The relationship of the intrapelvic vasculature to the acetabulum. Implications in screw-fixation acetabular components.

The use of screw-fixation acetabular components in total hip arthroplasty could increase the incidence of vascular injury because of the increased use of drills and screws placed into the acetabulum in close proximity to major vessels. Analysis of two illustrative case studies, anatomic specimen cross sections, and computed tomographic scans demonstrate which vessels are at risk of injury should the inner cortex of the pelvis be penetrated. The iliac vessels are at risk of injury when penetration of the inner cortex of the pelvis occurs in the anterosuperior region of the acetabulum. The obturator vessels are at risk when penetration occurs in the anteroinferior quadrant of the acetabulum. The vessels can be within 0.5 cm of the inner cortex of the pelvis and tend to become closer with advancing age. Damage to the intrapelvic vessels may cause profound blood loss and hypotension when screw-fixation acetabular components are used. Rapid identification and immediate surgical repair of vessel lacerations are essential in the treatment of this complication.