External iliac vein compression secondary to osteolysis-induced hematoma in total hip arthroplasty.

A 62-year-old man with a history of right total hip arthroplasty, who was managed conservatively for moderate osteolysis, presented with acute-onset, painless, significant, and diffuse right lower extremity edema. Initial laboratory markers were negative for infection. Advanced imaging demonstrated a complex extrapelvic fluid mass along the psoas sheath causing compression of the external iliac vein. Intraoperatively, significant hematoma was removed from the iliopsoas sheath, followed by metal head and liner exchange as well as bone grafting of the osteolytic defects adjacent to the hip implant. Postoperative imaging showed adequate decompression, no deep vein thrombosis, and a patent external iliac vein. At 2 weeks, postoperative swelling completely resolved. At 3 months, the patient recovered to normal baseline level and underwent contralateral total hip arthroplasty for symptomatic osteoarthritis.