We report the treatment experience of a patient who developed pain in the right anterior thigh and buttock 3 months later after lumbar disc surgery. He was treated as failed back surgery syndrome and had no symptom improvement. On physical examination, groin pain was elicited by Patrick's test and internal rotation of the hip. Plain radiographs of the pelvis showed calcification or osteophytes near the superior lip of the acetabulum. On magnetic resonance imaging, the lesion was identified as osteophytes and joint effusion was also noted. Under C-arm guidance, we injected corticosteroids and local anesthetics, and the patient obtained dramatic pain relief and no recurrence of symptoms.