Penetrating bladder injury caused by a medially placed acetabular screw.

Cancellous bone screws are frequently used to improve the early stability of HA coated acetabular components during total hip arthroplasty. Avoidance of the anterosuperior and anteroinferior quadrants is recommended for transacetabular screw placement to minimize the risk of injury to intrapelvic structures. Revision arthroplasty in rheumatoid patients presents additional hazards in that the acetabular bone is often soft and deficient, and the protective depth of obturator internus and psoas is usually reduced. I report a case of delayed, but fatal, perforation of the bladder associated with a medially placed acetabular screw during revision arthroplasty in a rheumatoid patient. Unless directed safely into the superior pubic ramus, anterior quadrant screws should be avoided in these circumstances.