Early lateral migration of head after bipolar hemiarthoplasty in a cerebral palsy patient.

Migration of the outer head after bipolar hemiarthroplasty within several years after surgery is not a rare complication. We present a patient with cerebral palsy who showed lateral migration of the outer head seven months after bipolar hemiarthroplasty for femoral neck fracture. The patient had no acetabular pathology prior to the fracture, and lacked ambulatory ability in a community setting. She underwent conversion to a total hip arthroplasty and returned to her previous lifestyle.