Acute febrile calf: Early diagnosis in the emergency department of one patient with ankylosing spondylitis with a ruptured baker's cyst

Acute rupture of a Baker's cyst can cause sudden-onset swelling and pain in the affected calf, and may be confused with symptoms of deep vein thrombosis. We describe a case of a young man presenting with an acute febrile calf at our emergency department where multidetector computed tomography (MDCT) with coronal reformation was performed. A ruptured Baker's cyst was diagnosed. After admission, ankylosing spondylitis was diagnosed by advanced clinical and radiological examinations. It is important to ensure that patients afflicted with a ruptured Baker's cyst are diagnosed early, typically by the application of appropriate and useful clinical imaging modalities (e.g. MDCT) in the emergency department.