The patient experienced postoperative dislocation after bipolar hip arthroplasty.At the initial surgery on (b)(6) 2019, it was confirmed that the cup and head were firmly attached.Subsequent to the initial surgery, an x-ray determined that the head was dislocated from the cup and the cup was dislocated from the acetabulum.On (b)(6) 2019, the surgeon performed a revision to replace the cup and the femoral head.This report is two of two for this incident.