Tehran University of Medical Sciences Journal of Orthopedic and Spine Trauma 2538-2330 4 4 2020 05 07 80 83 Seyedeh Tahereh Faezi Associate Professor, Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Mohammad Nejadhosseinian Orthopedic Surgeon, Department of Orthopedics, Joint reconstruction research center, Imam Khomeini Hospital, Tehran University of Medical Science, Tehran, Iran Farhad Shahram Associate Professor, Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Nahid Sadighi Associate Professor of Radiology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran Masoumeh Banihashemian MD, Department of Radiology, Yas Women's Hospital, Tehran University of Medical Sciences, Tehran, Iran Pedram Paragomi Department of Internal Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA Fereydoun Davatchi Associate Professor, Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran 2019 10 14 2020 05 07 Background: Osteonecrosis is the death of bone tissue due to the interruption of the blood supply. It can occur in autoimmune disease due to multiple mechanisms. It occurs rarely in some kind of multisystem disease such as Behcet’s disease (BD). The aim of this article is to present a case of BD with multifocal osteonecrosis. Case Presentation: A 26-year-old woman with oral aphthosis, panuveitis, and retinal vasculitis was diagnosed to have BD, and oral treatment of prednisolone (0.5 mg/kg/day) together with azathioprine (2 mg/kg/day) and intravenous (IV) cyclophosphamide (CYC) (0.75 g/m2) was administered for her. Prednisolone was tapered to 15 mg/day after 3 months. Because of unresponsiveness of eye involvement to traditional immunosuppressive therapy, infliximab (5 mg/kg) was started for her, and IV CYC was discontinued. 4 months after initial therapy, she complained of her right shoulder pain. Regarding shoulder pain, magnetic resonance imaging (MRI) showed osteonecrosis of the right shoulder. After the diagnosis of osteonecrosis, prednisolone was discontinued by herself. 3 months later, she complained of both knees, both hips, and right ankle pain. According to the previous diagnosis of osteonecrosis of her right shoulder, MRI was done for all involved joints, which revealed osteonecrosis of all of them. After the diagnosis of multifocal osteonecrosis, the following tests were done that all results were normal: anticardiolipin antibody (ACA) [immunoglobulin G (IgG), immunoglobulin M (IgM)], lupus anticoagulant (LA), anti-beta-2 glycoprotein 1 (antiB2GP1) (IgG, IgM), coagulation tests, and lipid profiles. Conclusions: Bone infarction should be considered in the differential diagnosis of patients with joint pain and without the evidence of arthritis; however, it rarely occurs in patients with BD. https://jost.tums.ac.ir/index.php/jost/article/view/120 https://jost.tums.ac.ir/index.php/jost/article/download/120/134