RESUMEN
INTRODUCTION: Brucellosis is a zoonotic illness caused by Brucella bacteria, primarily transmitted through contaminated dairy products or direct contact with infected animals. Brucellosis is highly prevalent in Iran, with Brucella melitensis biovar 1 being the primary causative agent. Musculoskeletal symptoms, including spondylitis, sacroiliitis, and peripheral arthritis, are common in brucellosis patients, but avascular necrosis of the hip joint is extremely rare. CASE PRESENTATION: This case report presents a middle-aged woman from Iran with untreated brucellosis infection, who developed rapidly progressing avascular necrosis affecting both hip joints. The patient's social history did not indicate any use of tobacco or alcohol. Furthermore, there was no indication of any traumatic events affecting the patient's hip joints. The patient's family history did not reveal any rheumatologic disorders, and the patient had not been diagnosed with or reported using immune suppressant medications. Laboratory results confirmed that the patient was not diagnosed with sickle cell anemia. The patient had been intolerant to the prescribed medications, Rifampin and Doxycycline. Initially, she presented with severe bilateral hip pain, anorexia, vomiting, periodic chills and fever, myalgia, and night sweats. Pelvis X-ray confirmed bilateral hip avascular necrosis, and total hip arthroplasty was scheduled but subsequently canceled due to persistent brucellosis infection. Physical examination revealed limited hip motion, pain, and inability to bear weight. Laboratory tests indicated leukocytosis, elevated levels of CRP, and high titers on Wright and 2ME tests. Intravenous Ciprofloxacin was initiated, and further investigations were scheduled. DISCUSSION: Osteoarticular complications are common in individuals with brucellosis. The sacroiliac joints are affected in 80 % of cases, while the spinal joints are affected in 50 %. Brucella-induced arthritis can be found in over 50 % of patients, with the lower limb joints being the most commonly affected. Failure to diagnose and treat hip arthritis caused by brucellosis promptly can lead to severe complications, including dislocation and avascular necrosis of the femoral head. Avascular necrosis is a condition where bone tissue dies due to compromised blood supply. It often remains asymptomatic initially and is usually found incidentally during radiographic imaging. Osteonecrosis of the femoral head can manifest as Legg-Calve-Perthes disease or as a complication of other medical conditions. Various factors can contribute to avascular necrosis, including hip dislocation or fracture, prolonged use of certain medications, excessive alcohol consumption, and certain medical conditions. Magnetic resonance imaging is considered the standard method for diagnosing avascular necrosis. Delay in diagnosing and treating brucellosis can result in permanent bone complications. CONCLUSION: Brucellosis, a disease prevalent in endemic regions, should be considered as a cause of severe hip pain and other vague symptoms. Timely diagnosis and management are important, especially for high-risk patients with other health conditions and poor drug compliance, to prevent complications such as avascular necrosis.