[Heterotopic excessive wear granuloma mistaken for an aneurysm of the external iliac artery].

Reimplantation of a total hip arthroplasty (THA) with excessive heterotopic polyethylene granuloma is reported. An 84- year-old woman, who had undergone THA reimplantation on the right side 4.5 years previously, was indicated for revision surgery due to aseptic failure of the acetabular component. Pre-operative examination revealed a pulsating mass below the right inguinal ligament that raised the suspicion of a pseudoaneurysm of the external iliac artery. Because of this suspected late complication of the first revision arthroplasty, surgical exploration was indicated by the vascular surgeon prior the second reimplantation. A CT-scan showed a large mass attached to a preserved lumen of the external iliac artery, and this was diagnosed by the vascular surgeon as a pseudoaneurysm. However, no pseudoaneurysm was found by a vascular surgery procedure, and the large mass ventrally extending the external iliac artery appeared to be a large polyethylene granuloma well enveloped in a fibrous pseudocapsula. The granuloma was removed and the wound sutured. Twelve days later, revision total hip arthroplasty and acetabular reconstruction were successfully carried out.