osteoporosis