Hemiarthroplasty or partial hip replacement is a procedure in which only head of the femur ( ball of the ball and socket joint ) is changed with a metallic implant. This is still a common operation done for fracture of the neck of femur in elderly, who are above age of 80 years.

This operation lasts for few years without pain. Later because of poor quality bone or because of increased friction between the metal ball and the bone of the socket, it may become painful. Some times the stem of the ball may even break. In any of these events, the hip becomes painful and the patient is unable to walk. In such a situation, revision to total hip replacement is the only remedy, which will restore pain free movements.