Mycotic aneurysm of the external iliac artery caused by migration of a total hip prosthesis.

A 77-year-old patient had a mycotic aneurysm of the left external iliac artery secondary to migration of a total hip prosthesis. Symptoms included pain, numbness, decreased hip motion, and a temperature of 38.5 degrees. The left leg was shortened, externally rotated, and swollen. There was anterior thigh hypoesthesia and quadriceps paralysis. A pulsatile mass in the lower left quadrant of the abdomen emitted a thrill and a loud bruit. A preoperative arteriogram facilitated diagnosis and planning of surgery. A transpubic femorofemoral bypass graft was used to reroute blood to the left lower limb, avoiding vascular reconstruction in the area of the aneurysm, a suspected site of infection. A false aneurysm was determined and was then isolated. The prosthesis was removed. During this operation, the acetabular component was found freely mobile within the false aneurysm. Cultures of the removed vascular tissue grew Staphylococcus epidermidis. An arteriogram should be obtained prior to operation for any medial intrapelvic displacement of a total hip prosthesis to diagnose the extent of vascular involvement. Physical examination may not reveal the aneurysm, but signs of neuropathy or venous thrombosis may suggest this diagnosis.