Management of a pelvic mass following a worn uncemented total hip arthroplasty.

Intrapelvic granulomatous masses from polyethylene wear debris can easily be misdiagnosed if orthopaedic etiology is not considered. This article presents the case of a 50 year old woman with history of hip joint trauma and total hip arthroplasty (THA) revisions who presented to her gynecologist with a large intrapelvic cyst. Prolonged use of an indwelling drain and failure to recognize the orthopaedic origin of the mass resulted in articular infection that required an antibiotic spacer and subsequent THA revision. This patient did not have pain or evidence of medial wall defects, but did have a history of trauma, revision arthroplasty and acetabular allograft. In the presence of these findings, wear-induced polyethylene debris should be considered in the differential diagnosis of the pelvic mass.