Figure 4

A 37- year - old woman with type 2 diabetes mellitus who complained of painful swelling of the thigh for one month. (A) A plain film showing a thin monolayer periosteal reaction with cortical destruction and moth-eaten osteolytic lesion. (B, C) Unenhanced T1-weighted magnetic resonance imaging (MRI) showing cystic lesion with a hyperintense granulation layer surrounding the central abscess cavity, and a T2-weighted image showing extensive soft tissue edema and lobulated abscess accumulation, representing the penumbra sign. (D) A plain film taken one year after the debridement and prophylactic ORIF surgery showing bony union and bone cement at the medial wall without signs of recurrence.