Pyoderma gangrenosum complicating bilateral total knee arthroplasty.

Pyoderma gangrenosum is an ulcerative, necrotic dermatosis of unknown etiology. It is frequently associated with inflammatory, hematologic, or neoplastic disease. Clinical and physical evaluation can imitate postoperative wound infections. This article reports a case of pyoderma gangrenosum in a patient who underwent bilateral total knee arthroplasty. Her postoperative course was complicated by wound dehiscence and ulceration in both knees. Her condition deteriorated despite debridements and antibiotic therapy. Deep intraoperative cultures were all negative. Once the diagnosis of pyoderma gangrenosum was established and once appropriate treatment with steroids was initiated, her condition improved. The diagnosis of pyoderma gangrenosum should be considered in patients with wound deterioration who remain culture-negative and fail to respond to debridement and antibiotic treatment. This case report highlights the presentation of pyoderma gangrenosum and its ability to be misdiagnosed as infection. A delay in treatment may result in unnecessary surgery that will further exacerbate this inflammatory condition.