Unusual implant-related soft tissue reaction presenting as a swollen leg: a case report

INTRODUCTION: There are several causes of peri-implant edema, pain, and swelling around implants after orthopedic fixation device application for fracture repair. The most common and well-known reason is infection, however, granulomas associated with foreign body reactions are rarely seen. In this report we present a case of a granulomatous reaction mimicking a hydatid cyst and sarcoma. We emphasize the importance of differential diagnosis in triggering appropriate management of the patient. Our case was unusual; to the best of our knowledge no similar clinical or pathological findings have been reported in current literature. CASE PRESENTATION: A 56-year-old Turkish man who had been treated for a right femoral fracture via a plate fixation 10 years prior underwent an operation to treat pain and swelling around the plate. A hydatid cyst-like mass was observed during surgery, but subsequent examination revealed that no hydatid cyst was present; both malignancy and infection were also absent. CONCLUSIONS: Although infection is generally the first possibility that should be considered in a patient complaining of pain and swelling in the vicinity of an implant, malignancies, hydatid cysts, and (finally) foreign body reactions should also be kept in mind as differential diagnoses. A soft-tissue reaction around a previously implanted plate should be managed carefully. Pre-operative radiological assessment, and biopsy to allow pathological and microbiological examination, should be considered in all suspected cases.