Ortho Dx: Sudden Onset Knee Pain
SONK often starts with a sudden onset of knee pain that may worsen at night. SONK must be differentiated from secondary osteonecrosis, which most commonly results from corticosteroid use. Other conditions that cause secondary osteonecrosis include alcoholism, smoking, and coagulopathy. SONK is thought to result from an insufficiency fracture of the femoral condyle that fails…