Multifocal Osteonecrosis in the Hips and Shoulders Bilaterally after Severe COVID-19 Infection Misdiagnosed as Fibromyalgia: A Case Report.

Introduction: Multifocal osteonecrosis (MFON) (avascular necrosis [AVN] in more than three joints) is rare. It occurs when blood flow to multiple osseous sites is disrupted, and it is usually associated with systemic disease, coagulopathies, or high cumulative doses of steroids. The current report describes a case of bilateral femoral and humeral head AVN misdiagnosed as fibromyalgia several years after a severe COVID-19 infection with complications of asystole and multi-organ failure. Case Report: A 37-year-old woman presented with joint pain that started 2 years and 4 months after a COVID-19 infection that was complicated by respiratory failure and cardiac arrest. She denied drinking alcohol or smoking and had no past medical history of osteoporosis, autoimmune diseases, coagulopathies, or chronic steroid use. In the hospital, respiratory distress was managed with a cumulative dose of 1640 mg of steroids over 27 days. Her disease course was complicated by asystole and an exacerbated systemic inflammatory process, as evidenced by multi-organ failure, including acute kidney disease, shock liver, and encephalopathy. Conclusion: Patients should be monitored for bone and joint pain indicative of possible osteonecrosis complications for several years after recovery from systemic diseases like COVID-19, regardless of whether they received high-risk cumulative steroid doses. Further, MFON should be considered with prolonged proinflammatory states, especially with concomitant cardiac events that compromise systemic sanguinous perfusion. Misdiagnosis and late magnetic resonance imaging can defer definitive treatment during the early, treatable stages of this disease.