Hemi replacement of the hip

A hemiarthroplasty is an operation that is used most commonly to treat a fractured hip. The operation is similar to a total hip replacement, but it involves only half of the hip. Hemi means half, and arthroplasty means joint replacement. The hemiarthroplasty replaces only the ball portion of the hip joint, not the socket portion. In a total hip replacement, the socket is also replaced.