Iliopsoas bursitis following total hip replacement.

We report the imaging features of a 52-year-old man presenting with a groin mass and gross lower limb oedema secondary to venous occlusion by massive cystic enlargement of the iliopsoas bursa 4 years after uncemented primary total hip replacement. Ultrasonography of the groin mass demonstrated a large cystic lesion extending into the pelvis. CT showed displacement of the external iliac vessels with venous compression. Bursography showed the bursa's margins and no communication with the hip joint. Diagnostic aspiration excluded infection, but fluid recollection occurred subsequently. Complete resolution of symptoms, including limb swelling, followed surgical excision with no recurrence at the 5-year follow-up. We believe iliopsoas bursitis occurred as a tissue response to polyethylene wear within the prosthetic hip and occurred even in the absence of loosening or a direct communication between bursa and joint.