Rapid destructive osteoarthritis of the hip: Vanishing femoral head with MRI findings mimicking septic arthritis

Abstract

Introduction: Rapid destructive osteoarthritis of the hip is a rare disorder of unknown etiology characterized by rapid destruction of the hip joint. We present a case with complete destruction of the femoral head and extensive soft tissue involvement on magnetic resonance imaging (MRI) mimicking septic arthritis, but with lack of clinical evidence of infection. Case Report: A 75-year-old woman presented with left hip pain and leg discrepancy. Imaging showed complete destruction of the left femoral head and acetabular irregularities, joint effusion, synovitis, extensive soft-tissue edema, and contrast enhancement of the gluteal musculature with an intramuscular loculament on MRI initially interpreted as possible septic arthritis with abscess formation. There were no clinical findings suggestive of infection or other destructive arthropathy. She was successfully operated with a single-stage total hip arthroplasty, and recovered without any complications. Conclusion: The MRI appearance of rapid destructive osteoarthritis may mimic septic arthritis. The radiologist should be aware of the diagnosis and differential diagnoses of destructive arthropathy in order to avoid unnecessary delay of surgery.