Bipolar hemiarthroplasty has been used for both arthritis treatment and, more recently, the treatment of displaced femoral neck fractures. The authors report an unusual care of impingement of the bipolar cup and prosthetic femoral neck. This was noted on radiographs 10 years after bipolar hemiarthroplasty. This example supports the use of unipolar hemiarthroplasty to avoid such impingement.