Pelvic synovial cyst formation secondary to perforation of the quadrilateral plate: a case report.

A seventy seven-year-old female presented to her gynaecologist with right-sided pelvic pain and irregular per vaginal bleeding. Ten years earlier she had undergone a right cementless total hip arthroplasty. The press fit acetabular component had been augmented by screws. Radiological investigation requested by her gynaecologist identified a right iliac fossa mass. This communicated with the hip joint via a screw track formed by a fixation screw that had penetrated the medial wall of the acetabulum at total hip arthroplasty. Following aspiration of the fluid within the cyst, microscopy demonstrated it to be of synovial origin. Her symptoms subsequently resolved. This condition has not been reported previously.