Clinical Images: Osteonecrosis of the sternum in antiphospholipid syndrome

The patient, a 25-year-old woman with primary antiphospholipid syndrome receiving prolonged anticoagulation therapy complicated by stroke, recurrent miscarriage, and recent bilateral adrenal infarct, presented with chest pain refractory to opioids. Three weeks before presentation, the patient's anticoagulation therapy had been held in the setting of ovarian cyst rupture and hemoperitoneum requiring emergent surgical intervention. Anticoagulation therapy had recently been changed from warfarin to enoxaparin in the setting of pregnancy; however, she experienced a miscarriage two days before presentation. On examination, the patient had excruciating pain with palpation of the lower third of the body of the sternum and at the insertion of multiple costal joints. Recent computed tomography imaging of the abdomen and pelvis with contrast revealed likely avascular necrosis of bilateral femoral heads, prompting concern for microvascular pathology. (A) Magnetic resonance imaging of the chest was obtained, and coronal Proton Density (PD) fat suppression and T1-weighted postcontrast images showed bilateral peripheral linear serpiginous low signal intensity at both sides of the sternum. (B) These areas showed enhancement post contrast administration. Osteonecrosis of the sternum has not been reported in the literature as a sequela of antiphospholipid syndrome. The combination of appropriately held anticoagulation therapy, pregnancy, intra-abdominal hemorrhage, and the inability to use direct vitamin K antagonists may have resulted in a hypercoagulable state and subsequent sternal infarct. Disclosure form Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.