Abstract Hip arthroplasty apparatus and methods are described to determine an orientation of an acetabular cup impactor, the acetabular cup impactor being moveable to a desired orientation relative to a patient's pelvic region for implantation of an acetabular cup. In one embodiment, an electronic orientation sensor is transitionable between a first location on the patient's pelvic region and a second location on the acetabular cup impactor. In a second embodiment, an image capture device is locatable on the acetabular impactor or the patient's pelvic region to capture images including markers located on the other of the patient's pelvic region or the acetabular impactor. 270a 271a 271b 271c 271d 274 271e 12 [ 3j Fig. 13 270b 271a 271c 271d 274 271e