Vascular injury during total hip arthroplasty: the anatomy of the acetabulum.

We encountered a massive retroperitoneal haemorrhage due to perforation of the external iliac vein by a drill tip passing through the antero-superior quadrant of the acetabulum during cementless total hip arthroplasty. An anatomical study of the acetabulum was undertaken to determine the safe zones for transacetabular screw fixation. Five cadavera were studied to find the proper locations for screws using acetabular quadrants. The postero-superior and postero-inferior acetabular quadrants have good bone stock and are safe for the transacetabular replacement of screws. The antero-superior and inferior quadrants should be avoided. Screws placed in these quadrants may damage the external iliac artery and vein or the obturator vessels.