The acetabular branch of the obturator artery supplies the acetabulum through the acetabular notch.

http://en.wikipedia.org/wiki/Acetabulum

Blood supply

The acetabular branch of the obturator artery supplies the acetabulum through the acetabular notch. The pubic branches supply the pelvic surface of the acetabulum. Deep branches of the superior gluteal artery supply the superior region and the inferior gluteal artery supplies the postero-inferior region.